Mitochondrial DNA variation in social wasps (Hymenoptera,Vespidae)

Summary Patterns of restriction fragment length polymorphisms (RFLP) of European Vespinae were more similar within genera than between them. Distance trees were constructed that support the hypothesis of monophyly of the generaVespula andDolichovespula. Within the genusVespula, V. germanica was more closely related toV. rufa than toV. vulgaris. The position of the genusVespa remained uncertain due to the precision limits of the RFLP technique.     

Chemical attraction of the eastern yellowjacket,Vespula maculifrons (Hymenoptera: Vespidae)

Summary Workers and queens of the eastern yellowjacket,Vespula maculifrons, are attracted to the artificial long-range attractant pheromone of the predaceous pentatomid,Podisus maculiventris. A 11 mixture of linalool or -terpineol and (E)-2-hexenal is as attractive toV. maculifrons workers as the pheromone.We thank A.S. Menke of the Systematic Entomology Laboratory, USDA, for identifying the yellowjackets. Mention of a company name does not imply endorsement by the US Department of Agriculture.     

Mitochondrial DNA variation in geographic populations of Colorado potato beetle,Leptinotarsa decemlineata (Coleoptera; Chrysomelidae)

Summary This study demonstrates variability in restriction enzyme cleavage sites of mitochondrial DNA (mtDNA) among four popalations of Colorado potato beetle (CPB). A suite of three enzymes (EcoRI,HpaI,PstI) was sufficient to discriminate among the populations tested. Individuals heteroplasmic for restriction enzyme patterns were found in some populations. Variability in CPB mtDNA should prove useful in efforts to trace the origin and dispersal of the species in North America.     

The isolation,identification and synthesis of the alarm pheromone ofVespula squamosa (Drury) (Hymenoptera: Vespidae) and associated behavior

Summary A material that elicits alarm and attack behavior byVespula squamosa (Drury) workers was isolated from venom extracts and identified by spectroscopic methods as N-3-methylbutylacetamide. This compound elicited attack responses from worker wasps identical to those responses observed when venom was applied at the same dosage. This is the first behavioral role reported for this compound.The authors thank E. Adamak, R. Murphy and F. Takken for technical assistance. This article reports the results of research only. Mention of a proprietary product does not constitute an endorsement or the recommendation for its use by USDA.     

Microorganism-associated variation in host infestation efficiency in a parasitoid wasp,Trichogramma bourarachae (Hymenoptera: Trichogrammatidae)

InTrichogramma bourarachae (Hymenoptera: Trichogrammatidae), the infestation efficiency presents important variation among strains: 60 eggs/5 days/female in the High (H) strain and 25 eggs/5 days/female in the Low (L) strain. Crosses show that between-strains variation is inherited by the matrocline route. Antibiotic and heat treatments reduce infestation efficiency in the H strain and have no effect on the L strain. The hypothesis of cytoplasmic-symbiotic microorganisms accounting for the higher infestation efficiency in the H strain is supported by microscopic observations. The origin and the significance of this between-strains variation are discussed.     

Heat production by balling in the Japanese honeybee,Apis cerana japonica as a defensive behavior against the hornet,Vespa simillima xanthoptera (Hymenoptera: Vespidae)

Summary As an effective counterattack strategy against predacious hornets, especiallyVespa simillima xanthoptera, workers ofApis cerana japonica showed a distinct balling reaction, usually involving 180–300 bees. This produced heat for as long as 20 min, giving rise to temperatures inside the ball higher than 46°C, which is lethal to the hornet but not to the bees.     

Juvenile hormone promotes dominance behavior and ovarian development in social wasps (Polistes annularis).

Repeated topical application of juvenile hormone to workers of the primitive social wasp, Polistes annularis resulted in a disruption of colony social structure as indicated by a sharp increase in the frequency of dominance interactions. Ovarian maturation was also observed, probably as both a direct and an indirect effect of hormone treatment.     

An analysis of allozyme,mitochondrial DNA and morphological variation in mussel (Mytilus galloprovincialis) populations from Greece

Three populations ofM. galloprovincialis from northern Greece were investigated using isozyme analysis, discriminant analysis of morphological characteristics and analysis of restriction fragments of mtDNA. For all three types of analysis significant intra- and interpopulation differentiation was found. This differentiation is very noticeable at the mtDNA genotype frequencies. Furthermore, the restriction patterns of mtDNA were different from those reported for Atlantic populations of this species.     

