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1.
Aphids display divergent adult phenotypes, depending on environmental conditions experienced during their embyonic and nymphal
stages in their complex life cycles. The plastic developmental mode is an extreme case of phenotypic plasticity, so-called
“polyphenism”, in which discrete multiple phenotypes are produced based on a single genome. For example, winged and wingless
adult females are derived from a single genotype. However, the developmental mechanisms producing these polyphenic traits
according to the extrinsic stimuli, such as density conditions, still remain unknown. In this study, to analyze the developmental
processes underlying the wing polyphenism, we extensively observed and compared wing development in the winged and wingless
individuals in parthenogenetic generations of the aphid Acyrthosiphon pisum (Harris), using scanning electron microscopy and histological sectioning. At the first-instar stage, the wing primordia were
observed both in the future winged (W) and wingless (WL) nymphs. Developmental differences can be seen from the second-instar
stage, when wing primordia degenerate in the WL nymphs, while they develop and become more thickened in the W nymphs, suggesting
that the developmental programs should be launched prior to this stage. Furthermore, during the third- to fifth-instar stages,
wing buds and flight muscles were well developed in the W nymphs, while wing primordia completely disappeared in the WL ones.
In addition, the observation on the detailed developmental process of wing primordia during the third-instar W nymphs showed
that the wing buds become swollen especially at the basal part, even during the intermolt period. This was caused by the development
of wing epithelia under the cuticle of this instar nymph. Actually on the surface of the cuticle of wing-bud bases, there
were numerous furrows, which gradually expand during the intermolt period. The similar situation was also observed at the
forth-instar nymphs, in which the wings are formed in the complicated manner inside the wing pads. Furthermore, the developmental
process of flight muscles was also described in detail. These dynamic developmental differences between the wing morphs should
be regulated under the gene expression cascades that switch according to environmental stimuli. 相似文献
2.
Sonia Ganassi Pasqualina Grazioso Antonio Moretti Maria Agnese Sabatini 《BioControl》2010,55(2):299-312
This study investigated the effects of a strain of the fungus Lecanicillium lecanii (Zimm.) Zare and Gams (Hypocreales: Ascomycota) on the aphid Schizaphis graminum (Rondani) (Hemiptera: Aphididae). The fungus was administered to fourth instar nymphs and to alate and apterous adult morphs
as a ground rice-kernel formulation. This study showed that L. lecanii formulation affected the survival of the aphids and interacted differently with the studied morphs, the Lethal Time values
being lower for alate compared to apterous morphs and nymphs. The treatment also caused a significant reduction in the fecundity
of the three treated aphid groups. Histological analysis revealed that the hyphae invaded the host hemocoel of a limited number
of alate and apterous morphs: the fungus only entered through the spiracles. Scanning Electron Microscope observations revealed
that L. lecanii adhered to the body surface of both adults and nymphs without differentiation. In conclusion, the present study suggests
that this strain might be a good candidate for a programme of biological control of S. graminum and other aphid species. 相似文献
3.
In social insects, caste-specific characters develop in the postembryonic differentiation processes. However, the mechanisms
of caste-specific organ development have yet to be elucidated. In order to obtain insights into the relationship between caste
differentiation and the regulation of organ development, we determined the caste-developmental pathway and observed compound-eye
development accompanying alate differentiation in the dry-wood termite, Neotermes koshunensis. As previously reported in other Neotermes, this species has a linear caste-developmental pathway, comprising six larval- and two nymphal-instar stages. Although the
apparent eye formation occurs during the last nymphal stages, just prior to the imaginal molt, individuals possess eye primordia
from the first larval-instar stage. The outer morphological structure of the eye was observed from the third larval-instar
stage. The detailed differentiation of cells constituting ommatidia appeared to occur in relatively young larval instars (fourth
stage), although the pigmentation of pigment cells and detailed structural formation of ommatidia occurred during the final
stage of alate development, i.e., during the late second nymphal-instar stage. This suggests that eye development is arrested
in the larval stages, and then resumed during the late nymphal stage to complete functional eye formation, which is required
for nuptial flight. In comparison to major hemimetabolous insects, which possess functional compound eyes even at the first
instar larva, this termite species shows the heterochronic shift in terms of compound-eye development.
