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1.
The male annihilation technique (MAT) and sterile insect technique (SIT) are often used to control pestiferous tephritid fruit flies (Diptera: Tephritidae). MAT involves the deployment of traps containing a male attractant and insecticide with the goal of drastically reducing male abundance and ultimately eliminating the entire population. SIT, which involves the mass production, sterilization, and release of the target species, may also be implemented to achieve final extirpation. Generally, simultaneous implementation of MAT and SIT is counterproductive, because the presence of large numbers of male-specific traps in the environment (MAT) would greatly reduce the number of sterile males available for copulating with wild females (SIT). However, studies on the Queensland fruit fly, Bactrocera tryoni (Froggatt), indicate that concurrent use of MAT and SIT may be feasible. Sexually mature males of B. tryoni are attracted to the raspberry ketone and its synthetic analogue cue-lure. Males of B. tryoni fed raspberry-ketone-supplemented diet when newly emerged showed lower attraction to cue-lure baited traps than control males. In addition, newly emerged males provided this diet displayed accelerated sexual maturation, which would allow the early release of sterile males and reduce pre-release holding costs. Here, we examined whether the addition of raspberry ketone to the adult diet of male melon flies, Zeugodacus cucurbitae (Coquillett), produced effects similar to those observed for B. tryoni. Despite using similar methods, no significant effect of raspberry ketone-supplemented diet on time to sexual maturity, survival, mating competitiveness, or attraction to cue-lure baited traps in mass-reared Z. cucurbitae males. 相似文献
2.
3.
In experimentally infected insects, the sex ratio of first generation nematodes of five species of Steinernema was female-biased (male proportion 0.35-0.47). There was a similar female bias when the worms developed in vitro (0.37-0.44), indicating that the bias in these species is not due to a lower rate of infection by male infective juveniles (IJs). Experimental conditions influenced the proportion of males establishing in insects, indicating that male and female IJs differ in their behaviour. However, there was no evidence that males are the colonising sex in any species, contrary to what has previously been proposed. Time of emergence from the host in which the nematodes had developed influenced sex ratios in experimental infections. In three species (Steinernema longicaudum, Steinernema glaseri and Steinernema kraussei), early emerged nematodes had a higher proportion of males than those that emerged later, with the reverse trend for Steinernema carpocapsae and Steinernema feltiae. In a more detailed in vitro study of S. longicaudum, the proportion of males was similar whether or not the nematodes passed through the developmentally arrested IJ stage, indicating that the female bias is not due to failure of males to exit this stage. The sex ratio in vitro was independent of survival rate from juvenile to adult, and was female-biased even when all juveniles developed, indicating that the bias is not explained by failure of males to develop to adults. The female-biased sex ratio characteristic of Steinernema populations appears to be present from at least the early juvenile stage. We hypothesise that the observed female bias is the population optimal sex ratio, a response to cycles of local mate competition experienced by nematodes reproducing within insect hosts interspersed with periods of outbreeding with less closely related worms following dispersal. 相似文献
4.
Synopsis Testicular maturation indices (TMI) were determined for wild-caught males ofPoecilia mexicana by quantitative analysis of the frequency of ongoing stages of spermatogenesis and spermatid differentiation in sections of testes stained with the Feulgen reaction for DNA. In nature, males maintain essentially constant levels of sperm production throughout the year and show no significant variations in mean TMI values associated with season, microhabitat, standard body length, or rank in male dominance hierarchies. Winter males or males isolated from females in the laboratory show accumulation of mature spermatophores. These findings suggest that fluctuations in the microstructure of wild populations ofPoecilia from northeastern Mexico may be due primarily to differences in the temporal scheduling of female reproductive cycles and not to limitations imposed by sperm availability or male reproductive competence. The data are discussed in terms of competitive interactions within unisexual-bisexual breeding complexes involving the Amazon mollyP. formosa, its related triploid hybrids, and the bisexual species,P. mexicana. 相似文献
5.
