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Development and Reproduction of Cotton Aphids in the Field

M.N. Parajulee and A.P. Sapkota


Life history parameters of the cotton aphid, Aphis gossypii Glover were investigated under field conditions in Lubbock, Texas. Newly emerged aphid nymphs (n=30) were reared singly in aphid cages on the fifth mainstem node leaf in cotton and followed through all life stages until the last individual from the cohort died. Instar-specific nymphal duration consisted of 37, 42, 35, and 33 degree-days (>5.8 ÂșC developmental threshold) for first, second, third, and fourth instars, respectively. Cotton aphid mortality began at 432 degree-days and the last aphid died at 924 degree-days. Aphid reproduction began at 142 degree-days and the daily fecundity peaked at 266 degree-days; reproduction ceased at 773 degree-days. The cotton aphids produced an average of 63 offspring in the 30-day reproductive lifespan for the cohort. The gross reproductive rate, net reproductive rate, and finite rate of increase were 62.24, 59.06, and 1.4326, respectively.

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Document last modified 04/27/04