Lepidoptera genitalia

About: Lepidoptera genitalia is a research topic. Over the lifetime, 10114 publications have been published within this topic receiving 78876 citations. The topic is also known as: Uncus.

Effects of Bacillus thuringiensis Berliner var. kurstaki and defoliation by the gypsy moth [Lymantria dispar (L.) (Lepidoptera: Lymantriidae)] on native arthropods in West Virginia

Abstract: Impacts of Bacillus thuringiensis var. kurstaki (Btk) and defoliation by gypsy moth [Lymantria dispar (L.)] on native, non-target arthropods were evaluated in eastern West Virginia from 1990 to 1992. Adult and larval arthropods were collected by foliage sampling and light-trapping at 24 20-ha (50-acre) plots, representing six replicates of four treatments: unsprayed, gypsy moth absent (control); unsprayed, gypsy moth present (defoliation); sprayed, gypsy moth absent; and sprayed, gypsy moth present. Pre-treatment data were collected in 1990. In May 1991, one application of Btk was made to 12 plots at a dosage of 14.4 BIU/ha (36 BIU/acre). Post-treatment data were collected in 1991 and 1992. With few exceptions, detectable effects from Btk application were restricted to Lepidoptera. Although abundance and species richness of larval and adult non-target Lepidoptera decreased at all plots between 1990 and 1992, abundance and species richness were reduced at Btk-treated plots relative to untreated plots. Richness and abundance of some larval and adult Lepidoptera declined at defoliation plots. Although the short-term ( 1 year) of reduced abundance of gypsy moth larvae may be beneficial for some native species. Although Btk application and defoliation reduce abundance of native Lepidoptera, environmental conditions such as weather may have a greater influence on population fluctuations.

Juvenile hormone esterases of Lepidoptera - I. Activity in the hemolymph during the last larval instar of 11 species

Abstract: The juvenile hormone esterase (JHE) titer was measured during the last larval instar of 11 species of Lepidoptera (Pieris rapae, Junonia coenia, Danaus plexippus, Hemileuca nevadensis, Pectinophora gossypiella, Spodoptera exigua, Orgyia vetusta, Ephestia elutella, Galleria mellonella, Manduca sexta andEstigmene acrea). All species had a peak of JHE at or near the time of wandering. The peak activity at this time ranged from 0.8 to 388 nmoles JH III cleaved/min·ml. All species exceptJ. coenia had a second peak of JHE during the late prepupal stage. The height of the second peak ranged from 0.4 to 98.4 nmoles/min·ml. However, there was no apparent correlation between size of the first and second JHE activity peaks for the lepidopteran species examined. There was an apparent relationship between the height of the first and second JHE peaks and reports on titer of JH just prior to these peaks. These data support, with some qualifications, the extension of developmental information obtained on several well studied species to a variety of Lepidoptera.

Evidence for lock-and-key mechanisms in the internal genitalia of the Apamea moths (Lepidoptera, Noctuidae)

Abstract: . Fifty of the fifty-six species of the genus Apamea known from North America and three Palaearctic species were analysed for lock-and-key characters in their internal genitalia, mainly in the male vesica and the female bursa copulatrix. There were an average of 4.5 such characters per species, structurally corresponding in the two sexes. Anatomically they form a postcopulatory but prezygotic isolation mechanism. In some closely related species, the internal genitalia are very similar, but these species have a precopulatory isolation mechanism in the presence or absence of male abdominal coremata. Closely related species did not have more lock-and-key characters than unrelated species, which is taken to indicate absence of character displacement. The anatomical distribution of the lock-and-key characters was examined and the organs of eight species are illustrated. The lock-and-key hypothesis has been abandoned by several earlier authors but mainly on consideration of external genitalia. In Apamea the invariable functional correspondence between sexes in the sperm transferring organs, and the overall species-specifity of characters but non-existence of interspecific differences under a precopulatory mechanism indicate that (a) lock-and-keys are functioning and (b) they act as isolation mechanisms. Alternative hypotheses of genitalic evolution are reviewed.

Pheromone Biosynthesis: Enzymatic Studies in Lepidoptera

Abstract: Publisher Summary This chapter presents some enzymatic studies in Lepidoptera. The pheromones of the Lepidoptera are generally a blend of long-chain unsaturated aldehydes, alcohols, and acetate esters. Specificity in the pheromone signal is achieved by variation in the chain length, the number, location, and isomeric nature of the double bonds, the nature of the functional group, and by the blending together of several compounds in a precise ratio. Consequently, investigation of the mechanisms of fatty acid biosynthesis, desaturation, and reduction and characterization of the pathways for interconversion of the aldehydes, alcohols, and acetate esters in Lepidoptera are essential for understanding the control of pheromone biosynthesis in these insects. The pheromone of the eastem spruce budworm, Choristoneura fumiferana, is a blend of (E)-11-tetradecenal and (Z)-11-tetradecenal (V) in a 96:4 ratio. The pheromone, which attracts male moths of the same species, is secreted from a specialized gland located at the end of the abdomen of the female moth.