 
The following social insects have been found harboring cockroaches in a state of commensalism in which the cockroaches presumably benefit by acquiring food from their hosts. Benefits accruing to the hosts are not apparent. Unfortunately, biological details are not always sufficient to substantiate the suspected association. However, it seems significant that the cockroach commensals of the insects listed below have been found only in association with their hosts and, so far as we know, have never been found apart from them. Chopard (1938) has pointed out that the myrmecophilous cockroaches are all small, being only a very few millimeters long; they are apterous or subapterous; their eyes are reduced; and they are all of American origin. HOSTS OF COMMENSAL COCKROACHES Order ISOPTERA Family RHINOTERMITIDAE Coptotermes ceylonicusHolmgrenCommensal.—Sphecophila ravana, Ceylon (Fernando, 1957): Six females, 50 males, and nymphs of both sexes were found among decaying Family TERMITIDAE Macrotermes barneyiLightCommensal.—Nocticola sinensis, Kowloon (Silvestri, 1947): Among specimens of termites collected from a nest. Macrotermes bellicosus(Smeathman)or Macrotermes natalensis(Haviland)Synonymy.—Termes bellicosus [Snyder, 1949]. Commensal.—Sphecophila termitium, Kibonoto, East Africa (Shelford, 1910): Two males were collected in a termite mound. Macrotermes malaccensis(Haviland)Synonymy.—Termes malaccensis Haviland [Snyder, 1949]. Commensal.—Nocticola termitophila, Tonkin (Silvestri, 1946): The cockroach was found in the termite nest. Odontotermessp.Commensals.—Nocticola sinensis, Kowloon (Silvestri, 1946): In termite nest. Nocticola termitophila, Penang (Silvestri, 1946): In termite nest. Termessp.Commensal.—Nocticola sinensis, Repulse Bay, Australia(?) (Silvestri, 1946): In a termite gallery. TermitesCommensal.—Ergaula capensis [= Dyscologamia wollastoni] French Equatorial Africa, Brazzaville (Rehn, 1926; Chopard, 1949). Order HYMENOPTERA Family FORMICIDAE Subfamily FORMICINAE Camponotus femoratus(Fabricius)Commensal.—Phorticolea boliviae, Bolivia, Cachuela Esperanza (Caudell, 1923): Three males collected in the joint nests of C. femoratus and Crematogaster limata. Camponotus maculatus(Fabricius)?Note.—Dr. W. L. Brown (personal communication, 1957) states that this ant is an Old World species only. So presumably Mann's record pertains to a different species. Commensal.—Myrmecoblatta rehni, Mexico (Mann, 1914): "They were very abundant, several occurring in almost every nest, where they are no doubt very efficient scavengers." Camponotus rufipes(Fabricius)Commensals.—Atticola mortoni, Nothoblatta wasmanni, and Phorticolea testacea, Brazil, San Leopoldo (BolÍvar, 1905): Found in the formicaries of C. rufipes. Formica rufibarbisFabriciusand Formica subcyaneaWheelerCommensal.—Myrmecoblatta rehni, Mexico (Mann, 1914): "They were very abundant, several occurring in almost every nest." Subfamily MYRMICINAE Acromyrmex lobicornisEmeryCommensal.—Attaphila bergi, or possibly a variety of this species, HuasÁn, Argentina? (Bruch, 1916). Acromyrmex lundi(GuÉrin)Synonymy.—Atta lundi [Brown, personal communication, 1957]. Commensal.—Attaphila bergi, Argentina and Uruguay (BolÍvar, 1901): The cockroach was found in the nests of the ants sitting on the back, neck, or head of sexual individuals. It remains attached to the ant during swarming. The antennae seem always to be mutilated. Bruch (1916) stated that in La Plata A. bergi is encountered by hundreds in every nest of A. lundi. Acromyrmex niger(F. Smith)Synonymy.—Atta nigra Schupp [Brown, p.c., 1957]. Commensal.—Attaphila schuppi, Brazil, Porto Alegre (BolÍvar, 1905): Found outside the nest of the ant and mixed in the columns of ants on the march. Acromyrmex octospinosus(Reich)Synonymy.—Atta octospinosa [Brown, p.c., 1957]. Commensals.—Attaphila fungicola, Panama (Wheeler, 1928): Taken in the fungus gardens of the ant. Attaphila aptera, Esperanza, Dibulla, Colombia (BolÍvar, 1905). Acromyrmex silvestriiEmeryCommensal.