The following is based on information taken from H L Saffell's book: "BENEFICIAL INSECTS - HOW TO MASS-REAR FOR A PROFIT". If you would like a copy for your own, CLICK HERE.
Is the above a misnomer? Perhaps, but a few people are trying to rear ladybugs. If their efforts prove successful, it will be a boon to the ladybug industry. Ladybugs sold today are from the wild where they cluster together by the thousands when the weather turns cold. They're brought in and sold to the public. Most of the time this is done in a slipshod manner,
Wild ladybugs are often infected with parasites - up to 20% of them. Also when they're sold without being pre-conditioned the ladybugs fly away from the release area and the customer has spent his money for nothing. This procedure doesn't bode well for good business relations.
Those growers who try to do better pre-condition the ladybugs with food and also weed out the parasitized ladybugs. Then the handler has a reasonably healthy crop to sell to the customer. Pre-conditioning helps satisfy the ladybug's instinct to fly away upon release. Even with a heavy aphid population at hand, a recently released ladybug taken from the wild will fly away.
Pre-conditioning entails surrounding the captured ladybugs with a large tent-like structure and feeding them well. The food is usually wheast or other preparations. Both of these activities satisfy the ladybug's tendency to fly away and keep them in good health where they are ready to lay their eggs as soon as the customer applies them to his crops. Unless you get your ladybugs already pre-conditioned, this should be the procedure you should use if you also deal in ladybugs.
ARE THEY WORTH ANYTHING?
The value of ladybugs to the customer is that each adult will consume as much as 5,000 aphids! They are indeed voracious eaters and have a variety of pest insects upon which they will feed. These include the Colorado potato beetle larvae as well as may kinds of aphids and thrips.
Ladybug larvae which look like little alligators with orange spots have an appetite just as great as the adult's. A ladybug larva will consume 50 or more aphids a day.
Ladybugs will lay up to 50 eggs per day. If conditions are good, the ladybug will lay a total of up to 1500 eggs. The eggs are laid on the bottom side of plant leaves. Within 2 to 5 days the larvae will hatch out and live for three weeks. At the end of that time they will pupate. It then takes about 4 days for them to emerge as adults.
The ideal temperature for ladybugs is between 62 and 80 degrees. If the temperature goes lower than 55 degrees ladybugs will slow down and not fly. They can be kept in storage for up to three weeks at a temperature of 40 degrees Fahrenheit. The relative humidity should be around 70 per cent.
IS IT POSSIBLE TO REAR THEM?
Perhaps. Here is a suggested way of going about it. If you try this method do so on a limited scale. Make sure it works before going whole hog at it.
One producer has been raising ladybugs on Angoumois grain moth eggs for well over a year. To do this you would have to construct an open type setup. You would first make an enclosure which would keep the ladybugs and their larvae inside. This enclosure could be some sort of netting with holes too small for either the adult or the larvae to get through. The enclosure should be large enough to allow the adults to fly around inside.
You would have to have a means of feeding them. Sheets of waterproofed paper with smears of wheast could be hanging about. Also cotton balls which have been wetted down with water should be hanging here and there. Also there should be selected areas where the larvae might get a drink. Overall even this strategy would be difficult to maintain. How to collect them or their eggs? Difficult under this plan.
You can't keep them cooped up like you do with lacewing or Trichogramma. Ladybugs must have room to fly. Perhaps you can come up with a practical scheme. I don't see any problems with the feeding part of it; you could supplement with meal worms which you can raise yourself.
THE MAIN PROBLEMS WOULD BE SETUP AND SANITATION:
It would be difficult to sterilize a setup as outlined above. If you get your ladybugs from a supplier, be sure to get those which have been pre-conditioned and which don't have parasites. Be on guard for parasites anyway and get rid of them immediately if you find any. Remember: a satisfactory and sterile setup is mandatory. As an aside, a parasitized ladybug is immobile. It's alive but cannot move. The parasite is inside.
Since ladybugs are sold to the customer as adults, you would have to have a way to collect them. Perhaps by temporarily lowering the temperature to that listed above you could immobilize them to where they could be collected and sold.
But let's face it. This is all conjecture. The results of that one producer who says he's rearing ladybugs are not known. Ladybugs at present are still taken from the wild. Sometimes they're pre-conditioned and de-parasitized.
In the final analysis, this is something a producer would do when curiosity got the best of him.
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