Insect Nests

Cockroaches adapted to living in the nests of social insects are always apterous or have wings reduced to varying degrees. Pseudoanaplectinia yumotoi, associated with Crematogaster sp. ants in canopy epiphytes in Sarawak, is among those with the longest wings. The tegmina and wings reach to about the sixth tergite in the female, and to about the supra-anal plate in the male (Roth, 1995c); it is unknown as to whether these allow for flight. Females of Nocticola termitofila, from nests of Termes sp. and Odontotermes sp. termites, are apterous (Fig. 1.16C). Males are brachypterous, with transparent wings about half the length of the abdomen (Silvestri, 1946); these are fringed around the edges (like thrips) and may allow for passive wind transport. Attaphila living in the fungus gardens of leaf-cutting ants have apterous females and brachypterous or apterous males (Gurney, 1937; Roth, 1991a). Both Att. fungicola and Att. bergi have evolved a unique solution for moving between nests—they are phoretic on ant alates leaving the nest on their mating flight (Fig. 2.11) (Wheeler, 1900; Bolívar, 1901; Moser, 1964; Waller and Moser, 1990). These myrmecophiles have large arolia (Gurney, 1937) that may assist them in clinging to their transport. Several questions arise concerning this phoretic relationship. Do both male and female cockroaches disperse with the alates, or only fertilized females? Since the nuptial flight of male ants is invariably fatal (Holldobbler and Wilson, 1990), do the cockroaches choose the sex of their carrier? If cockroaches do choose male alates, perhaps they can transfer to female alates while the ants are copulating. The vast majority of the thousands of released virgin queens die within hours of leaving the nest (Holldobbler and Wilson, 1990); do their associated cockroaches subsequently search for nests on foot? Because they disperse together, would molecular analysis reveal a co-evolutionary relationship between this myrmecophile and its host? A comparison of Attaphila to Myrmecoblatta wheeleri also

Fig. 2.11 Phoretic female of Attaphila fungicola attached to the wing base of Atta sp. host. The cockroach is about 2.7 mm in length. Courtesy of John Moser.

would be of interest. The latter lives in the nests of a variety of ant genera (Campanotus, Formica, Solenopsis), but have no arolia or pulvilli on the tarsi, and there are no records of host transport (Fisk et al., 1976).

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