RESUMO
Mating induces behavioral and physiological changes in female insects-collectively referred to as the female post-mating response (PMR)-that facilitate the production of progeny. PMRs are elicited by transfer of male-derived seminal components during mating, but are altered by other factors, including adult age. Increased female age is often accompanied by declines in fertility. However, mating shortly after emergence also impacts fertility in the insect model Drosophila melanogaster. Here, we determined the age post-emergence when females of the vector mosquito Aedes aegypti can be inseminated and blood-feed. We next examined fecundity, fertility, and the storage of sperm in the female reproductive tract in "young" (30-41 hours-old) and "old" (2- and 3-week-old) females, finding that blood-feeding began at 14 hours, and mating at â¼24 hours post-emergence. Although young females consumed smaller blood quantities and stored fewer sperm, they were similarly fertile to 4-day-old controls. Old females, however, suffered significant declines in fecundity by 2 weeks of age. Our results show that female Ae. aegypti start to become sexually receptive 1 day after their emergence, but can ingest blood much sooner, suggesting that mating is not a prerequisite to blood-feeding, and that females can ingest an arbovirus infected blood-meal shortly after emergence.
Assuntos
Aedes , Dengue , Masculino , Feminino , Animais , Aedes/fisiologia , Drosophila melanogaster , Sêmen , Mosquitos Vetores/fisiologia , Fertilidade , Inseminação , Espermatozoides/fisiologiaRESUMO
Promiscuous mating systems provide the opportunity for females to bias fertilization toward particular males. However, distinguishing between male sperm competition and active female sperm choice is difficult for species with internal fertilization. Nevertheless, species that store and use sperm of different males in different storing structures and species where females are able to expel all or part of the ejaculates after copulation may be able to bias fertilization. We report a series of experiments aimed at providing evidence of female sperm choice in Euxesta eluta (Hendel), a species of ulidiid fly that expels and consumes ejaculates after copulation. We found no evidence of greater reproductive success for females mated singly, multiply with the same male, or mated multiply with different males. Female E. eluta possesses two spherical spermathecae and a bursa copulatrix for sperm storage, with a ventral receptacle. There was no significant difference in storing more sperm in spermathecae 24 h after copulation than immediately after copulation. Females mated with protein-fed males had greater reproductive success than similar females mated to protein-deprived males. Protein-fed females prevented to consume the ejaculate, retained more sperm when mated to protein-fed males than when mated to protein-deprived males. Our results suggest that female E. eluta can exert control of sperm retention of higher quality males through ejaculate ejection.
Assuntos
Dípteros , Masculino , Feminino , Animais , Sêmen , Espermatozoides , Copulação , Reprodução , Comportamento Sexual AnimalRESUMO
The coffee berry borer, Hypothenemus hampei (Ferrari), can survive in residual coffee berries during the inter-harvest period, while new fructification only appears 2-3 months after the last harvest. The dispersal of colonizing females is an adaptation that enables the life cycle of the species to go ahead whenever his flight aptitude allows. This paper focuses on accurately determining the rate of inseminated females ready to reproduce when emerging from residuals berries to colonize new ones, which constitutes a characteristic of the live cycle far from common in Curculionidae. We dissected females caught in traps baited with a mixture of alcohols during the inter-harvest season, females from infested residual berries collected from branches, and virgin females obtained from pupae reared individually in the laboratory. After microscopic preparation with Giemsa stain, spermathecae were observed to identify the physiological status of each specimen. Out of the females found in the traps, 98.4% displayed recent and abundant insemination and 1.6% sporadic insemination. In contrast, in residual berries, most of females were recently inseminated (84.5%), followed by virgin females (10.5%) and older inseminated females (5%). In addition, the flight tests of the virgin females were negative. These results indicate that all colonizing females were inseminated, ready for flying and oviposition, females inside residual berries showed different physiological status, and virgin females could not migrate since they could not flight. The large number of inseminated females inside the residual berries, and the capacity of migrating females to colonize and reproduce, suggest that it is necessary to control residual berries and use traps to stop the dispersal and reproduction of this pest.
Assuntos
Coffea/crescimento & desenvolvimento , Produção Agrícola , Gorgulhos/fisiologia , Animais , Feminino , Inseminação , México , Reprodução , Estações do AnoRESUMO
ABSTRACT The genus Neogriphoneura Malloch, 1924 is currently composed of 11 species with New World distribution. Neogriphoneura timida Curran, 1942 is recorded for the first time in South America, with occurrences in Brazil, Colombia and Trinidad and Tobago; and new Central American records are presented: Belize, Honduras and Mexico. Here we redescribe the species and present, for the first time, illustrations of the male terminalia and female spermathecae, and discuss the main diagnostic characteristics of external morphology. A brief discussion about the postcopulatory sexual selection in this species is proposed based on morphology of the spermathecae.
RESUMO
Female genital morphology of secondarily haplogyne spiders has been poorly studied, hampering the analysis of its possible phylogenetic significance. We conduct a comparative morphological study of 12 species of the secondarily haplogyne spider genus Glenognatha Simon, 1887 using scanning electron microscopy. Representatives of the closely related genera Pachygnatha Sundevall, 1823 and Dyschiriognatha Simon, 1893 were also examined. The female genitalia of Glenognatha, Dyschiriognatha, and Pachygnatha species examined are composed of a spiracle-shape gonopore, a membranous chamber, a pair of copulatory ducts (CD) leading to spermathecae and a large uterus externus (UE). The most significant variation among Glenognatha species, previously unregistered within Araneoidea, is related with the absence or presence of CD and spermathecae. In addition, several characters as the form and distribution of long stem gland ductules and compartmentalization of the UE may be important for phylogenetic inference at species and generic level. Our results corroborate the close relationship between Dyshiriognatha and Glenognatha. A table with potentially informative female genitalic characters for phylogenetic inference within Glenognatha is provided. Understanding the general structure of the female genitalia in secondarily haplogyne taxa is a crucial step in order to propose characters for phylogenetic inference and to understand its possible functional significance.