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1.
The influence of variable photoperiods on the feeding activity and fecundity of Galendromus occidentalis (Nesbitt) was studied on a diet of Tetranychus urticae Koch eggs. Starved G. occidentalis females were fed T. urticae eggs under ten 24-h light:dark regimes. Half of the tests started during photophase and the other half during scotophase. T. urticae eggs that were consumed and G. occidentalis eggs that were laid were counted at the end of each photophase and scotophase in a 24 h period. In general, G. occidentalis consumed more T. urticae eggs per h in the first phase of the experiment than in the second, regardless of whether the lights were on or off. In contrast to egg consumption, there were no statistical differences in the mean daily fecundity at the end of the 24-h periods. However, when the experiment was started during photophase, higher fecundity/h was encountered during scotophase than during the photophase. As a result, egg consumption rates were affected by photoperiods in both phases of the experiments. Logistic regression analysis revealed that variable photoperiods and egg consumption did not influence the fecundity of G. occidentalis.  相似文献   

2.
The biology of barley shoot fly Delia flavibasis was studied using resistant (Dinsho and Harbu) and susceptible (Holker) barley cultivars at Sinana Agricultural Research Center, Ethiopia. A higher number of eggs was laid on Holker (17 eggs/female) than on Dinsho (11 eggs/female) or Harbu (12 eggs/female). However, there were no differences between cultivars in preoviposition and total reproductive periods. The shortest time required to complete larval, pupal and total developmental stages from egg to adult emergence occurred when the insect was reared on the cultivar Holker. Pupal weight, adult emergence and adult longevity did not differ between cultivars. The female to male sex ratio was 1:1. This study enabled us to understand the duration of each of the life stages of D. flavibasis, which will undoubtedly aid researchers and growers to design a sustainable management strategy against barley shoot fly.  相似文献   

3.
I examined the adult potential fecundity of the bamboo gall maker,Aiolomorphus rhopaloides Walker (Hymenoptera: Eurytomidae), and its inquiline,Diomorus aiolomorphi Kamijo (Hymenoptera: Torymidae) by dissection just after emergence, and at death after rearing. Emerging females ofA. rhopaloides hadca. 80 mature eggs in their ovaries. The number of eggs at emergence and after death at rearing was not significantly different. However, emerging females ofD. aiolomorphi had no eggs in their ovaries but hadca 20 eggs at death after rearing. These results suggest thatA. rhopaloides is pro-ovigenic andD. aiolomorphi is synovigenic. Female body sizes of both species were positively correlated with the size of galls from which each emerged. Number of eggs in each species was also correlated with female body size, suggesting that gall size might be a good predictor of potential fecundity. This study was supported in part by a Grant-in-Aid for scientific Research (No. 11460068) from the Ministry of Education, Science, Sports, and Culture, Japan.  相似文献   

4.
不同宿主植物和饲养密度对蠋蝽生长发育和生殖力的影响   总被引：2，自引：0，他引：2  
为促进蠋蝽规模化养殖,在室内测定不同宿主植物和饲养密度对蠋蝽若虫存活率、发育历期和成虫生殖力的影响,并利用Weibull分布函数S(t)=exp(-btc)拟合蠋蝽若虫在不同饲养密度下的存活率曲线。结果表明:蠋蝽若虫的存活率、发育历期和成虫生殖力因不同的饲养条件而异。宿主植物为榆树幼苗时,蠋蝽若虫存活率最高,平均为82.09%;无宿主植物时若虫存活率最低,平均仅达16.38%。不同宿主植物对若虫发育历期无显著影响,而无宿主植物时若虫发育历期延长。不同宿主植物对蠋蝽成虫生殖力影响显著,宿主为榆树时成虫产卵量最大,平均每雌产卵量可达330.89粒,无宿主植物时产卵量仅为96.64粒。以榆树作为宿主植物,不同饲养密度对蠋蝽若虫存活率影响较大,较低密度饲养时,其存活率差别不大,均达85.56%以上;但饲养密度超过每罩40头时,其存活率显著降低。不同饲养密度对蠋蝽若虫各龄发育历期的影响无规律。不同饲养密度对蠋蝽生殖力有不同程度的影响,密度过高或过低都显著降低其生殖力。  相似文献   

