The efficacy of some pesticides on cotton yield, damage symptoms, and population of the cotton shredder bug, Creontiades pallidus (Hemiptera: Miridae) under field conditions

The cotton shredder bug, Creontiades pallidus Rambur (Hemiptera; Miridae), is a significant pest of cotton, causing extensive damage to cotton leaves and bolls. This study assessed the effectiveness of commercial formulations of phosalone (PHO), thiamethoxam (THX), thiamethoxam + lambda-cyhalothrin (THX + LAM), and spirotetramat (SPI) under field conditions, using both one-time and two-times spray applications. In the one-time spray plots, THX and THX + LAM demonstrated the highest efficacy in reducing C. pallidus populations, as well as mitigating damage symptoms like black spots on cotton bolls and leaves and shredding of cotton blossoms for up to ۴۹ days compared to the control group. However, the effects of SPI and PHO were temporary and diminished after approximately ۳۱ days. When the plots were sprayed for the second time after ۳۰ days, all pesticides significantly decreased pest populations and damage symptoms for up to ۴۹ days. The highest cotton yield in the one-time spray plots was achieved with THX application (۳۲۳.۸ ± ۱۰.۶۲ g cotton/m۲), while the SPI-treated plots exhibited the lowest yield (۲۷۵.۷ ± ۵.۱ g cotton/m۲). All THX, THX + LAM, and PHO treatments yielded statistically similar results in the two-times spray plots. Our findings suggest that THX and THX + LAM were the most effective pesticides for controlling C. pallidus populations and mitigating damage symptoms in cotton fields.

Keywords:

Creontiades pallidus , cotton , pesticides , cotton pests’ control , cotton blossom shredding