Received 20 March 2006; revised 24 September 2006; accepted 4 October 2006. 相似文献
4.
Yang D 《Journal of genetics》2007,86(1):51-57
It has long been noted that high temperature produces great variation in wing forms of the vestigial mutant of Drosophila. Most of the wings have defects in the wing blade and partially formed wing margin, which are the result of autonomous cell
death in the presumptive wing blade or costal region of the wing disc. The vestigial gene (vg) and the interaction of Vg protein with other gene products are well understood. With this biochemical knowledge, reinvestigations
of the high-temperature-induced vestigial wings and the elucidation of the molecular mechanism underlying the large-scale
variation of the wing forms may provide insight into further understanding of development of the wing of Drosophila. As a first step of such explorations, I examined high-temperature-induced (29°C) vestigial wings. In the first part of this
paper, I provide evidences to show that the proximal and distal costae in these wings exhibit regular and continuous variation,
which suggests different developmental processes for the proximal and distal costal sections. Judging by the costae presenting
in the anterior wing margin, I propose that the proximal and distal costal sections are independent growth units. The genes
that regulate formation of the distal costal section also strongly affect proliferation of cells nearby; however, the same
phenomenon has not been found in the proximal costal section. The distal costal section seems to be an extension of the radius
vein. vestigial, one of the most intensely researched temperature-sensitive mutations, is a good candidate for the study of marginal vein
formation. In the second part of the paper, I regroup the wing forms of these wings, chiefly by comparison of venation among
these wings, and try to elucidate the variation of the wing forms according to the results of previous work and the conclusions
reached in the first part of this paper, and provide clues for further researches. 相似文献
5.
Hirokazu Yamada Masatoshi Tomaru Muneo Matsuda Yuzuru Oguma 《Journal of Insect Behavior》2008,21(4):222-239
Drosophila ananassae and D. pallidosa are closely related, sympatric species that lack postmating isolation. Sexual isolation has been considered important in
maintaining them as independent species. To clarify the behavioral processes leading to sexual isolation, we analyzed behavioral
sequences and examined the effect of courtship song on mating success and on behaviors of both sexes by surgically removing
male wings (song generators), female aristae (song receivers), or female wings (means of fluttering). We found that heterospecific
courtship songs evoked female wing fluttering, whereas conspecific courtship song did not. Furthermore, female wing fluttering
made courting males discontinue courtship. These findings suggest that strong sexual isolation is achieved through the following
behavioral sequence: heterospecific song→female wing fluttering→courtship discontinuation. 相似文献
6.
As physiological factors may influence the predatory behavior of insects, this study was designed to evaluate the possible impact that hunger has on the search path of a polyphagous predator: Deraeocoris lutescens Schilling (Heteroptera: Miridae). D. lutescens was fed a diet of Rhopalosiphum padi (Linné) (Homoptera: Aphididae) nymphs and Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs at 21±1 °C and a photoperiod of 16:8 (L:D). After moulting, third and fifth instar nymphs and adults were placed in Petri dishes containing an abundant food source for 24 h. After 24 h, the food was removed and groups were randomly assigned to increasing periods of prey deprivation. Each D. lutescens nymph or adult was placed at the center of an empty arena and its searching path was recorded to calculate different path parameters and to determine the type of movement mode adopted. Results show an effect of starvation on both nymphal and adult D. lutescens searching paths. Satiated third instar nymphs manifested an intensive search path whereas fifth instar nymphs and adults adopted an intermediate one. When starved, the extensive search path appeared early in young nymphs, and later in the last instar nymphs and adults, according to the degree of prey deprivation. 相似文献
7.
