New pest record of emerald stem borer, Agrilus sp. (Coleoptera: Buprestidae) on clove in South Bolaang Mongondow district, North Sulawesi, Indonesia

Abstract

The attack of emerald stem borer, Agrilus sp. on clove plant was first detected in 2007 by plant census officers at the plantation of P.T. Kawanua Kahuripan Pantera (KKP) in Bolaang Mongondow Selatan District. The surveys of clove pests at the end of 2016 to early 2017 in several clove plantations in South Bolaang Mongondow District, clove trees were found to have died from the attacks of the emerald stem borer. The attack occurred on the young clove tree about 5 to 20-yr-old plant, at a location with a height elevation of about 400 m above sea level (asl) on Lungkap village plantation up to 900 m asl on Tonsili plantation. As a result, the attack can cause the death of clove trees because the larvae bore around the tissue under the bark (cambium, xylem and phloem) so that it interferes with nutrient transport. In clove tree can be found in 1 to 4 larvae. Attack symptoms is in the form of zig-zag grooves. The average attack rate ranged from 17%, 26%, and 25% in each of the plantation resorts observed, namely: Lombuguwon resort, Tapamayondi and Tamonok. Distribution pattern in type fields are clustered with range I values (index of relationship variance and mean) greater than 1 (2,68, 3,03, 2,71); Iδ (Morisita index) greater than 1 (5,88, 3,99, 3,92); and k (negative binomial distribution index) smaller 2 (0,60, 0,49, 0,59). Agrilus sp. is categorized as a new pest in clove plant in Indonesia because it has never been reported before.