Development of an Artificial Liquid Diet for Allelochemical Delivery in <i>Lycorma delicatula</i>

ABSTRACT Spotted lanternfly, Lycorma delicatula White (Hemiptera: Fulgoridae), is an invasive phloem‐feeding planthopper native to Asia, which poses a growing threat to US agriculture due to its broad host range and rapid spread since its 2014 detection. To better understand how L. delicatula responds to chemical compounds such as plant specialised metabolites or insecticides, the development of a standardised artificial diet is essential. Here, we tested L. delicatula responses to different nutritional and bioactive compounds. Third and fourth instar L. delicatula nymphs survived significantly longer on a mixed sugar‐based diet (up to 30 days) than a sucrose‐based diet supplemented with vitamins and amino acids. Supplementation of the diet with ailanthone, a natural defence compound of Ailanthus altissima (tree of heaven), which is a preferred host of L. delicatula , caused increased diet consumption by third instar nymphs but did not alter their survival. Ailanthone also increased diet consumption by fourth instar nymphs and adults. Our findings indicate that multiple sugars may be sufficient to sustain the metabolism of L. delicatula and its endosymbionts for a prolonged time and that ailanthone may serve as a feeding stimulant independent of host plant cues, yet without a concomitant survival benefit under these assay conditions. The artificial diet system presented here provides a valuable tool for investigating L. delicatula nutritional ecology and toxicological responses to a broad spectrum of allelochemicals under controlled conditions.