Jeong Jun Kim 《BioControl》2007,52(6):789-799
The activity of entomopathogens on insect pests has been investigated for many species but the influence of entomopathogenic
fungi on factors other than mortality relating to population increase has not been frequently studied. The influence of Lecanicillium attenuatum CS625 (=Verticillium lecanii CS625) on development and reproduction of cotton aphid (Aphis gossypii) was investigated. A conidia suspension of the isolate was applied onto first instar nymphs. Increased spore concentration
did not significantly affect each nymphal stage, total nymphal period, pre-reproductive period and the age of first larviposition.
A significant dose effect on reduction of life span, reproductive period and fecundity was observed in 1st and 3rd instars
after spore application. When conidia were applied to 1st instars, life span was significantly reduced to 10.8 and 8.4 days
at 1 × 104 and 1 × 108 conidia/ml, respectively from 12.2 days in the control. During the life span, total fecundity was 41 ± 7.3, 26 ± 0.8 and
22 ± 5.7 nymphs per female at 1 × 104, 1 × 106 and 1 × 108 conidia/ml, respectively compared with 51 ± 2.0 nymphs per untreated female. Reproduction period was also significantly shortened
with increasing spore concentration. Application of spores to 3rd instars showed a similar trend. However, daily fecundity
of individual aphids was not affected by spore dose. It was concluded that the isolate of L.
attenuatum is able to affect populations of cotton aphid by reducing life span and total fecundity as well as by killing the aphids
directly. 相似文献
8.
S. A. Kopyl N. V. Dorogova E. M. Akhmametyeva L. V. Omelyanchuk L. -S. Chang 《Russian Journal of Genetics》2010,46(3):276-282
The protein Merlin is involved in the regulation of cell proliferation and differentiation in the eyes and wings of Drosophila and is a homolog of the human protein encoded by the Neurofibromatosis 2 (NF2) gene whose mutations cause auricular nerve tumors. Recent studies show that Merlin and Expanded cooperatively regulate the
recycling of membrane receptors, such as the epidermal growth factor receptor (EGFR). By performing a search for potential
genetic interactions between Merlin (Mer) and the genes important for vesicular trafficking, we found that ectopic expression in the wing pouch of the clathrin adapter
protein Lap involved in clathrin-mediated receptor endocytosis resulted in the formation of extra vein materials. On the one
hand, coexpression of wild-type Merlin and lap in the wing pouch restored normal venation, while overexpression of a dominant-negative mutant Mer
DBB
together with lap enhanced ectopic vein formation. Using various constructs with Merlin truncated copies, we showed the C-terminal portion
of the Merlin protein to be responsible for the Merlin-lap genetic interaction. Furthermore, we showed that the Merlin and Lap proteins colocalized at the cortex of the wing imaginal
disc cells. 相似文献
9.
Tetraphleps galchanoides Ghauri (Hemiptera: Anthocoridae) nymphs were collected from hemlock woolly adelgid (HWA) Adelges tsugae Annand (Hemiptera: Adelgidae) infested Tsuga sp. in Baoxing, Sichuan, China. First and second stage nymphs collected from foliage shipped from China; were reared to adults
and tested for feeding rates and host preferences. They were reared at 5, 8, 12, and 15 ± 1 °C from November to December,
January to March, April, and May to June, respectively, in the quarantine laboratory at Virginia Polytechnic Institute and
State University. At 8 °C, development time was 15, 20, and 40 days for the N-III, IV, and V nymphal stages, respectively.
Adult males lived 83 days with a range of 21–147 days. A single adult female lived for 21 days. At 5 °C, second stage T. galchanoides nymphs consumed 0.8 HWA nymphs per day, and 2.0 HWA nymphs per day at the N-V stage. At 8 °C, consumption of HWA nymphs ranged
from 1.3 to 3.4 nymphs per day for the N-III to N-V stages, respectively. Adult T. galchanoides consumed more HWA eggs than HWA adults, pine bark adelgid (PBA) Pineus
strobi (Hartig) (Hemiptera: Adelgidae) adults, and eggs in no-choice tests. In choice tests with HWA eggs and PBA eggs, more HWA
eggs were eaten. Adult and nymph body measurements are presented for determination of nymphal instars. 相似文献
10.