Untersuchungen zur Verdauungsphysiologie vonFormica polyctena Foerst. (Hymenoptera,Formicidae)

Summary In this investigation the spectrum of digestive-acting carbohydrates present inFormica polyctena Foerst. was analysed. The digestive tract of worker ants was dissected and the enzymatic activity tested by incubation with different carbohydrates. The results for crop, midgut, malpighian tubes and hindgut are given in the Table.     

Visual spatial memory in desert ants,Cataglyphis bicolor (Hymenoptera: Formicidae)

Summary For navigation, desert ants apply piloting and dead-reckoning strategies based on terrestrial and celestial visual cues, respectively. Visual spatial memories, rather than general concepts derived from landmark constellations, are most probably used to define points on earth by nearby landmarks. The visual field of a specialized dorsal part of the ant's retina is mapped on to the celestial sphere to consider the possibility that similar mechanisms are used to define directions on earth by exploiting skylight patterns present at infinity.Supported by the Hescheler Foundation (Zurich) and the Swiss National Science Foundation grants Nos 3.529-0.75 and 3.313-0.78.     

重症急性胰腺炎病人外周血单个核细胞线粒体DNA拷贝数的意义

目的探讨重症急性胰腺炎患者外周血单个核细胞线粒体DNA拷贝数与患者病情严重程度、预后的相关性。方法分离研究对象（重症急性胰腺炎患者34名,健康对照组17名）外周血单个核细胞,采用荧光实时定量PCR检测各组PBMC线粒体DNA相对舍量,其与严重程度、预后的相关性。结果重症急性胰腺炎患者线粒体DNA含量较健康对照组明显降低（P〈0．05）。患者单个核细胞线粒体DNA拷贝教与APACHEⅡ评分呈负相关（r=-0．425）其中并发症组mtDNA拷贝数显著低于无并发症组（P〈0．05）。结论重症急性胰腺炎患者外周血单个核细胞中线粒体DNA含量显著下降,与患者APACHEⅡ评分呈负相关,且低水平的线粒体DNA拷贝数提示并发症发生率的升高,因此,线粒体DNA拷贝数可作为潜在评估患者病情危重程度及预后的指标,这一发现值得进一步大型,前瞻性的研究。     

Location of a lure by the drumming insectPimpla instigator (Hymenoptera,Ichneumonidae)

Summary Females of the parasitoidPimpla instigator (Hymenoptera, Ichneumonidae) are able to locate a lure hidden in a paper sheath. The lure is located without having been touched or sighted, and without any olfactory stimuli. We propose that the ability to locate the lure is linked with the drumming behavior of the females.     

High genetic variability despite haplodiploidy in primitive sawflies of the genusCephalcia (Hymenoptera,Pamphiliidae)

Hymenoptera are haplodiploid and usually display very low genetic variation. Most data concern social or parasiticApocrita, while the little information available for the primitive phytophagous species of the suborder Symphyta is contradictory. The present study is related to seven species of the genusCephalcia, living in coniferous forests of Northern Eurasia and sharing spruce (Picea sp. pl.) as host plant. Individuals from 22 populations belonging toCephalcia abietis, C. alashanica, C. arvensis, C. erythrogaster, C. fallenii, C. fulva, C. klugii from Europe and China were surveyed for genetic variation at 28 loci using enzyme electrophoresis. Pairs of sibling species were recognized withinC. arvensis andC. fallenii, corresponding to different phenological and morphological forms. In the latter case, reproductive isolation in sympatry occurs despite low genetic distance (D=0.059). Large genetic distances and fixed alternate alleles were observed between Chinese and European populations ofC. abietis andC. arvensis. Expected heterozygosity ofCephalcia populations (0.197, SD 0.064) is significantly higher than that of other Symphyta (Tenthredinoidea) (averageH _exp 0.059, SD 0.032) (two-tailed Mann-Whitney test, Z=4.39, p<0.01). These data suggest that haplodiploidy per se does not reduce the genetic variation in mostCephalcia populations. Most of the factors that can lower the potential for genetic diversity in a haplodiploid genetic system are not so effective inCephalcia populations, which seem to be comparable to diplodiploid insect populations in diversity. In a few isolated populations the large number of fixed loci and the large genetic distances may support the predicted faster rate of fixation, as a consequence of haplodiploidy.     

Ecdysteroid titre and caste determination in the ant,Pheidole pallidula (Nyl.) (Hymenoptera: Formicidae)

Summary In the antPheidole pallidula, ecdysteroid level is higher in worker-biased eggs than queen-biased eggs. Moreover queens laying worker-biased eggs exhibit a higher ecdysteroid level than queens laying queen-biased eggs.