镰尾姬蜂属一新种(膜翅目:姬蜂科)(英文)

本文记述镰尾姬蜂属Grypocentrus Ruthe一新种:卡镰尾姬蜂Grypocentrus kasparyani sp.nov.本种与室镰尾姬蜂G.areolaris Kasparyan相似,以下特征可与后者区别:唇基宽为长的2.7-3.0倍:眼颚距为上颚基部宽的0.10-0.15倍;触角鞭节16-18节(绝大多数为17节);卵柄较长也较细。正模,1991-06-09;配模,1993-05-30;副模:1,1991-06-09,2,2,1993-05-30;辽宁沈阳,盛茂领采。     

Effects of Metarhizium anisopliae on the pollen beetle Meligethes aeneus and its parasitoids Phradis morionellus and Diospilus capito

The efficacy of two Finnish strains of Metarhizium anisopliaeagainst the rape blossom beetle Meligethes aeneus (Coleoptera:Nitidulidae) and the effect on its parasitoids Phradismorionellus (Hymenoptera: Ichneumonidae) and Diospilus capito(Hymenoptera: Braconidae) were studied in laboratory and semi-fieldexperiments. Several bio-assays were performed using either directexposure of the host beetle to the pathogens, or pots containing soilinoculated with M. anisopliae conidia at a rate of 2 ×10⁸ per ml soil. Parasitised and unparasitised M. aeneuslarvae were collected in the field and were placed for pupation in thetest soil. The effect of treatment on M. aeneus andD. capito was estimated after adult emergence, and the effecton P. morionellus was estimated by dissecting hibernating pupae.While both of the M. anisopliae strains were highly pathogenicto M. aeneus adults and larvae upon direct exposure, soiltreatment resulted in no significant difference between the number ofinsects emerging (or found) from the treated and untreatedpots. However, the treated insects appeared to be latently infectedand the actual infection rate had to be estimated after their deathand incubation in a moist chamber. The mortality of the beetles causedby direct exposure to the fungus was 85% (range 70–88%). The rateof latent infection following indirect exposure via treated soil indeep pots in laboratory was 80% (range 49–100%), while that inP. morionellus was only 17% (range 0–85%), and inD. capito significantly higher, 76% (range 72–100%).The results indicate that M. anisopliae is a potentially usefulcandidate to be used as a bio-insecticide to control the pollenbeetle, and that at least the most abundant parasitoid, Phradismorionellus, is less affected than the target pest itself. Thepossible ecological role of latent infections in the host as well asin some of the parasitoids needs to be clarified.     

Stand edge effects on distribution and condition of Diprionid sawflies

1 We investigated stand edge effects on Diprion pini cocoon condition and distribution after an outbreak of unprecedented magnitude in Finland. We hypothesized that forest fragmentation and the resulting proportional increase in stand edge habitats may have led to the increase in outbreak area: D. pini may profit from edge habitats and so escape its control mechanisms more easily. This hypothesis was based on the observation that no outbreak occurred in neighbouring Russian Karelia, where the proportion of edge habitats between different stand types and/or successional stages is significantly less than in Finland. 2 To test the hypothesis, we determined the amount and condition of cocoons in an outbreak area, along transects going from stand centres through edge habitats, towards neighbouring stand centres. 3 Both the total number and number of cocoons in different conditions varied significantly between edges and centres. The effects were more pronounced when age difference between neighbouring stands increased. 4 Edge habitats did not benefit D. pini. Both the total number and number of hatched cocoons were consistently higher in centre than in edge habitats. 5 Defoliation was unrelated to distance from the edge, even on transects where cocoon density and condition was correlated to distance from the edge. 6 We conclude that edge habitats have an inhibitive effect on D. pini densities, and therefore our original hypothesis was rejected. The importance of small mammals to D. pini mortality was demonstrated, and we suggest further investigation of this predator–prey relationship because of its potential for limiting outbreak risk and/or damage through silvicultural measures.     

