Biology of citrus mealybug, Planococcus citri Risso (Hem., Coccidae) under laboratory conditions and its seasonal fluctuations in citrus orchards in Mazandaran province
Subject Areas : entomology and othea arthropods
1 - Agricultural and Natural Resources Research Centre of Mazandaran, Sari, Iran
Keywords:
Abstract :
Biology of citrus mealybug, Planococcus citri Risso (Hem., Coccidae) and its seasonal fluctuations were studied in citrus orchards in Mazandaran province, Iran, during 1996-1997. The pest has 3-4 generations and over-winters as eggs, 2nd and 3rd stages and adults on different citrus varieties and ornamental plants in the region of study. The shortest and longest developmental periods of one generation were 38 and 50 days, respectively. The mean numbers of eggs per female were 159, 229 and 171 in spring, summer and autumn, respectively. The mean life-span of males was 41.1 and 65.8 and for females were 52.4 and 84.3 days at 20 and 25℃, respectively. The activity of over-wintering individual began at the end of April in both sprayed and unsprayed orchards. However, the peak of the mealybug population occurred in August and September in unsprayed orchards and in September and October in sprayed ones. The peak of population of natural enemies synchronized with the peak of the pest in unsprayed orchards. This synchronization might be a reason for reduction of the pest damage to fruit by 30%-40% in unsprayed orchards.
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