Chapter IV: Foreword (3)

_Florida._--Very common among dead leaves, under logs, beneath loose bark, and wanders about at night in pinelands, hammock, turkey oak, and sand-scrub habitats (Hubbell and Goff, 1940). Beneath drift, cow dung, leaves, boards, bark of logs, and other debris, usually in open pine woods in sandy areas; frequent at the base of thistle leaves (Blatchley, 1920). Friauf (1953) found this species in leaf duff, debris, or decaying wood in these habitats: Scrub (dominant), sandhills (dominant), xeric hammock (dominant), mesic hammock, longleaf-pine flatwoods (infrequent), low hammock (infrequent), and alluvial hammock (infrequent). In the shrub stratum in these habitats: Scrub (dominant), sandhills (dominant), xeric hammock (dominant), and longleaf-pine flatwoods (infrequent). In the herbaceous stratum of the longleaf-pine flatwoods habitat, and under bark and beneath logs in the woodpile habitat.

=Parcoblatta lata=

_Southeastern and southern U.S._--Under bark of pine logs and stumps; in sweet-gum logs and stumps; moderately numerous under bark of dead shortleaf pines; under bark of longleaf-pine stumps; under signs on red oak and longleaf pines; in dead oak. In Texas, under bark of pine stumps (Hebard, 1917).

_North Carolina._--All stages under loose bark of dead pines, both prostrate and upright, and stumps. "It seems to prefer the space under the bark to be rather damp" (Brimley, 1908). Under bark of dead pine trees (Rehn and Hebard, 1910).

_Florida._--Infrequent in leaf duff and decayed wood of low hammock habitat (Friauf, 1953).

_Indiana._--Beneath rocks on sides and tops of high hills, in limestone glades where cedar abounds (Blatchley, 1920).

_Missouri._--In leaf stratum of oak-hickory forest (Dowdy, 1951). Earlier, Dowdy (1947) reported finding numerous immature Pseudomopinae [presumably _Parcoblatta_ sp.] in soil and leaf strata of oak-hickory forest.

_Texas._--Captured in molasses-baited traps in low, wet, oak woods and in dry woodlot on hillside (Hebard, 1943a).

=Parcoblatta pensylvanica=

_Eastern and southeastern U.S._--Trapped in molasses-baited jars; in oak and in chestnut forests, and on knoll with high deciduous trees. Found in oak and pine woods, under bark of decaying chestnut log and dead chestnut stump, and under signs on trees including oaks (Hebard, 1917).

_North Carolina._--In all stages under loose bark of upright, dead pines, when the space under the bark was dry (Brimley, 1908).

_Virginia, North and South Carolina._--Under signs on trees (white and red oaks); under bark of dead shortleaf-pine and sweet-gum logs and stumps (Rehn and Hebard, 1916).

_Indiana._--Beneath bark of logs and stumps; empty oöthecae common beneath loose bark of logs, especially shellbark hickory (Blatchley, 1920). Under loose bark on logs in January (Blatchley, 1895).

_Illinois._--In pine forest associes, in black oak forest on sand, in oak-hickory forest on clay, and in climax forest; it evidently moved into the pine associes nightly, great numbers of oöthecae were found under bark of pine logs, where, in October and November, hibernating nymphs were found (Strohecker, 1937). In nests of _Vespula maculata_ (Balduf, 1936; McClure, 1936).

_Missouri._--Usually in hollow trees, under loose bark, in woodpiles, and in cracks in rural buildings (Rau, 1940).

_Michigan._--Common in oak-dune and beech-maple forests, under loose bark on dead trees and fallen logs, and under debris on forest floor (Hubbell, 1922). "A characteristic inhabitant of the low shrub-terrestrial and probably the terrestrial-hypogeic stratum." It occurred throughout the upland forests; groups were found established in and under logs 100 to 200 feet from the nearest forest (Cantrall, 1943).

_Ontario._--Very abundant in rocky, sparsely-wooded country, where it occurred in rotten logs and under loose bark; on tree trunk at night on rocky island in lake (Walker, 1912).

=Parcoblatta uhleriana=

_North Carolina._--Under pine straw on ground in woods (Brimley, 1908). Under bark of dead trees; 92 males attracted to lights (Rehn and Hebard, 1910).

_Virginia._--Resting on woods foliage; at night on road (Rehn and Hebard, 1916).

_Eastern and southeastern U.S._--Trapped in molasses-baited jars: in oak and pine woods, in heavy barrier-beach forest, in both scant and typical undergrowth on pine barrens, in heavy grassy undergrowth on pine barrens, on border of pine barrens, on edge of swamp, in heavy deciduous forest, in heavy oak woods, in upland oak and chestnut forest, in chestnut forest, in forested ravine, and on ridge with heavy oak, chestnut, and maple forest. Found under damp leaves on edge of forest, under bark of decayed chestnut log, inside decaying chestnut log with _Cryptocercus punctulatus_, under palmetto roots, under bark of pine stump, and in dry leaves under live oaks (Hebard, 1917).

_Tennessee._--In traps baited with cornmeal or cantaloupe in maple-gum-oak forest in a mesic valley, and in a stand of oak on a dry ridge (Walker, 1957).

_Indiana._--Beneath cover on slopes of high wooded hills. "This is essentially a forest-loving species; usually occurring beneath leaves and other debris on or along the borders of heavy hardwood timber." (Blatchley, 1920.)

_Illinois._--In oak-hickory forest on clay and in climax forest (Strohecker, 1937).

_Michigan._--In oak-dune woods (Hubbell, 1922). Restricted to woodlands, where it inhabited piles of moist dead leaves and rotten logs in oak-hickory forest (Cantrall, 1943).

_U.S.A._--This species, _P. uhleriana_, and _P. virginica_ were attracted at night to honeydew secreted by aphids on _Pyrus_ sp. (Davis, 1918).

=Parcoblatta virginica=

_New England._--Females under loose stones, boards, and other debris on ground; beneath loose bark (Morse, 1920).

_North Carolina._--Under debris in dead shortleaf-pine needles (Rehn and Hebard, 1916).

_Florida._--Infrequent in the shrub stratum of the scrub habitat. This was the only habitat of 25 studied in which this species was found (Friauf, 1953).

_Eastern and southeastern U.S._--Trapped in molasses-baited jars: in pine and oak woods, in pine barrens, in pine woods with heavy grass undergrowth, in oak forest, in heavily forested ravine, on rocky slope with few deciduous trees, on knoll with high deciduous trees, in lofty chestnut forest, and in heavy low chestnut and oak forest on high ridge; under bark of decaying chestnut log and stump; under stones in chestnut forest; under bark of pine stumps (Hebard, 1917).

_Indiana._--Frequents borders of open woods and fields; under debris, loose bark, and half-buried logs (Blatchley, 1920).

_Illinois._--In black-oak forest on sand, in oak-hickory forest on clay, and in climax forest (Strohecker, 1937).

_Michigan._--Common in oak-dune and beech-maple forests; under loose bark on dead trees and fallen logs and under debris on forest floor (Hubbell, 1922). Restricted to woodlands, where it inhabited piles of moist dead leaves and rotten logs in oak-hickory forest (Cantrall, 1943).

_Texas._--Captured in molasses traps in moist woods of maple, oak, and pine with much undergrowth and a heavy layer of duff; in open, rather dry woodlot of Spanish oak and other trees; and in low wet woods of willow and oak along creek (Hebard, 1943a).

=Parcoblatta zebra=

_Indiana._--Beneath log in cypress swamp (Blatchley, 1920).

_Louisiana and Mississippi._--In decay cavity in sweet gum; under sign on shortleaf pine (Hebard, 1917).

