Exploring the diversity of leafrollers (Lepidoptera: Tortricidae) associated with eucalypts in South African forestry nurseries and plantations, with a new report of Strepsicrates sp.

Abstract

A number of insect pests cause damage to eucalypts in South Africa. Their accurate identification is a key part of managing and controlling these pests. The aims of this study were to identify leafroller insect species in South African eucalypt nurseries and plantations, and to determine whether the species were native insects that had developed new host associations with eucalypts or introduced non-native species. A section of the mitochondrial cytochrome c oxidase subunit 1 (CO1) gene of multiple specimens from nurseries and plantations was sequenced. The sequence data were compared and validated using sequences available in BOLD systems and GenBank databases. Results revealed the presence of an introduced non-native Strepsicrates sp. in both nurseries and plantations. In addition, the native species Choristoneura occidentalis and Eccopsis incultana were confirmed as present in plantations only and the native species Lozotaenia capensana was confirmed as present in one of the nurseries. Eucalypts are reported as host plants of C. occidentalis, E. incultana and Lozotaenia capensana for the first time. The findings contribute valuable insights into the identification and diversity of leaf rollers in eucalypt plantations in South Africa, with potential implications for pest management.