Abstract
Quadrastichus mendeli Kim & La Salle, a parasitoid of Leptocybe invasa Fisher & La Salle, is a uniparental species. This study assessed the biological traits of Q. mendeli in the laboratory at a temperature of 27 ± 1 °C. Diets had a highly significant effect on the mean longevity of female Q. mendeli. Feeding honey solution prolonged the mean longevity of the parasitoid to 4.80 days. The estimated 50% survival period was 3 days. The mean potential fecundity in all ages was 8.85 eggs per female. Age had a highly significant effect on the mean egg load. There was a positive relationship between egg load and female size. The mean of realized fecundity throughout the life span was 2.47 progenies per female. The mean developmental time of Q. mendeli from the egg to adult stage was 27.06 days. The shorter developmental time of Q. mendeli in comparison to its host can be considered a reason for the successful control of L. invasa in Thailand.