Finding of Torymus koreanus (Hymenoptera: Torymidae) attacking Dryocosmus kuriphilus (Hymenoptera: Cynipidae) in Japan

Torymus koreanus (Hymenoptera: Torymidae) was reared from galls of Dryocosmus kuriphilus (Hymenoptera: Cynipidae) for the first time in Japan. We here report morphological features and partial mtDNA sequencing data of T. koreanus. Torymus koreanus has several common characteristics with species of the cyaneus group defined by Zavada (2003 ). According to the key to species groups defined by Graham and Gijswijt (1998 ), it does not belong to any species group because of the entire posterior margin of metasomal tergum five.     

Potential non-target effects of Sclerodermus harmandi (Hymenoptera:Bethylidae) on Triaspis sp. (Hymenoptera:Braconidae)

Sclerodermus harmandi (Buysson) (Hymenoptera: Bethylidae) is a generalist parasitoid that has been mass-produced and released for biological control of many agricultural and forest pests in China. However, few studies have examined the potential non-target risks of this parasitoid in targeted agriculture or forest ecosystems. In this study, we demonstrate that S. harmandi successfully attacks Triaspis sp. (Hymenoptera: Braconidae), an important native natural enemy of the pine weevil pest Pissodes punctatus Langor et Zhang in Yunnan Province of China. When exposed to older larvae of Triaspis sp. at three different parasitoid-to-host group sizes (1:1, 2:2 and 3:3) with a constant 1:1 parasitoid-to-host ratio, S. harmandi successfully attacked 100%, 75% and 83.3% of the test larvae, respectively. All life stages (egg, larva, pupa and adult) of S. harmandi were observed on Triaspis sp. larvae, indicating that Triaspis sp. are suitable for the completion of S. harmandi development. There were no significant differences in the number of S. harmandi progeny produced among the different parasitoid-to-host exposure treatments. Immature stages of S. harmandi on parasitized Triaspis sp. took 25.4 days to complete their development (the egg stage: 3.6 days, the larval stage: 5.0 days, the pupal stage: 16.5 days). Together, results from our study indicate that mass-releases of S. harmandi for biological control of forest pests in Yunnan Province may adversely affect some valuable non-target insects such as Triaspis sp. We suggest that the potential non-target risk of S. harmandi be considered in future augmentative release biological control programmes against forest pests.     

Interspecific competition between two endoparasitoids Cotesia vestalis (Hymenoptera: Braconidae) and Oomyzus sokolowskii (Hymenoptera: Eulophidae)

Two endoparasitoids, Cotesia vestalis and Oomyzus sokolowskii, parasitize the same host, larvae of Plutella xylostella. These two species have evolved different parasitization strategies. O. sokolowskii expresses a single factor, venom, and exerts virtually no detrimental effects on the development of its host. C. vestalis, on the other hand, injects polydnavirus (PDV) and venom during oviposition, and teratocytes are released into the host's hemolymph after egg hatching. Parasitization suppresses host immune reactions and redirects its developmental program. Because both these species parasitize the same stage of their hosts, there is the possibility of multiparasitism in nature. Only one species survives multiparasitism and because of its parasitic strategy, we hypothesized that C. vestalis would invariably be the stronger competitor. We designed competition experiments which revealed that C. vestalis is a stronger competitor than O. sokolowskii. We also show that C. vestalis survives intrinsic competition with O. sokolowskii through two mechanisms: physical attack and physiological suppression. We discovered melanized wounds on O. sokolowskii eggs and larvae, which is strong evidence of physical attacks. The physiological suppression is due to PDV and venom injected by C. vestalis. To test this idea more rigorously, we designed a pseudoparasitization experiment which revealed that no O. sokolowskii emerged from multiparasitized hosts when infertile C. vestlais eggs and normal O. sokolowskii larvae are both present inside the same host. These results support our hypothesis that C. vestalis is the stronger competitor and demonstrate two mechanisms that account for the outcome of intrinsic competition between these two endoparasitoids.     

Functional responses of aphid parasitoids,Aphidius colemani (Hymenoptera: Braconidae) and Aphelinus asychis (Hymenoptera: Aphelinidae)

We evaluated the functional responses of two aphid parasitoids: Aphidius colemani on the green peach aphid Myzus persicae (Hemiptera: Aphididae), and Aphelinus asychis on M. persicae and the potato aphid, Macrosiphum euphorbiae (Hemiptera: Aphididae). Parasitoid oviposition occurred at host densities of 5, 10, 20, 30, 50, 80 or 100 aphids for A. colemani and 5, 10, 20, 30 or 50 aphids for A. asychis. More M. persicae were parasitized by A. colemani than by A. asychis at an aphid density of 50. Among the three types of functional response, type III best described the parasitoid response to the host densities both in A. colemani and A. asychis. The estimated handling time was shorter for A. colemani than for A. asychis (0.017 and 0.043 d, respectively). The proportion of aphids that were parasitized exhibited the same characteristic curve among the three host-parasitoid combinations: a wave form that appeared to be a composite of a decelerating (as in type II) response at low host density and an accelerating-and-decelerating (as in type III) response at medium to high host density. We hypothesize that the novel host species (and its host plant), density-dependent superparasitism, and/or density-dependent host-killing may have induced the modified type III response.     