=Parcoblatta= spp.

_Alabama._--In the dry wall of a sweet-gum stump together with serropalpid and tenebrionid beetles (Snow, 1958).

_Ohio._--Oöthecae under loose bark of fallen trees, where as many as 184 oöthecae were found within a few feet of each other; others found under boards and in piles of firewood (Edmunds, 1952).

=Pelmatosilpha coriacea=

_Puerto Rico._--Mona Island, under bark of dead trees and under guava leaves (Ramos, 1946). Under bark of _Sideroxylon foetidissimum_ (Wolcott, 1941). Common along the coast and in mountains. "Very much at home" under the loose bark of _Sideroxylon foetidissimum_ (Wolcott, 1950).

=Pelmatosilpha kevani=

_Trinidad._--Under debris in bush (Princis and Kevan, 1955).

=Pelmatosilpha purpurascens=

_Dominica._--In decaying logs in forest (Rehn and Hebard, 1927).

=Periplaneta americana=

_Bermuda._--Among and under decaying debris, just above high-tide line (Verrill, 1902).

_Johnson Island._--Nocturnal, coming out at night in great numbers about _Tribulus_ blossoms. Under timbers on French Frigate Shoals (Bryan, 1926).

_United States._--Alleyways and yards may be overrun during the summer; adults and hundreds of nymphs found in decaying maple trees along residential street (Gould and Deay, 1938, 1940). Around fumaroles where a railroad fill was burning internally (Davis, 1927). Common in palm trees along the gulf coast of Texas, where they often fly around street lights at night (Zimmern _in_ Gould and Deay, 1940).

=Periplaneta australasiae=

_Bermuda._--Very abundant under stones (Rehn, 1910).

_Jamaica._--Under bark of dead tree and under bases of leaves of coconut palms (Rehn and Hebard, 1927).

_Virgin Islands, St. Croix._--Common in sugarcane fields and in woodlands (Beatty, 1944).

_Florida._--Juveniles under bark of dead logs of _Pinus caribaea_ (Hebard, 1915). Frequently found under signs on trees near borders of towns; under bases of dead petioles of cabbage palmetto (Hebard, 1917). Beneath logs, burlap bags, and other cover in old orange orchards (Blatchley, 1920).

_Marquesas Islands._--Under coconut fronds and grass (Hebard, 1935).

_Nihoa Island._--Nymphs only, on _Sida_, _Pritchardia_, bunch grass, and about camp (Bryan, 1926).

=Periplaneta brunnea=

_Georgia._--Under signs on oaks (Rehn and Hebard, 1916).

_Florida._--Beneath bark of stump (Blatchley, 1920).

=Periplaneta fuliginosa=

_Southeastern and southern U.S._--"This species is usually encountered out of doors, in or near towns. Over its range it is frequently found under signs on trees" (Hebard, 1917).

=Phidon (?) dubius=

_Chile._--Collected from mosses and lichens on tree trunks (Princis, 1952).

=Phoraspis= spp.

_Brazil and Guiana._--In grasslands, plantations of maize, sugarcane, and other plants on the borders of forests; the cockroaches were always found between the leaves which form the branches of the plants (Doumerc _in_ Blanchard, 1837).

=Phyllodromica brevipennis=

_Asia Minor and western Europe._--On ground among grasses; under moss and brushwood in mountain meadows (Bei-Bienko, 1950).

=Phyllodromica graeca=

_U.S.S.R., western Georgia._--In pine forest mixed with deciduous trees (Bei-Bienko, 1950).

=Phyllodromica irinae=

_U.S.S.R., Turan Lowland._--Along margins of "tugas" under half-fallen bushes of _Salsola kali_ that overhang the ground (Bei-Bienko, 1950).

=Phyllodromica maculata=

_Central Europe and western U.S.S.R._--On the edges of forests of the central-European type that are lighted by the sun; under fallen leaves; on bushes and conifers (Bei-Bienko, 1950).

=Phyllodromica meglerei=

_U.S.S.R._--Among fallen leaves under bushes; on oak branches; under mown hay (Bei-Bienko, 1950).

=Phyllodromica polita=

_Caucasus._--Under fallen leaves on slopes of mountains covered by forest or brushwood (Bei-Bienko, 1950).

=Phyllodromica pygmaea=

_U.S.S.R._--In the sands of Un-dzhal-kum and Zhety-konur it is found in the dense turf of _Aristida pennata_ (Bei-Bienko, 1950).

=Phyllodromica tartara=

_Central Asia._--In lowlands and in mountains up to 2,500 meters; in fruit orchards under trap rings fastened to trees to combat lesser apple worm (Bei-Bienko, 1950).

=Phyllodromica tartara nigrescens=

_Southern Uzbekistan._--Under bark of _Juniperus_ sp., under stones and on flowers of _Scorzonera acanthoclada_ (Bei-Bienko, 1950).

=Platyzosteria castanea=

_Australia._--Under loose wood or bark (Shaw, 1914).

=Platyzosteria novae seelandiae=

_New Zealand._--Swarms under loose dry bark and logs (Walker, 1904).

=Plectoptera dominicae=

_Dominica._--On moss-covered lime trees. "The species of the genus _Plectoptera_ are all foliage and flower frequenters, generally secured by beating low arborescent vegetation, or are attracted to light" (Rehn and Hebard, 1927).

=Plectoptera dorsalis=

_Puerto Rico._--In caladium, grass, weeds, coffee, and bananas; in flowers of _Ipomoea tiliasea_ (Rehn and Hebard, 1927). "... living in trees between leaves, or in 'butterfly-nests' of _Tetralopha scabridella_ in leaves of _Inga vera_, or of _Pilocrocis secernalis_ in the leaves of 'capá blanco' (_Petitia domingensis_) in the mountains. Along the coast they have been found under the bracts of cotton squares or bolls, and under the leaf-sheaths of sugar cane, in curled-up leaves of grapefruit, or in the dry flower clusters of 'espino rubial' (_Zanthoxylum caribaeum_)." These observations apply also to _Plectoptera infulata_ and _P. rhabdota_ (Wolcott, 1950).

=Plectoptera floridana=

_Florida._--On fringe of tall bushes at edge of mangrove swamp (Rehn and Hebard, 1914). Rehn and Hebard (1927) stated that on the Keys it frequented dry scrubby vegetation, particularly _Ilex cassine_.

=Plectoptera infulata=

_Puerto Rico._--See Wolcott's (1950) comments under _Plectoptera dorsalis_ above.

=Plectoptera lacerna=

_Cuba._--In grasses, sedges, etc., about a waterhole; on grass, pines and oak (Rehn and Hebard, 1927).

=Plectoptera perscita=

_Dominica._--On moss-covered lime trees (Rehn and Hebard, 1927).

=Plectoptera porcellana=

_Cuba._--Taken on flowers of "Júcaro" (Gundlach _in_ Rehn and Hebard, 1927).

=Plectoptera pygmaea=

_Jamaica._--In relatively dense forest foliage; in shrubbery (Rehn and Hebard, 1927).

=Plectoptera rhabdota=

_Puerto Rico._--In mixed vegetation; on grapefruit tree and guava (_Psidium guajava_); on bushes and shrubs (Rehn and Hebard, 1927). On coffee trees; on _Spondias_; on sugarcane; in caterpillar nests of _Tetralopha scabridella_ on _Inga vera_; in old cotton bolls; on grapefruit (Wolcott, 1936). See also Wolcott's (1950) comments under _Plectoptera dorsalis_.

=Plectoptera vermiculata=

_Cuba._--On pine in palmetto region (Rehn and Hebard, 1927).

