Twig traps: a sustainable and eco-friendly management option for pistachio bark beetle [Hylesinus (= Chaetoptelius) vestitus (Mulsant & Rey, 1860) (Coleoptera: Scolytidae)]

Turkey is among the three largest pistachio ( Pistacia vera L.) producers in the world. Several harmful organisms adversely affect pistachio production. Pistachio bark beetle (PBB) [ Hylesinus ( = Chaetoptelius) vestitus (Mulsant & Rey, 1860) (Coleoptera: Scolytidae)] is an important pistachio pest in several parts of the world, including Turkey. Dry twig traps could be used to attract the pest for breeding and then destroying these traps could serve as a sustainable management approach against the pest. Therefore, this 3-year (2019–2021) study assessed the efficacy of twig traps in suppressing PBB infestation. The traps were prepared from waste, dry twigs obtained after pruning. Each trap contained 10 twigs tied together and hanged on the trees. Three different trap densities [67 (high), 40 (medium), and 20 (low) traps per hectare] along with a control (no trap) were used in the study. Furthermore, optimum number of twigs per trap was determined. The traps were prepared with 5, 10, and 15 twigs and hanged after each 5th tree (40 traps per hectare). The traps were hanged during the first week of February and collected during first week of April upon emergence of new generation adult. The pest infestation was recorded in pistachio shoots and buds once the tree shed the leaves. Ten trees were randomly selected and 10 last-year shoots with fruit buds were collected from the four sides of each to determine the pest infestation. A total 100 shoots were observed from each treatment in each replication. The pest infestation significantly differed among trap densities. The traps lowered pest population by 95–98% during 2nd year of the study. Data relating to number of twigs per trap indicated non-significant differences in infestation rate; therefore, 10 twigs per trap are recommended. Although high trap density trapped higher number of insects, non-significant difference between high and medium density warrant that 40 traps per hectare would effectively suppress PBB infestation. Therefore, hanging 40 traps per hectare and destroying them through burning could give complete control over the pest in few years.