Submitted to: Annals of the Entomological Society of America
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 9/30/2006
Publication Date: 1/20/2007
Citation: Prischmann, D.A., James, D.G., Storm, C.P., Wright, L.C., Snyder, W.E. 2007. Identity, abundance, and phenology of Anagrus spp. (Hymenoptera: Mymaridae) and leafhoppers (Homoptera: Cicadellidae) associated with grape, blackberry, and wild rose in Washington State. Ann. Entomol. Soc. Am. 100(1):41-52. Interpretive Summary: A survey was conducted to identify the Anagrus species parasitizing eggs of pestiferous Erythroneura leafhoppers in both managed and non-managed vineyards in Washington State. Additionally, we recorded the identity and phenology of Anagrus species and potential leafhopper hosts within grape, blackberry, and wild rose patches, as these plants might serve as important refuges for Anagrus parasitoids. We found that Anagrus erythroneurae, A. daanei, and A. tretiakovae parasitized Erythroneura elegantula eggs, and that the latter two species also parasitized E. ziczac eggs. We collected all three species, in addition to A. atomus, from traps associated with blackberry, grape, and wild rose plants, along with several potential leafhopper hosts. It appears that Anagrus daanei, A. erythroneurae, and A. tretiakovae are important biocontrol agents of Erythroneura leafhoppers this region, and it appears that E. elegantula may be better regulated by Anagrus species than E. ziczac. Furthermore, Anagrus wasps are associated with leafhoppers in blackberry and rose habitats, relationships that could potentially be exploited in pest leafhopper biocontrol.
Technical Abstract: In 2001 and 2002, we monitored densities of grape leafhopper (Erythroneura elegantula Osborn and E. ziczac Walsh) eggs from June through September in managed and non-managed vineyards in Washington State. Anagrus parasitoids (Hymenoptera: Mymaridae) were reared from sampled parasitized leafhopper eggs. Densities of non-parasitized and parasitized E. elegantula eggs, and non-parasitized E. ziczac eggs, were significantly higher in non-managed grapevines, although this pattern was not consistent for the latter two groups. Densities of parasitized E. ziczac eggs were consistently low across management regimes. Anagrus erythroneurae, A. daanei, and A. tretiakovae emerged from parasitized E. elegantula eggs, while the latter two mymarid species also parasitized E. ziczac eggs. Of these species, A. tretiakovae was the most common parasitoid of Erythroneura leafhopper eggs within sampled vineyards. From 2001-2003, we used yellow sticky traps to collect Anagrus wasps and potential leafhopper hosts from blackberry, grape, and wild rose sites, because these habitats might serve as refugia for the wasps. All three Anagrus species collected within vineyards and a fourth species, A. atomus, were found on traps in these plant habitats. Several leafhopper taxa that could serve as potential alternative hosts for Anagrus spp. were also collected. Our collection of A. daanei, A. tretiakovae, and A. atomus in Washington represent range extensions for these species, revealing several novel candidate species for conservation. Because we consistently found Anagrus species of agricultural importance within rose and blackberry patches, cultivation of these plants close to vineyards may enhance colonization by Anagrus and thus improve grape leafhopper biocontrol.