=Polyphaga aegyptiaca=

_Algeria._--Nymphal females under decaying leaves at the end of November (Lucas, 1849).

_Transcaucasia._--In burrows in argillaceous cliffs along ravines. Females often covered by attached clay particles, an indication, according to Bei-Bienko, that this species is ecologically connected to compact clay soils or at least does not avoid them (Bei-Bienko, 1950).

See also the section on desert habitats (p. 29).

=Polyphaga saussurei=

_South-central Asia._--Occupies compact clay soils; distributed in drier regions than _P. aegyptiaca_; frequently found near dwellings, in yards, stables, and houses (Bei-Bienko, 1950).

=Polyzosteria limbata=

_Australia._--Common, usually "resting among the foliage or sunning itself on a fence or stumps, seldom or never hiding under bark or logs like most of the species" (Froggatt, 1906).

=Poroblatta= spp.

_Tropical America._--"The species of _Poroblatta_ apparently live as borers in stumps and logs in a manner similar to those of _Cryptocercus_ Scudder in the United States" (Gurney, 1937).

=Pseudomops septentrionalis=

_Texas._--In dead-brush pile; not scarce in heavy weeds, sunflowers, etc., in openings of river-plain jungle scrub (Hebard, 1917). It lives largely in herbage (Hebard, 1943a).

=Pycnoscelus surinamensis=

_Florida._--Under stones and rubbish; very abundant under coquina boulders in woods at Key West (Rehn and Hebard, 1905). "This species is common under planks, stones, and other debris on the ground ... also found at Long Key in the dry fibres at the base of the petioles of a coconut palm" (Rehn and Hebard, 1912). At Musa Isle, found burrowing in sand (Hebard, 1915). In fallen leaves and decaying wood in xeric and mesic hammock habitats (Friauf, 1953).

_Hawaii._--The soil swarmed with young of various stages during the summer (Illingworth, 1915). In soil about roots of pineapple under mulching paper; feeding on pineapple roots (Illingworth, 1927, 1929).

_Fakarava, Tuamoto Archipelago._--Numerous among dead leaves in tree holes (Cheesman, 1927).

_West Indies._--Under decayed stalks of sugarcane and in siftings from mangrove swamps, Cuba. Under manure, bases of leaves of coconut palm, litter, logs, and stones on coral rock and in bromeliads, Jamaica. Under wood, tiles, and boards in stable yards; immature individuals bored into the soil, Puerto Rico. (Rehn and Hebard, 1927.)

_Barbados._--Frequents cane fields (Tucker, 1952).

_Puerto Rico._--"Altho primarily a xerophytic species: collected among dry stones on Mona Island, under dry cow dung at Boquerón, and under boxes at Guánica, it is reasonably common in the more humid parts of Puerto Rico" (Wolcott, 1950).

_Virgin Islands, St. Croix._--Common under rubbish; frequently seen feeding on chicken feces around chicken roosts (Beatty, 1944). By feeding on chicken feces it may become the vector of the chicken eyeworm, _Oxyspirura mansoni_, as described in the references cited on page 204.

_Egypt._--Large numbers were found in moist soil at the site of a manure pile (Chakour, 1942).

_Germany._--Under greenhouse conditions the depth to which _P. surinamensis_ penetrated the soil was determined; 21 dug down to a depth of 8 to 10 cm., 3 dug down 10 to 12 cm., but only one dug 13 cm. below the surface. Often the tubes in the soil ended in a chamber which the cockroach might not leave for several days; nymphs molted in such chambers and females bore their young there (Roeser, 1940).

=Rhytidometopum dissimile=

_Trinidad._--Male on low herbage in orchard at night; under sacking; on _Hibiscus_ at night (Princis and Kevan, 1955).

=Riatia orientis=

_Trinidad._--Numerous specimens of both sexes at night on roadside _Hibiscus rosa-sinensis_ or low herbage in orchard (Princis and Kevan, 1955).

=Simblerastes jamaicanus=

_Jamaica._--Numerous in fragmentary debris of an abandoned termite nest on ground in the dry Liguanea Plain; a specimen was also taken under a stone in a field of short grass (Rehn and Hebard, 1927).

=Styphon bakeri=

_Costa Rica._--Among humus and rubble in crevices and large cavities in rocks of the Tertiary limestone rim and the metamorphosed and igneous rocks of the interior of the islands (Baker _in_ Rehn, 1930).

=Supella supellectilium=

_Virgin Islands, St. Croix._--Under rubbish heaps; in sugarcane straw (Beatty, 1944).

_Africa._--"A cosmotropical species which occurs both out of doors and as a household pest in many warmer parts of the world. It is apparently endemic to non-forested areas in much of Africa north of the Equator." (Kevan and Chopard, 1954.)

=Symploce flagellata=

_Puerto Rico._--Under low trees on hillside and dead leaves in thicket of sea grape (Hebard, 1916c).

=Symploce hospes=

_Hawaii._--Under stones and rubbish (Illingworth, 1915).

_Virgin Islands, St. Croix._--Under rubbish and on shrubbery at night (Beatty, 1944).

=Symploce jamaicana=

_Jamaica._--In dead leaves under acacia and other shrubs in desert tract; under log and rubbish in open on limestone sand near beach (Hebard, 1916c). Very common in short dry grass in roadside gutter at night, often clustered together; under beach trash in stony wash of Hope River (Rehn and Hebard, 1927).

=Symploce ruficollis=

_Virgin Islands, St. Croix._--Under rubbish and on shrubbery at night (Beatty, 1944).

_Puerto Rico._--In siftings from sea-grape thicket on sandy soil (Rehn and Hebard, 1927). Often living under leaf-sheaths of sugarcane (Wolcott, 1950).

=Tartaroblatta karatavica=

_Asia, Kara-tau Mountains._--Many hundreds of individuals found only under stones on moist earth and not where ground seemed dry; found on very stony slopes with sparse vegetation, often with undergrowth present (Bei-Bienko, 1950).

STRUCTURAL HABITATS

In this category we include all man-made structures, whether inhabited by man or not, that may become infested with cockroaches. A nonexhaustive list of such structures would include dwellings, restaurants, mess halls, barracks, groceries, markets, bakeries, dairies, drug stores, department stores, hotels, hospitals, warehouses, mills, factories, packing houses, animal houses, breweries, incinerators, privies, sewers, sewage treatment plants, ships, aircraft, etc. Although dwellings are only one of the many kinds of structures that are colonized by cockroaches, the several species that have adopted this mode of life are generally referred to as domiciliary cockroaches. This term is adequate only if we remember that these cockroaches are not restricted to domiciles but are pests in other structures as well.

Associations between man and certain species of cockroaches possibly started as casually as the short-lived association that Beebe (1953) observed when he discovered three cockroaches in the newly built couch of an orang-utan. Obviously, when man came down from the trees, his fellow travelers found his cave dwellings and other abodes particularly favorable habitats. From such primitive beginnings, domiciliary cockroaches have spread into every kind of structure that man has since devised. We predict that when man develops a suitable vehicle, cockroaches will someday accompany him into space. Yet despite the apparent predilection of certain species of cockroaches for man, man is only incidental to these associations. Only the shelter and food that man unwittingly provides for these unwelcome guests attract cockroaches to him; man's physical presence is unnecessary.