—Attaphila bergi, or possibly a variety of this species, San Luis Province, Argentina (Bruch, 1916): According to Bruch, the behavior of this species of Attaphila is identical with the one encountered in HuasÁn in the nests of Acromyrmex lobicornis Emery; it differed from A. bergi in size and color. Atta cephalotes(Linnaeus)Commensal.—Attaphila fungicola, British Guiana (Wheeler, 1928): Taken in the fungus gardens of the ant. Attaphila sp., British Guiana (Beebe, 1921): 7 of 12 queens in one nest had cockroaches hanging on them. Atta sexdens(Linnaeus)Commensal.—Attaphila sexdentis, Brazil, San Leopoldo (BolÍvar, 1905): Found in nests of the ant. Atta texana(Buckley)Synonymy.—Atta fervens Say [Wheeler, 1910]. Commensal.—Attaphila fungicola, U.S.A., Texas (Wheeler, 1900, 1910): The cockroach does not feed on the fungus in the ants' nest, as Wheeler (1900) first supposed, but mounts the back of the soldiers and licks their surfaces. It is tolerated by the ants with no signs of hostility. The antennae of the cockroach are clipped short. Although Wheeler (1910) stated that this is probably accidental or unintentional, it is peculiar that BolÍvar (1905) noticed the same invariable mutilation of the antennae of Attaphila bergi. Wheeler (1900) had originally suggested that the antennae were probably clipped off by the ants which are continuously trimming the fungus hyphae. Louisiana (Moser, personal communication, 1959): Numerous specimens were encountered in some nests of A. texana. This cockroach is the most closely associated inquiline in the nest and maintains very intimate terms with the ants. It is found living in the fungus cavities and tunnels. Crematogaster limata parabioticaForelCommensal.—Phorticolea boliviae, Bolivia, Cachuela Esperanza (Caudell, 1923): Collected in joint nests of C. limata and Componotus femoratus. Solenopsis geminata(Fabricius)Commensal.—Myrmecoblatta wheeleri, Guatemala (Hebard, 1917a): Collected from a colony of this ant under a stone on the shores of Lake Atitlan, altitude 11,719 feet. Unknown hostCockroach.—Attaphila flava, British Honduras (Gurney, 1937): Because the known hosts of the other five species of Attaphila are ants, we presume that this species also lives in the nest of some myrmecine ant. Subfamily PONERINAE Odontomachus affinis(GuÉrin)Commensal.—Myrmeblattina longipes, Brazil, Rio de Janeiro (Chopard, 1924, 1924a; Hancock, 1926): Originally described as Phileciton longipes by Chopard (1924) from the nest of an ant mistakenly identified as Eciton sp. Family VESPIDAE Polybia pygmaeaFabriciusCommensal.—Sphecophila polybiarum, French Guiana (Shelford, 1906a): Shelford stated that it was probable that the cockroaches living on the floor of the paper nest fed on small fragments of insects and spiders that were dropped by the wasp larvae feeding in the cells above. Family MEGACHILIDAE Melipona nigraLepeletierCommensal.—Oulopteryx meliponarum, Brazil (Hebard, 1921): According to Hebard, this cockroach is the first one to be known to inhabit the nests of bees. Nothing is known of the relationship between the cockroach and the bees. [See comment by Sonan (1924) on page 318.] CHECKLIST OF COMMENSAL COCKROACHES WITH THEIR HOSTSThe cockroaches are arranged alphabetically by genus and species. The page references are to citations in the classified section above, where details and/or sources of the records are given. Attaphila aptera OBSCURE ASSOCIATIONSCockroaches that are sometimes found in the nests of, or in association with, other animals are not necessarily commensals. This is particularly true of cockroaches that normally are found unassociated with other animals or that merely occupy the same habitat with the other animals because of similar microclimatic requirements (see Chopard, 1924c). McCook (1877) excavated in February a nest of Formica rufa in Pennsylvania. A