| 1. |
- Anderson, Peter, et al.
(författare)
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Does Host Size and Feeding Status Influence the Egg Load of Microplitis rufiventris (Hymenoptera: Braconidae)?
- 2011
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Ingår i: Annals of the Entomological Society of America. - 0013-8746. ; 104, s. 221-228
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Tidskriftsartikel (refereegranskat)abstract
- Laboratory experiments were conducted to determine the effect of host instar and feeding status on the egg load of early life stage in Microplitis rufiventris Kokujev (Hymenoptera: Braconidae), a solitary koinobiont endoparasitoid of some noctuid pests. The wasps that developed from fourth or fifth instars of Spodoptera littoralis (Boisduval) larvae were heavier in weight than those from earlier stages. Different numbers of mature eggs were found in the two ovaries of the female wasp. Egg loads, corresponding to fitness, were significantly influenced by female weight and feeding status. However, the interactions between the two treatment factors were not significant. The average number of mature eggs carried by females at eclosion time ranged from 52 eggs in smaller wasps to 62 eggs in larger wasps. Females that were fed had higher egg loads and egg maturation rate than unfed females. However, female wasps were capable of maturing considerable number of eggs without feeding; suggesting that they produce a certain portion of eggs from nutritional reserves that had been stored during larval stage. Female wasps are weakly synovigenic, with an egg maturation at a rate of approximate to 1.8 eggs per h. Further investigation is required to verify the rate of egg maturation and eventually egg resorption in different stages of adult female M. rufiventris.
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| 2. |
- Sawangproh, Weerachon, et al.
(författare)
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Life History Traits of the Liverwort Herbivore Scatopsciara cunicularius (Diptera: Sciaridae)
- 2016
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Ingår i: Annals of the Entomological Society of America. - : Oxford University Press (OUP). - 1938-2901 .- 0013-8746. ; 109:3, s. 343-349
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Tidskriftsartikel (refereegranskat)abstract
- We studied the behavior, life cycle, and reproductive biology of the sciarid fly Scatopsciara cunicularius (Lengersdorf, 1943) under two constant temperatures. The sciarid was reared at 12.3 ± 0.6°C and 22 ± 1.7°C on its host, the liverwort Marchantia polymorpha L. Our results show that the sciarid fly is able to complete its life cycle with liverwort tissue as its only source of food. The egg-laying potential of the insect ranged from 70–174 eggs per female (mean 110 ± 31 eggs). Reproduction was digenic, meaning that one female can produce both male and female progeny. The overall sex ratio did not depart from 1:1, although the progeny sex ratio was highly variable. The developmental period of S. cunicularius was considerably longer in the colder than the warmer temperature. Mean development time of the egg, larva, and pupal stages, and adult longevity in the warm regime was 4, 20, 4, and 5 d, whereas mean development time of each juvenile stage and adult longevity in the cold regime was 13, 95, 11, and 8 d, respectively. The results suggest that the phenology of S. cunicularius is temperature dependent. Scatopsciara cunicularius could constitute a promising agent for biological control of M. polymorpha.
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| 3. |
- Schlyter, Fredrik
(författare)
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Pattern of Egg Maturation and Oviposition for Microplitis rufiventris (Hymenoptera: Braconidae) Wasps Given Different Schedules of Host Availability and Food Resources
- 2014
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Ingår i: Annals of the Entomological Society of America. - 0013-8746. ; 107, s. 878-885
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Tidskriftsartikel (refereegranskat)abstract
- The effects of the oviposition regime on egg maturation rate in the synovigenic parasitoid, Microplitis rufiventris Kokujev were investigated. In non-ovipositing wasps, females normally reach a peak of egg maturation rate on 1 d posteclosion. Egg maturation slowed down once the maximum oviduct egg load was reached on 2 d posteclosion. In wasps manipulated for 20 ovipositions per day, the egg maturation rate during the first 3 d posteclosion was lower compared with those manipulated for 40 ovipositions per day. The rate of egg maturation in 1-d-old wasps was found to be the highest for those that experienced 60 ovipositions per day. The maturation rate in females offered unlimited hosts was not significantly greater than those manipulated for 40 ovipositions per day. The act of oviposition significantly increased the rate of egg maturation and minimized egg resorption in the female wasp. The distribution of mature eggs in the ovaries at death is apparently associated with the oviposition regime. Trade-offs between egg maturation rate and female longevity were quite evident.
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| 4. |
- Schäfer, Martina, et al.
(författare)
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Comparison of mosquito (Diptera: Culicidae) fauna characteristics of forested wetlands in Sweden
- 2001
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Ingår i: Annals of the Entomological Society of America. - 0013-8746 .- 1938-2901. ; 94:4, s. 576-582
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Tidskriftsartikel (refereegranskat)abstract
- We studied mosquito faunas of four wetlands from northern to southern Sweden by trapping female mosquitoes in June, July, and August. A total of 52,298 individuals comprising 32 species in five genera were identified. The number of species increased from 10 and 12 in the two northern wetlands, to 16 in the central Sweden study area, to 24 in the wetland in southern Sweden. For a further characterization of mosquito fauna diversity, we organized all species recorded from Sweden into 14 functional groups based on biological and life history characteristics. The number of groups increased from three in the two northern study areas, to eight in central Sweden, and 13 in the southernmost study area. All functional groups present at one site were also present at the sites located farther south. Most successful species were univoltine, respiring from the water surface, laying their eggs on soil, overwintering in the egg stage, preferring forested or partly forested habitats, and having mammals as hosts for blood meals. The mosquito faunas of the two northern study areas were similar and lacked several of the functional groups occurring further south. The mosquito fauna of the study area in central Sweden included species feeding on birds and with overwintering larvae. In the southernmost study area, 13 out of 14 functional groups were found, indicating a large variety of habitats. Our results demonstrated a southward increase in the number of both mosquito species and functional groups in forested wetlands.
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| 5. |
- Yamane, Takashi
(författare)
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Reduction of Female Mating Receptivity After Injection of Male-Derived Extracts in Trigonotylus caelestialium (Heteroptera:Miridae)
- 2013
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Ingår i: Annals of the Entomological Society of America. - 0013-8746 .- 1938-2901. ; 106:2, s. 258-264
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Tidskriftsartikel (refereegranskat)abstract
- The effects of male-derived extracts on female receptivity to remating were investigated in Trigonotylus caelestialium (Kirkaldy) (Heteroptera: Miridae). The aqueous extracts of male reproductive tracts were observed to reduce receptivity both at 3 h and at 1 d after injection into the abdomens of females. Next, ultrafiltration was used to divide the aqueous extracts of the male reproductive tracts into three molecular-weight (MW) fractions: <3.5 kDa, 3.5-14 kDa, and >14 kDa. The filtrate containing the MW substances <3.5 kDa reduced female receptivity 3 h after injection, whereas the fraction containing MW substances >14 kDa inhibited receptivity at 1 and 2 d after injection. Finally, the male reproductive tract organs were divided into the accessory glands, testes, and the remaining reproductive organs, including the seminal vesicles. Aqueous extracts of the accessory glands reduced the receptivity of females both at 3 h and 2 d after injection, whereas those of the testes decreased the receptivity of females at 3 h after injection. Together, the results indicate that more than one mechanism may be involved in the effects of male-derived substances on female receptivity in T. caelestialium. The findings suggest that low-MW male-derived substances in the accessory glands and testes cause short-term inhibition and that the high-MW substances in the accessory gland inhibit female mating at a later period.
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