The olive fly, Bactrocera oleae (Rossi) (Diptera: Tephritidae), is a key-pest in the main olives producing areas worldwide, and displays distinct preference to different olive cultivars. The present work intended to study oviposition preference towards three Portuguese cultivars (Cobrançosa, Madural, and Verdeal Transmontana) at different maturation indexes. Multiple oviposition bioassays (multiple-choice and no-choice) were conducted to assess cultivar preference. No-choice bioassays were conducted to assess the influence of different maturation indexes (MI 2; MI 3, and MI 4) in single cultivars. The longevity of olive fly adults according to the cultivar in which its larvae developed was also evaluated through survival assays.

Cultivar and maturation are crucial aspects in olive fly preference. Field and laboratory assays revealed a preference towards cv. Verdeal Transmontana olives and a lower susceptibility to cv. Cobrançosa olives. A higher preference was observed for olives at MI 2 and MI 3. The slower maturation process in cv. Verdeal Transmontana (still green while the other cultivars are reddish or at black stage) seems to have an attractive effect on olive fly females, thus increasing its infestation levels. Olive fly adults from both sexes live longer if emerged from pupae developed from cv. Verdeal Transmontana fruits and live less if emerged from cv. Cobrançosa. Therefore, olive cultivar and maturation process are crucial aspects in olive fly preference, also influencing the longevity of adults.

The effects of six constant temperatures ranging from 15 to 40°C on the rate of development, progeny production, sex ratio and adult longevity of the grape mealybug parasitoid, Anagyrus dactylopii (How.) were determined. It was found to complete the development in the temperature regimes of20–35°C but neither sex emerged as adults at 15 and 40°C. Developmental time of male and female decreased from 32.75 to 10 days, and from 34.50 to 11.75 days respectively, as the temperature increased from 20–35°C. Progeny production increased with the rise in temperature up to 30°C, and a maximum of 182 offspring emerged at 30°C. Sex ratio was altered considerably by different temperatures. Maximum female progeny was also obtained at 30°. Adult longevity of both sexes declined with increasing temperature. Mean longevity of male reduced from 2730 days at 15°C to 2.75 days at 40°C. The findings on the effects of temperature in relation to the rearing in the laboratory and the activity of Anagyrus dactylopii in the field are also discussed.