The caste developmental system of the Neotropical termite Constrictotermes cyphergaster was investigated in 12 natural colonies from the semi-arid Caatinga region of northeastern Brazil. Twelve measurements were taken of different body parts of the larvae, workers, presoldiers,
soldiers, nymphs, and alates for morphometric analyses, and principal component analyses (PCA) were performed based on these
parameters. The nymphal line comprised one larval instar, followed by five nymphal instars, and alates, in agreement with
the developmental pattern described for Termitidae species. The apterous line included two larval instars, followed by workers,
presoldiers, and soldiers. Both workers and soldiers were found to be monomorphic and composed only of male specimens, with
only one instar phase each. C. cyphergaster, like most of the Nasutitermitinae, has only male soldiers. The presence of male workers, with only one instar, suggests
a simplified system of differentiation in the apterous line of C. cyphergaster. These patterns, which had not previously been described for ‘full nasute’ Nasutitermitinae, are similar to the differentiation
patterns of the ‘mandibulate nasute’ Cornitermes walkeri. 相似文献
11.
Temperature-dependent development and oviposition component models were developed for Deraeocoris brevis (Uhler) (Hemiptera: Miridae). Egg development times decreased with increasing temperature and ranged from 35.8 d at 15 °C
to 6.7 d at 32 °C. Total development times of nymphs reared on frozen Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs decreased from an estimated 55.6 d at 15 °C to 9.2 d at 32 °C and 10.0 d at 34.6 °C.
By fitting linear models to the data the lower developmental threshold temperatures for eggs, small nymphs (1st to 3rd instar),
large nymphs (4th to 5th instar), and all nymphs combined were calculated as 10.5, 12.5, 11.8, and 11.9 °C, respectively.
The thermal constants were 144.1, 90.3, 95.0, and 190.8 degree-days for each of the above stages. The non-linear model was
based on a Gaussian equation, which fit the relationship between development rate and temperature well for all stages. The
Weibull function provided a good fit for the distribution of development times of each stage. Adult longevity decreased with
increasing temperature and ranged from 52.9 d at 21.7 to 16.8 d at 32.0 °C. D. brevis had a maximum fecundity of 471 eggs per female at 24 °C, which declined to 191 eggs per female at 32 °C. Also, three temperature-dependent
components for an oviposition model of D. brevis were developed including models for total fecundity, age-specific cumulative oviposition rate, and age-specific survival
rate. 相似文献
12.
The susceptibility of unfed and fed stages of larvae, nymphs and adult females of Amblyomma variegatum ticks were tested using Shaws filter paper dip method against four acaricides; chlorfenvinphos and dioxathion, chlorfenvinphos, gamma benzene hexachloride and amitraz at four different concentrations including the recommended dose rates. Based on their lethal concentrations (LC50 & LC90) chlorfenvinphos and dioxathion combined and chlorfenvinphos alone placed first and second, respectively, in all stages except at the unfed nymphal stage where gamma benzene hexachloride topped with a LC50 of 0.001629, while chlorfenvinphos and dioxathion combined and chlorfenvinphos alone had LC50 of 0.001794 and 0.002258, respectively. Amitraz appeared to have a quick knock-down effect on larvae and nymphs but at the recommended dose rate, showed no mortality of the ticks at that stage. However, at a concentration of 0.040%, amitraz showed a 100% inhibition of oviposition and hatching of laid eggs. Gamma benzene hexachloride produced only 66% inhibition of oviposition while chlorfenvinphos and dioxathion combined and chlorfenvinphos alone produced 100% inhibition of oviposition at their recommended dose rates. Fed nymphs were more susceptible than the unfed nymphs. Eggs laid by engorged female ovipositing ticks, applied with gamma benzene hexachloride, hatched.This revised version was published online in May 2005 with a corrected cover date. 相似文献
13.