5.
Effects of white mustard oil on egg deposition and on egg masses viability ofSpodoptera littoralis were determined. The bioactivity of different concetrations of oil emulsion on moths was assayed in semifield trial. Spraying of 2.5% of the oil on cotton plants caused reduction in egg laying. The moths laid only 7% of their egg masses and the percentage of repellency was 89.4%. The moth longevity was significantly reduced and the female ones were more affected by the treatment than males.At 2.5% conc., egg masses of different ages (24, 48 and 72 h old) were highly affected and the reductions were 66.6, 45 and 92%, respectively compared to the control. In general, the older eggs had the higher susceptibility to the tested concentrations in comparison to newly deposited eggs.  相似文献   

6.
Laboratory experiments investigated the effect of host instar, light and food on the number of mature eggs in ovaries (egg load) of the synovigenic parasitoid Venturia canescens (Grav.) (Hymenoptera: Ichneumonidae). The wasps that developed from third or fifth instar larvae of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) were exposed to food (honey) or had no food, had access to water or not, and were reared at the photoperiod 16:8 h light:dark or in continuous darkness at 25 ± 1°C, and 60–70% relative humidity. After death, the parasitoids were dissected to remove the reproductive systems, and mature eggs in ovaries were counted. A three-way ANOVA for egg number with host instar, food and light as factors revealed that egg load varied significantly. In addition, some interactions among the three factors were also found to be significant. The maximum average number (215.80 ± 8.51) of mature eggs was found when the parasitoids developed from third instar larvae, were exposed to continuous darkness and fed with honey. In conclusion, host instar, food supplement and photoperiod could have potential for improving biological control efficacy in stores. However, further studies determining the effect of these factors on egg laying behavior and fecundity should be done.  相似文献   

7.
Halyomorpha halys, the brown marmorated stink bug, is a serious agricultural and horticultural pest native to East Asia, which became an invasive pest in northern temperate parts of other regions in the mid-1990s. Trissolcus japonicus is a dominant egg parasitoid of H. halys in its native range. In this paper, we investigated mating, oviposition and fecundity of both virgin and mated females of H. halys. Virgin H. halys females produced unfertilized eggs, while mated females produced fertilized eggs, but mating states of adult females did not affect the number of eggs produced. We further compared the development and fecundity of T. japonicus on fertilized or unfertilized eggs of various ages. Fertilized eggs were tested continuously for up to 5 days (time to hatch), while unfertilized eggs were tested for up to 11 days (time to egg collapse). The fertilization status of the host egg had a significant effect on the development, emergence success, and sex ratio of T. japonicus progeny. A small increase in development time was observed for T. japonicus in fertilized eggs, fewer T. japonicus emerged from fertilized eggs than unfertilized eggs, and the proportion of female progeny was lower on fertilized eggs. The age of host eggs also significantly affected the development rate and fecundity of T. japonicus, with unfertilized eggs becoming more favorable than fertilized eggs as egg age increased. In summary, unfertilized H. halys eggs were better suited for T. japonicus development and fecundity, indicating their potential use in T. japonicus mass rearing.  相似文献   

8.
The effect of two insect growth inhibitors (PH-6040 and H-24108) on the fecundity, hatchability, viability and sterility of eggs laid by treatedHeliothis armigera female moths had been studied. Moths treated with these compounds laid less number of eggs than untreated moths. The egg laying capacity decreased as the concentration of any compound increased and vice versa. The same trend could be applied for egg hatchability and sterility as being affected by insect growth inhibitors and their concentrations.  相似文献   

