Spillover of tent caterpillar (Malacosoma americanum) herbivory onto willow bioenergy crops in an agricultural landscape

Abstract

The circumstances and potential for insects to damage perennial bioenergy crops is not well understood in the United States. In this study, we evaluated the spillover and herbivory of eastern tent caterpillars (Malacosoma americanum) from host trees onto short rotation coppice (SRC) willow bioenergy crops (Salix sp.). Host trees were all in the Rosaceae family and included Prunus americana, Prunus virginiana and Malus sp. Willow showed greater leaf herbivory with increasing proximity to a defoliated host tree, suggesting that tent caterpillars spilled-over to willow after denuding their host. More tent caterpillar herbivory was associated with greater mortality of willow. This study suggests that landscape context and spatial position of host trees is important to the early establishment of a willow bioenergy crop.

Contrasting late season pest insect abundance in non‐crop vegetation areas and nearby canola fields in the Canadian Prairies

“…For example, previous studies did find a spillover effect for two canola pest species in these taxonomic groups. In these studies, tent caterpillars ( Malacosoma americanum Fabricius) and L. lineolaris nymphs tended to aggregate closer to non‐crop areas in fields (D'Ambrosio et al, 2019; Eckberg et al, 2015). These previous studies occurred in agroecosystems that were geographically remote from the Canadian Prairies or looked at large global trends (Karp et al, 2018; Severtson et al, 2015; Tonina et al, 2018).…”

“…Spillover effects have been demonstrated in both beneficial and pest species, by measuring changes in abundance at different distances from non‐crop areas (Tscharntke, Rand, & Bianchi, 2005; Vickruck et al, 2019). Many of these studies have been conducted in Europe or the United States (Eckberg et al, 2015; Goethe et al, 2021; Shapira et al, 2018; Tonina et al, 2018); however, pest spatial distribution with respect to non‐crop vegetation has seldom been studied elsewhere. Changes in herbivore distribution at different distances from non‐crop vegetation areas can be used to determine if spillover is occurring, and if herbivores rely on these non‐crop vegetation areas at the time of collection.…”