RESUMEN
A wasp (Orasema sp.) parasitic on the fire ant,Solenopsis invicta Buren, develops to the adult stage within the ant colony, where wasp larvae are ectoparasitic on ant pupae. This phase of the parasite's life cycle requires a mechanism of integration into the host colony. Gas Chromatographic profiles of hexane soaks of various stages of the parasite and host suggest that during development within the ant colony the parasite acquires the colony odor of the host through a passive mechanism, based on simple contact and other social interactions. No parasite-specific components were observed. After leaving the host nest as adults, the parasite biosynthesizes a parasite-specific cuticular compound, while retaining residual amounts of the host acquired components. This complicated scenario is consistent with current knowledge of nestmate recognition and the preferential treatment of ant workers to their brood.
RESUMEN
The myrmecophilus beetle Myrmecaphodius excavaticollis (Blanchard) was found to have species-specific cuticular hydrocarbons acquired-from one of its hosts, the ant Solenopsis richteri Forel. Removal from its ant host resulted in loss of the host hydrocarbons, leaving a cuticular pattern innate to the beetle. When beetles were transferred to colonies of three other Solenopsis species, they acquired the specific hydrocarbons associated with each of the new hosts. This passive integration mechanism is coupled with the beetle's armored exterior to enable it to cope with multiple aggressive hosts.
RESUMEN
The 10-5 bait formulation of mirex insecticide was applied to a 20,000-acre area of northeast Florida. For 24 months after application, samples of a wide variety of fauna were collected and analyzed for mirex content. Insects accumulated mirex to the greatest extent in the first 6 months after application; most residues had decreased greatly by 12 months. Other invertebrates showed low mirex levels during the first 9 months after application and none after 12 months. Fish possessed low levels of insecticides for 9 months; amphibians showed mirex residues for 12 months after application. In general, reptiles had low levels throughout the 24-month period and mammals had higher levels, particularly in fat tissues. Birds consistently had low to moderate mirex levels. After a single application of 10-5 mirex bait, only relatively low levels of insecticide were detected in exposed fauna. After 24-months, mirex was found infrequently and at low levels.
Asunto(s)
Insecticidas/análisis , Mírex/análisis , Residuos de Plaguicidas/análisis , Animales , Hormigas , Florida , Factores de TiempoRESUMEN
Mirex, the only compound approved for control of the red imported fire ant (Solenopsis invicta) and the black imported fire ant (Solenopsis richteri), is normally applied at a rate of 1.40 kg/ha. (1.25 lb/acre). Influenced by recent studies showing that low levels of mirex are toxic to certain nontarget organisms, particularly estuarine species, authors report here on a monitoring study of mirex in three large treatment areas of southwest Georgia. Four formulations of bait were applied aerially in 1971-72. Low-level residues were observed in small terrestrial vertebrates and invertebrates and in fresh-water inhabitants. Levels detected were about the same for all baits. Maximum residues were detected 1-3 months after treatment and gradually declined to low levels of 0.02-1.16 ppm 1 year after treatment.
