Developing biological control methods for spotted lanternfly (Lycorma delicatula): an investigation into non-targets and potential control agents
Date
2024
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
University of Delaware
Abstract
This project encompassed three separate objectives. First, to rear potential non-target insect species for host specificity testing of Lycorma delicatula (Spotted lanternfly, SLF) parasitoids that are being considered as biological control agents and create “care sheets'' for each non-target species to fully describe the developed rearing methods. “Care sheets'' were developed for the species Poblicia fuliginosa, Rhynchomitra microrhina, Scolops sulcipes, Thelia bimaculata, Acanalonia conica, A. bivittata, Metcalfa pruinosa, and Flatormenis proxima. More detailed life history information was documented for Poblicia fuliginosa, Rhynchomitra microrhina, and Scolops sulcipes. These “care sheets” include information on collection techniques, rearing, eggs, nymphs and adults for each species, and troubleshooting. Poblicia fuliginosa was confirmed to have five nymphal instars with time spent in each successfully recorded. Through this work novel findings were documented. Eggs of S. sulcipes were observed for the first time and described, and three nymphal instars were obtained. Eggs and three nymphal instars were obtained and described for R. microrhina. ☐ The second study objective was to collect target local parasitic microhymenopteran, seeking taxa potentially useful for SLF augmentative biological control (mainly Eupelmidae with a focus on the genus Anastatus and the family Dryinidae). A total of 5,533 microhymenopteran wasps were collected from 2021 to 2023 from Delaware. Eupelmidae was collected using several methods and a total of 166 specimens were obtained with 28 being Anastatus. Six dryinids were successfully reared to adulthood from parasitized hosts. From the 28 Anastatus specimens field collected, two Anastatus species (A. pearsalli, A. reduvii) were successfully identified. Through several field collection methods, passive collections such as malaise traps showed lower success rates in collecting Anastatus compared to field collecting other insect eggs. ☐ The third study objective was to investigate the foraging and prey searching behavior of two Anastatus species–A. orientalis and A. reduvii– in the presence of chemical and physical cues of host and non-target species. This was conducted by tracking their movements in arenas exposed to different cues. Anastatus orientalis tested on microscope slides with trace residues from adult insects showed a positive arrestment response to SLF footprints by adjusting their movement for host tracking. It did not respond similarly when exposed to Halyomorpha halys or Poblicia fuliginosa. Anastatus reduvii exposed to SLF footprints also showed a positive arrestment response. When using SLF and Poblicia fuliginosa egg mass dust, A. orientalis showed no arrestment response. ☐ Investigating the life histories of insect species such as Poblicia fuliginosa or species of Dictyopharid provides us with information on how our native insects behave and develop. This research coupled with the collecting of native parasitoid species better aids us in understanding the diversity of insects in our area. This is important both for understanding the insect fauna and how they interact with our environment and provides us with information to better protect them when controlling pest species. Spotted lanternfly is an invasive species that has the potential to cause significant crop damage in the United States, and biological control is one way we can manage their populations (explained more in Chapter 1). By investigating native insect species that could be harmed by such control (Chapter 2), collecting and learning what native control agents we might have (Chapter 3), and testing control agents’ ability to utilize other species as hosts (Chapter 4), the control of spotted lanternfly will be both more efficient and safer in the future.
Description
Keywords
Anastatus, Biological control, Poblicia fuliginosa, Spotted lanternfly, Insect species