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1.
Ground beetles (Coleoptera: Carabidae) are important components of soil ecosystems in temperate zones, but our knowledge regarding the ecology of many species is limited. This study examined larval food habits in the ground beetle Amara (Curtonotus) gigantea (Motschulsky) using laboratory‐rearing experiments. Because this beetle is a member of the tribe Zabrini, which includes several species that exhibit granivory during larval and/or adult stages, three diet types were tested, with starvation as a control: Tenebrio larvae, mixed seeds (Bidens pilosa (Asteraceae), Setaria spp., Digitaria ciliaris (both Poaceae), and Humulus scandens (Moraceae)), and Tenebrio larvae + mixed seeds. Because of high larval mortality during overwintering under laboratory‐rearing conditions, survival and the duration of development through pre‐overwintering stages (first and second instars) were compared. Larvae fed the diet of Tenebrio larvae + mixed seeds showed the highest survival (89%), followed by the diet of Tenebrio larvae (83%), but the difference between the two treatments was not significant; similarly, developmental durations did not differ between these two diets. Larvae fed the mixed‐seeds diet showed markedly lower survival, and no larvae reached the second instar. Therefore, for A. gigantea larvae, animal food results in high larval performance, whereas seeds provide a low value diet; animal food is essential for larval development, but seeds provide no benefit, even as a dietary supplement. Overall, the present results suggest that A. gigantea larvae are omnivorous but with a mainly carnivorous food habit.  相似文献   

2.
The role of symbiotic microbes in insects, especially the beneficial character of this interaction for insects, has received much attention in recent years as it has been related to important aspects of the host insects' biology such as development, reproduction, survival, and fitness. Among insect hosts, tephritid fruit flies are well known to form beneficial associations with their symbionts. To control these destructive agricultural pests, environmentally friendly approaches, like the sterile insect technique as a component of integrated pest management strategies, remain most effective. In this study, changes in the bacterial profile of mass‐reared oriental fruit flies, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), were examined in both larval and adult stages and also after irradiation by employing a 16S rRNA gene‐based Illumina sequencing approach. Proteobacteria was the prevalent bacterial phylum in non‐irradiated adults and larvae. Alphaproteobacteria was the most abundant class in larvae but almost absent in adults, which was dominated by Gammaproteobacteria. Firmicutes were present in both developmental stages but at lower relative abundance. At genus level, Acetobacter prevailed in the larval stage and members of the Enterobacteriaceae family in adults. Irradiated samples exhibited higher diversity and richness indices compared to the non‐irradiated oriental fruit flies, whereas no significant changes were observed between the two developmental stages of the non‐irradiated samples. Lactobacillus, members of the Orbacecae family, and Morganella were detected but to a lesser degree upon irradiation, whereas the relative abundance of Lactococcus and Orbus increased. The bacterial profile of larvae appeared to be different compared to that of adult B. dorsalis flies. The subsequent application of irradiation at the pupal stage led to the development of different microbiota between treated and untreated samples, affecting diversity and operational taxonomic unit composition. Irradiated samples of oriental fruit flies were characterized by higher species diversity and richness.  相似文献   

3.
The effects of temperature on the development and survival of Lycaeides argyrognomon were examined in the laboratory. The eggs, larvae and pupae were reared at temperatures of 15, 17.5, 20, 25, 30 and 33°C under a long‐day photoperiod of 16‐h light and 8‐h darkness. The survival rates of the first–third instars ranged from 40.0 to 82.4%. The mortalities of the fourth instar were lower than those of the first–third instars. The development time of the overall immature stage decreased from 78.33 days at 15°C to 21.07 days at 30°C, and then increased to 24.33 days at 33°C. The common linear model and the Ikemoto–Takai model were used to estimate the thermal constant (K) and the developmental zero (T0). The values of T0 and K for the overall immature stages were 10.50°C and 418.83 degree‐days, and 9.71°C and 451.68 degree‐days by the common model and the Ikemoto–Takai model, respectively. The upper temperature thresholds (Tmax) and the optimal temperatures (Topt) of the egg, the first–third instars and the overall immature stages were estimated by the three nonlinear models. The ranges of Topt estimated were from 30.33°C to 32.46°C in the overall immature stages and the estimates of Tmax of the overall immature stages by the Briere‐1 and the Briere‐2 models were 37.18°C and 33.00°C, respectively. The method to predict the developmental period of L. argyrognomon using the nonlinear models was discussed based on the data of the average temperature per hour.  相似文献   

