 BackResearch Article ScienceAsia 20 (1994): 101-114 |doi: 10.2306/scienceasia1513-1874.1994.20.101
DEVELOPMENT AND LIFE TABLE OF GONIOZUS THAILANDENSIS GORDH & WITETHOM (HYMENOPTERA: BETHYLIDAE), A GREGARIOUS ECTOPARASITOID OF A PHYCITINE FRUIT BORER (LEPIDOPTERA: PYRALIDAE)
BOONGEUA WITETHOM1 AND GORDON GORDH2ABSTRACT: The development of the recently described Goniozus thailandensis Gordh & Witethom (Hymenoptera: Bethylidae), a gregarious ectoparasitoid of phycitine sapodilla fruit borers, was studied at 26 1 Department of Biology, Faculty of Science, Prince of Songkla University, Hat Yai, Songkhla 60112, Thailand.
Received June 10, 1994
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1oC 70-80 % RH and under a 12:12 (L:D) photocycle. Females temporarily paralyzed the host before oviposition. Eggs were laid along the intersegmental folds of the host's
cuticle, usually on the middle segment and the dorsal aspect of the host's body. The percentage of
eggs hatching was 96.1%. On average, 78.3% of eggs developed to adults. The egg incubation period, the larval and pupal stages took 3.1, 4.1, and 13.5 days, respectively. Development time from egg to adult emergence did not differ between sexes requiring a mean of 20. 7 days. Mated host-provided females lived (7.2 days) as long as mated host-deprived females (7.7 days). Mated host-provided females (7.7 days) lived significantly longer than mated males (5.7 days). The survivorship curve resembled most a type I hypothetical survivorship curve. G. thailandensis was arrhenotokous.
The preoviposition period was 4.4 days. On average, each female parasitized 1.6 hosts and produced 7.6 females throtlghout her lifetime. The sex ratio of G. thailandensis was female biased and it was randomly determined. Female progeny production curve was bimodal. The generation time (Tc) and cohort generation time (T,) were 25.5 and 25.7 days, respectively. The net reproductive rate (R0) was 59.1 females per female per lifetime. The intrinsic rate of increase(rm), the capacity for increase (rc) and the finite rate of increase (
) were 0.160, 0.159 and 1.174 females per female per day, respectively.
An increasing population was predicted.
