Handling and Environmental Effects on Viability of Mechanically Dispensed Green Lacewing Eggs

Mechanical distribution and release of commercially produced green lacewing eggs,Chrysoperla rufilabrisBurmeister (Neuroptera, Chrysopidae), was simulated by dispensing an egg/vermiculite mixture through a prototype mechanical distributor. The distributor was subjected to vibration similar to that measured on a tractor traveling in a field. Lacewing egg survival was determined following passage through the vibrating distributor and exposure to environmental conditions that simulated greenhouse and vineyard canopy conditions. The hatching rate from all treatments was no different from the hatching rate from untreated controls. Consistency of egg distribution, as measured by rate of egg release (the product of concentration of eggs in vermiculite carrier, eggs/ml, and discharge rate of carrier, ml/min) was uniform over 60 min of vibration and release. The results establish the feasibility of mechanical distribution of viable green lacewing eggs.