Most, if not all, of the common domiciliary cockroaches apparently originated in the Tropics or sub-Tropics from whence they have spread, through normal commercial channels, into most of the inhabited world. At least eight domiciliary cockroaches originated in Africa (Rehn, 1945): _Blatta orientalis_, _Blattella germanica_, _Leucophaea maderae_, _Nauphoeta cinerea_, _Oxyhaloa buprestoides_, _Periplaneta americana_, _P. australasiae_, and _Supella supellectilium_; and, perhaps, _Periplaneta brunnea_ as well; _Neostylopyga rhombifolia_ was probably of Indo-Malayan origin; _Pycnoscelus surinamensis_ was of oriental origin; and _Leurolestes pallidus_ was endemic in the West Indies (Rehn, 1945). Princis (1954a) rejected Africa as the original home of _Blatta orientalis_ and advanced reasons for placing its origin in Central Asia.

Several domiciliary species have become well established in temperate zones and some even in the Arctic. Bei-Bienko (1950) listed the following 10 species as sinanthropes in the Palearctic zone: _Blatta lateralis_, _B. orientalis_, _Blattella germanica_, _Leucophaea maderae_, _Periplaneta americana_, _P. australasiae_, _Polyphaga saussurei_, _Pycnoscelus surinamensis_, and _Supella supellectilium_. In the warmer parts of the temperate regions, as in their native Tropics, certain domiciliary species breed outdoors as well as indoors. In the less temperate extensions of their ranges most domiciliary species are nearly always found indoors. In regions with low winter temperatures these cockroaches do not survive in unheated structures; but in heated buildings _Blattella germanica_, for example, has been able to withstand the rigorous climate of Alaska, where it has caused severe infestations (Chamberlin, 1949).

The limiting factors that determine whether man-made structures will provide suitable habitats for cockroaches are favorable temperature and availability of water and food. The range of temperatures that man provides for his own comfort and protection fosters the rapid increase of cockroach populations indoors. Gunn (1934, 1935) has demonstrated that the preferred temperature range (zone of indifference) of _Blatta orientalis_ is 20-29° C. The upper limit of the preferred temperature of _Blattella germanica_ and _Periplaneta americana_ is 33° C. (Gunn, 1935). The lower limits of temperature tolerance were not sharply defined in Gunn's work. However, less than optimum temperatures, if they last for only short periods, are not necessarily lethal. The 24-hour mortality for _P. americana_ that had been held for one hour at 0° C. was only 2±2 percent (Knipling and Sullivan, 1957). Gunn (1934) observed that _Blatta orientalis_ would not settle at temperatures above 33° C. and would react violently against higher temperatures (e.g., 39° C.) by running away; thus the thermotactic behavior of cockroaches might be presumed to bring them into favorable environments within structures. Thermal death points have been determined for the above three species by Gunn and Notley (1936).

It is common knowledge among those who rear cockroaches experimentally that, unless the water content of the food is high, fluid water is essential in the insects' dietary. Ten species of domiciliary cockroaches have been shown to be unable to survive as long on dry food alone as they could on food and water at 36-40 percent relative humidity (Willis and Lewis, 1957). _Blatta orientalis_, when in a state of normal water balance, usually spent more time in the drier part of a humidity gradient; but desiccated insects tended to become hygropositive (Gunn and Cosway, 1938). We presume that other domiciliary species behave similarly. If water is available nearby, it may be presumed that partially desiccated cockroaches could locate a source through the mediation of a humidity sense. Hygroreceptors have been demonstrated on the antennae of _Blattella germanica_ (Roth and Willis, 1952a) and suggested for _Blatta orientalis_ (Gunn and Cosway, 1938).

Drinking water is available to cockroaches in the traps of sinks, wash basins, tubs, and toilet bowls; in flush tanks; as condensation on cold pipes, flush tanks, and windows; around leaking pipes and faucets; as spillage; in miscellaneous water-filled containers, such as pet drinking dishes, aquaria, vases; empty beverage bottles; and drainage from ice boxes. Soft, juicy fruits and vegetables can provide both moisture and food. There seems to be a tendency for certain species (_Blatta orientalis_ and _Blattella germanica_) to become established in the more humid parts of structures, such as basements, around sinks, and in bathrooms. Whether this is a reaction to a preferred humidity or merely a fortuitous aggregation near sources of drinking water and food has never been clearly demonstrated. The rather widespread dissemination of these species into zones of low as well as high humidity suggests that detailed studies of the microclimatic conditions of structural microhabitats will be needed before meaningful conclusions can be drawn about the stratification of cockroaches within structures according to species.

In nearly all structures infested by cockroaches, food of some kind is available, either in the structure itself or nearby. This may be the food stored by man for his own use or the use of kept animals; it may be crumbs, food spillage, garbage, or excreta; glues and pastes on cartons, boxes, stamps, envelopes, labels, and wall paper; sizing on cloth and book covers; various dried animal and plant products; dead insects; living plants; etc. In fact, it is almost impossible, despite good housekeeping, to keep any structure used by man free of all food suitable for cockroaches.

That the requisite temperature, water, and food are provided, more or less adequately, by a variety of structures is attested by the innumerable infestations of cockroaches that develop when control measures are relaxed. Within structures the accessibility of certain harborages to cockroaches probably depends on the habits of the species and to some extent on their size. Similar types of harborages in different structures may be used by the same species, although there seems to be some overlapping by different species into the same kinds of daytime shelters. The comparative ecology of domiciliary cockroaches has not been thoroughly investigated, so any interpretation of observational data is necessarily speculative and inconclusive at this time. Our discussion on pages 324 to 343 is also pertinent to this section.

LAND-BASED STRUCTURES

Dwellings provide a variety of microhabitats that are acceptable to cockroaches. It has been stated that old houses, or houses that have many cracks and crevices, or have basement kitchens that are not kept clean and in good repair are particularly liable to invasion by cockroaches (Laing, 1946; British Museum [Nat. Hist.], 1951). Although this statement is undoubtedly true, it has been our personal experience, as well as the experience of others, that new, clean, and well-planned houses and apartments are also easily and sometimes quickly invaded by cockroaches. Mallis (1954) has cited the following places that are frequently infested by cockroaches in homes. In the kitchen, cockroaches are found in and around sinks, in cupboards above and below sinks, under tables and chairs, in stoves, around breadboards, in utility cabinets, in kitchen closets, under linoleum, behind, under, and inside refrigerators and iceboxes. In living rooms cockroaches are found in furniture, studio couches, sewing machines, closets, and bookshelves; behind picture frames, pennants, calendars, and other wall ornaments. In bathrooms cockroaches are found in and behind utility cabinets and toilets; they may be found in wicker clothes hampers, in brooms and mops, and in door hinges. Ordinarily, cockroaches are not found in bedrooms unless they are abundant elsewhere in the dwelling. Additional harborages are cited under specific cockroaches in the list below.

In markets DeLong (1948) found the German cockroach in bags of potatoes and onions, in crates of citrus fruits, in pads and shredded papers in banana boxes, and in cases of bottled beverages. The insects were attracted by coffee and crawled into the folds of coffee bags. They were found in cartons of canned goods; in bread and baked goods; in cartons of packaged cookies, cakes, and crackers. Packaged cereals were attractive, and cockroaches were sometimes found in packages of cigarettes. The insects occurred in scales (by the hundreds) and in cash registers. Rather heavy infestations were found under stainless-steel cappings that covered wooden arms on the fish cleaning stand. The insects were numerous in display cases where they were warm and sheltered. They were also found behind mirrors above produce racks, in electrical switch boxes and conduits, and in telephone boxes, as well as generally in cracks and behind loose moldings or loose wall boards. Enclosed boxlike tables were frequently heavily infested.

In restaurants cockroaches may be found in the following places: Crevices in wood, plaster, concrete, and metal; in the bar; in the kitchen and in the associated equipment; in cupboards, lavatories, and garbage storage areas; and on the undersides of chairs and tables (Mallis, 1954).