Cell-wall lysing enzymes and products of cell-wall digestion elicit ethylene in citrus 总被引:2,自引:0,他引:2
Ethylene production was induced in Valencia oranges [ Citrus sinensis (L.) Osbcck] by injection of the fungal enzyme mixture Pectolyase ( Aspergillus japonicus ) which contains pectolytic enzymes into the peel. The mixture also stimulated production of 1-aminocyclopropane-1-carboxylic acid (ACC). Cycloheximide partially inhibited the Pectolyase-induced ethylene response. Pectin fragments, resulting from partial acid hydrolysis or Pectolyase digestion, caused an increase in ethylene production when injected into the peel of intact orange fruits. Pectic fragments produced by fungal enzymes are known to be elicitors of phytoalexins and in this study are shown to elicit ethylene in citurs. 相似文献
6.
H. Abplanalp J. Eklund 《TAG. Theoretical and applied genetics. Theoretische und angewandte Genetik》1978,51(6):277-280
Summary A selection index for two traits has been constructed which allows partial restriction for one of the traits. The index is used in a situation where correlated response to selection in one sex is compenstated for by selection for other traits in the opposite sex. A numerical example is given. 相似文献
7.
It is not clear whether males in all mammalian species adjust their copulatory behavior when faced with risk of sperm competition
(RSC). Previous work on meadow voles, Microtus pennsylvanicus, indicated that males increase their sperm expenditure but not the number of ejaculations in the presence of odors of a conspecific
male. The present study follows up on this work and asks whether male meadow voles modify any aspect of their copulatory behavior
when they face a RSC. We examined 46 variables of copulatory behavior and found that the presence of odors from a conspecific
male did not affect any of these variables. Thus, male meadow voles, unlike some other species of mammals, do not adjust their
copulatory behavior when exposed to cues associated with an elevated RSC. 相似文献
8.
Myosin associated with the male germ cells of angiosperms interacts with actin, promoting transport of the non-motile generative
and later sperm cells in the pollen tube. Myosin localizing on the sperm cell plasma membrane seems negligible in Plumbago, as reflected by the absence of: (i) anti-myosin labeling using immunoelectron microscopy, (ii) sperm motility on actin matrices,
and (iii) electrophoretic movement changes after addition of antibody. Sperm cells injected directly into actively streaming
Nitella internodal cells, however, follow actin bundles and their movement is sensitive to ATP and Mg2+. This may be based on simple charge binding since negatively charged latex beads also migrate on actin, whereas neutral or
positively-charged latex beads do not. Sperm cells are negatively charged according to capillary microelectrophoresis, whereas
killed sperm cells, which are positively charged do not migrate. The sperm cell that normally fertilizes the egg has a higher
calculated charge (8.277 × 103 esu/cm2) compared with the sperm cell that fuses with the central cell (6.120 × 103 esu/cm2).
Received: 15 December 1998 / Accepted: 21 January 1999 相似文献
9.
The Migadopini are a small tribe of Carabidae with 47 species that occur in South America, Australia, and New Zealand, in the sub-Antarctic areas. In South America, most of the genera inhabit areas related to sub-Antartic Nothofagus forest except two monogeneric genera, the Ecuadorian genus Aquilex Moret and the Pampean genus Rhytidognathus Chaudoir. These two genera are geographically isolated from the remaining five South American genera. New material of Rhytidognathus from the northeast of Buenos Aires province and from Entre Ríos province permits establishing that the previous records of Rhytidognathus ovalis (Dejean) for Argentina were erroneous and that it belongs to a new species. Based on external morphological characters and from male and female genitalia we describe Rhytidognathus platensis as a new species. In this contribution we provide illustrations, keys, habitat characteristics and some biogeographic considerations on the distribution of Rhytidognathus. 相似文献
10.
M. V. Achi J. M. Figueroa V. González Nicolini M. J. Villar J. H. Tramezzani 《Cell and tissue research》1995,281(2):375-378
The presence and distribution of peptidergic nerve fibers were studied in the testis and mesorchium of the toad by means of immunohistochemistry. Cryostat sections of the testis and whole-mount preparations of mesorchia were immunostained with antisera to calcitonin gene-related peptide (CGRP) and neuropeptide tyrosine (NPY). After leaving the mesorchium CGRP-immunoreactive (IR) fibers were seen predominantly running in between the seminiferous tubules. In addition, a small population of CGRP-IR nerve fibers formed thin plexuses around blood vessels. Conversely, NPY-like immunoreactivity predominated in nerve fibers that formed dense plexuses around vessels both in the mesorchium and testis. Additionally, some single NPY-IR nerve fibers could be seen in both structures studied. The functional significance of these peptidergic systems in the testis of the toad remains to be analyzed. 相似文献