Afrotropical Cynipoidea (Hymenoptera)

The Afrotropical Cynipoidea are represented by 306 described species and 54 genera in four families: Cynipidae, Figitidae, Liopteridae and Ibaliidae, the latter represented by a single introduced species. Seven of these genera are only represented by undescribed species in the region. Seven new genus-level synonymies, one genus resurrected from synonymy, 54 new combinations, one combination reinstated, and one new replacement name are presented. We provide identification keys to the families, subfamilies and genera of cynipoid wasps occurring in the Afrotropical region (Africa south of the Sahara, including Madagascar and southern Arabian Peninsula). Online interactive Lucid Phoenix and Lucid matrix keys are available at: http://www.waspweb.org/Cynipoidea/Keys/index.htm. An overview of the biology and checklists of species for each genus are provided. This paper constitutes the first contributory chapter to the book on Afrotropical Hymenoptera.     

Biology of Nomioides variegatus (Olivier) (Hymenoptera: Halictidae)

The nesting biology, life history and pollen foraging of the minute Nomioides variegatus (Olivier) is described and illustrated. All Nomioides biological studies are reviewed. Nesting and foraging were observed over two years in a sandy natural area in the Rhône River delta region of southern France. Nest and cell structure was obtained from soil blocks removed from the nesting area and examined in the laboratory. Females, which were on average only 4.2 mm long, nested solitarily in loose aggregations in areas free of vegetation. Cells were placed from 6 to 12 cm deep, each terminating a lateral burrow off the main burrow. Cell walls were lined with a water proof wax-like lining. The pollen-nectar provision was a flattened sphere. The posterior end of the egg was embedded on the dorsal surface of the provision. Larval and pupal development was rapid, proceeding to adults by August, the over-wintering stage. Pollen foraging patterns were analyzed from both pollen provisions and fecal material for different nests (3) and cells (8). Nomioides variegatus is polylectic, but individuals bees exhibited a high degree of foraging consistency for the provisioning of single cells. Eleven different pollen types representing 10 plant families were found. In 1996, Ecballium elaterium (Cucurbitaceae) was the dominant pollen present in all samples but it was absent in 1997. Tamarix gallica (Tamaricaeae) was the dominant pollen type in 1997 and absent in 1996. A third pollen, Centaurium (Gentianaceae) was present in both years and represented 70% of some samples.     

美丽青背姬小蜂生物学特性研究

美丽青背姬小蜂Chrysonotomyiaformosa（Westwood）是美洲斑潜蝇的优势天敌,在美洲 斑潜蝇的自然控制中发挥着非常重要的作用。本文对其生物学进行了研究,结果表明：在实验 温度范围内,随着温度的升高,寄生蜂羽化趋早,羽化时间更集中,羽化高峰也更明显;随着 温度的升高,成蜂的寿命逐渐缩短。在提供清水时,寄主可以显著地延长雌蜂的寿命;在有寄 主时,提供10%蜂蜜水,雌蜂的寿命显著延长。美丽青背姬小蜂对3龄寄主幼虫有偏好,对3龄寄 主幼虫的致死率和寄生率都高于对1～2龄寄主幼虫的,且产下后代的雌雄性比为5.11∶1。在 实验温度范围内,发育历期随温度的升高而缩短。     

日本佳盾蜾蠃的生物学特性观察

日本佳盾蜾蠃Euodynerus nipanicus（Schulthess）是一种重要的独栖捕食性天敌昆虫,对我国南方林区鳞翅目蛾类害虫的控制具有一定作用。本文报道了日本佳盾蜾蠃的形态特征、生活史及幼虫和成虫的行为等生物学特性。该蜂在江西赣州地区 1 年发生 4 代,以滞育的老熟幼虫在巢管虫室内越冬,滞育期约 190 d。翌年的4月下旬成虫开始外出活动,主要包括交配、筑巢、产卵、捕食等行为。通过野外收集筑巢巢管,室内饲养观察等,发现该蜂的卵近似微弯的长圆柱形,长 2.912 ± 0.127 mm,卵期2-4 d,平均 2.5 ± 0.99 d;非越冬幼虫期 8. 1 ± 0. 99 d;预蛹期4.3 ± 0. 48 d;蛹期7. 4 ± 0.84 d;雌雄比约为 2. 95:1。本研究丰富了日本佳盾蜾蠃的生物学基础知识,为进一步利用该蜂防治南方林区鳞翅目蛾类害虫提供了依据。     

Bombus impatiens (Hymenoptera: Apidae): an alternative to Apis mellifera (Hymenoptera: Apidae) for lowbush blueberry pollination.

