Bactrocera tryoni

The Queensland fruit fly (Bactrocera tryoni) is a species of tephritid fruit fly native to Australia. Adult flies are about 5 to 8 mm in length in the adult stage. Their larvae hatch in various fruit species, causing significant damage to crops. The fly has been the subject of extensive control regimens, including a Fruit Fly Exclusion Zone, where taking fruit is illegal, and postharvest dipping of fruit in dimethoate and fenthion. As of October 2011, the use of these chemicals was under review by the Australian Pesticides and Veterinary Medicines Authority, with dimethoate suspended from use. In May 2012, January 2013, February 2015, and February 2019, the fly was found in Auckland, posing a risk to horticulture and leading to a quarantine (see Biosecurity in New Zealand). Unlike several of the other most important fruit fly pests, B. tryoni does not breed continuously, but passes the winter in the adult stage. The total lifecycle requires 2-3 weeks in summer and up to 2 months in autumn. Adult females live many months, and four or five overlapping generations may develop annually. Adult females, after passing through a 2-week preoviposition stage following emergence from the pupae, deposit eggs in groups, up to seven eggs per group, in fruit punctures. Females often oviposit in punctures made by other fruit flies, such as the Mediterranean fruit fly (Ceratitis capitata), with the result that many eggs often occur in a single cavity. As many as 40 larvae have been found in one peach, and as many as 67 adults have been reared from one apple. Eggs hatch in 2-3 days under favorable weather conditions. The ensuing larval development may be completed in as little as 5 days. Pupation normally occurs in the soil. Pupal development requires from a week in summer to a month or more in cooler weather. Adults may live a year or more. Adults feed primarily upon juices of host plants, nectar, and honeydew secreted by various kinds of insects. The genome of B. tryoni has been sequenced and published by a group at the University of New South Wales, Australia. While the coding regions are largely completely sequenced, about one-third of the genome appears to consist of highly repetitive sequences. A gene for white eye found in Drosophila is found to have homologs in this species, as well as numerous other Diptera.