hundred or more lively cockroaches occupied a part of the nest that contained few ants. Near the cockroaches McCook also found a colony of Termes flavipes. Ischnoptera deropeltiformis has been found in the company of ants, but it is probably not myrmecophilous (Donisthorpe, 1900). Mann (1911) found an "Ischnoptera" sp. (probably a species of Parcoblatta) abundant in the nests of, and tolerated by, Camponotus maccooki Forel in California. Dead and mutilated specimens of this cockroach were common in the nests of "Formicas." "Ischnoptera" sp. was also common in the nests of Veromessor andrei (Mayr) [= Stenamma andrei]. Hebard (1917) reported that W. M. Wheeler collected Eremoblatta subdiaphana in Arizona as an ant guest. Rehn (1906a; Rehn and Hebard, 1927) reported that Pholadoblatta inusitata had also been taken by Wheeler from the galleries of a jumping ant, Odontomachus clarus Roger [= O. haematodes insularis GuÉrin var. pallens Wheeler; Brown (personal communication, 1958)], on Andros Island, Bahamas; Rehn and Hebard (1927) stated that "This genus and species is the only blattid, which is presumably a myrmecophile, known from the West Indies." Rehn (1932a) reported Dendroblatta sobrina as taken in an ant nest in a tree in the Amazon Basin. Tivia australica was taken in an ant nest in Australia (Princis, 1954). The male of Compsodes schwarzi was taken in an ant nest in the Santa Rita Mountains of Arizona (Ball et al., 1942). A male and female of Stilpnoblatta minuta were taken in a migrating column of the ant Myrmicaria natalensis Sm. subsp. eumenoides Gerst. in Nyasaland (Princis, 1949). Princis cautioned that it is premature to derive any inference from this, possibly accidental, association. Four females of Parcoblatta desertae were taken about a nest of an ant, Ischnomyrmex sp. (Hebard, 1943a). A nymph of Parcoblatta virginica was found in a nest of Formica sp. (Hauke, 1949). Chorisoneura texensis has been found in nests of webworm in Florida (Rehn and Hebard, 1916). Karny (1924) in Malaya found an oÖtheca of Aristiger histrio (sp.?) between leaves (Costus sp.) SeÍn (in Rehn and Hebard, 1927) in Puerto Rico found Aglaopteryx facies in abandoned cocoons of Megalopyge krugii (Dewitz) and in leaves webbed together by caterpillars and in abandoned spiders nests. Wolcott (1950; and in Rehn and Hebard, 1927) also found A. facies in the empty cocoons of M. krugii and in the larval tents of Tetralopha scabridella Ragonot on Inga vera (coffee shade tree); and "Where there are no butterfly-nests, it lives in abandoned spider-nests on the leaves of other forest trees." Cotton (in Wolcott, 1950) found the type of Aglaopteryx absimilis also living in the abandoned cocoon of M. krugii on bucare trees in Puerto Rico. Wolcott (1950) reported that Plectoptera dorsalis, Plectoptera infulata, and Plectoptera rhabdota have been found living in trees between leaves or in "butterfly-nests" of Tetralopha scabridella in leaves of Inga vera, or nests of Pilocrocis secernalis (MÖschler) in the leaves of Petitia domingensis in the mountains of Puerto Rico. SeÍn (in Rehn and Hebard, 1927) had collected P. rhabdota in the nest of larvae of T. scabridella. Wolcott (1950) reported that Nyctibora lutzi had been found in a large rotten stump associating with "'comejÉn' termites [Nasutitermes costalis (Holmgren)], yellow wood-ants and rhinoceros beetle grubs." Rehn and Hebard (1927) found Simblerastes jamaicanus in numbers in the debris of an abandoned termites' nest in Jamaica: "To what extent the species is dependent upon the protection of the termite or other structures remains to be determined." In Virginia Cryptocercus punctulatus has been found living in the same galleries with Reticulitermes sp., and on the Pacific Coast it has been found occupying the same log with Termopsis sp. (Cleveland et al., 1934). Shelford (1909) found one male and one female of Balta platysoma in a nest of a spider of