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1.
Bracon lissogaster Mues., a key parasitoid of Cephus cinctus Norton in northern Montana USA, is reported in Canada for the first time. Resurgence of C. cinctus in Alberta and Saskatchewan has led to renewed interest in biological control of this cereal pest in Canada.  相似文献   

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3.
Banker-plant systems using Aphidius species have been employed to control pest aphids in greenhouses growing eggplant and sweet pepper in Japan. However, a strong negative correlation between the occurrence of secondary parasitoids and aphid-control success by this system was reported by Nagasaka et al. (2010). To control secondary parasitoid populations, detailed knowledge of their ecological characteristics is needed. In this paper, the development and parasitization ability of Dendrocerus laticeps (Hedicke) (Hymenoptera: Megaspilidae), a major secondary ectoparasitoid of Aphidius species in Japan, were examined under 25 °C laboratory conditions. The maximum female longevity was about 11 days when honeydew was available. Parasitization occurred only on mummified aphids, and the age of mummified aphids did not influence the ecological value of offspring. The maximum parasitization ability was 18.9 hosts/day estimated by Holling’s disc equation. Possible lifetime fecundity was 100.35. The intrinsic rate of natural increase estimated by the bootstrap method ranged from 0.211 to 0.321, depending on the assumptions made about larval mortality. The countermeasures for avoiding the negative impacts of D. laticeps in a banker-plant system include the development of a refuge for mummified aphids and increasing the temperature around the banker plants.  相似文献   

4.
In the spring of 1985, a species of chaicid wasps was reared from the pupae of fall webworm, Hyphantria cunea (Drury) (Lepidoptera:Arctiidae) during myinvestigation on the parasitoids of this introduced harmful insect pest inShaanxi Province, China. With high parasitic ratio (over 80 percent) and a largenumber of individuals (over 200 were usually reared from a single pupa of the  相似文献   

5.
We investigated the spectral sensitivity and response to light intensity of Pachyneuron aphidis (Hymenoptera: Pteromalidae), which is a common hyperparasitoid of Aphidius gifuensis (Hymenoptera: Braconidae), a key natural enemy of the green peach aphid, Myzus persicae (Hemiptera: Aphididae). To do so, we used 15 monochromatic lights (emitting various specific wavelengths from 340 to 649 nm) and white light. P. aphidis adults are diurnal insects that show a positive phototaxis to a broad spectrum of light. Significant differences were found between sexes in the phototactic responses of P. aphidis to different monochromatic lights. Female P. aphidis showed four peaks of sensitivity at 380, 450, 504 and 589 nm. Male P. aphidis show two peaks of sensitivity, one at 450 nm and second at 628 nm. P. aphidis adults showed an increased phototactic response at low intensities and a decreased phototactic response at high intensities for both UV light and blue light. This experiment will help provide a scientific basis for the development of colour traps for insect pest management.  相似文献   

6.
Species distribution patterns are widely studied through species distribution models (SDMs), focusing mostly on climatic variables. Joint species distribution models (JSDMs) allow inferring if other factors (biotic interactions, shared phylogenetic history or other unmeasured variables) can also have an influence on species distribution. We identified current distributional areas and optimal suitability areas of three species of the solitary snail‐shell bee Rhodanthidium (Hymenoptera: Megachilidae), and their host gastropod species in the Iberian Peninsula. We undertook SDMs using Maxent software, based on presence points and climatic variables. We also undertook JSDMs for the bees and the snails to infer if co‐occurrence could be a result of biotic interactions. We found that the three bee species: (1) use at least five different species of Mediterranean snails; (2) use empty shells not only for nesting but also for sheltering when there is adverse weather and during the night; (3) have their most suitable areas in the eastern and southern Iberian Peninsula, mostly on limestone areas; and (4) have their optimal range under Mediterranean climatic values for the studied variables. There is positive co‐occurrence of Rhodanthidium with the gastropod species, especially with the snail Sphincterochila candidissima. The contribution of the environmental component to the co‐occurrence is less than that of the residual component in those cases, suggesting that: (i) the use of biotic resources (between Rhodanthidium and the gastropod species); (ii) shared phylogenetic history (between R. septemdentatum and R. sticticum); or (iii) unmeasured variables are largely responsible for co‐occurrence.  相似文献   

