Effect of temperature on biological characteristics and life table parameters of Dicrodiplosis manihoti Harris on cotton mealybug, Phenacoccus solenopsis Tinsley

The cotton mealybug Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae) is one of the polyphagous and destructive pests in the world. It has caused a lot of damage in cotton fields and settles on other host plants, especially Chinese hibiscus shrubs Hibiscus rosa-sinensis L. and causes irrecoverable damages to these ornamental plants and urban landscape. Midge fly Dicrodiplosis manihoti Harris (Dip.: Cecidomiidae) is one of the most common fly species which was collected in mealybugs colonies. In this study, the biology and age-stage, two-sex life table parameters of Dicrodiplosis manihoti, was evaluated at four constant temperatures (22, 27, 32 and 37 +/- 1 degrees C, 65 +/- 5 % RH and a photoperiod of 16: 8 (L: D) h) in the laboratory conditions. The developmental pre-adult period was found as 36.12 +/- 0.38, 24.09 +/- 0.41, 14.96 +/- 0.34 and 12.68 +/- 0.26 days and the average egg produced by females was 23.65 +/- 2.86, 11.14 +/- 2.09, 12.32 +/- 3.94 and 8.57 +/- 0.67 at those temperatures, respectively which decreased as the temperature increased from 22 to 37 degrees C, respectively. The population intrinsic rate of increase (rm) was 0.0247 +/- 0.0051, 0.0291 +/- 0.0099, 0.0374 +/- 0.0206 and 0.0103 +/- 0.0129 (d(-1)), and the population finite rate of increase (+/-) for the above mentioned temperatures was 1.0249 +/- 0.0052, 1.0295 +/- 0.0101, 1.0384 +/- 0.0212 and 1.0104 +/- 0.0130 (d-1), respectively. Also, the net reproductive rate (R0) at the above mentioned temperatures was 2.62 +/- 0.5, 2.19 +/- 0.53, 2.05 +/- 0.73 and 1.18 +/- 0.22 offspring respectively. The shortest (T = 14.88 +/- 0.45 days) and the longest (T = 38.28 +/- 0.65 days) mean generation time was recorded at 37 and 22 degrees C, respectively. According to the results of this study D. manihoti has a good potential to control of Ph. solenopsis and the temperature of around 32 degrees C is the best for mass rearing this predator.

Automated summary

The cotton mealybug is a destructive pest that causes damage in cotton fields and other host plants. This study evaluated the biology and life table parameters of a common fly species, Dicrodiplosis manihoti, and found its potential for controlling the cotton mealybug.