Effect of some plant extracts on fecundity of Aphis gossypii glover (Hemiptera: Aphididae)

Cotton aphid is a polyphagous pest found on many host plants, distributed in various areas of the world. Aphis gossypii causes damage directly by sucking, and indirectly because it produces fumagin by secreting honeyed substances and carries many viruses and virus-like disease factors. In this study, some biological parameters were determined under controlled laboratory conditions in individuals treated with Melia extract, Neem, Onion extract and Euphorbia herbal extract of Aphis gossypii by dipping and spraying methods. Preadult, Prereproduction time, Reproduction time, Postreproduction time and adult life span of cotton aphid, average number of offspring of a female individual, the effects of applied extracts were determined. Total pre-adult development time of the cotton aphid, which was applied using dipping and spraying methods, was determined as the longest 6.16 days and 6.20 days in Onion extract application, and the shortest in Neem application with 3.46 days and 3.52 days. Net reproductive power (Ro) of Aphis gossypii individuals applied by immersion and spraying method was determined the lowest in Neem application with 0.28 and 0.28 nymph/female values, respectively, and the highest in Euphorbia extract application with 32.63 and 33.78 nymph/female values. Mean reproductive period (To) of Aphis gossypii individuals who were applied dipping and spraying method, completed the longest with 14.48 days and 13.99 days, respectively, in Onion extract application, and the shortest time in Neem application with 8.41 and 8.24 days. Hereditary reproductive ability (rm) values of Aphis gossypii individuals who were applied dipping and spraying method were found to be 0.309136 and 0.314678 in Euphorbia extract application, respectively, and the lowest values were found as -0.146208 and -0.148943 in Neem application. The number of offspring of Aphis gossypii individuals who were applied dipping and spraying method was calculated as 1958 and 2003 with the highest number of offspring in Euphorbia extract application, while the minimum number of offspring was calculated as 17 and 23 in Neem application. In this study, when the results (To, rm, Ro and reproduction time, etc. parameters) obtained from A. gossypii individuals with dipping and spraying method were examined, it was determined that the most effective application result was obtained in Neem applications. It was determined that the herbal application following this result was observed in the Melia extract application.