Posted on: 02 March, 2017

Author: Alexander P

There is little more evidence for specificity in the Danaiinae. Chemicals are different for each of the species identified (g. 7.1), although only one, the ketone, has been shown to have biological a... There is little more evidence for specificity in the Danaiinae. Chemicals are different for each of the species identified (g. 7.1), although only one, the ketone, has been shown to have biological activity. Antennae of the monarch (which lacks the ketone) respond equally to hair-pencils of the queen, to Lycorea ceres, and to the pure ketone. (2) Pliske and Eisner (1969) suggested that, since the diol from the hair-pencils of Danaus gilippus has some chemical similarities to farnesol — a juvenile hormone mimic, it might stimulate yolk deposition during oogenesis. Topical administration during courtship would be perfect timing for a pheromone acting in this way. How- ever, this exciting possibility seems at most to be a very minor effect, if it occurs at all. Virgin females hand-paired to males lacking the hair-pencils produced normal numbers of viable offspring, nor did the diol later show any juvenile hormone activity when tested in Pyrrhocoris according to http://thongchaimedical.org/do-pheromones-really-work-the-shocking-results/ (3) Several males may compete to copulate with a receptive female possibly resulting in delayed copulation, no copulation, or attraction of predators to the scene. If so, it would be an advantage to the female or to the first male to be able to shut off female pheromone production or to deter males from approaching. It is conceivable, though quite hypothetical at this time, that the male pheromone could act in these ways in addition to inhibiting female locomotion. We only know that males of several Noctuidae (Grant 1971b; Grant et al. 1972) and Danaiinae (Schneider and Seibt 1969) are capable of perceiving their own pheromone. (4) The last function postulated is that of deterrence to predators. One reason why this is likely is that the compounds so far identified from the male brushes are similar to defensive secretions. Benzaldehyde has been implicated as a possible antibacterial agent in aquatic Dytiscidae (Gilmour 1965), and as a defensive com- pound of an ant (Blum et al. 1969) and of numerous Diplopoda (Weatherston and Percy 1970). [so-butyric acid is also a defensive compound in a wide range of insects (e.g. Schildknecht et al. 1968; Eisner et al. 1970; Pattendon and Staddon 1972). The second reason is that the copulation period in moths may last from a few minutes to several hours, either immobile on the ground or in clumsy ight, and is undoubtedly a very vulnerable period in the life of moths. There would be a considerable selective advantage to predators able to key in to the sex pheromones of their prey. This is well documented in other orders (e.g. Borden ch. 8 sect. 5). A predator could also respond to the site of increased activity when several males are attracted to a female, bats to moths, for example; production of a deterrent would then be selected for and if used only when male and female are in proximity, might also explain why a defensive substance should be found only in one sex The extreme range of male scent structures in Lepidoptera indicates consider- able parallel evolution and convergence. Male structures may take the form of brush-organs, as in the Noctuidae (Birch 1970b); brushes associated with the geni- lalia, as in Trichoplusia ni (Grant 197la); coremata, the eversible tubes inated with air found in numerous Arctiidae, Geometridae, and some Noctuidae (Varley I962); or small tufts of hair or brushes on almost any part of the body. Source: Free Articles from ArticlesFactory.com Alexander P is a blogger that studies pheromones. He lives in Los Angeles, CA.