HAWAIIAN TEPHRITID FRUIT-FLIES (DIPTERA) - INTEGRITY OF THE INFESTATION-FREE QUARANTINE PROCEDURE FOR SHARWIL AVOCADO

In 1900, the infestation-free quarantine procedure for 'Sharwil' avoca dos grown tephritid fruit flies. In February 1992, the infestation-fre e quarantine procedure was suspended because of discovery of oriental fruit fly, Bactrocera dorsalis (Hendel), larval infestation in fruits on trees in certified orchards. Subsequently, an intensive field study was conducted to determine the lever of tephritid fruit fly infestati ons in 'Sharwil' fruits. Results gathered negated two assumptions of t he infestation-free quarantine procedure. First, the procedure assumed that only immature and mature green fruits are attached on trees; our data showed that, although most fruits on trees were either immature or mature green, a few ripe fruits occurred during the fruiting season . Second, the procedure assumed that mature green fruits have absolute resistance to tephritid fruit flies occurring in Hawaii; our field da ta showed that mature green 'Sharwil' avocados are suitable hosts of o riental fruit By albeit poor hosts. We present several hypotheses that may explain the failure of the infestation-free quarantine procedure for 'Sharwil' avocados. Morphological, physical, and chemical attribut es of maturing 'Sharwil' fruits that may be useful in developing indic es of fruit maturity and quality are also presented.