نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
The American white webworm, Hyphantria cunea Drury, was reported from the Guilan province in 2002. Due to its economic importance in the north of Iran, its biology, population fluctuation, host plants and other life characteristics were studied in Rezvanshahr (Guilan) in 2003 and 2004. The larvae feed on a wide range of forest trees, orchards, crops and weeds. The pest had two generations per year and overwintered as pupae in cocoons mostly under tree barks, fences and a few in the soil. The adults were appeared in mid spring and mated 2-3 days after emergence. Females laid their eggs in a cluster underside of host leaves. The maximum number of eggs laid in laboratory and field conditions was 1053 (490.4 ± 86.47) and 1500 (758.85 ± 79.10) per cluster respectively. In optimum conditions (23 ± 1°C and 60-70 % RH and 16L: 8D), the eggs hatched within 7-9 days (7.29 ± 0.22). The first and second larval instars fed gregariously in their nested webs on the leaves where the eggs were deposited. The pest had five larval instars and each larval instar lasted 4-6 days (4.26 ± 0.31). The third and fourth instars left their nests and made webs on other leaves. The pupal stage lasted 10 days in first generation and 9 months in second generation as overwintering pupae.
کلیدواژهها [English]
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