The importance of Chrysoperla carnea (Steph.) (Neuroptera: Chrysopidae) as a predator is due to nourishing this predator on some dangerous pests as the cotton mealybug, Phenacoccus solenopsis Tinsley, belongs to Hemiptera: Pseudococcidae. So the predator C. carnea was used in the management of various pests. The basic aim of this study was the indirect effect of some natural materials against some stages of C. carnea through feeding of the predator on the treated prey, Phenacoccus solenopsis Tinsley (Hemiptera: Pseudococcidae).
The results showed the comparison between the effectiveness of cinnamaldehyde and cinnamic oil in controlling the pest as soon as ineffectiveness on the predator. Cinnamaldehyde was very save against C. carnea which did not effect on the biology of it and the predator completed its life cycle as control (water + tween 80). Thus, the results suggested that cinnamaldehyde could be included in the Integrated Pest Management (IPM) Program without any adverse effect on bio-control agents used in an IPM.
This study may be a great alternative to chemical pesticides in controlling cotton mealybug, P. solenopsis, and at the same time, this material is saving to the predator C. carnea. This alternative is cinnamaldehyde (the active ingredient of cinnamon oil).