4.
Summary Wild-type nuclei from eggs ofDrosophila melanogaster at various developmental stages and from different regions of the egg—cleavage nuclei, pole nuclei from preblastoderm, and lateral nuclei from syncytial blastoderm—were singly implanted into unfertilizedy w sn 3 lz 50e eggs to determine their developmental potencies.All three types of transplanted nuclei were almost equally effective in initiating development of unfertilized eggs. Development was arrested in one of five critieal embryonic stages or in one of the three larval instars. The frequency of individuals reaching a distinct stage was approximately the same for all three types of donor nuclei. The stage-specific pattern of defects was independent of the type of nucleus transplanted.The deviations from normal development were broadly similar to those seen in controls developing from fertilized eggs which had only been punctured or into which cytoplasm had been injected. Many defective embryos also occurred in these control experiments. These and other observations indicate that a large proportion of irregularly developed individuals found after nuclear transfer can be ascribed to loss of egg material, disturbances in the internal organization of the egg during nuclear implantation, and the difficulty the implanted nucleus has in adjusting to the autonomous processes within the egg, such as the formation and migration of cytoplasmic islands.Some of the defective embryos and larvae originating from nuclear transfer were implanted into adult hosts. After culture for 14 days the early embryonic stages had formed several larval structures, and the late embryonic and larval stages had developed all larval organs. The proliferated imaginal primordia of thesein vivo cultured embryos and larvae, as well as the imaginal disks of the third instar larva, were then implanted into larval hosts with which they passed through metamorphosis and differentiated into imaginal structures. All three types of donor nuclei were capable of producing all adult structures derivedin situ from imaginal disks. The phenotype of these structures waswild-type, thus demonstrating their origin from the transplanted nuclei.The problem as to why not all transplanted nuclei initiated development, and why development after nuclear transplantation was arrested at the third larval instar, at the latest, is discussed.This article is dedicated to Professor Friedrich Seidel on the occasion of his 75th birthday.  相似文献   

5.
Abstract: A method of distinguishing different larval instars of Liriomyza huidobrensis morphologically, using measurements of the cephalopharyngeal skeleton was developed. The growth ratios of cephalopharyngeal skeletons between first and second and second and third instar larvae were 1.80 and 1.47, respectively, enabling clear separation to be achieved for experimental work. Using this method the development rates of the immature stages of L. huidobrensis feeding on Lactuca sativa were determined under constant temperatures of 11, 16, 19, 26 and 28 ± 1°C and were shown to increase linearly with temperature over the range investigated. The theoretical lower threshold temperatures for development from oviposition to the end of each larval instar or pupal stage were 5.35, 6.30, 6.20 and 5.70°C, respectively. The overall threshold temperature for development from oviposition to 50% adult emergence (5.70°C) was used to calculate degree‐day (DD) requirements for development from oviposition to each larval instar or pupal eclosion, which were 84.3, 30.1, 58.9, 143.7 DD, respectively. The use of these data for optimizing the timing of application of control agents which are effective against specific developmental stages is discussed.  相似文献   

6.
7.
The apple ermine moth, Yponomeuta malinellus Zeller (Lepidoptera: Yponomeutidae), is a tent caterpillar that feeds on Malus spp. in Korea. Populations of the moth in native areas appeared to be regulated by the assemblage of parasitoids. Phenological associations between host stages and parasitoids, susceptible stage(s) of the host for each parasitoid, and stage‐specific parasitism were studied. The egg larval parasitoid Ageniaspis fuscicollis (Dalman) had highest parasitism of first instar larvae (24%), with 14% parasitism of other larval stages. Dolichogenidea delecta (Haliday) was recovered from all larval instars with the highest parasitism rate of second instar larvae (20.1%), followed by 19.9% parasitism of mid‐larval hosts. Herpestomus brunicornis Gravenhorst was reared from second instar larvae through to pupal collection, and had the highest parasitism rate (29.9%) at the pupal stage. The larval pupal parasitoid Zenillia dolosa (Meigen) was recovered from mid‐larval to pupal stages with the highest parasitism rate (5.5%) occurring in third to fourth instar larvae. The host stages for developing A. fuscicollis completely overlap with those of D. delecta, and with those of H. brunicornis to some degree. A statistically significant negative correlation exists between A. fuscicollis and these dominant parasitoids, indicating competitive interaction within the host.  相似文献   

