Vol. 8 No. 1
Biology of the parthenium infested mealybug [Ferrisia consobrina Willams and Watson] (Psudococcidae: Hemiptera)
Author(s): A. SENI AND A. K. SAHOO
Abstract: Studies wre conducted to determine the nymphal development of males amd females, pre-oviposition, oviposition period and fecundity of Ferrisia malvastra on sprouted potatoes under laboratory conditions. F. malvastra were collected on infested parthenium in the field and reared in the laboratory. Daily observations were made on the ecdysis of nymphs, sex ratio, pre-oviposition and oviposition periods, fecumiity and incubation period of ova. Morphological observations were also recorded. Results showed that The femae and male nymphs completed development in 12-9 (15.34±1.76) days and 14-21 (17.04±1.98) days,respectively, at 21-24°C and 71-99% RH. The ratio of male:female was 1:1.25. The duration of pre-oviposition and oviposition periods were 4-8 (5.7±0.60) days and 4-6 (4.6±0.80) days, respectively. The mode of reproduction was sexual and ovoviviparous. The pre-oviposition and oviposition periods were 4-8 (5.7±0.60) and 4-6 (4.6±0.80) days, respectively. Fecundity was 494 (467-507) nymphs per female. Adult female F. malvastra were oval bodied and yellowish in colour with waxy particles found on their bodies. The body was approximately 3.53 mm long and 2.39 mm wide. The dorsum had only one pair of cerarii on the prominent anal lobe. The anal lobe had 2 conical setae, 8-10 auxiliary setae and 30-34 trilocular disc pores. The numbers of auxiliary setae on the remaining body segments were 2. The dorsal surface had setae of various sizes, blunt, slightly knobbed or spatulate. The male possessed a pair of short waxy anal projections.
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