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The Mantids
Praying mantises are very fast predators. They are ambushers meaning they sit and wait for their prey to come by. Once their prey is within their reach, they can quickly attack and grab this passing by insect prey with their spiny forelegs, and then munch on it. They are also known to camouflage with their surroundings to mislead their victim insects. Both nymphs and adults feed on different kinds of insect pests. Young nymphs feed on small soft bodied insects such as aphids and flies whereas adults feed on large insects such as beetles, grasshoppers, moths etc. They are very effective against moths because they are active during night.
Another advantage for the praying mantis is its coloring. Not only does the mantid’s green to grayish-brown offer excellent camouflage in the plant foliage where it prefers to hunt, this color can be somewhat altered by an individual to better match its specific surroundings. The praying mantis will sit and wait or very slowly stalk its prey, sometimes swaying back and forth to mimic plants moving in a breeze, only to become lightning fast when it snares its target. It immediately uses its strong mouthparts to start chewing the still-living prey. Sometimes, the mantid will bite its victim on the neck first, thus paralyzing the insect and avoiding its escape. It is fast enough to catch flies and mosquitoes that venture within its grasp.
All of these characteristics combine to make mantids formidable and almost perfect predators. Why the “almost” qualification? One problem is that the entire family is indiscriminate in what they eat. While they consume pests such as flies, crickets, moths and mosquitoes, they also devour other beneficial insects, including each other. Larger species (especially those in tropical areas) Some species are large enough to eat lizards, small mammals and even hummingbirds.
Aphidius colemani - Aphid Parasites
This tiny parasitic wasp (A. colemani) hones in on its prey by sensing the distress signals of infested plants as well as detecting the aphid’s honeydew secretions. Once there, it injects an egg into the aphid. When the egg hatches, the larvae begin to consume the pest from inside. The resulting wasp then emerges from the rear of the dead aphid to seek out other prey. Surviving aphids react by emitting an “alarm” pheromone which causes the colony to flee, often falling to the ground where they die.
Appropriate for garden and greenhouse use, aphid parasites can be used both as a preventive measure and to combat infestations. Adult wasps live two to three weeks and will lay eggs in as many as 300 aphids over the period of their lives, increasing the numbers of wasps as they do. Proof they’re at work can be found by searching for the brown, mummified shells left of dead aphids.
Aphelinus abdominalis work in the same way and have a similar appearance.
Aphidoletes aphidimyza - Aphid Predators
In its larval stages, Aphidoletes aphidimyza is a voracious aphid killer. The more aphids present, the more it will consume. Also known as the gall midge, it’s known to feed on some 60 types of aphids. It’s a popular means of aphid control in greenhouses.
This image has been resized. Click this bar to view the full image. The original image is sized 800x702.
Basically night feeders, the larvae hide on the undersides of leaves during the day. In its adult, midge stage, the delicate fly feeds on aphid honey dew and deposits eggs in aphid colonies. The larvae take two-three days to hatch and go through three stages over two weeks, feeding on aphids as they go. The predator spends its pupal stage in the ground. The adult emerges in one to two weeks to lay more eggs among the remaining aphids.
Steinernema carpocapsae & Heterorhabditis heliothedis - Predatory Nematodes
Parasitic nematodes seek out insects harmful to garden plants, shrubs and trees in their soil-borne stages and destroy them from the inside out. Present in soils throughout the world, these microscopic, non-segmented worms destroy over 250 different insects, including Fleas, Thrips, Fungus Gnats, even insects as large as Cutworms! Nearly any insect that spends a part of its lifecycle in the soil is likely prey before they reach adult stages.
When released into the soil, Predatory nematodes seek out the larvae and pupae of susceptible pests by sensing the heat and carbon dioxide they generate. They enter pests through various orifices or directly through the “skin.” Once inside the host, they release a bacterium that kills it within a day or two. They will continue to feed on the remains, multiplying as they do, before exhausting it and leaving to seek another food source.
Nematodes do not prey on lady bugs, earthworms or most other beneficial insects. They are harmless to plants and humans as is the bacterium they produce. Evidence of the nematodes effectiveness, other than reduced pest populations, is difficult to spot as these microscopic creatures consume their hosts in the soil, leaving little trace behind. They’re appropriate for use on lawns, in gardens and around trees and shrubs. They need generally moist condition to facilitate their movement.
Dacnusa sibirica & Diglyphus isaea - Leafminer Parasites
The parasitic wasp Dacnusa sibirica occurs naturally in North America and Europe. The adult is dark brown to black and is 2-3 mm long. Dacnusa sibirica can easily be distinguished from Diglyphus isaea by its long antennae. As an adult, it differs from Opius pallipes, another beneficial insect against leafminers, only in the front wing venation.
The Dacnusa sibirica female deposits her egg in a leafminer larva. Diglyphus isaea egg is laid beside the host. If there are too few hosts, Dacnusa sibirica may deposit more than one egg per larva, but eventually only one parasitic wasp develops in the leafminer larva.
The parasitized leafminer larva does not die, but keeps on feeding. First Dacnusa sibirica evolves in the leafminer larva. Then, when the leafminer larva pupates, the Dacnusa larva mutates. Further development of the pupa also takes place in the leafminer pupa. Finally, not a leafminer, but an adult parasitic wasp leaves the pupa. So the different development stages are not visible without opening the leafminer larva or pupa.
Dacnusa sibirica can hibernate in leafminer pupae thereby allowing it to occur simultaneously with its host already early in the season. Adult parasitic wasps do not feed on hosts as Diglyphus isaea does. Dacnusa sibirica is able to locate mines at very low densities. It looks mainly low in the crop. Once it has found a mined leaf, it searches for larvae with its antennae. The wasp can distinguish parasitized from non parasitized leafminer larvae (host discrimination).