8.
Pyrgomorpha vignaudii (Guérin‐Méneville, 1849) is a pest of a wide variety of crop plants in Africa. To facilitate the search for a sustainable strategy against this pest, we have studied the post‐embryonic development, morphology and reproduction on Manihot esculenta in the laboratory. Five‐hundred and two larvae at the first stage of development obtained in the laboratory were individually reared in cages. Post‐embryonic development passed through seven stages. The total number of days spent for larval development varied from 77 to 108. The mean duration of development of stages 1, 2, 3, 4, 5 and 6 larvae were, respectively, 16.48 ± 0.43, 14.40 ± 0.55, 13.70 ± 0.61, 15.07 ± 0.84, 15.21 ± 1.31 and 16.21 ± 1.27 days. After the final molt, the females of P. vignaudii take an average of 12.7 ± 1.04 days before the first mating. The time between the first mating and first oviposition ranged from 14 to 34 days (averagely 25.2 ± 4.62 days). The females realized one to nine ovipositions during their lives. The number of eggs per egg‐pods (ootheca) varied from 16 to 93 with a mean of 45.31 ± 3.51. Our results provide valuable information for the search for a control strategy against P. vignaudii.  相似文献   

9.
The life history of polysphinctine parasitoids is poorly understood. As a result, their effect on their host has not been evaluated. Here, we present the phenology of Zatypota percontatoria, an ectoparasitoid wasp of theridiid spiders, using rich field, semi‐field and laboratory investigations of selected life‐history parameters. The wasps overwintered as larva attached to the spider abdomen and the imagos of the first generation emerged at the beginning of May. The sex ratio (F/M) of overwintered wasp larvae was 1.4. The wasp spent an average of 6.4 days in the egg stage, 27.67 days in the larval stage and 9.6 days in the pupal stage. Adult longevity was on average 14.34 days. Oviposition occurred on average 8.44 days following maturity. The wasp laid on average 0.35 eggs/day. The total fecundity was on average 7.4 eggs per wasp and decreased with age (data from unmated females). The developmental rate increased with experimental temperature up to 28 °C. The lower developmental threshold for pupae was estimated at 6.6 °C. The sum of effective temperatures for pupae was estimated at 157.8 degree days. Using daily temperature records from the Czech Republic over the last 41 years, we estimated an average of 3.5 generations of Z. percontatoria per year. Mortality was 48% in semi‐field conditions and 23% in the laboratory. The incidence of mortality was highest during egg and larval stages caused by the detachment of eggs or larvae during spider molting, the mortality of the spider‐host and egg deposition on the spider prosoma.  相似文献   

10.
This study investigated the effect of temperature on the development and overwintering potential of the predatory thrips Franklinothrips vespiformis (Crawford) (Thysanoptera: Aeolothripidae), a biological control agent used against glasshouse pests in continental Europe and Israel. Developmental rates increased linearly with rearing temperatures. It was estimated that 304.9 degree days, above a lower threshold temperature of 11.9 °C, were required for F. vespiformis to complete development from egg to adult eclosion. The effect of low temperatures (–5, 0, and 5 °C) was examined on adult female and larval survival. Subsequent reproductive and developmental attributes of survivors were also investigated. Lethal time experiments indicated that larval stages are more cold tolerant than adult F. vespiformis females. Surviving larvae increased their developmental times to adults with decreasing temperature and increasing exposure periods and second instars were significantly more successful than first instars in reaching adulthood. Surviving adult females decreased their oviposition rate with decreasing temperature and increasing exposure periods, and exposures to low temperatures affected the number of viable eggs produced. The results are discussed in the context of overwintering and establishment potential of F. vespiformis in the UK in the event of introducing the predatory thrips as a biological control agent against glasshouse pests.  相似文献   

11.
Mouthpart and alimentary canal development was examined in Lysmata amboinensis larvae using scanning electron microscopy and histology. The gross morphological features of external mouthparts and internal digestive tract structures of larvae at different developmental stages indicate that ingestive and digestive capabilities are well developed from early on. With increasing age of the larvae the mouthpart appendages increased in size, the hepatopancreas in tubular density and the midgut in length. The density of setae and robustness of teeth and spines of individual structures increased. The most pronounced changes from early to late stage larvae involved formation of pores on the paragnaths and labrum, transformation of the mandibular spine‐like teeth to molar cusps, development of the filter press in the proventriculus and of infoldings in the previously straight hindgut. The results suggest that early stage L. amboinensis larvae may benefit from soft, perhaps gelatinous prey, whereas later stages are better equipped to handle larger, muscular or more fibrous foods. J. Morphol. 2011. © 2011 Wiley‐Liss, Inc.  相似文献   