M. W. Brown 《BioControl》2011,56(1):65-69
The biological control of aphid populations may only be possible when natural enemies arrive soon after aphid colonization.
This study was done to identify how quickly adult Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) need to arrive at newly established spirea aphid [Aphis spiraecola Patch (Homoptera: Aphididae)] colonies on apple (Malus domestica Borkh.) to provide population control. A total of 100 newly established spirea aphid colonies were caged in an experimental
apple orchard in West Virginia, USA. A single adult H. axyridis was added to each of ten caged colonies at day 0, 5, 10, 15 and 20 days after caging. An additional ten caged colonies were
opened for exposure to natural levels of predation at each of the treatment intervals as a control. The single H. axyridis eliminated the aphid colonies significantly more quickly than natural predation for up to ten days after colony establishment.
The probability of an aphid colony producing alates was significantly lower in the presence of a single H. axyridis adult than when exposed to natural predation for the first ten days. Adult H. axyridis beetles are capable of completely controlling individual spirea aphid colonies on apple only if they are abundant enough
to find colonies within one week of colony establishment. 相似文献
14.
Hornbostel VL Zhioua E Benjamin MA Ginsberg HS Ostfeldt RS 《Experimental & applied acarology》2005,35(4):301-316
Effectiveness of the entomopathogenic fungus Metarhizium anisopliae, for controlling nymphal Ixodes scapularis, was tested in laboratory and field trials. In the laboratory, M. anisopliae (Metschnikoff) Sorokin strain ESC1 was moderately pathogenic, with an LC50 of 107 spores/ml and induced 70% mortality at 109 spores/ml. In a field study, however, 109 spores/ml M. anisopliae did not effectively control questing I. scapularis nymphs, and significant differences were not detected in pre- and post-treatment densities. For nymphs collected and returned to the laboratory for observation, mortality was low in treatment groups, ranging from 20 to 36%. To assess whether a chemical acaricide would synergistically enhance pathogenicity of the fungus, we challenged unfed nymphal I. scapularis with combinations of M. anisopliae and permethrin, a relatively safe pyrethroid acaricide, in two separate bioassays. Significant interactions between M. anisopliae and permethrin were not observed, supporting neither synergism nor antagonism. 相似文献
15.
The North American seed-harvester ant Pogonomyrmex (Ephebomyrmex) pima displays a dimorphism that consists of winged (alate) and wingless (intermorph) queens; both types of queens are fully reproductive.
Microsatellite allele frequencies and a mitochondrial phylogeny demonstrate (1) alate and intermorph queens represent an intraspecific
wing polymorphism, and (2) an absence of assortative mating and inbreeding by males. Surveys at our field site in southcentral
Arizona, USA, demonstrated that only one type of queen (intermorph or dealate) occurred in each colony, including those excavated
during the season in which reproductive sexuals were present. Colony structure appeared to vary by queen type as most intermorph
colonies contained multiple mated queens. Alternatively, dealate queen colonies rarely contained a mated queen. Our inability
to find mated dealate queens in these colonies probably resulted from difficulty in excavating the entire colony and reproductive
queen, especially given that these colonies were only excavated over one day.
A morphometric analysis demonstrated that intermorph queens are intermediate in size to that of workers and alate queens,
but that intermorph queens retain all of the specialized anatomical features of alate queens (except for wings). Some colonies
had queens that foraged and performed nest maintenance activities, and these queens sometimes accounted for a significant
portion of colony foraging trips. Dissections revealed that these queens were uninseminated; some of these queens produced
males in the laboratory.
Received 24 October 2006; revised 1 December 2006; accepted 8 December 2006. 相似文献
16.
