Calcium hypochlorite for removing stalks on eggs of the green lacewing Chrysoperla genanigra (Neuroptera: Chrysopidae)

Abstract

The release of lacewings eggs in the field requires the removal of their silk stalk, otherwise the release is impaired, as the eggs can become entangled in these pedicels. This study evaluated the effect of three concentrations of chlorine solution associated with two different exposure times for removing the stalks of eggs of Chrysoperla genanigra Freitas, and on the hatchability of the treated eggs. The concentrations used were 0.0 (control), 2.0, 4.0, and 6.0 % chlorine granules of hth®—containing as major components calcium hypochlorite and sodium chloride—dissolved in distilled water. The times used for each concentration were 60 and 120 s. Fifty eggs were used for each treatment. After each treatment, the eggs were washed in running water and then dried with a directed air flow. The best results were obtained with the concentrations of 2 % for 120 s and 4 % for 60 and 120 s, removing 100 % of stalks without reducing hatchability. At 6 %, egg destruction started to occur. We conclude that calcium hypochlorite can be used for removing stalks of C. genanigra eggs with no reduction in hatchability.