Acalolepta vastator (Newman) (Coleoptera: Cerambycidae) Infesting Grapevines in the Hunter Valley, New South Wales 2. Biology and Ecology

Abstract

ABSTRACTResearch into seasonal development of fig longicorn, Acalolepta vastator, demonstrated an annual life cycle with adults emerging between October and March, with a 12–21 d pre‐ovipositional period and longevity up to 6 months. Peak adult emergence occurred in January and February and male: female sex ratio varied between 1:1 and 1:2. Males outnumbered females in the early emergence period, whilst females were more numerous between January and March. Peak oviposition also occurred between January and March, with the base of young vine canes on main or secondary arms less preferred as an oviposition site (49%) than the trunk (51%). Data indicated that while, on average, 2.25 eggs were laid per female and up to six new egg laying sites may be selected per vine, only 0.8 mature larvae per vine survived. Egg hatch with a 60% success rate took 2–4 d and early larval development occurred on and just under the surface of the bark during the first four instars. Nine larval instars were identified with a mean total larval period of 38 weeks. Pupae were recorded from August and had a developmental period of around 20 d. No parasites or predators were recorded, but Beauvaria bassiana did infect a small number of larvae during wet conditions in the field. Data show that 75% of mature larvae occur in the trunk, with over 60% of all larvae completing their development in the area proximal to the fork in the grapevine.