Chrysoperla zastrowi sillemi (Esben-Petersen)

In mass production, the adults are fed on various types of diets. The larvae are either reared in plastic tubes or empty injection vials or in groups in large containers or in individual cells. The most common method for the production of chrysopids is detailed below.

200 pairs of adults are kept in oviposition cage, measuring 75 x 30 cms. The sides of the cage are lined with smooth nylon wiremesh (not preferred for egg laying) but the sliding top cover is fitted with black cloth for obtaining eggs. To prevent damage to the eggs the top is slided over a comb fitted on both the sides of the cage. The sliding top cover is replaced everyday starting from 4th day onwards. The oviposition cage is kept for 30 days and the dead adults are removed every alternate day.

One day old eggs (egg chorion gets hardened) are dislodged from the black cloth top cover of oviposition cage by gently working with a piece of sponge. Eggs collected can be used for further multiplication or for field release.

In the first step of larval rearing, 120 three day old chrysopid eggs are mixed with 0.75 ml of Corcyra eggs (the embryo of Corcyra eggs are inactivated by keeping them at 2 feet distance from 15 watt ultraviolet tube light for 45 minutes) in a plastic container (27 x 18 x 6 cms). On hatching, the larvae start feeding. On 3rd day the larvae are transferred to 2nd step individual rearing in 2.5 cm cubical cells of plastic louvers. Each louver can hold 192 larvae. Corcyra eggs are provided in all the cells of each louver by sprinkling through a modified salt shaker. Feeding is provided in two doses. First feeding of 1.5 ml Corcyra eggs for 100 larvae and second feeding of 2 ml for 100 larvae with a gap of 3-4 days. Total quantity of Corcyra eggs required for rearing 100 chrysopid larvae is 4.25 ml. The lovers secured on one side by organdy or brown paper sheet and after transfer of larvae covered with acrylic sheet and clamped. Organdie or brown paper is used for facilitating pupation and clear visibility of eggs. The louvers are stacked in racks. One 2m x 1m x 45 cms angle iron rack can hold 100 louvers containing 19,200 larvae.

Cocoons are collected after 24 hours of formation (when they get hardened) by removing organdie or paper from one side. The cocoons are placed in adult oviposition cages for emergence. (Adults are sometimes allowed to emerge in louvers and released on glass window panes from where they are collected using suction pumps).

One set of louvers remains in use for 13 to 15 days. After utilization, louvers are cleaned, sterilized and reused.

Recently single phase rearing of larvae in Biosec Bioassay trays has been tried successfully. Each tray (44x21 cms) comprises 8 blocks, each block containing 16 wells and the entire tray containing 128 wells. The diameter of each well is 2 cm and depth 1.5 cm. The blocks in the tray are individually fixed by using 'Pull-N-Peel' tab, which gets firmly glued to the block covering each of the 16 wells.

Eggs of C. carnea (about to hatch) are transferred in each of the wells along with 0.045 cc Corcyra eggs. Each of the blocks is firmly covered with Pull-N-Peel tab cover and trays stacked one over the other. The larvae complete development in 6-8 days at 27°C and 70% RH. The adults from the cocoons emerge in 6-7 days time. The adult recovery from cocoons is 95% and from larvae 90%. The adult males live for about 37 days and the female 36 days. The female produces about 665 eggs. Compared to other methods of rearing, the rearing in Biosec Bioassay trays prevents wastage of Corcyra eggs, gives better recovery of healthy adults, prevents escape of larvae, occupies less space and the unit is also relatively cheaper.

For field release, viable eggs are mixed with Corcyra eggs, saw dust and paper strips before sending the shipment. Once the larvae emerge they are released.

The eggs of C. cornea could be stored at 7.2°C for 3 weeks.

The following diets have been found promising but needs further refinement

A diet encapsulation machine is being installed at NBAII which will facilitate real mass production of chrysopids for large scale releases and demonstration.

Production procedure for most of the chrysopids, the adults of which are not feeding on insect diet is same except for the amount of food consumed and time taken to complete the development.