In drug stores Frings (1948) found cockroaches behind the mirror and between the sink and the cooler. Thousands were found in hollow ornamental shelf edging. The hollow bases of malted-milk dispensers and drink mixers were cockroach havens.

In a hospital Frings (1948) found cockroaches in decorative trim around doorways, by the thousands in wicker laundry baskets, and in incubators for premature babies. In military hospitals we have seen cockroaches (_Blattella germanica_) in kitchens and dining halls in the usual hiding places mentioned above and on the undersides of stainless-steel serving tables.

In department stores cockroaches have been found in food departments, beauty salons, rest rooms, dressing rooms, linen departments, and stationery departments (Anonymous, 1952). The infestation in the linen department was traced to clean towels which, when returned from the laundry, contained at least 500 cockroaches per bundle. The insects were carried into the rest rooms and beauty salon when the towels were distributed.

The microhabitats of cockroaches in privies and sewers have not been studied. These habitats are particularly important in view of the demonstrated migrations of cockroaches from sewers into dwellings and the possible dissemination of pathogenic microorganisms from feces to food. The reader is referred to our 1957(a) paper for a summary of the known information on cockroach dispersal from sewers.

COCKROACHES ASSOCIATED WITH LAND-BASED STRUCTURES

Most of the cockroaches listed below are either known domiciliary species or they have been found one or more times in houses or other man-made structures. The known structural pests breed within the building. Certain other species, which have been observed only infrequently in structures and are not known to breed there, may possibly be incipient pests; these latter species may attain future economic importance if they establish breeding colonies within a structure. A few species have undoubtedly wandered indoors by accident. It is difficult to decide whether a particular species was an accidental invader or whether it was attracted indoors in response to some stimulus. Only additional information will provide the desired answers.

=Aglaopteryx ypsilon=

_Trinidad._--Male found indoors (Princis and Kevan, 1955).

=Allacta similis=

_Hawaii._--Found only indoors at Nauhi. Otherwise this is apparently an outdoor species (Swezey and Williams, 1932).

=Blaberus craniifer=

_Cuba._--Household pest (Deschapelles, 1939). Particularly abundant in houses in Santiago and Havana (Rehn and Hebard, 1927).

_Florida._--Under boards in woodshed (Rehn and Hebard, 1912, 1914).

=Blaberus discoidalis=

_Ecuador._--In eating places (Campos R., 1926).

_Hispaniola._--In houses (Rehn and Hebard, 1927).

_New Jersey._--In greenhouse (Weiss, 1917).

_Puerto Rico._--In homes (Seín, 1923). In fruit stores (Wolcott, 1950).

=Blatta lateralis=

_Central Asia._--Household pest, often found in homes with clay floors (Bei-Bienko, 1950).

_Turkmen S.S.R._--Males and females occurred in dwellings (Vlasov, 1929).

=Blatta orientalis=

This species is a cosmopolitan domiciliary pest (Hebard, 1917; Rehn, 1945). It is reported to occur particularly in basements and crawl spaces under basementless houses (Mallis, 1954). In damp basements where food is available large colonies are not unusual, but it also may infest offices and apartments several floors off the ground (Gould and Deay, 1940). The number encountered on upper floors is seldom large, but the frequency of occurrence may reach 30 percent of the observations (Spear et al., _in_ Shuyler, 1956). In supermarkets this species hides during the day inside concrete blocks or cracks in the foundation, under furniture, or behind cartons; it is conspicuous on the floors of the markets at night (De Long, 1948). In Great Britain the kitchen is preferred by this pest (and by _Blattella germanica_); they shelter beneath steam radiators and gas stoves, behind hot-water pipes, underneath furniture and floor coverings, sinks and baths; basements and underground kitchens are especially likely to be infested (Laing, 1946; British Museum [Nat. Hist.], 1951). Goodliffe (1958) noted that _B. orientalis_ may travel long distances to find food.

=Blattella germanica=

This species is a cosmopolitan domiciliary pest (Hebard, 1917; Rehn, 1945). It is one of the commonest insects in homes and restaurants (Gould and Deay, 1940). It is found in kitchens, larders, bathrooms, furnace rooms, and storage rooms of bakeries, breweries, hospitals, barracks, as well as dwellings, where, during daylight, it hides behind cupboards, furniture, hanging pictures, panels and skirting boards, in cracks around drains, water pipes, electric wires, and hot-water and steam heating units (Wille, 1920). The German cockroach may be found in cracks around baseboards, pipes, conduits, sinks, and drawers; behind cabinets; inside switch boxes and refrigerators; on under surfaces of tables, chairs, and shelves; between stacks of stored goods, and in almost every place that is not readily observed (Kruse, 1948). We have also seen this species packed in electric-clock cases and loud-speaker baffles, in cash registers, and clinging to the undersurface of stainless-steel steam tables. The infestation of markets by this species has been described above. Very narrow cracks provide refuges for the German cockroach. Wille (1920) found first-instar nymphs in cracks 0.5 mm. wide and adult males and females without oöthecae in cracks 1.6 mm. wide.

Shuyler (1956) has observed extensions into relatively new structural habitats by _Blattella germanica_ in the north-central area of the United States. A few German cockroaches are now being encountered in living rooms, bedrooms, clothes closets, bedroom furniture, lobbies, entrance halls, checkrooms, nonfood storerooms, nonfood warehouses, and coin-vending machine repair shops. In these situations this species is behaving much like the brown-banded cockroach, _Supella supellectilium_.

=Blattella schubotzi=

_Cameroon._--Five specimens in a house (Princis, 1955).

=Blattella vaga=

_U.S.A._--Although this is mostly an outdoor species, during dry seasons it may temporarily enter houses in great numbers, occasionally breeding indoors in Arizona (Flock, 1941a). Two adults were collected indoors in Texas (Riherd, 1953).

=Chromatonotus notatus=

_Trinidad._--A male was found indoors (Princis and Kevan, 1955).

=Cutilia soror=

_Hawaii._--Almost as common in houses as _Neostylopyga rhombifolia_ (Hebard, 1922).

=Ectobius duskei=

_U.S.S.R._--Frequently occurs in living apartments in farming localities as an accidental inhabitant (Bei-Bienko, 1950).

=Ectobius pallidus=

_Massachusetts._--A summertime pest in houses along coast (Gurney, 1953; E. R. Willis, personal observation). Generally an outdoor species.

=Epilampra abdomen-nigrum=

_Trinidad._--Male, indoors (Princis and Kevan, 1955). An outdoor species generally.

=Ergaula capensis=

_Cameroon._--A male taken in a house (Princis, 1955).

=Eublaberus posticus=

_Trinidad._--Indoors, feeding on bat feces (Princis and Kevan, 1955).

=Eurycotis floridana=

_Florida._--Occasionally found in homes (Creighton, 1954; Roth and Willis, 1954a).

=Euthyrrhapha pacifica=

_Hawaii._--Found outdoors and indoors where it breeds in neglected cupboards and in rubbish (Fullaway and Krauss, 1945).

=Holocompsa azteca=

_Mexico._--Household pest (Ball et al., 1942).

=Holocompsa cyanea=

_Costa Rica._--One specimen in house (Rehn, 1906).

=Holocompsa nitidula=

Apparently domiciliary in American Tropics (Hebard, 1917). In houses under chests, etc., Cuba (Gundlach, 1890-1891); Puerto Rico (Gundlach, 1887). In folds of burlap bag, Florida (Rehn and Hebard, 1914).

=Ischnoptera rufa occidentalis=

_Panama._--Thrives about human habitations under litter, though not domiciliary (Hebard, 1920).