9.
The sensitivity of the Mediterranean flour moth, Ephestia kuehniella, eggs in different stages of development to gamma irradiation was studied and the acceptability of irradiated eggs by Trichogramma cacoeciae females was examined. Eggs ranging in age from 1–24 to 49–72 h were exposed, at 24 h intervals, to gamma radiation dosages ranging from 25 to 400 Gy and effects of gamma radiation on egg hatch and adult emergence was investigated. In addition, the developmental rate of immature stages (larvae and pupae), resulting from irradiated eggs, to the adult stage was examined and the acceptance of irradiated eggs to T. cacoeciae females was evaluated. Results showed that the radio-sensitivity of E. kuehniella eggs decreased with increasing age. Egg hatch in 1–24-h-old eggs was significantly affected at 25 Gy dose and at 75 Gy dose, no egg hatch was observed. When irradiating 25–48-h-old eggs, however, egg hatch was less than 5% at 100 Gy dose, and eggs 49–72-h-old were more resistant; 50 Gy had no significant effect on egg hatch and 300 Gy did not completely prevent it. Irradiation also negatively affected survival to the adult stage. When 25–48-h-old eggs were irradiated, survival to the adult stage was completely prevented at 75 Gy dose and no survival was observed beyond 100 Gy dose in 49–72-h-old eggs. In addition, the rate of development of immature stages resulting from irradiated eggs was negatively affected. While more than 97% of control moths emerged within 30 days, this ratio decreased to 53 and 69% in 1–24 and 25–48-h-old eggs exposed to 25 Gy dose. Furthermore, irradiation positively affected the degree of acceptance of eggs to parasitization; irradiated eggs (≤49-h-old) were more acceptable to T. cacoeciae than cold-treated ones.  相似文献   

10.
The entomophagous Serangium parcesetosum Sicard (Col., Coccinellidae) is an effective predator of some whitefly species. However, information on the influence of the preys host plant species on its biological and ecological characteristics is still lacking in the literature. Therefore, the current study focuses on the possible influence of three greenhouse and two field host plant species of Bemisia tabaci (Genn.) (Hom., Aleyrodidae) on the number of eggs laid by S. parcesetosum. In addition, because of the economic importance and widespread planting of cucumber in greenhouses and cotton in the field, these plants were selected for further investigation into the development, mortality, longevity and reproduction of S. parcesetosum at a high temperature in the laboratory. Results showed that S. parcesetosum was able to lay eggs on all five host plant species of B. tabaci, whether greenhouse or field plants. However, among the three greenhouse plant species studied, S. parcesetosum females laid the highest number of eggs on cucumber followed by tomato and then sweet pepper. Of the two field plant species, significantly higher numbers of eggs were laid on tobacco than on cotton. S. parcesetosum could develop either on cucumber or on cotton as preferable host plant species for B. tabaci. There were significant differences in mean developmental duration of larval instars of the same sex between both host plant species; the duration was significantly shorter on cucumber than on cotton. There were no significant differences for mean total developmental duration from egg to adult emergence between both host plant species within the same sex; females showed a mean of 15.9 days and males of 15.1 days on cucumber, while on cotton the means were 17.2 days for females and 16.2 days for males. Total mortality percentage of S. parcesetosum during development from egg to adult stage was lower on cucumber than on cotton, 20.6 and 23.8%, respectively. Longevity of S. parcesetosum varied according to host plant species and sex with a mean of 63.4 days for females and 50.3 days for males on cucumber, and 92.4 days for females and 52.5 days for males on cotton. On cucumber, mean period of oviposition of S. parcesetosum was significantly longer than on cotton. Mean total fecundity was significantly higher on cucumber than on cotton, with means of 97.7 and 31.0 eggs/female, respectively.  相似文献   

11.
This study was carried out to determine the development, survival and reproduction responses of Adalia fasciatopunctata revelierei (Mulsant) (Coleoptera: Coccinellidae) feeding on Hyalopterus pruni (Geoffroy) (Homoptera: Aphididae), using 20, 40, 80, 160 and 250 prey densities. All experiments were conducted at 25±1°C, 60±5% relative humidity, 16:8 light:dark under laboratory conditions. The average daily prey consumption of A. fasciatopunctata revelierei immatures and adults increased with increasing prey densities. Predation was not different for the larval stages at 80, 160 and 250 prey densities. The longevities of adult females were 35.67, 35.33, 49.00, 58.33 and 57.16 days when 20, 40, 80, 160 and 250 H. pruni were provided, respectively. The mean daily and total fecundity of A. fasciatopunctata revelierei increased with increasing prey densities. Females of A. fasciatopunctata revelierei feeding on H. pruni laid 89 eggs at 20 prey density and 301.67 eggs at 160 prey density. The search rate of females was higher than that of all larval instars; and the search rate of the fourth-instar larvae was higher than that of younger instars. Handling time decreased with development from larval stages to adult.  相似文献   

