Host plant range of Aproceros leucopoda is limited within Ulmaceae

Abstract

Although much research has been carried out to develop taxa resistant to Dutch elm disease (DED), newly occurring pests represent a new challenge for the protection of elms (Ulmacae). The invasive zigzag elm sawfly (Aproceros leucopoda) is a recent invader of Asian origin in Europe defoliating elm trees that are otherwise often characterized with major resistance to DED. The range expansion of this pest poses a major threat to elms. The aim of this study was to identify the susceptibility of Ulmus crassifolia, Hemiptelea davidii and Zelkova serrata to this pest by using three different methods (oviposition trials with cut shoots and with plants in pots, and larval feeding trials with plants in pots) to define the performance of A. leucopoda on potential hosts. The fact is that A. leucopoda was unable to complete its development on either of these three taxa of Ulmaceae, whereas Ulmus pumila (the reference during the trials) was again confirmed as a true host of the pest clearly indicating that the host plant range of A. leucopoda is probably limited not only to Ulmus but also within this genus. Our results may be considered in future resistance breeding programmes, pest risk assessments, and for the selection of Ulmaceae species.