=Ischnoptera rufa rufa=

_Jamaica._--In hotel. "While hardly a domiciliary form it would seem to frequent environments where man has considerably disturbed natural conditions, as under debris, docks, under logs and stones in cultivated areas" (Rehn and Hebard, 1927).

=Leucophaea maderae=

_West Indies._--In habitations, warehouses, and other structures; "At times it is a very abundant and serious pest" (Rehn, 1945). In Puerto Rico it was also found in fruit stores, markets, and inns (Seín, 1923; Wolcott, 1950).

Reported as a domiciliary pest in Madeira (Heer, 1864); Windward Islands (Marshall, 1878); Tropics and sub-Tropics (Rehn, 1937); Philippine Islands (Uichanco, 1953); New York City (Anonymous, 1953; Gurney, 1953); Trinidad (Princis and Kevan, 1955). This species is also established in coastal Brazil, Central America, all the Greater Antilles, several other tropical islands, and tropical Africa, where it probably originated (Rehn, 1945).

=Leurolestes circumvagans=

_Hispaniola, Grenada._--Largely domiciliary (Rehn and Hebard, 1927).

=Leurolestes pallidus=

_Cuba._--All over island, in houses, under lockers, etc. (Rehn, 1945; Gundlach, 1890-1891).

_Florida._--Rehn and Hebard (1914).

This species has been recorded from various islands in the West Indies, from Mexico, Guatemala, and Brazil (Rehn, 1945).

=Methana marginalis=

_Australia._--Reported entering houses (Pope, 1953a).

=Nauphoeta cinerea=

_Australia._--In hospital (Mackerras and Mackerras, 1948). In dwellings, grain stores, and fowl-feeding pens (Pope, 1953).

_Sudan._--Domiciliary in huts of the Shilluk natives; fairly widely distributed in eastern Africa (Rehn, 1945).

_Hawaii._--In feed rooms of poultry plants (Illingworth, 1942).

_Florida._--Established in feed mills around Tampa (Gresham, 1952; Gurney, 1953).

The wide distribution of this species from East Africa, where it originated, to the Orient and the New World was undoubtedly mediated by shipping (Rehn, 1945).

=Neoblattella= sp.

_Puerto Rico._--Observed [as _Blatta caraibea_, Rehn and Hebard (1927)] in houses (Gundlach, 1887).

=Neostylopyga rhombifolia=

Domiciliary in Indo-Malaya and New World Tropics (Rehn, 1945); Philippine Islands (Uichanco, 1953); and Hawaii (Hebard, 1922).

=Oxyhaloa buprestoides=

Presumably to some extent domiciliary, as it evidently spread from Africa to the New World via slave ships (Rehn and Hebard, 1927; Rehn, 1945).

=Panchlora nivea=

_Colombia._--A male and a female taken in a dwelling (Princis, 1946). This is primarily an outdoor species which is frequently taken indoors as an adventive on bananas (see p. 150 for references).

=Parcoblatta fulvescens=

_Florida._--Males found in laboratory and dormitory buildings, ostensibly attracted by lights (Friauf, 1953).

=Parcoblatta lata=

_Connecticut._--Domiciliary pest (Moore, 1957). Generally an outdoor species.

=Parcoblatta notha=

_Arizona._--It may occasionally be a nuisance in houses (Ball et al., 1942).

=Parcoblatta pensylvanica=

_U.S.A._--Country houses often badly infested, Indiana (Blatchley, 1920). Frequently taken in houses in wooded areas, Michigan (Hubbell, 1922). Infestation by males, females, and nymphs on fourth floor of building, South Dakota (Severin, 1952). Houses in wooded areas infested by nymphs and occasionally by adults (Gould and Deay, 1940).

_Canada._--Pest in summer cottages in Ontario (Walker, 1912).

=Periplaneta americana=

This is a cosmopolitan domiciliary pest (Hebard, 1917; Rehn, 1945). It is common in restaurants, grocery stores, bakeries, and where food is prepared or stored; it was trapped regularly in the basement and upper floors of store buildings, and it was also found in all heated parts of an old meat-packing plant (Gould and Deay, 1938). _P. americana_ was numerous in latrines in Iran (Bei-Bienko, 1950) and in privies in Texas (Dow, 1955) and Georgia (Haines and Palmer, 1955). Large numbers of this species also occur in sewers adjacent to human habitations (Roth and Willis, 1957a).

=Periplaneta australasiae=

Generally domiciliary, but also occurs outdoors in the West Indies (Rehn and Hebard, 1927). It is a very abundant domiciliary pest in tropical Africa and tropical America (Rehn, 1945); Ecuador (Campos R., 1926); Puerto Rico (Sein, 1923); Philippine Islands (Uichanco, 1953); Australia (Pope, 1953).

Also occurs as a pest in greenhouses in Pennsylvania (Thilow and Riley, 1891); France (Giard, 1900); Italy (Boettger, 1930); Great Britain (Laing, 1946; British Museum [Nat. Hist.], 1951).

=Periplaneta brunnea=

Circumtropical domiciliary pest which is apparently more nearly peculiar to the Tropics and adjacent regions than _P. americana_ (Hebard, 1917). This species has been trapped in significant numbers in privies and dwellings in Georgia (Haines and Palmer, 1955). It is the species of _Periplaneta_ present in homes in San Antonio, Texas (Mallis, 1954).

=Periplaneta fuliginosa=

_U.S.A._--Frequently encountered out of doors, but has been reported common after dark about a hotel in Alabama and was captured in a house in Louisiana; it was also extremely abundant on the wharves at night in Jacksonville, Florida (Hebard, 1917). As a domiciliary pest it was, next to _Blattella germanica_, the most common cockroach inside homes in southwest Georgia, where it was also the most common cockroach in privies (Haines and Palmer, 1955). This species has become a very common domiciliary pest in Texas (Eads, personal communication, 1955). It infested a greenhouse for five years in Indiana (Gould and Deay, 1940).

=Periplaneta ignota=

_Australia._--It occurs in dwellings occasionally (Pope, 1953).

=Phaetalia pallida=

_Colombia._--Three specimens from three dwellings (Princis, 1946).

_Trinidad._--Male indoors; male and female at light (Princis and Kevan, 1955).

=Plectoptera dorsalis=

_Puerto Rico._--According to Gundlach (1887) it enters houses at night attracted by light (Rehn and Hebard, 1927).

=Polyphaga aegyptiaca=

_Iraq._--Common in houses (Weber, 1954).

_Caucasus._--Winged male in kitchen (Burr, 1913).

_U.S.S.R._--Listed as a sinanthrope (Bei-Bienko, 1950).

=Polyphaga saussurei=

_South-central Asia._--One of the commonest domiciliary species (Bei-Bienko, 1950).

=Pseudophoraspis nebulosa=

_East Indies._--This species is sometimes difficult indoors (Karny, 1925).

=Pycnoscelus surinamensis=

A household pest in the East Indies (Karny, 1925); Philippine Islands (Uichanco, 1953); Tanganyika (Smith, 1955); Trinidad, eight records indoors (Princis and Kevan, 1955). It is also a greenhouse pest (Hebard, 1917; Zappe, 1918; Doucette and Smith, 1926; Saupe, 1928; Roeser, 1940). Common in or around chicken batteries and yards in Hawaii (Schwabe, 1949).