12.
The olive fruit fly, Bactrocera oleae (Gmelin.) (Diptera:Tephritidae) is a pest on olives (Olea europea) in the Mediterranean basin. An olive fruit fly colony was maintained on olives at 24 ± 1°C, 60% RH, and 16:8 h (light:dark) photoperiod with fluorescent lighting. We investigated oviposition behavior, developmental duration and weights of the biological stages, and adult longevity. A single female laid an average of 19 eggs/day and 200–350 eggs in her lifetime. The maximum number of oviposition stings in a single olive was 156.0 ± 5.77, and 28.00 ± 3.62 larvae out of it completed their development, all pupated, and all emergence successfully. Although the development period was similar for larvae and pupae, adult longevity varied. Male and female emergence percentages ranged as 38.7–52.8, and 32–39.9%, respectively. The results are presented in relation to published studies on olive fruit fly rearing.  相似文献   

13.
The effect of different host plants including cabbage, cauliflower, mustard, radish, and broccoli on biological parameters of Pieris brassicae (L.) was studied in the laboratory at 28°C, 65 ± 5% RH and 12L:12D photoperiod. Duration of each life stage, longevity, the intrinsic rate of natural increase (r m), net reproductive rate (R 0), mean generation time (T), doubling time (DT), and finite rate of increase (λ) of the cabbage white butterfly on the different cole crops were estimated. Differences in fertility life table parameters of the P. brassicae among host plants were analyzed using pseudo-values, which were produced by Jackknife re-sampling. The results indicating that cabbage might be the most suitable food for P. brassicae due to the shorter development time (16 days), longer adult longevity (12 and 9 days for female and male, respectively), higher fecundity (281 eggs/female), higher intrinsic rate of natural increase (0.1156 females/female/day), lower doubling time (6.00), lower larval mortality (70.33%), and higher yield of adult (30%). Therefore, it can be concluded from the present study that P. brassicae prefers cabbage for fast and healthy development with low larval mortality and highest number of adult yield than other cole crops.  相似文献   

14.
Summary A simple method for rearing Clysia ambiguella (Lepid., Tortricidae) A method for mass rearing the vine grape tortricid,Clysia ambiguella, in laboratory is described. The moths lay their eggs into folded folies of plastics. The caterpillars are feeded with vine leaves (stored in a freezer). Since spring of 1973 six generations of the pest were reared in succession.   相似文献   

15.
Non-choice laboratory experiments were conducted to evaluate the influence of host acceptance, previous rearing host, host age and the contact time between parasitoids and host on the efficacy of Trichogramma cacoeciae Marchal and T. principum Sug. et Sor. against the codling moth Cydia pomonella. The tendency of T. cacoeciae and T. principum females to attack the codling moth was similar to E. kuehniella, and it was not affected by the previous rearing host. T. cacoeciae showed a greater preference for codling moth eggs than T. principum. A high mean number of emerged F1 progeny was observed when both parasitoids were sequentially reared on codling moths. Codling moth acceptance, the number of parasitized eggs and the number of emerged progeny were higher when younger codling moth eggs were offered. The tendency of female parasitoids to oviposit remained unchanged when the contact time with the host was prolonged. When the contact time was increased, the number of parasitized eggs and emerged offspring was higher. The results showed that the codling moth fertility (egg hatch) was reduced when younger eggs were offered and when the contact time with the parasitoids was increased. T. cacoeciae was more efficient in reducing codling moth fertility. The current study provided essential information necessary to increase the efficiency of T. cacoeciae and T. principum against the codling moth.  相似文献   

16.
The release of mass propagated egg parasitoids could be one option to control the lepidopteran pests. The efficiency of the parasitoid Trichogramma evanescens (Westwood) reared on eggs of three different factitious hosts; Sitotroga cerealella, Ephestia kuehniella and Galleria mellonella was studied for controlling bollworm Helicoverpa armigera. Efficiency of Trichogramma was studied by measuring parasitism rates, emergence rates, longevity and sex ratio. Wasps reared from each source were tested on the source host and on the target host, H. armigera under laboratory conditions. Rates of parasitism on H. armigera eggs, emergence rates of parasitoids and their longevity were the highest for wasps reared on H. armigera. Wasps reared on S. cerealella gave comparable rates. However, wasps from E. kuehniella gave the lower rates and G. mellonella gave the lowest ones. Parasitized eggs of H. armigera and S. cerealella produced more parasitoid females than eggs of E. kuehniella and G. mellonella. Results are discussed for magnifying efficiency of the parasitoid in controlling H. armigera in the field.  相似文献   

