Status of forest trees infested with Endoclita sinensis (Lepidoptera: Hepialidae).

Abstract

A field study on the status of forest trees infested with Endoclita sinensis (Lepidoptera: Hepialidae) was conducted in a natural forest around Renyi Lake in Chiayi County, southwestern Taiwan. Host plants of E. sinensis included Macaranga tanarius and Mallotus paniculatus in the family Euphorbiaceae, as these plants showed the highest infestation rates. Endoclita sinensis larvae bored into the trunks of 6~24 cm diameter and 10~200cm high and fed on callus tissue around the hole, which was covered with silk, debris, and feces. Normally, only 1 larva was found per tree; however, when the trunk diameter was larger than 10cm, more than 2 well-separated larvae could be found. In the forest, larvae dispersed in a cluster or in a clumped pattern. Female larvae were significantly larger than male larvae in body length and weight, head capsule width, and pupal length and weight. Field-collected E. sinensis larvae exhibited a male to female ratio of 1: 1.2 after being fed an artificial diet.