=Supella supellectilium=

Domiciliary wherever distributed (Rehn, 1945), this species is especially difficult to control because of its apparently nonselective dispersal throughout dwellings. For example, Mallis (1954) observed in Texas that it was widely distributed throughout the apartment and was probably the most common cockroach seen in the bedroom; its favorite harborages were beneath and behind corner braces on kitchen chairs, underneath tables, behind pictures and other objects on walls, and in shower stalls; its oöthecae were commonly fastened on walls and ceilings throughout the house. Gould and Deay (1940) reported that this species prefers high locations, such as shelves in closets, behind pictures, and picture molding; oöthecae were found about kitchen sink, desks, tables, and other furniture, and even in bedding. Hafez and Afifi (1956) stated that the adult wanders in nearly all rooms of the house and only visits the kitchen when searching for food; it hides in cupboards, pantries, closets, bookshelves, drawers, and behind picture frames; the nymphs normally hide in the corners of drawers, behind frames, and in similar situations.

=Symploce bicolor=

_Puerto Rico._--In houses, Sardinera Beach, Mona Island (Ramos, 1946).

=Symploce hospes=

_North American Tropics._--Domiciliary, but not exclusively so, and apparently widely distributed (Hebard, 1917). In Florida, as _Ischnoptera rufescens_, found in a greasy cupboard (Rehn and Hebard, 1914).

_Hawaii._--Illingworth (1915).

SHIPS

Sailing ships have long been notorious for their unwelcome hordes of cockroaches, and it was by ship that at least 11 domiciliary species migrated from their centers of origin to other parts of the world (Rehn, 1945). Over 40 nondomiciliary species have been carried by ship from the American Tropics to other parts of the world in cargoes of bananas (p. 146). In addition to these, other adventive cockroaches appear from time to time in ports to which they have been carried by ships. Yet by far the most numerous cockroaches on shipboard are the breeding populations of a few common domiciliary pests. Except in the most rigorously disinsectized ships, this commerce in cockroaches has continued to the present day.

Cockroaches undoubtedly infested the first ships that sailed the Mediterranean; of these we have no records. The earliest recognizable record of cockroaches on shipboard is Moffett's (1634) statement that when Drake captured the ship _Philip_, he found it overrun with cockroaches [_Blattarum alatarum_]. Bligh (1792) described disinfesting H.M.S. _Bounty_ with boiling water to kill cockroaches. Chamisso (1829) reported that he had seen ships casks, in which rice or grain had been stored, that were found to be filled with _Blattella germanica_ when opened. During a voyage from England to Van Diemen's Land, Lewis (1836) was greatly annoyed by hundreds of cockroaches flying about his cabin at night; the most numerous resembled _Periplaneta americana_ and another was similar to _Ectobius lapponicus_. This latter was undoubtedly _B. germanica_, which is the only ship-infesting species that resembles the feral _E. lapponicus_. Lewis continued, _P. americana_ "were in immense profusion, and had communication with every part of the ship, between the timbers or skin. The ravages they committed on everything edible were very extensive; not a biscuit but was more or less polluted by them, and amongst the cargo 300 cases of cheeses, which had holes in them to prevent their sweating, were considerably damaged, some of them being half devoured and not one without some marks of their residence."

Kingsley (1870), Kellogg (1908), Gates (1912), Heiser (1936), and Bronson (1943) have all reported that cockroaches were so numerous on ships that they gnawed the skin and nails of the men on board. These are all independent observations of what may well have been a common occurrence on ships. We have discussed in detail the subject of cockroaches biting man in our 1957(a) paper.

Mosely (1892) reported, "At the time that England was left the ship [H.M.S. _Challenger_] seemed nearly free of animals, other than men, dogs, and livestock required for food. The first cockroaches apparently came on board at St. Vincent, Cape Verdes.... Cockroaches soon became plentiful on board, and showed themselves whenever the ship was in a warm climate.

"At one period of the voyage, a number of these insects established themselves in my cabin, and devoured parts of my boots, nibbling off all the margins of leather projecting beyond the seams on the upper leathers."

Sir Edmund Freemantle (1904) recalled some of his experiences in the British Navy. "Cockroaches in the tropics were also terrible scourges. One saw little of them in fine, dry weather, but in damp, wet weather they seemed to come from every hidden corner ... our remedy in the 'Spartan' was to make the boys catch them--on pain of being caned.... One brig, the 'Lily,' was so overrun by cockroaches that the officers' clothes smelt of them."

The quotation from Sonan (1924) on page 348 describes similar conditions in the Japanese Navy.

On modern cargo ships cockroaches are reported to be extremely numerous in the galley, the crew's quarters, and sometimes in the holds; they dwell in hot, humid environments such as the casing around steam pipes (Monro, 1951). Williams (1931) reported that _Blattella germanica_ was the most important cockroach pest on ships seen at New York. Although often numerous in the holds, the cockroaches as a rule congregated in living quarters. They were also frequently found between tarpaulins covering the hatches. It was not unusual to kill 20,000 to 50,000 in the forecastle, and more than 20,000 have been taken from a single stateroom. Simanton (1946) inspected the S.S. _William Kieth_ when it berthed at San Francisco from a 10-month voyage to the South Pacific. The holds were infested with thousands of _Periplaneta americana_, but in the crew's quarters, mess halls, and storerooms _B. germanica_ predominated. After insecticidal treatment about 2,000 _P. americana_ were seen in each hold and as many as 24 _B. germanica_ in each cabin. Richardson (1947) reported that in Army transports inspected between 1943 and 1946 at New York, _P. americana_ was found in the galleys and messes, and occasionally heavy infestations were found deep in the holds; _B. germanica_ was found in the galleys and messes; _Blatta orientalis_ was found only in the hold.

Additional references indicating the presence of _Blattella germanica_ on ships may be found in the account of its parasite _Ripidius pectinicornis_ (p. 232). Although Rice (1925) and Williams (1931) cite _B. germanica_ as the most numerous cockroach on ships, Brooke (1920) stated that the great majority of ship cockroaches were _Periplaneta americana_. In addition to citing cockroach infestations on ships, the following authors reported various methods for disinfecting ships: Canalis (1916), Pryor (1918), Brooke (1920), Rice (1925), Williams (1931), Simanton (1946), Richardson (1947), and Anonymous (1951, 1954).

COCKROACHES ASSOCIATED WITH SHIPS

In the following list we include some previously unpublished data on cockroaches that were recovered from ships at the Miami, Fla., Quarantine Station for the periods November 1945 through May 1946; May, June, August, and September 1950; and 17 July 1957 (Porter, personal communication, 1958). These data were lumped, without breakdown to species, under the entry Orthoptera in Porter (1958).

Certain of the species listed below occur only accidentally on shipboard and will probably never establish breeding colonies on ships or become pests on shipboard or elsewhere; some were merely passengers between one land-based colony and another. Others, the truly domiciliary pests, are as likely to be pests on shipboard as they are in land-based structures.

=Blaberus discoidalis=

_Hispaniola._--On board ship (Rehn and Hebard, 1927).

=Blatta orientalis=

_U.S.A._--At Port of New York (Richardson, 1947).

=Blattella germanica=

_At sea?_--In ships casks (Chamisso, 1829).

_U.S.A._--Port of New York (Williams, 1931; Richardson, 1947). San Francisco (Simanton, 1946). At Miami, 7,852 live specimens recovered from ships (Porter, personal communication, 1958). Most numerous species on ships (Rice, 1925).

=Epilampra maya=

_At sea._--One male and one female found dead on S.S. _Tenadores_ (Hebard, 1917).

=Epilampra= sp.

_Florida._--One dead specimen, Miami (Porter, personal communication, 1958).

=Ischnoptera= sp.

_Florida._--Five live and one dead specimen, Miami (Porter, personal communication, 1958).

=Latiblattella= sp.

_At sea._--One female alive in hold of S.S. _Tenadores_ (Hebard, 1917).

