Thermal death kinetics in eggs and larvae of Bactrocera latifrons (Diptera: Tephritidae) and comparative thermotolerance to three other tephritid fruit fly species in Hawaii

Eggs, 1st, and 3rd instars of Bactrocera latifrons (Hendel) were subjected to hot water immersion to determine its thermal death kinetics. All stages exhibited nonlogarithmic death (survivorship) curves that were characterize d by an initial lag in mortality followed by increasing death rates with ti me at a prescribed temperature. Increasing temperatures reduced the time ne cessary to kill 90 or 99% of the insects for a given developmental stage. A rrhenius plots of the death rate function (k) showed a reduced slope for 3r d instars compared with eggs or Ist instars. Based on calculation of estima ted lethality times needed for 90 or 99% mortality, eggs were more resistan t to heat than Ist instars at lower temperatures but were more susceptible at higher temperatures. Comparison of thermal death kinetics of B. latifron s with other tephritid fruit flies present in Hawaii revealed this species to be more resistant to heat than either Mediterranean fruit fly, C. capita ta, oriental fruit fly, B. dorsalis or melon ny, B, cucurbitae using our as say conditions. These results are discussed in relation to the use of he;lt treatments for disinfestation of tephritid fruit flies from agricultural c ommodities and the need for an international database to facilitate compari sons among these and other economically important tephritids, which could b ecome pests in areas where they do not currently exist.