A NEWLY EMERGING INSECT PEST DAMAGING Cinnamomum cassia PLANTATIONS IN YEN BAI PROVINCE

Abstract

Plantations of Cinnamomum cassia are important contributors to the livelihoods of communities living in the mountainous areas of northwest Vietnam. Recently, a Cricula species (Lepidoptera: Saturniidae) has emerged as a major threat to these plantations. Morphologically the species is similar to Cricula variabilis Naumann & Loffler in China, but preliminary analysis of the mitochondrial cytochrome oxidase 1 gene region indicates the need for detailed phylogenetic analysis to confirm the taxon in Vietnam. In a laboratory study (30±2^oC, 85±5% RH and 12 h light: 12 h dark photoperiod), the life cycle took 69.6±5.2 days, females laid 200 to 310 eggs, eggs hatched after 8 to11 days, the larval period was 38 to 48 days, the pupal period was 9 to 15 days, and adults survived 4 to 8 days. There are four generations per year in the field. In ten plantations in Yen Bai province assessed in 2019, the damage incidence ranged from 47.2 to 71.5% and the damage index from 1.03 to 2.14. Cinnamon growers are concerned that the severity of defoliation will lead to a loss in bark yield and reduced income. Field studies are underway to develop an integrated pest management plan for this pest.