Comparative Study of Sap-Feeding Insects in Cotton Agroecosystems of District Khairpur, Sindh, Pakistan

Abstract

Cotton (Gossypium hirsutum) is a key crop supporting the textile-based economy of  Pakistan. However its productivity  is frequently threatened by various insect pests. Among these, sap-sucking insects such as,  mealy bugs (Phenacoccus solenopsis), dusky cotton bug (Oxycarenus laetus) and aphid (Aphis gossypii) are considered majorconstraints to cotton production. These pests weaken plants by extracting phloem sap, leading to reduced plant vigor and lower boll formation. In addition, the secretion of honeydew encourages the growth of sooty mold, which further deteriorates plant health and crop quality. The present study was conducted in District Khairpur, sindh particularly in Taluka, Gambat and Kotdiji, to evaluate the occurrence and infestation patterns of these pests in cotton fields. Field surveys and quadrat sampling indicated that mealybugs were more abundant under hot and dry enviornmental conditions, whereas dusky cotton bugs were commenly observed in Bt cotton varieties. Aphid populations showed clear variation in response to rainfall and humidity. Statistical analysis confirmed significant differences in infestation intensity among pest species and enviornmental conditions. Overall the findings highlight the influence of agro- climatic factors on pest dynamics and emphasize the importance of integrated pest management strategies to reduce losses caused by sap-sucking insects in cotton agroecosystems.