12.
Abstract 1. Granivory is a specialised food habit in the Carabidae and is considered to have evolved from ancestral carnivory. Despite recent investigations, the mechanisms underlying this peculiar feeding shift have not been sufficiently elucidated. In particular, no studies have examined the effects of diet composition on male reproductive traits. 2. This study examined male gonad maturation, female fecundity, and larval development under different diets (insect larvae, mixed seeds, and insect larvae + mixed seeds) for Anisodactylus punctatipennis (Coleoptera: Carabidae). 3. Whereas sperm‐bundle length, the durations of larval stages, and adult weight did not differ among diets, the weights of seminal substance‐producing organs, fecundity, and larval survival were higher with diets containing seeds compared to the pure‐animal diet. These findings provide the first conclusive evidence for granivory in Anisodactylus. 4. This study is the first that demonstrates the effects of diet on male reproductive traits in a granivorous carabid. The results were consistent with similar observations for fecundity and larval performance in this and other studies. Thus, in addition to the female and larval traits, the dietary effects on male reproductive traits may also have played an important role in the evolution of granivory in the Carabidae.  相似文献   

13.
Based on the analysis of 12 egg and larval variables and temperature of 65 temperate freshwater fish species, the possible relationships between oocyte diameter, larval size at hatch, time and temperature were reassessed and the main early life‐stage strategies were described and compared. Time and degree‐days required to reach hatching and mixed feeding were weakly related to oocyte diameter and strongly to temperature. These results are chiefly because oocyte diameter and yolk reserves are weakly related and temperature strongly increases tissue differentiation rate, activity of hatching glands and embryo motility. Strong positive relationships were found between larval size and oocyte diameter and degree‐days for incubation. No relationship was found between larval size and degree‐days from hatching to mixed feeding and between degree‐days for incubation and degree‐days from hatching to mixed feeding. These last two results are chiefly because the developmental stages at hatching and at the onset of exogenous feeding are not fixed in ontogeny and are not directly related to either larval size or degree‐days for incubation, but more probably are species specific. Whatever the spawning season, which can occur almost all year long, the different trade‐offs at the early life‐stages ensure that most larvae are first feeding during spring, when food size and abundance are the most appropriate.  相似文献   

14.
Mud crabs, Scylla spp. , are commercially important in many Indo-Pacific countries. The larval development of mud crabs has been reported previously as five zoeal and one megalopal stages. This paper reports larval rearing experiments that revealed variability in larval developmental stages in the mud crab Scylla paramamosain, one of four mud crab species. In addition to normal five zoeal stages, an alternative pathway of developing through six zoeal stages was observed for the crab. There were evidences suggested that the appearance of the additional Zoea-VI larvae was associated with unfavourable dietary conditions, including poor quality of diet, inadequate quantity of dietary supply and a period of starvation for newly hatched larvae. Based on exuviae and larval specimens, the morphology of the additional Zoea-VI larvae was described.  相似文献   

15.
The lifespan of herbivorous Rana pipiens larvae is ~3 months, while that of carnivorous Ceratophrys ornata larvae is only about 2 weeks. During metamorphic climax, the larval gut shortens dramatically, especially in R. pipiens, and its luminal epithelium is replaced by adult‐type epithelium. To determine when programmed cell death occurs during the metamorphic restructuring of the gut, we prepared cross‐sections of the stomach, small intestine, and large intestine from representative larval stages and from juvenile frogs of both species. The sections were incubated with monoclonal antibody against active caspase‐3, one of the key enzymes in the apoptotic cascade. We observed apoptosis in some luminal epithelial cells in each of the three regions of the larval gastrointestinal tract of both species. However, apoptotic cells appeared earlier in larval stages of R. pipiens than C. ornata and few were seen in juvenile frogs of either species. The results demonstrate the occurrence of apoptosis in the metamorphic remodeling of the gut of both R. pipiens larvae and C. ornata larvae. J. Morphol., 2011. © 2011 Wiley Periodicals, Inc.  相似文献   

