Two new species of Hymenoepimecis (Hymenoptera: Ichneumonidae:Pimplinae) with notes on their spider hosts and behaviour manipulation

摘要

The wasp genera included in the Polysphincta genus-group develop exclusively askoinobiont ectoparasitoids of spiders, an unusual pattern within Hymenoptera.All known species of Hymenoepimecis attack orb-web spiders and Hymenoepimecisargyraphaga was previously described inducing a sudden modification of its host'sweb-building behaviour. Information on parasitoid–host interactions and even onhost identities for most members of the genus-group, however, remain scarce. Inthis study we describe two new species of Hymenoepimecis and present informa-tion on their hosts, spiders of the genera Leucauge (Tetragnathidae) and Manogea(Araneidae). Cocoon webs of both host species are distinct from their normalwebs. The modified cocoon web of Leucauge roseosignata constructed under theinfluence of Hymenoepimecis japi sp. nov. is very similar to the cocoon webdescribed for Leucauge argyra. It is composed of three axes, including severalradial threads each, and a hub used by the larva to attach the cocoon's suspensionline. Spiral viscous threads, present in normal webs and in webs of parasitized spi-ders carrying larvae in the initial instars, are absent in cocoon webs. In the cocoonweb of Manogea porracea the horizontal sheet is poorly structured and the cocoonis attached far from the spider's normal resting position, in an area composed of adensely tangled structure.