17.
Pear lace bug, Stephanitis pyri (F.) (Heteroptera: Tingidae) is a pest of apple and pear trees and ornamental Rosaceae plants in Mediterranean countries and palearctic region. The aim of this study is to determine the effects of temperatures on S. pyri in the laboratory. Development and fecundity of S. pyri reared on apple leaves (Pyrus malus L.) were investigated at five constant temperatures (20, 23, 26, 29 and 32 ± 1°C) and a 16L:8D photoperiod. Longevity was determined to be 12.6 days at 32°C and 58.7 days at 20°C for females, and 9.7 and 37.7 days for males. Females laid 186.9 eggs per female with the highest number achieved during 28.5 days of oviposition period at 26°C. Female lifetime fecundity was reduced at 32°C (40.0 eggs per female). While the net reproductive rate (R 0) was highest at 26°C, the intrinsic rate of natural increase (r m ) was highest at both 26 and 32°C. The mean generation time (G) was estimated to be 27.2–78.4 days at 20 and 32°C, respectively. The longest development times for egg and total nymph stages were obtained as 22.0 and 24.9 days, respectively, at 20°C. S. pyri developed fastest from egg to egg in 24.3 days at 32°C. The lower developmental threshold (T 0) was 9.7°C and the thermal constant (K) was 517.3 degree-days for S. pyri. Thus, S. pyri is calculated to have 3.8 theoretical generations in Tekirdag. The optimum developmental temperature for S. pyri was 26°C.  相似文献   

18.
The pine processionary moth (Thaumetopoea pityocampa) is an important defoliating insect of native cedar stands in Northern Africa. In 2002 and 2003, we studied the size of needles of Atlas cedar trees that had been defoliated or not in the previous year, and compared the oviposition preference and larval performance of processionary moth on these two types of trees in cedar stands of central Algeria. Needle length and their number per needle cluster were twice as high on non-defoliated trees than on defoliated trees. There were about ten times fewer egg batches on defoliated than on non-defoliated trees in both study years. Young larvae raised in the laboratory on the foliage of previously defoliated trees were smaller compared to those fed on the foliage from healthy trees. Larval colonies transferred to trees in the field showed two times higher mortality on defoliated trees. It was concluded that the decline in population density in defoliated stands often observed after outbreaks results both from the fact that the female moths avoid laying their eggs on defoliated trees and the lower performance of larvae which later feed on the new-grown needles.  相似文献   

19.
A series of investigations have been carried out on the effect of the entomopathogenic fungusBeauveria bassiana on the various developmental stages ofPhthorimaea operculella. Both first and second insatar larvae were more susceptible than the third or fourth instars. The infected prepupae and pupae resulted in marked decrease in the emergence, longevity of moths, deposited eggs and their egg hatchability. An obvious increase in the pupal duration was observed and the resulting malformed adults were also recorded. The latent effects were markedly obvious, specially in high doses ofBeauveria bassiana.  相似文献   

20.
The effect of the chloronicotinyl insecticide (thiacloprid 480 SC) was evaluated to determine its potential in controlling the potato tuber moth, Phthorimaea operculella. Application of thiacloprid at various concentrations (0.1–0.4 ml/l) on different age groups of eggs (1–4.5 day-old) had no effect on egg hatchability. However, slight embryocidal effect was noted in all egg age groups exposed to 0.4 ml/l concentration. Egg incubation period was increased (20%) when 4–4.5 day-old eggs were treated with thiacloprid at a rate of 0.4 ml/l compared with the untreated control. Thiacloprid was effective in reducing larval survival on potato seedlings or adults emergence from potatoes, exhibiting activity for at least 14 days after application. When already infected potato seedlings or tubers were treated with thiacloprid at a rate of 0.4 ml/l, adult emergence was decreased. Larvae that hatched from thiacloprid-treated eggs and fed, untreated tubers, encountered some difficulties in surviving and emerging as adults. Our data suggest that potato plants or tubers treated with thiacloprid at a commonly used rate (0.4 ml/l) should be well protected from the possibility of infestations by the potato tuber moth. Publication of this article was held up owing to technical problems. The publisher apologizes sincerely for this lengthy delay.  相似文献   

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