(1st Place) Multiplex PCR primers reveal the biodiversity and phenology of roseau cane scale (Nipponaclerda biwakoensis) parasitoids in Louisiana

Roseau cane scale, Nipponaclerda biwakoensis, (RCS) is a scale insect from east Asia that feeds on roseau cane (Phragmites australis). The scale is considered invasive in Louisiana, Texas and Mississippi; and its distribution continues to expand. Feeding by this scale has been associated with the die-back of Phragmites within the Mississippi River Delta. Four species of endoparasitoid wasps, Astymachus lasallei, Neastymachus japonicus, Boucekiella depressa, and Aprostocetus sp., can be found attacking the scale in Louisiana. These wasps are gregarious, with multiple larvae developing inside the host at once, and successful multiparasitism is frequent between all species. The objective of this study was to understand the life history of these parasitoids inside the scale using multiplex PCR primers. Whole-body DNA was extracted from scales at varying life stages and multiplex PCR performed. 28S rRNA primers developed for each parasitoid species allowed for simultaneous identification of larvae present within without the need for rearing wasps to adulthood. Species identification with this method allows us to monitor parasitoid diversity in the field and gives insight on the biology of these wasps by determining the life stage at which each parasitoid species oviposits within its host. Information collected from this study will be used to inform future biocontrol decisions for roseau cane scale in the United States.