Eretmocerus mundus is native to the Mediterranean region where it is often observed to enter greenhouses to parasitize B. tabaci on fruiting vegetables and other host crops. Fecundity on tomato and pepper was evaluated by placing newly emerged pairs
(n = 15) of E. mundus on leaf discs infested with second instar B. tabaci, the preferred stage, maintained at 25 °C and changed daily until death of the female. All whitefly nymphs were observed
for host feeding and inverted to count parasitoid eggs. Adult longevity was estimated at 7.3±0.8 d on tomato and 10.1±1.0 d
on sweet pepper. Fecundity (number of hosts parasitized) was estimated 147.8±12.6 per female on tomato and 171.1±21.5 on pepper.
Incidence of host feeding (number of hosts killed) was significantly greater on sweet pepper than on tomato, 15.6±1.9 vs.
10.4±1.3 nymphs per female, respectively. No significant differences were detected in the duration of life stages between
sweet pepper and tomato. Preimaginal survivorship in clip cages was estimated at 69.5±11.9% on tomato and 76.6±10.5% on sweet
pepper, with no statistical differences. Net reproductive rate (R
o) was estimated at 63.8±8.2 and 51.0±4.4 on tomato and sweet pepper respectively. Generation time (T) was significantly greater on sweet pepper (19.3±0.5) than on tomato (17.9±0.4), but the estimate of intrinsic rate of increase
(r
m) was not statistically different at 0.216±0.005 and 0.219±0.004 respectively. These values are well above those reported
for B. tabaci on any crop, indicating the potential of E. mundus to control this pest on solanaceous crops in the greenhouse. 相似文献
17.
18.
Khaled M. Abdel Rahman Marek Barta Ľudovít Cagáň 《Central European Journal of Biology》2010,5(4):472-480
We tested the combined effect of the fungus Beauveria bassiana and the microsporidium Nosema pyrausta on the European corn borer larvae, Ostrinia nubilalis, in the laboratory. The first instar of O. nubilalis larvae was the most sensitive to the B. bassiana infection followed by the fifth, second, third, and fourth instar (LC50s were 4.91, 6.67, 7.13, 9.15, and 6.51 × 105 conidia/ml for the first to fifth instars, respectively). Mortality of each instar increases positively with concentration
of conidia. When B. bassiana and N. pyrausta were used in combination, mortality increased significantly in all instars. Relative to the B. bassiana treatment alone, the B. bassiana + N. pyrausta treatment decreased the LC50s by 42.16%, 37.63%, 21.60%, 27.11%, and 33.95% for the first to fifth instars, respectively. The combined effects of the
two pathogens were mostly additive. However, at the two highest concentrations the pathogens interacted synergistically in
the first and second instar. Individuals that survived the B. bassiana and B. bassiana + N. pyrausta treatments and developed into adults had significantly shorter lifespans and females oviposited fewer eggs than non-exposed
insects. The effects on the longevity and the egg production were most pronounced at high concentration of B. bassiana conidia. 相似文献
19.
Jerzy Woyke Jerzy Wilde Maria Wilde Venkataramegowda Sivaram Cleofas Cervancia Narajanappa Nagaraja Muniswamyreddy Reddy 《Journal of Insect Behavior》2008,21(6):481-494
Defense behavior of three, free living giant (Megapis) honey bee subspecies, Apis laboriosa, A. dorsata dorsata and A. dorsata breviligula, was compared. Disturbed worker bees responded with characteristic dorso-ventral defense body twisting (DBT). Workers of
A. laboriosa twisted the thorax by 55°, and the two other A. dorsata subspecies by about 10° more. A. laboriosa workers raised the tip of the abdomen by 90° and workers of the two other bee subspecies by about 20° higher. Differences
in those traits were highly significant between A. laboriosa and both A. dorsata subspecies, but were not significant between those two subspecies. The whole cycle of DBT was the most vigorous in A. d. breviligula (0.11 s), and it was twice as vigorous as in A. d. dorsata (0.26 s) and trice as in A. laboriosa (0.32 s). A. laboriosa twisted the body together with wings folded over the abdomen, while the two A. dorsata subspecies raised the abdomen between spread wings. This supports the opinion to treat A. laboriosa as a separate species.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
20.