Foraging behaviors by the nymphal parasitoid Dryinus sinicus (Hymenoptera: Dryinidae), a promising biological control agent for spotted lanternfly

Authors: Schramm, Spiro; Kaser, Joseph; BROADLEY, HANNAH - Animal And Plant Health Inspection Service (APHIS); SIPOLSKI, STEVEN - Animal And Plant Health Inspection Service (APHIS); Wang, Xingeng

Submitted to: Journal of Insect Behavior
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/20/2026
Publication Date: 4/29/2026
Citation: Schramm, S., Kaser, J.M., Broadley, H.J., Sipolski, S., Wang, X. 2026. Foraging behaviors by the nymphal parasitoid Dryinus sinicus (Hymenoptera: Dryinidae), a promising biological control agent for spotted lanternfly. Journal of Insect Behavior. https://doi.org/10.1007/s10905-026-09906-4.
DOI: https://doi.org/10.1007/s10905-026-09906-4

Interpretive Summary: The spotted lanternfly (SLF) is a serious invasive agricultural pest that attacks grapes and other U.S. crops. We imported a key native natural enemy of this pest, a parasitic wasp that attacks SLF nymphs, for evaluating its suitability and potential for biological control of this emerging invasive pest in the US. As part of the systemic evaluations, this study for the first time describes and quantifies the parasitic wasp’s foraging behavior towards different host developmental stages. Our particular interest is to examine how the host-searching/predation behaviors are integrated and expressed by this wasp and analyze the temporal patterns of behavioral pathways leading to successful attacks on different stages of SLF nymphs. Our results showed that this wasp could attack all three instars of SLF nymphs; attacking the 1st instar was more likely to lead to host feeding, attacking the 2nd instar was more likely to lead to a successful oviposition, while attacking the 3rd instars resulted in a lower successful rate of oviposition or feeding. The information gained through this study has important implications for developing efficient protocols for the rearing, study, or field release of this agent against SLF.

Technical Abstract: Insect parasitism is the result of a sequence of directed searching behaviors at progressively finer environmental levels, from host detection and host location to host acceptance and host suitability. A knowledge of parasitoid foraging behavior may help define the effective attributes used by parasitoids to exploit host resources efficiently and thus evaluate the desirability of the parasitoids for biological control of insect pests. Dryinus sinicus (Hymenoptera: Dryinidae) is a key parasitoid attacking the nymphal stages of spotted lanternfly, Lycorma delicatula (Hemiptera: Fulgoridae), in its native range. As part of the evaluation of this parasitoid for biological control introduction against the invasive L. delicatula in the USA, we here quantified the foraging behaviors by D. sinicus towards different instars (1st, 2nd, and 3rd instars) of L. delicatula nymphs. A behavioral catalogue was developed, and various behavioral events were continually recorded with BORIS software. The temporal patterns of behaviors were analyzed and examined by constructing behavioral flow diagrams. The results showed that D. sinicus could attack all three instars of L. delicatula nymphs; attacking the 1st instar was more likely to lead to host feeding, attacking the 2nd instar was more likely to lead to to successful oviposition, while attacking the 3rd instars resulted in a lower successful rate of oviposition or feeding. The information gained through this study not only provides insights into the adaptive host stage selection behaviors by this parasitoid but also has important implications for developing efficient protocols for the rearing, study, and field release of this parasitoid against L. delicatula.