Bionomics of the melon worm Palpita (Diaphania) indica (Saund) (Pyralidae: Lepidoptera) in PDR of Yemen

Abstract

Field and laboratory studies have been carried out on the biology and food preference of Diaphania indica Saund. in PDR of Yemen. The effect of different constant temperatures on the development of the insect has shown that as the temperature increases, egg incubation period, larval and pupal periods decreases considerably. At fluctuating temperatures of 25–35.9 °C, the egg, larval and pupal periods were 3.5, 11.5 and 6.2 d, respectively. Field and laboratory studies have shown that the insect prefers Cucumis melo (sweet melon) than Citrulus vulgaris (water melon) and Cucumis sativa (cucumber). Although the larvae consume more food of C. vulgaris (121.7 mg) than of C. melo (101.6 mg), they produce more faeces when fed on the former. The average larval weight (65.3 mg) of caterpillars fed on C. melo is more than those fed on C. vulgaris (54.3 mg). This shows more assimilation of food from C. melo when compared to C. vulgaris. Zusammenfassung Über die Bionomie des Melonenzünslers Palpita (Diaphania) indica (Saund) (Pyralidae: Lepid.) in der Volksrepublik Yemen Zur Bionomie und Nahrungswahl von Diaphania indica wurden im Yemen Freiland‐ und Laboruntersuchungen durchgeführt. Bei wachsenden Temperaturen zwischen 25 und 36 °C betrugen die Ei‐, Larven‐ und Puppen‐Perioden 3.5, 11.5 und 6.2 d. Als Nahrungspflanze wurde die Süßmelone (Cucumis melo) der Wassermelone (Citrulus vulgaris) und der Gurke (Cucumis sativa) vorgezogen. Obgleich die Raupen mehr C. vulgaris (121.7 mg) als C. melo (101.6 mg) frassen, produzierten sie mehr Kot bei letzterer Nahrung. Das mittlere Gewicht der Raupen nach Fraß an C. melo war mit 65.3 mg höher als nach Fraß an C. vulgaris (54.3 mg). Dies zeigt, daß C. melo in größerem Umfang als C. vulgaris assimiliert wurde.

Pest categorisation of Diaphania indica

“…The average pupal period in Yemen (lab experiment) was found to be about 10, 7, 5 and 6 days at 20°C, 25°C, 30°C and 35°C, respectively (Ba-Angood, 1979). In South Korea, larvae were found to descend from hosts and enter the soil during October and burrow to between 5 and 10 cm below the soil surface where they form pupae and overwinter (Choi et al, 2003;MacLeod, 2005) Kinjo and Arakaki (2002) found the developmental threshold temperature for pupa at 14.90°C, whereas Peter and David (1992) At 25°C, the mean adult longevity of males (21.6 days) on cucumber (Cucumis sativus) was significantly longer than that of females (16.7 days) (Kinjo & Arakaki, 2002).…”

“…In a field study, Ba-Angood (1979) found that among three cucurbit crops, D. indica preferred to lay eggs on melon (C. melo) over watermelon (C. lanatus) and cucumber (C. sativus). In field host preference experiments in Bangladesh, T A B L E 2 Important features of the life history strategy of Diaphania indica.…”

Seasonal dynamics of Diaphania indica (Saunders) (Lepidoptera: Crambidae) on ridge gourd

“…The change in the population of this pest was studied in India on pumpkin, Coccinia grandis L. (Peter and David 1992) [15] . The field biology of this pest was studied in South Korea (Choi et al 2003), Yemen (Angood and Angood 1979) [1] , and China (Ke et al, 1988) [11] . Various aspects of the biology and natural enemies of this pest were studied by Ganehiarachchi (1997) [7] [8,4,9,2,5,12] .…”

Oviposition preference and olfactory response of Diaphania indica (Lepidoptera: Pyralidae) to volatiles of uninfested and infested cucurbitaceous host plants

“…A previous fi eld study shows that D. indica prefers to lay eggs on sweet melon (Cucumis melo cv Hales Best Jumbo) than on watermelon (Citrullus vulgaris cv Charleston Gray) and cucumber (Cu. sativus cv Alpha Beta) (Ba- Angood, 1979). Currently control programmes largely rely on the application of chemical insecticides.…”