Studies on the biology of Diadegma Eucerophaga Horstm (Hymenoptera: Ichneumonidae), a parasitoid of Plutella Xylostella Linn. (Lepidoptera: Yponeumotidae)

• Main Author: Domondon, Denisa L.
• Format: text
• Language: English
• Published: Animo Repository 1991
• Subjects: Parasitological research; Hymenoptera; Lepidoptera > Larvae; Moths > Cultures and culture media; Wasps; Insect rearing; Ecology and Evolutionary Biology
• Online Access: https://animorepository.dlsu.edu.ph/etd_masteral/1417
• Institution: De La Salle University

Studies on the duration of development, lifespan of male and female adults, morphological and behavioral characteristics, reproductive capacity, percent adult emergence, sex ratio of progenies, and percent parasitism of D. eucerophaga, a parasitoid imported from Taiwan were conducted under greenhouse condition at Benguet State University Experimental Area, La Trinidad, Benguet from November, 1989 - July, 1990 and October, 1990 - December, 1990. Developmental duration from egg to pupal stage of the parasitoids is shortened at higher temperature. Egg to pupal development is 23.6 +/- 3.39, 19.03 +/- 4.7 and 16.2 +/- 1.47 days at temperature readings of 18 +/- 6.9 degrees C, 19.5 +/- 6.2 degrees C and 21.29 +/- 5.8 degrees C, respectively. Male and female adult parasitoids survived for 17.07 and 17.51 days, respectively, when fed with 10 percent honey solution. The third filial generation of male parasitoids had a longer lifespan, 21.1 +/- 7.55 days while the first and second filial generation survived for 15.4 +/- 7.55 and 14.7 +/- 10.74 days, respectively. Likewise, F3 female parasitoids survived for 19.4 +/- 9.9 days while F1 and F2 survived for 13.4 +/- 8.66 days and 19.73 +/- 10.26 days, respectively. Morphologically, the females are longer than the male parasitoids due to the presence of ovipositors in females. The parasitoids could lay an average of 113 +/- 66 eggs in their lifetime and reproduction was continuous as long as the females were alive. Oviposition peaked from the fifth day to the tenth day post-emergence of female adults and gradually declined until the female died. A mean of 94 percent emergence of the parasitoid was noted. Mortality was 6 percent which apprarently was due to bacterial, fungal infection and or ant infestation of the cocoons. Sex ratio of the progenies showed more males than females. Two female samples produced 100 percent males, due to arrhenotokous parthenogenesis. Percent parasitism of D. Eucerophaga was 14.04 percent and 37.66 percent on the 1st and 3rd day, respectively, post-emergence of female adults. Parasitism peaked on the 5th day with 89.97 percent then declined to 17.9 percent on the 7th day.