中国包姬蜂属一新种(膜翅目:姬蜂科)(英文)

INTRODUCTIONThegenusPerispudaFoerster,anewrecordofChina,belongingtothetribeMesoleiiniinthesubfamilyCtenopelmatinae,hasbeenrepresentedby3species,allfromthePalearcticregion.InthispaperanewspeciesofthisgenuscollectedfromChinaisdescribed.ThetypespecimensarepreservedintheGeneralStationofForestPestManagement,MinistryofForestry,Shenyang.GenusPerispudaFoersterPerispudaFoerster,1868.Verb.Naturh.Ver.Rheinlande25:205.Frontwing8.5to14.5mmlong.Clypeussmall,itshasalpartconvex,therestflatorwea…     

Floral shape mimicry and variation in sexually deceptive orchids with a shared pollinator

Mimics can have both accurate mimicry and phenotypic variation if deception operates in multiple sensory modes. Australian Tongue orchids (Cryptostylis species) attract their sole pollinator, male Lissopimpla excelsa wasps (Ichneumonidae), by accurately mimicking the scent and colour of female L. excelsa wasps. To test for shape mimicry of female wasps, both traditional and geometric morphometric comparisons were performed with allopatric Cryptostylis ovata and the often sympatric Cryptostylis erecta, Cryptostylis leptochila, and Cryptostylis subulata. Although some floral parts accurately mimicked the female wasp, the overall floral shape differed dramatically among orchid species. The function (if any) of this interspecific shape variation is unknown, although it does not cause character displacement of pollen attachment locations to reduce interspecific pollen transfer. Analyses showed that floral parts involved in pollinia transfer were similarly shaped for three of the four Cryptostylis species and all attach their pollinia to the same location on the pollinator's abdomen. Shape may interact with pollinator behaviour: in the field, pollination rates doubled when two Cryptostylis species were present, regardless of orchid abundances. Perhaps variation in shape hinders pollinator recognition and the avoidance of orchids, similar to scent and colour variation in other sexually deceptive orchid systems. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, 106 , 469–481.     

Plutella xylostella (diamondback moth) and its parasitoid Diadegma semiclausum show different gustatory and longevity responses to a range of nectar and honeydew sugars

Parasitoids as well as many of their herbivorous hosts, depend on carbohydrate‐rich food during the adult stage. Different types of nectar and honeydew vary with regard to their sugar composition. In order to successfully exploit a food source, the insect must show a positive gustatory response to its component sugars and be able to digest and metabolise them. Here we tested the herbivore Plutella xylostella L. (Lepidoptera: Plutellidae) and its parasitoid Diadegma semiclausum (Hellén) (Ichneumonidae: Campopleginae) with respect to their feeding response and longevity when provided with one of nine sugars (fructose, glucose, lactose, maltose, melibiose, melezitose, raffinose, sucrose, or trehalose). Both species responded to and showed a prolonged life span on a broad range of sugars. The impact of food supply on life span was about sixfold higher for the parasitoid than for the herbivore. In general, there was a good fit between gustatory response and achieved longevity, with some outliers. Both species showed only weak responses to melibiose, which significantly prolonged life span. The parasitoid showed a gustatory response to melezitose, which did not prolong its life span. The parasitoid and its herbivorous host responded differently to trehalose. These differences in gustatory response and longevity show the potential for application of selective sugar sources in conservation biological control. At the same time it also reveals a risk that the indiscriminate application of sugar sources may stimulate herbivory.     

Mechanism of mate detection in parasitoid wasps: sound and vibratory cues change with the developmental progress of future mates inside host pupal cases

Insects including parasitoid wasps use acoustic and vibratory signals in the context of sexual communication, mate recognition, courtship and mating. Males of the parasitoid wasp Pimpla disparis Viereck (Hymenoptera: Ichneumonidae) detect insect host pupae parasitized by a conspecific female, learn their location, visit them repeatedly and remain on or near them when the prospective mate nears emergence. In the present study, the acoustic and vibratory cues that males exploit to detect the presence and track the developmental progress of a future mate inside a host pupal case are investigated. Responses are acquired from developing parasitoids (DePa) by airborne sound and laser Doppler vibrometer recordings, after gently stimulating each of 20 wax moth host pupae with a paintbrush on days 1–23 post parasitism. Sound and vibratory cues produced by DePa are detectable from day 7 onward and relate mostly to spinning movements. Parameters of sound and vibratory cues (amplitude, dominant frequency, upper limit of frequency band) change significantly over time and thus could ‘inform’ a visiting adult male about the stage of development of DePa. Adult males antennating a parasitized pupa and flying around it also induce vibrations, which in turn may inform DePa about the presence of a male. There is no experimental evidence for true signalling and rapid information exchange between DePa and adult males. Delaying reply signals may help DePa avoid attacks by illicit receivers of such signals, including female (hyper)parasitoids and invertebrate predators.