Population of the fruit borer were survey in both longan and litchi orchards in Lamphun , Chiang Mai and Chiang Rai provinces in 1991 and 1992. Insect net and light trap were used to collect, only 2 moths were found. Eggs were found on fallen fruits of both species 2.35 and 12.00 percent and the percentage of pupae were 97.62 and 88.00 respectively.

The fruit borer moths laid eggs on the fruits. The average egg stage lasted 3.00 ± 0.05 days. The emerged larvae would eat the tissue called funiculus within the fruit. Three larval instars occurred after 4.30 ± 0.45, 5.75 ± 0.43 and 5.30 ± 0.46 days. The final instar came out of the fruit and spun fibers to make cocoon. The average prepupal stage was 1.04 ± 0.20 days and pupal stage was 6.08 ± 0.48 days. The moths then came out of the pupae with an average age of 4.80 ± 0.83 days.

Fruit borer moths were small with the average width and length size of 1.90 ± 0.20 mm. and 5.5 ± 0.5 mm. respectively. Coloration of the scales was a mixture of black, white and brown. The antenna were longer than abdomen. The male had 1 frenulum and very clear genitalia, while the female had 2 frenula and a small tube at abdominal terminal. Male reproductive system was not found due to small size, but 4 ovarioles were found for each ovary in the female. Moth’ s eggs were oval shape with an average size of 0.71 ± 0.06 and 0.87 ± 0.09 mm. The larval bored to eat the tissue called funiculus. Three stages of larvae were measured. The average head width were 0.11 ± 0.01, 0.41 ± 0.01 and 0.62 ± 0.02 mm. Obtect pupa was in a transparent adhered oval cocoon, with average width and length of 1.00±0 mm. and 7.10 ± 0.94 mm.

Two species of fruit borer’s parasitoids were in the Family Braconidae, Order Hymenoptera. The larvae-pupae stages of fruit borer were parasitised with the ratio 1:1 and 7 parasitised pupae were recorded.