7.
Three species of chalcidoid parasitoids of scale insects are recorded for the first time in Brazil: Adelencyrtus moderatus, Homalopoda sp., and Diglyphomorpha sp.; and new parasitoid–host associations are recorded between the chalcidoids Encarsia lounsburyi with Hemiberlesia palmae, Encarsia lounsburyi with Melanaspis smilacis, and Diglyphomorpha sp. with Dysmicoccus brevipes.  相似文献   

8.
Young queens of V. orientalis collected from nests in the field at the end of the season, just before the hornets naturally enter hibernation, were evaluated for longevity under varying laboratory conditions. Queens kept under full illumination and heating had a briefer life span than did queens kept under full illumination alone or under complete heating alone. All, however, were shorter lived than control queens kept under the thermal and photoperiodic conditions prevailing at that time in nature. Feeding of theophylline to the queens caused them to emerge from hibernation and succumb to an early death. Feeding of allopurinol to the queens diminished their activities relative to control queens but did not abbreviate their life span compared to the control queens.  相似文献   

9.
Sheng ML  Zeng XF 《ZooKeys》2010,(57):63-73
Four species of Mastrus Förster, 1869 are reported from China. Two, Mastrus nigrus Sheng & Zeng, sp. n. reared from Arge pullata (Zaddach) and Mastrus rugotergalis Sheng & Zeng, sp. n. reared from Diprion jingyuanensis Xiao & Zhang, are new to science. One, Mastrus deminuens (Hartig, 1838), is a parasitoid of Pachynematus itoi Okutani. A key to species of Mastrus Förster known in China is provided.  相似文献   

10.
The color pattern (two areas on each of 20 transverse bands along the dorsal surface of the body) in two reindeer oestrids, Hypoderma tarandi and Cephenemyia trompe (Diptera: Oestridae), was analyzed and compared with that of different bumblebee species found in an oestrid study area in northern Norway. A clustering analysis and multidimensional scaling analysis of the resulting matrix of pairwise similarity coefficients indicated that Bombus lapponicus, B. alpinus, and B. monticola (Hymenoptera: Bombinae) comprise a Mullerian guild whose members serve as Batesian models for H. tarandi, and that B. pratorum, B. jonellus, and B. lucorum comprise a Mullerian guild whose members may serve as Batesian models for C. trompe. The oestrid mimics also resemble their models in size.  相似文献   

11.
Species of Encarsia F?rster (Hymenoptera: Aphelinidae, Coccophaginae) are economically important for the biological control of whitefly and armored scale pests (Hemiptera: Aleyrodidae, Diaspididae). Whereas some regional keys for identification of Encarsia species are now available, few studies have addressed relationships within this diverse and cosmopolitan genus because of unreliable morphological data. Nuclear sequences of the D2 expansion region of 28S rDNA were determined from 67 strains of 24 species representing 10 species groups of Encarsia, 2 strains of Encarsiella noyesi Hayat, and 1 strain of Coccophagoides fuscipennis Girault. Analysis of molecular data alone and combined with morphological data resolves many nodes not resolved by morphology alone and offer insights into which morphological characters are useful for supporting group relationships. All analyses that include molecular data reveal Encarsia to be paraphyletic with respect to Encarsiella. If monophyly of Encarsia is constrained, the relationships are the same but with a different root within Encarsia, and these trees are presented as an alternate hypothesis. The luteola and strenua species groups are shown by both morphological and molecular data to be monophyletic, whereas the inaron group, the E. nigricephala + luteola group, and the E. quericola + strenua group are supported only by molecular data. The aurantii and parvella species groups are not supported in any of the analyses. The utility of morphological characters for defining species group relationships is discussed.  相似文献   

