COEXISTENCE OF TWO EFFECTIVE PARASITOIDS OF THE WHITE PEACH SCALE PSEUDAULACASPIS PENTAGONA (HEMIPTERA: DIASPIDIDAE): THE ROLE OF THE HOST STAGE AND TEMPERATURE.

ENCARSIA BERLESEI: (Howard) and Pteroptrix orientalis (Silvestri) are endoparasitoids of Pseudaulacaspis pentagona (Targioni Tozzetti), that are sympatric in Campania (Italy). The influence of host stages on several components of E. berlesei fitness and the effect of mating status on the production of Pteroptrix orientalis progeny were evaluated at 25 degrees C. Parasitization of earlier host stages resulted in an increase in the development time and a decrease in progeny number of E. berlesei. Adult parasitoids were largest when young female stages were parasitized. Pupal mortality did not differ among host stages. Mated female P. orientalis produced a greater number of progeny and proportionally fewer sons (13.6% of the total progeny) than did virgin females (21.7%). The reproductive potential of both parasitoids was also evaluated at four regimes of constant temperature (20, 24, 26 and 30 degrees C). Encarsia berlesei attained rm values nearly double those of P. orientalis at 20, 24 and 26 degrees C, whilst at 30 degrees C the two parasitoids achieved the same rm value, since at this temperature E. berlesei suffered a high pupal mortality. Sex ratio of P. orientalis, expressed as proportion of males, varied significantly between 20 and 24 degrees C only

PRESENCE OF TERATOCYTES IN HYMENOPTERA APHELINIDAE: COMPARATIVE DEVELOPMENT IN ENCARSIA BERLESEI AND ENCARSIA CITRINA.

In: Journal of Insect Science 3(33): 18 (available online: INSECTSCIENCE.ORG/3.33

Scanning Electron Microscopy of the Antennal Sensilla and Their Secretion Analysis in Adults of <i>Aromia bungii</i> (Faldermann, 1835) (Coleoptera, Cerambycidae)

Background: It has been proved that chemical signals play an important role in mating location and reproductive behavior in cerambycids; moreover, they rely on contact chemoreception for mate recognition. Methods: Adult antennae of Aromia bungii were observed using scanning electron microscopy and adult antennal secretions were collected and analyzed with gas chromatography-mass spectrometry. Results: Twelve different types of sensilla were morphologically described on the antennae of A. bungii. At least six mechanoreceptors&#8212;one gustative, one putative chemo- or thermoreceptor, and three multiporous olfactory receptors&#8212;are present on the antennae of both sexes while a receptor-type of unclear function is limited to males. Secretions associated with sensilla basiconica were observed for the first time in a cerambycid species. Conclusions: Sensilla basiconica should play a role in odor perception detecting host tree volatiles and/or pheromones. Sensilla basiconica type 1 and 2 produce a viscous material accumulating on the antennal surface. Chemical analysis of adult antennal secretions highlighted marked differences between sexes. Some of the identified compounds have been previously reported as contact pheromone components of other cerambycid species. Our observations strongly suggest sensilla basiconica as the production sites of compounds involved in mate recognition