Footprints and ootheca of Lycorma delicatula influence host-searching and -acceptance of the egg-parasitoid Anastatus orientalis

Authors: MALEK, ROBERT - University Of Trento, Italy; Kaser, Joseph; BROADLEY, HANNAH - University Of Massachusetts; GOULD, JULI - Animal And Plant Health Inspection Service (APHIS); CIOLLI, MARCO - University Of Trento, Italy; ANFORA, GIANFRANCO - University Of Trento, Italy; Hoelmer, Kim

Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/20/2019
Publication Date: 10/11/2019
Citation: Malek, R.N., Kaser, J.M., Broadley, H.J., Gould, J., Ciolli, M., Anfora, G., Hoelmer, K.A. 2019. Footprints and ootheca of Lycorma delicatula influence host-searching and -acceptance of the egg-parasitoid Anastatus orientalis. Environmental Entomology. 48(6): 1270-1276. https://doi.org/10.1093/ee/nvz110.
DOI: https://doi.org/10.1093/ee/nvz110

Interpretive Summary: The spotted lanternfly is an invasive agricultural pest first reported in North America in Pennsylvania in 2014. It attacks over 70 plant species, including many important crop, lumber, and ornamental plants. Large numbers of the pest have been reported in several U.S. counties, and a lack of native predators and parasites are allowing the pest population to grow unregulated. Long-term sustainable management at the landscape level will likely involve Asian predators and parasites to suppress the pest. A parasitic wasp that attacks and kills spotted lanternfly eggs at high rates in its native range in China appears to play a key role in reducing its population there. Our laboratory studies of the foraging behavior of this beneficial wasp showed that the wasp can detect the chemical footprints of spotted lanternfly adults, causing it to change it searching behavior in ways that increase the likelihood of finding lanternfly eggs to attack.

Technical Abstract: The spotted lanternfly Lycorma delicatula White (1845) (Hemiptera: Fulgoridae) is an invasive insect that was first reported in North America in Berks county Pennsylvania, USA in 2014. It is a polyphagous phloem feeder that attacks over 70 plant species, threatening the agricultural, lumber and ornamental industries of North America. Large densities of the pest have been reported in several U.S. counties, and a lack of endemic predators and parasitoids feeding on L. delicatula suggests a release from natural enemies in the invaded range. Long-term sustainable management at the landscape level would likely have to involve biological control agents to suppress the pest in its early stages. An egg-parasitoid Anastatus orientalis (Hymenoptera: Eupelmidae) was reported attacking L. delicatula at high rates in its native range and may play a key role in reducing its population. To better understand the foraging behavior of A. orientalis, a series of bioassays were conducted using the motion tracking software EthoVision. Furthermore, the effect of the oothecal structure on A. orientalis foraging females was evaluated through visual observations. Our results suggest that the wasp detects chemical trails of L. delicatula and exhibits an intense arrestment response. Moreover, a significant ovipositional preference to egg masses in ootheca was observed. The implications of these finding are herein discussed with regard to the exploitation of host kairomones by the foraging wasp, as well as to its ability to overcome host structural defenses.