=Leucophaea maderae=

Brought from West Africa to West Indies and Brazil by slave ships (Rehn, 1945).

=Nauphoeta cinerea=

Widely disseminated by sailing ships (Rehn, 1945).

=Neoblattella fratercula=

_At sea._--Two females found dead on S.S. _Tenadores_ (Hebard, 1917).

=Neoblattella fraterna=

_At sea._--One male found dead in hold of S.S. _Tenadores_ (Hebard, 1917).

=Neoblattella nahua=

_At sea._--One female dead in hold of S.S. _Tenadores_ (Hebard, 1917).

=Neoblattella= sp.

_Florida._--Five dead specimens recovered from ships, Miami (Porter, personal communication, 1958).

=Neostylopyga rhombifolia=

Widely distributed by sailing ships (Rehn, 1945).

_England._--Captured on a sugar vessel from Java (Lucas, 1920).

=Nyctibora noctivaga=

_At sea._--One male and one female nymph found dead on S. S. _Tenadores_ (Hebard, 1917).

=Nyctibora= sp.

_Florida._--Two dead specimens recovered from ships at Miami (Porter, personal communication, 1958).

=Oxyhaloa buprestoides=

Spread from Africa to New World by ships (Rehn and Hebard, 1927; Rehn, 1945).

=Panchlora nivea=

_At sea._--One female dead in hold of S.S. _Tenadores_ (Hebard, 1917).

_Florida._--Fifteen dead specimens taken from ships, Miami (Porter, personal communication, 1958).

From the numerous records of this species as an adventive taken on bananas (p. 150), it may be presumed to be a frequent traveler on banana boats.

=Periplaneta americana=

_At sea._--Lewis (1836). Hebard (1933a) stated that this is "often a serious pest on the smaller ships sailing the South Seas."

_U.S.A._--San Francisco (Simanton, 1946). Port of New York (Richardson, 1947). At Miami, 62 live and 123 dead specimens (Porter, personal communication, 1958).

=Periplaneta australasiae=

Migrated from West Africa to America in slave ships (Rehn, 1945).

=Pycnoscelus surinamensis=

Probably in part reached the New World by way of Africa in slave ships (Rehn, 1945).

=Supella supellectilium=

Reached America from West Africa by slave ship (Rehn, 1945).

=Xestoblatta festae=

_At sea._--One female found dead in hold of S.S. _Tenadores_ (Hebard, 1917).

AIRCRAFT

Michel (1935) stated that the development of air transportation brought the same insect dispersal problems that exist in land and water transportation; in addition, the problem of cockroach infestation had become a very serious one, quite aside from the hygienic point of view, because it had been discovered that these insects seek out the wings of airplanes, where they subsisted on the glue and dope used in airplane construction. However, Dethier (1945) found no cockroaches in dismantled or wrecked wing and tail structures of metal aircraft in central Africa. In fact, all-metal aircraft would seem to provide little in the way of food or water for stowaway cockroaches.

Laird (1951, 1952, 1956a) found living specimens of _Blattella germanica_, _Periplaneta americana_, and _Periplaneta australasiae_ in baggage compartments and/or kitchens in aircraft. Other species which have been recovered from undisclosed spaces in aircraft are listed below. Some of the cockroaches that were reported as dead may not have died from exposure during flight but may have been killed by insecticide applied by inspecting personnel at the airports.

COCKROACHES ASSOCIATED WITH AIRCRAFT

In the following list we include some previously unpublished data on cockroaches that were recovered from aircraft in Miami, Fla., International Airport from 1 July 1956 through 30 June 1957 (Porter, personal communication, 1958). These data were lumped under the entry Orthoptera without breakdown to species in Porter (1958).

Species reported by Hughes (1949), and cited below as from southern United States, were recovered from aircraft that arrived at Brownsville, Fort Worth, Miami, New Orleans, and San Juan. There was no way of linking a specific record with any particular city.

The comments we made above about species that are infrequently encountered on ships apply with equal validity to similar species found on aircraft.

=Anaplecta= sp.

_U.S.A._--One live and 15 dead specimens recovered from 16 aircraft at Miami (Denning et al., 1947).

=Blatta orientalis=

_U.S.A._--Six live and four dead specimens recovered from six aircraft at Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949).

=Blattella germanica=

_Hawaii._--Williams (1946a).

_Khartoum._--Whitfield (1940).

_New Zealand._--Laird (1951, 1952, 1956a).

_U.S.A._--At Miami 193 live and 184 dead specimens were recovered from 141 aircraft (Denning et al., 1947). Recovered at airports in southern U.S. (Hughes, 1949). Recovered at Miami, 51 live and 24 dead specimens (Porter, personal communication, 1958). Exposed experimentally in jet aircraft (Sullivan et al., 1958).

=Blattella= sp.

_Khartoum._--Whitfield (1940).

_Southern U.S._--Hughes (1949).

=Cariblatta= ssp.

_U.S.A._--One live and three dead specimens recovered from three aircraft at Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949).

=Epilampra= sp.

_U.S.A._--One dead specimen, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949).

=Eublaberus posticus=

_Southern U.S._--Hughes (1949).

=Ischnoptera rufa rufa=

_U.S.A._--Two dead specimens recovered from two aircraft at Miami (Denning et al., 1947).

=Ischnoptera= sp.

_U.S.A._--Two live and one dead specimen recovered from three aircraft, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949). One dead specimen, Miami (Porter, personal communication, 1958).

=Leucophaea maderae=

_U.S.A._--Three dead specimens recovered from three aircraft at Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949).

=Nauphoeta cinerea=

_U.S.A._--One live and one dead specimen, Miami (Denning et al., 1947).

=Neoblattella= sp.

_U.S.A._--One dead specimen recovered at Miami (Denning et al., 1947).

=Panchlora nivea=

_U.S.A._--Two dead specimens recovered from two aircraft, Miami (Denning et al., 1947).

=Periplaneta americana=

_U.S.A._--Five live and three dead specimens recovered from seven aircraft, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949). Three live and five dead, Miami (Porter, personal communication, 1958). Experimentally exposed in jet aircraft, U.S. (Sullivan et al., 1958).

_New Zealand._--Laird (1951, 1952).

=Periplaneta australasiae=

_U.S.A._--Two dead specimens recovered from two aircraft, Miami (Welch, 1939). Five live and three dead from five aircraft, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949). Three live and two dead, Miami (Porter, personal communication, 1958).

_New Zealand._--Laird (1952).

=Periplaneta= spp.

_U.S.A._--One live and three dead specimens from four aircraft, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949). One live and six dead, Miami (Porter, personal communication, 1958).

=Pycnoscelus surinamensis=

_U.S.A._--Two live and three dead specimens from five aircraft, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949).

_New Zealand._--Laird (1956a).

=Supella supellectilium=

_U.S.A._--Two live and one dead specimen from one aircraft, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949).

_Khartoum._--Whitfield (1940).

=Supella= sp.

_U.S.A._--Two live specimens from two aircraft, Miami (Welch, 1939). Southern U.S. (Hughes, 1949).

=Symploce= sp.

_U.S.A._--Two live and one dead specimen from three aircraft, Miami (Denning et al., 1947). Southern U.S. (Hughes, 1949).

=Unidentified cockroaches=

_Anglo-Egyptian Sudan._--At Khartoum (Whitfield, 1940).

_Brazil._--From flying boats, 62 specimens; from land planes, 45 specimens (Carneiro de Mendonça and Cerqueira, 1947).

_Central Africa._--Dethier (1945).

_Kenya._--At Kisumu (Symes in Whitfield, 1940).

_New Zealand._--Laird (1956a).