The pollination effectiveness of the commercially reared bumble bee Bombus impatiens Cresson, was compared in field studies to the honey bee, Apis mellifera L., for lowbush blueberry, Vaccinium angustifolium Ait. A preliminary study indicated that B. impatiens had potential as an alternative pollinator. In a 3-yr study, percentage fruit set, percentage harvested berries, berry weight, and seeds per berry were compared in blueberry fields stocked at 7.5 A. mellifera hives per hectare to 5, 7.5, or 10 B. impatiens colonies per hectare. Percentage of harvested berries (yield) was significantly higher in fields stocked with B. impatiens at 10 colonies per hectare. No other parameters measuring pollinator effectiveness were significantly different at 5, 7.5, or 10 colonies per hectare. Flower handling time was significantly faster for B. impatiens and it more frequently collected blueberry pollen. All parameters of pollinator effectiveness were similar for B. impatiens, A. mellifera, and native wild bees in a follow-up study. Overall, B. impatiens was a suitable alternative to A. mellifera.     

First report of Elasmus polistis Burks (Hymenoptera: Eulophidae) recovered from Polistes versicolor (Olivier) (Hymenoptera: Vespidae) nests in Brazil

The first record of Elasmus polistis Burks in Polistes versicolor (Olivier) nests in the Rio Grande do Sul state and in Brazil is provided. A total of 173 specimens of P. versicolor and 790 specimens of E. polistis were collected from two nests from Gramado and Santa Cruz do Sul, RS, Brazil.     

The Ectatommini (Hymenoptera: Formicidae) of Ghana

Three species of Ectatommini, one of which is described as new, are reported from Ghana. A key to workers of the Ghanaian species is included.     

Cardinium in Plagiomerus diaspidis (Hymenoptera: Encyrtidae)

The bacterial symbiont Cardinium (Bacteroidetes) was previously implicated in the thelytokous reproduction of the parasitoid Plagiomerus diaspidis Crawford (Hymenoptera: Encyrtidae). Horizontal transmission of the symbiont among the cactus scale Diaspis echinocacti Bouché (Homoptera: Diaspididae) and its hymenopteran parasitoids has been suggested. In this study, the bacteria associated with D. echinocacti, its parasitoids P. diaspidis and Aphytis sp. (Hymenoptera: Aphelinidae), and the hyperparasitoid Marietta leopardina Motschulsky (Hymenoptera: Aphelinidae) were characterized using molecular fingerprinting techniques, and the localization of Cardinium in P. diaspidis was studied using fluorescence in situ hybridizations (FISH). Cardinium was the only bacterium found in P. diaspidis, but it could not be detected in any of the other insects tested. The symbiont was specifically located in the reproductive tissues of its P. diaspidis host.     

The First Record of Endasys liaoningensis (Hymenoptera: Ichneumonidae) Parasitizing on Pachynematus itoi (Hymenoptera: Tenthredinidae) in Korea

An ichneumon species, Endasys liaoningensis Wang et al., is reported for the first time from Korea. Morphological characteristics of adults are redescribed with illustrations. In addition, the biological characteristics and their distributional ranges are discussed.     

Ultrastructure of Microplitis croceipes (Cresson) (Braconidae : Hymenoptera) teratocytes

The developing embryo of the braconid, Microplitis croceipes (Braconidae : Hymenoptera), is encased in an extraembryonic serosal membrane. Hatching of the parasitoid within the larva of its habitual host, Hehothis virescens (Noctuidae : Lepidoptera), is initiated about 40 hr after oviposition when held at 25 ± 2°C. At this time, the monolayered serosal membrane begins to dissociate into individual cells (teratocytes). After dissociation, teratocytes become dispersed in the hemolymph of the host. The average number of teratocytes released from each parasitoid embryo is 914 ± 43. Teratocytes average 14.1 ± 2.4 μm in diameter when first released, and reach a maximum average diameter of 68.1 ± 4.6 μm 6 days after liberation. Newly released teratocytes have ovoid nuclei, simple mitochondria and a limited number of profiles of the endoplasmic reticulum, all of which indicate relative metabolic inactivity. The ramified nuclei, extensive endoplasmic reticulum, polymorphic mitochondria and accumulation of glycogen granules and lipid droplets observed in older teratocytes provide circumstantial evidence that protein synthesis is occurring. Within hours after dissociation, microvilli begin to cover the surface of the teratocytes. Anatomical deformation (blebs) that occurred on some older (8-day-old) teratocytes probably resulted from enlargement or expansion of microvilli.     

The chalcidoid genus Leptofoenus (Hymenoptera: Pteromalidae)

Abstract. The world species of Leptofoenus (Chalcidoidea; Pteromalidae; Cleonyminae) are revised, and a key given for the six known species. One new species, rufus, is described, and two new synonymies proposed (phantasma and ashmeadi as junior synonyms of pelecinifor-mis). Lectotypes are designated for peleciniformis, westwoodi, and howardi. New distributional records are presented, including the first record of this genus from the Nearctic, rufus from Arizona and California (U.S.A.). Important characters and relationships between the species are discussed.