Department of Agricultural Entomology, Uttar Banga Krishi Vishwilvidyalaya, Pundibari, Coochbehar - 736165, India.
Distribution pattern of citrus blackfly (Aleurocanthus woglumi Ashby) was studied on mandarin orange (Citrus reticulala Blanco) at Darjeeling district of West Bengal during 1997–1998. Different indices of dispersion i.e variance mean ratio, dispersion Parameter ‘K’, David and Moore's index, Charlier coefficient and Lioyd patchiness index showed aggregative, clumped and contagious nature of distribution of citrus blackfly adult in all the successive flushes viz., Ambia (spring) Mrig(summer) and Hasta (autumn) flushes during a year. However, calculated ‘K’ values of most of the standard weeks observed to be slightly deviated from the negative binomial aggregative type of distribution.