16.
In poecilogony, different types of larvae are produced within the same species. Previous studies have suggested maternal control of the production of larval types; however, it is not clear which factors or mechanisms generate contrasting developmental patterns among siblings. The spionid polychaete Boccardia proboscidea produces within the same capsule adelphophagic larvae that eat nurse eggs and siblings and complete all or most of their development inside the capsule (Type A larvae), and larvae with little growth until they hatch as planktotrophic larvae (Type B larvae). In this study, we manipulated capsule content to explore the factors determining larval type in B. proboscidea and the role of extra‐embryonic maternal nutrition and sib–sib interaction in the developmental fate of offspring. When early larval stages were grown individually in vitro, with nurse eggs as the only food source, some of them remained small, while others continue developing into larger pre‐competent larvae by feeding on nurse eggs. This suggests that larval types in B. proboscidea are determined very early in development and are not solely the product of sib–sib interaction inside the capsule. However, our data also suggest that hatching size variability within larval types of a clutch depends on nurse egg availability. Type B larvae grew normally to metamorphosis when phytoplankton was available, but suffered high rates of cannibalism by Type A larvae. These results are consistent with the hypothesis that individual larval fates are determined very early in development and that once their fate is determined, hatching size and intracapsular survival are affected by maternal food provisioning and sibling interaction.  相似文献   

17.
Gravid females of Penaeus semisulcatus were spawned in the laboratory by natural means. The embryos were documented and the larvae were reared from hatching to postlarval stage at 28.2–30.0 °C and 33.5–34.5 g kg−1 salinity for about 10 days (223 h 55 min). Six naupliar stages, three protozoea stages, three mysis stages and the first postlarval stage were described and illustrated. The larvae were fed only with microalgae Tetraselmis tetrathele and Chaetoceros gracilis from first protozoea until the second mysis, with about 90% survival rate; from the third mysis until the first postlarva they were fed with similar microalgae coupled with rotifer Brachionus plicatilis and Artemia nauplii. The embryonic and larval stages of P. semisulcatus are generally similar to those of other closely related species in the family Penaeidae, such as Melicertus canaliculatus, Fenneropenaeus merguiensis, and Marsupenaeus japonicus, except for the size and structure of diagnostic characters, setation of appendages and duration of metamorphoses. The change in the feeding habit during ontogeny was related to morphological transformation of the feeding apparatus of larvae and postlarvae. This paper is the first comprehensive and complete account of the early developmental stages of P. semisulcatus.  相似文献   

18.
19.
The relationship between temperature and the development of the West Indian sweet potato weevil, Euscepes postfasciatus, on an artificial larval diet containing powdered sweet potato root, was examined at different fixed temperatures from 22 to 31°C. The developmental periods for egg, larvae, and pupae stages shortened in correlation with increased temperature. The thermal constant was 769.2 degree-days and the developmental zero for female and male was 11.1 and 11.7°C, respectively. Although we can rear this weevil at temperatures ranging from 22 to 31°C, rearing temperatures should be kept between 25 and 28°C because the developmental stages were too long at 22°C and the larval period was delayed at 31°C. The basis for these developmental data will be a useful key factor in designing a plan to eradicate the weevil by using a mass-rearing system and SIT.  相似文献   

20.
The temperature‐dependent development of the European larch bark beetle, Ips cembrae, was studied under long‐day conditions L:D 16:8 at three temperature regimes, 15°C, 20°C and 25°C, using the sandwich plate method. By observing the individual developmental progress, we calculated the developmental times and lower developmental thresholds of one entire generation and various ontogenetic stages. The mean developmental time of one generation was about 120, 64 and 37 days at 15°C, 20°C and 25°C, respectively. The egg stage comprised about 9% of the total development or about 16% of the pre‐imaginal development. The larval stages took about 39% of the entire and about 66% of the pre‐imaginal development. The pupal stage needed about 11% of the total or about 18% of the pre‐imaginal development. The lower developmental threshold for one generation was 11.2°C. The egg stage had the highest lower developmental threshold of 12.0°C, the pupa the lowest of 9.8°C and the total larval stages showed a value of 11.2°C. The thermal requirements for I. cembrae have never been studied in detail before. The results will be a valuable contribution for monitoring and risk assessment models to estimate the beetle's phenology and its potential impacts on forest ecosystems under changing climate conditions.  相似文献   

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