Investigation of pistachio beetle pests and their parasitoids in Tunisia based on molecular identification, with two new records for Tunisian entomofauna

Abstract

Pistachio cultivations are damaged by many pests such as beetles including several species that had a wide expansion due to climate change. We investigated the biodiversity of pistachio beetles and their parasitoids based on a barcoding approach. The trapping and rearing of insects present in pistachio branches showed the presence of seven species. These insects were identified using two molecular markers, the mitochondrial cytochrome oxidase I (COI) and the region (D2–D3) of the 28S gene of the nuclear ribosomal RNA operon. The obtained sequences allowed the identification of five species with an identity ≥ 97%. However, for the other two species, sequence identity did not exceed 93% and consequently their identification was limited to the genus level. Our results showed that pistachio trees are attacked by four species of beetles, namely Chaetoptelius vestitus (Mulsant & Rey, 1861) (Coleoptera, Curculionidae), Carphoborus perrisi (Chapuis, 1869) (Coleoptera, Curculionidae), Phoracantha semipunctata (Fabricius, 1775) (Coleoptera, Cerambycidae) and Sinoxylon sp. (Coleoptera, Bostrichidae). These beetles are parasitized by three identified species: Doryctes leucogaster (Nees, 1834) (Hymenoptera, Braconidae), Cheiropachus quadrum (Fabricius, 1787) (Hymenoptera, Pteromalidae) and Ecphylus sp. (Hymenoptera, Braconidae). This study is the first to record the species C. perrisi and D. leucogaster in Tunisia.