12.
Oviposition rates and related behaviours were quantified for Lariophagus distinguendusFörster attacking Calosobruchus chinensis (L.) and C. maculatus (F.). Oviposition rates varied with parasitoid age; parasitoids aged 1–7 days laid approximately twice as many eggs per day as those aged 8–14 days. Similar differences were noted in search rates and handling times; younger parasitoids had higher attack rates and lower handling times than older parasitoids. Search rates and handling times also varied with the host stage available for attack. Search rates were higher and handling times were lower on larger stages. The results are discussed with reference to their impact on the dynamical behavior of insect parasitoid-host populations.  相似文献   

13.
The foraging behavior ofVenturia canescens, a solitary endoparasitoid of lepidopteran larvae, was investigated in the laboratory. Females with a greater number of mature eggs in their ovarioles and oviducts parasitized a greater number of hosts and won a greater proportion of encounters with other searching females. Wasps which had been exposed to hosts prior to an experimental trial lost a higher proportion ofagonistic encounters with conspecifics than wasps which had no prior exposure to hosts. The behavior of a wasp at the time of the encounter influenced the outcome of the encounter. Wasps involved in active search of the host medium with the ovipositor (probing) were more likely to win encounters than wasps in any other behavioral category. In a situation where the agonistic encounter was between two probing wasps, both contestants were equally likely to win. Results are discussed in the light of the idea that mutual interference arises, in this species, as a result of agonistic encounters between searching females and recent dynamic-programming models which suggest that parasitoid oviposition should be influenced by mature egg load.  相似文献   

14.
The acclimation, foraging behavior, and pollination efficiency of stingless bees of the species Nannotrigona perilampoides Cresson were evaluated in tomato (Lycopersicon esculentum Mill.) plants cultivated in two greenhouses. The greenhouses were divided into three areas of 16 m2, and one of the following treatments was used for pollination: stingless bees (SB), mechanical vibration (MV), and no pollination (NP). Observations were conducted once a week from 0800 to 1600 hours during 2 mo. The acclimation of the bees to the greenhouses was estimated by the number of bees that did not return to the hive (lost bees) and by comparing the population of the colonies (brood and adults). The foraging activity of the bees across the day was evaluated by comparing the number of foragers per hour. The influence of environmental variables on the foraging activity was also analyzed. The pollination efficiency was compared among treatments through the percentage of fruit set, weight of individual fruit, kilograms of fruit produced per square meter, and the number of seed per fruit. The bees started foraging on the flowers approximately 7 d after the colonies were introduced to the greenhouse. There was a decline in the population of the colonies across the experiment, but colonies did not die out. Correlations of environmental variables with the foraging activity of the bees showed that none of them had a significant influence on pollen foraging. However, water collection was positively correlated with the temperature and negatively correlated with the humidity inside the greenhouse. The estimation of the pollination efficiency per treatment showed that there were significant differences in fruit set in SB (83 +/- 4.2) and MV (78.5 +/- 6.4) compared with NP (52.6 +/- 7.6). However, the average weight of the fruit was similar for the three treatments (65 g). There were significant differences for seed number in SB (200 +/- 15.3) and MV (232 +/- 21.4) compared with NP (120 +/- 16.6). The productivity in kilograms of fruit per square meter was higher in SB (5.72 +/- 0.61) and MV (5.66 +/- 0.58 kg) compared with NP (3.34 +/- 0.72). The number of seed was positively correlated with the weight of the fruit. We conclude that the use of Nannotrigona testaceicornis Rondani, for pollinating greenhouse tomatoes in tropical climates, could be an alternative to the use of highly defensive African-derived Apis mellifera or non-native bumble bees (Bombus spp.). However, more research is needed to evaluate the cost/benefit on large-scale greenhouse pollination using N. perilampoides Cresson against other bee species and pollination methods.  相似文献   