the genus Phryganoporus and assumed a symbiotic association. Chopard (1924) recorded Mareta acutiventris from empty nests of spiders on Barkuda Island, India; nothing is known of the relationships, if any, between these cockroaches and spiders. Chopard (1924c) found Margattea sp. in the nest of the ant Acropyga acutiventris Roger; he also found Margattea sp., Periplaneta sp., Polyphaga indica, and Temnopteryx obliquetruncata in deserted termite mounds in India. However, he believed that none of these species were more than accidental associates of the host insects; he considered them hygrophilous cockroaches which had found a retreat in the nests. McClure (1936) obtained a large nest of Vespula maculata (Linnaeus) [= Vespa maculata] in March in Illinois. In it were living 65 nymphs of Parcoblatta pensylvanica, 3 spiders (Philodromus pernix Blackwall), 2 immature spiders (Drassus sp.), and 6 mites. Balduf (1936) observed four individuals of Parcoblatta pensylvanica in a nest of Vespula maculata; he suggested that they probably fed on dead bodies and organic wastes of the wasps. However, Rau (1940) has observed this cockroach devour a Polistes larva in its cell. Although we do not imply that a commensal relationship exists between Parcoblatta and the wasp, it is well to recall a statement by Rothschild and Clay (1957): "A commensal relationship is potentially even more dangerous than a merely social tie, for by nature it is more intimate. The closer the association, the more easily is the balance upset. One partner can then suddenly take a mean advantage of the other." Cockroach nymphs may enter bees' nests where, according to Imamura (in Sonan, 1924), they do not feed on honey or pollen but presumably feed on excreta of bees or anything scattered by bees in their nest; the bees are not disturbed by the cockroaches. Cockroaches that have been found in the burrows of vertebrates are listed on pages 23-25. Paulian (1950) found immature cockroaches in the nests of birds (Ploceinae) in Madagascar and Ivory Coast. All nests of Fondia sp. examined in Madagascar contained many cockroaches, and Paulian believed that the blattid was a species peculiar to the nests of birds. Three nests of Ploceus sp. in Ivory Coast yielded one or two cockroaches each in association with more numerous mites, Psocoptera, Heteroptera, beetles, and lepidopterous larvae (Delamare, Deboutteville and Paulian, 1952). These last cited workers also found four cockroaches in a nest of Estrildine sp., and two in a nest of an undetermined bird, all in association with other arthropods. Moulton (1912) observed large numbers of Symploce cavernicola and Periplaneta australasiae swarming in soft bird guano on the floor of caves in Borneo. Abdulali (1942) found in India many Periplaneta americana in caves containing the edible-nest swift; there was no indication of association of the cockroaches with the birds. Danforth (in Wolcott, 1950) reported finding large numbers of Aglaopteryx facies "in the nests of the grey kingbird, in the region of the Cartagena Lagoon [Puerto Rico], 'living among the twigs.'" In Trinidad, Kevan found a male of Blaberus discoidalis in a bird's nest (Princis and Kevan, 1955). Davis (in Rehn and Hebard, 1914a) stated that "At Punta Gorda [Florida] there was a vacant house at the end of the town frequented at night by a Nanny and Billy goat, and on warm evenings many Periplaneta australasiae would run about on the piazza floor and on the sides of the house. They were seen feeding on the excrement of the goats and were no doubt to a great degree dependent upon them." This is another example of a coprophagous insect that has taken advantage of a particular situation favorable to its survival. Similar associations exist in which many of the domiciliary cockroaches feed on the feces of man and domestic and other animals (Roth and Willis, 1957a). |
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