Seasonal abundance of cotton mealybug, phenacoccus solenopsis and its effect on biochemical defence of okra plants [electronic resource].

Includes reference.

Seasonal abundance of cotton mealybug was monitored on okra plants at Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, Egypt during 2020 and 2021 cropping seasons. Biochemical changes have been monitored in infested okra plants by mealybug one, seven and fourteen days after feeding compared to healthy plants in the greenhouse. Additionally, the effectiveness of essential oils and insecticides were evaluated against this pest and its predators under field conditions. The population of cotton mealybug on okra started building up from June and reached its peak on August 14th and September 19th in 2020 season, while, it had two peaks on July 30th and August 28th in the second season. Biochemical changes showed an increase in carotenoids, meanwhile chlorophyll level exhibited significant decrease in okra plants seven and fourteen days after mealybug infestation, which led to a fall in the concentration of photosynthetic pigments. The level of catalase, peroxidase. superoxidase and malondialdehyde were much higher in infested than healthy plants, whereas carbohydrates and protein content decreased refereeing to plants damage. Profenofos provided an effective control against mealybug, which recorded rapid and long acting against this insect, although profenofos is advised for usage against high levels of mealybug. However, jojoba oil is an effective essential oil against low levels of mealybug infestation on okra plants, which was significantly the safest on predators. These findings might be used in integrated pest management programs (IPM) of cotton mealybug on okra and other plants.
Keywords: Seasonal abundance, mealybug, biochemical, insecticides.

Summary in Arabic.