A Comprehensive Guide to
Safe Biological Pest Control
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This "adored" insect is a general predator of most pest insects, mites, eggs, or any insect in reach. Each egg case contains approximately 200 baby mantis. Use 3 cases per 5,000 square feet or 10-100 cases per year per acre. Attract to twigs, leaves, fences, and other vegetation. Cases may also be placed in the crotch of a bush or tree. Do not place on ground, as they become easy prey for ants. Releases can begin after the last frost and continue through summer. The Praying mantis is a most interesting and enjoyable beneficial insect to have around the garden and farm. It is the only known insect that can turn its head and look over its shoulder. Mantis lie in wait for their food and when close enough, snap it up with a lightning movement of their strong forelegs. Measurements of their reflexes show they react more than 2 times quicker than houseflies. Mantis have enormous appetites, eating various aphids, leafhoppers, mosquitoes, caterpillars and other soft-bodied insects when young. Later they will eat larger insects, beetles, grasshoppers, crickets, and other pest insects. Praying mantises are large, solitary, slow moving, and predaceous insects that catch their prey with their front legs. They do not have jumping hind legs. Of the 20 species of mantises that occur in North America, the introduced Chinses mantis, at a lenght of as much as four inches, is the largest. Mantises are ambushers that sit on a plant, twig, often near a blossom, as they wait for prey to come close. The feed mainly on small and large insects. These ferocious-looking praying mantises actually make great pets. Some will even eat raw meat and insects from your fingers. With plenty to eat they usually will not stray far. If handled properly they don't bite.
In autumn the female will lay her eggs before she dies with the frost. She often deposits them on a branch or twig, but also leaves them on walls, fences and eaves. They are surrounded by a frothy liquid, called ootheca, which hardens into an egg case about the size and shape of a cigarette filter. The following spring the nymphs hatch and burst out of the case in a small army of hungry youngsters, each the size of a small ant. From birth mantis are predators. The nymphs immediately begin attacking leafhoppers, aphids and even small flies. It's important for every gardener to recognize these egg cases that become most visible in the winter when deciduous trees and shrubs lose their leaves. When pruning, keep a sharp eye out for them. Any found on twigs and branches should be set aside in protected parts of the garden. If they must be removed from a wall, for example, simply relocate to a sheltered place, and the nymphs will survive. Never put an egg case on the ground; the eggs inside quickly will be consumed by ants. A healthy organic garden relies on a delicate balance of predator and prey species. Beneficial mantis, lacewings and ladybugs are vital to keeping plant damaging insects under control. Just one blanket application of chemical pesticides can wipe out whole populations of mantis that can take years to reestablish. In the meantime, plant-damaging pest insects will return in droves to infest the garden, proliferating without any threat of predators. If your mantis population has been wiped out or if you want to expand the current population, buy dormant mantis egg cases. They are available in most garden centers or online garden-supply stores. They are sold in sets of three for less than $14, ready to distribute around your garden. Each case contains about 200 eggs, and three cases will cover about 6,500 square feet. Position your egg cases in the crotches of trees and shrubs. Use wire or twine to tie them to branches. Set on shelves or ledges in wood fencing or structures. They prefer a warm location and will hatch after the last frost and 10 to 15 days of warm weather. While gardens may appear to be peaceful loving environments, they are, when healthy, ruled by ferocious insect predators vital to population control.
FOOD AND REARING:
Providing food for a mantis can easily be done by trapping flies or other insects, and releasing them into the mantis's container; a wide-mouth jar covered with a net or screen on top and a twig or branch inside the jar. Insects used for food must be alive and not much bigger than the mantis. If the insect is too small, the mantis will consistently miss and be unable to grasp the prey. Mantis will eat insects dangled from tweezers, and most mantis will not except dead insects. Mantis in captivity do need additional water. Gently place a small wet sponge inside the container every week. The Praying mantis will gather the water off the sponge.
Both native and introduced species of Praying mantis are quite large, some over 3 to 4 inches long. The body is tarnish-brown with the longitudinal forewing's outer margins edged in a pea green color. The forelegs are modified to close like a knife blade back against its handle (pocket knife-like). Prey is held securely between these serrated, spiny forelegs.
Life Cycle and Habits
One generation develops each season. In the autumn, females lay eggs in a large mass or cluster (an inch or so long), in a frothy, gummy substance glued to tree twigs, plant stems and other objects. Overwintering occurs in the egg stage in this case. Tiny nymphs emerge from the egg mass in the spring or early summer.
Rearing praying Mantis
The space involved and the time required in rearing food material are the most difficult aspects of mantis rearing. Mantis are among the more difficult of insects to rear. They are carnivorous, feeding in nature on smaller insects and other small animals. Rearing mantis requires rearing of other insects - such as vinegar flies or aphids - as food material (in large quantities)!
Small developing nymphs tend to become cannibalistic and require separation or isolation in the later stages. Adults will mate readily in captivity.
After Praying mantis have completed their early stages, they may be fed insects larger than aphids and vinegar flies such as mosquitoes, flies, and roaches. Mature Chinese mantis readily attack, kill, and devour large crickets and grasshoppers. Some people like to watch the capture of this prey. Others like to collect adult mantis (especially females full of eggs), then place them in a large glass container (empty fish aquarium) and watch egg masses being glued to an inserted tree branch. After egg laying, mantis death usually occurs a few weeks later.
Egg masses, collected in September or October and brought into the warm classroom, have been known to hatch in early December of the same year. Then, large numbers of very tiny mantis will suddenly appear and, if not furnished fresh, live food, they will eat each other until only one or a few mantis are left. In the laboratory, the egg mass may be refrigerated for a few weeks, and then incubated at room temperature. Often, no refrigeration appears necessary.
While the praying mantis plays a very important part in nature's insect control plan, one should not expect to achieve total pest control with the use of praying mantis alone. Nevertheless, the mantis is the only predator which feeds at night on moths (most moths are active only after darkness) and the only predator fast enough to catch mosquitoes and flies. Since mantis are quite large and more visible than most beneficial insects, they are fun to watch, and children are fascinated to see a Praying Mantis grasp its prey.
Where to find: Praying mantis and /or their egg cases are very difficult to locate by just looking at plants because of their camouflage. To find adults, look on flowering plants and at porch lights in August through late September. Adult males will often fly to porch lights in the late fall. Home vegetable and flower gardens that are organic or where no insecticides have been used may be a good place to look. Egg cases can be purchased from Buglogical control Systems.
How to collect: To collect an egg case, carefully cut the branch with the egg case several inches below the case. If the case is attached to a wall or board, you will not be able to remove it without damaging the case. In capturing immature or adult mantis, you can use your hands to cup around the insect or gently coax them into a container. Using an insect net may be helpful to capture adults with wings. Carefully lay the net over or to the side of the mantis and with one hand gently usher the mantis into the net. Transfer the Praying mantis into a container large enough for the mantis to move around in.
Best results will be achieved by attaching the egg cases to a twig or a plant using a twistum or wire tie, wrap around the egg case and tie it to a branch in warm location, filtered sunlight. A hanging, swinging egg case is safer from birds and other predators. It will take about 10 to 15 days of good continue warm weather for them to hatch. When hatching the young will crawl from between the tiny flaps in the egg cases and hang from silken threads about 2" below the case. After drying out the long legged young disappear into the vegetation around the area, leaving little if any trace of their hatching. This happens within an hour or two and it is difficult to know hatching has occurred unless the elusive, well camouflaged young are found. Use this valuable insect in conjunction with all other beneficial insect releases.