15.
Egg parasitoids of the genus Trichogramma Westwood play an important role in the control of the velvetbean caterpillar Anticarisa gemmatalis Hübner in soybean crops in Southern Brazil. The effectiveness of Trichogramma species as biocontrol agents is dependent of several factors, but their adaptation to the climatic conditions of the region where they will be released is one of the most important. In this context, this study evaluated the effects of five constant temperatures ranging from 14 to 30°C on parasitism, age-specific survival, progeny production and longevity of Trichogramma pretiosum Riley, Trichogramma atopovirilia Oatman & Platner, Trichogramma acacioi Brun, Moraes & Soares, Trichogramma lasallei Pinto, and Trichogramma rojasi Nagaraja & Nagarkatti. We demonstrate that temperature differently affected the species of Trichogramma investigated when using eggs of the velvetbean caterpillar. We also demonstrate that T. pretiosum and T. atopovirilia are better adapted to a wide range of temperatures than the other species evaluated, and are therefore better suited as biocontrol agents for applied biological control programs of A. gemmatalis.  相似文献   

16.
Two new species of Podogaster Brullé, Podogaster brunneus n. sp. and Podogaster lagartensis n. sp., are described. The material was collected with Malaise traps operated for a year in the Ría Lagartos Biosphere Reserve, a dry tropical area of Southeast Mexico. Podogaster rosteri Gauld & Bradshaw is synonymized with Podogaster mexicanus (Cresson). A key to the Mexican species is also provided.  相似文献   

17.
The distinctive braconine wasp genus Rhytimorpha Szépligeti is distributed through Africa and the Near East. We provide photographic illustrations of the type specimens of the two species of Rhytimorpha known up to the present, R. coccinea Szépligeti and R. nigriceps Szépligeti. Previous published records of R. coccinea from Israel by J. Papp are confirmed. A new species, R. pappi Quicke & Butcher sp. n. is described based on a female from Holot Agur, a semi-desert area in the Negev Dunes in northeastern Sinai Peninsula.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:B5CDA65C-5341-4A61-9C85-2A7A70D7D4C1  相似文献   


18.
Myrmecia dispar (Clark) is found in the drier inland areas of New South Wales and southern Queensland in Australia. Its nests, which are situated adjacent to trees, have a distinctive structure of simple architecture. The composition of the colonies varies seasonally with little or no brood production during the colder months. Colony founding probably takes place in March, April, and/or May. Several myrmecophiles are found in nests ofM. dispar, and some of these are present in relatively large numbers.  相似文献   

19.
Two new species of Hartigia Schidte, 1838 from China are described: H. maculothoracica sp. nov. from Xinjiang and H. fuscicosta sp. nov. from Jilin. A diagnosis of Hartigia and a key to Hartigia maculothoracica and its relatives are provided.  相似文献   

20.
Seasonal parasitism of Habrobracon hebetor (Say) on Helicoverpa armigera (Hübner) in chickpea was studied for three consecutive years. Parasitism by H. hebetor on larvae of H. armigera reached 12.3%. The parasitoid maintained reproductive activity on H. armigera from February to April coinciding with pod formation and maturation stages of the crop. In laboratory assays, we investigated the suitability of larval instars of H. armigera to the parasitoid H. hebetor. This parasitoid attacked third to sixth instars, though fourth and fifth instar larvae were found most suitable with 100% parasitism and development to adults. Parasitoid developmental time was longest in fifth instar (9.1 days) compared to other instars (8.1–8.9 days). Fifth instar larvae resulted in highest numbers of cocoons and adult emergence. In addition, suitability of seven lepidopteran species to H. hebetor was investigated. Corcyra cephalonica, Galleria mellonella and H. armigera were the most suitable hosts with 100% parasitism and development to adults. It was followed by Maruca vitrata and Autographa nigrisigna with 60–76.7% and 40–70% parasitism and parasitoid developmental success, respectively. Though there was 23.3% parasitism, there was no parasitoid development in Spodoptera litura. No parasitism was recorded in Spilarctia obliqua. Development of H. hebetor was most rapid in C. cephalonica (8.7 days), and longest in G. mellonella (9.3 days). Parasitoids that developed on these hosts resulted in highest numbers of cocoons and adult emergence. The parasitoid could be exploited for the biological control of H. armigera in a chickpea ecosystem.  相似文献   

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