Praying mantises are very fast predators. They are ambushers meaning they sit and wait for their prey to come by. Once their prey is within their reach, they can quickly attack and grab this passing by insect prey with their spiny forelegs, and then munch on it. They are also known to camouflage with their surroundings to mislead their victim insects. Both nymphs and adults feed on different kinds of insect pests. Young nymphs feed on small soft bodied insects such as aphids and flies whereas adults feed on large insects such as beetles, grasshoppers, moths etc. They are very effective against moths because they are active during night.
Another advantage for the praying mantis is its coloring. Not only does the mantid’s green to grayish-brown offer excellent camouflage in the plant foliage where it prefers to hunt, this color can be somewhat altered by an individual to better match its specific surroundings. The praying mantis will sit and wait or very slowly stalk its prey, sometimes swaying back and forth to mimic plants moving in a breeze, only to become lightning fast when it snares its target. It immediately uses its strong mouthparts to start chewing the still-living prey. Sometimes, the mantid will bite its victim on the neck first, thus paralyzing the insect and avoiding its escape. It is fast enough to catch flies and mosquitoes that venture within its grasp.
All of these characteristics combine to make mantids formidable and almost perfect predators. Why the “almost” qualification? One problem is that the entire family is indiscriminate in what they eat. While they consume pests such as flies, crickets, moths and mosquitoes, they also devour other beneficial insects, including each other. Larger species (especially those in tropical areas) Some species are large enough to eat lizards, small mammals and even hummingbirds.
Aphidius colemani - Aphid Parasites
This tiny parasitic wasp (A. colemani) hones in on its prey by sensing the distress signals of infested plants as well as detecting the aphid’s honeydew secretions. Once there, it injects an egg into the aphid. When the egg hatches, the larvae begin to consume the pest from inside. The resulting wasp then emerges from the rear of the dead aphid to seek out other prey. Surviving aphids react by emitting an “alarm” pheromone which causes the colony to flee, often falling to the ground where they die.
Appropriate for garden and greenhouse use, aphid parasites can be used both as a preventive measure and to combat infestations. Adult wasps live two to three weeks and will lay eggs in as many as 300 aphids over the period of their lives, increasing the numbers of wasps as they do. Proof they’re at work can be found by searching for the brown, mummified shells left of dead aphids.
Aphelinus abdominalis work in the same way and have a similar appearance.
Aphidoletes aphidimyza - Aphid Predators
In its larval stages, Aphidoletes aphidimyza is a voracious aphid killer. The more aphids present, the more it will consume. Also known as the gall midge, it’s known to feed on some 60 types of aphids. It’s a popular means of aphid control in greenhouses.
This image has been resized. Click this bar to view the full image. The original image is sized 800x702.
Basically night feeders, the larvae hide on the undersides of leaves during the day. In its adult, midge stage, the delicate fly feeds on aphid honey dew and deposits eggs in aphid colonies. The larvae take two-three days to hatch and go through three stages over two weeks, feeding on aphids as they go. The predator spends its pupal stage in the ground. The adult emerges in one to two weeks to lay more eggs among the remaining aphids.
Steinernema carpocapsae & Heterorhabditis heliothedis - Predatory Nematodes
Parasitic nematodes seek out insects harmful to garden plants, shrubs and trees in their soil-borne stages and destroy them from the inside out. Present in soils throughout the world, these microscopic, non-segmented worms destroy over 250 different insects, including Fleas, Thrips, Fungus Gnats, even insects as large as Cutworms! Nearly any insect that spends a part of its lifecycle in the soil is likely prey before they reach adult stages.
When released into the soil, Predatory nematodes seek out the larvae and pupae of susceptible pests by sensing the heat and carbon dioxide they generate. They enter pests through various orifices or directly through the “skin.” Once inside the host, they release a bacterium that kills it within a day or two. They will continue to feed on the remains, multiplying as they do, before exhausting it and leaving to seek another food source.
Nematodes do not prey on lady bugs, earthworms or most other beneficial insects. They are harmless to plants and humans as is the bacterium they produce. Evidence of the nematodes effectiveness, other than reduced pest populations, is difficult to spot as these microscopic creatures consume their hosts in the soil, leaving little trace behind. They’re appropriate for use on lawns, in gardens and around trees and shrubs. They need generally moist condition to facilitate their movement.
Dacnusa sibirica & Diglyphus isaea - Leafminer Parasites
The parasitic wasp Dacnusa sibirica occurs naturally in North America and Europe. The adult is dark brown to black and is 2-3 mm long. Dacnusa sibirica can easily be distinguished from Diglyphus isaea by its long antennae. As an adult, it differs from Opius pallipes, another beneficial insect against leafminers, only in the front wing venation.
The Dacnusa sibirica female deposits her egg in a leafminer larva. Diglyphus isaea egg is laid beside the host. If there are too few hosts, Dacnusa sibirica may deposit more than one egg per larva, but eventually only one parasitic wasp develops in the leafminer larva.
The parasitized leafminer larva does not die, but keeps on feeding. First Dacnusa sibirica evolves in the leafminer larva. Then, when the leafminer larva pupates, the Dacnusa larva mutates. Further development of the pupa also takes place in the leafminer pupa. Finally, not a leafminer, but an adult parasitic wasp leaves the pupa. So the different development stages are not visible without opening the leafminer larva or pupa.
Dacnusa sibirica can hibernate in leafminer pupae thereby allowing it to occur simultaneously with its host already early in the season. Adult parasitic wasps do not feed on hosts as Diglyphus isaea does. Dacnusa sibirica is able to locate mines at very low densities. It looks mainly low in the crop. Once it has found a mined leaf, it searches for larvae with its antennae. The wasp can distinguish parasitized from non parasitized leafminer larvae (host discrimination).
