Wednesday, March 20, 2013

Beneficial Insects Attack These Insects

Beneficial Insects are insects that prey on other insect pests. This list is not complete, and just reinforces the idea that not all bugs are bad. Some larvae of good bugs eat eggs of pests, but initial sightings of caterpillars on a leaf may confuse the gardeners in assuming the caterpillar is a pest, not the beneficial he really is.

Top Left: Parasitic Wasp.  This wasp lays eggs in and on its prey.  The larvae of the wasp feeds on the host insect and kills it.  Some insects that the Parasitic Wasp attacks are aphids, beetles, flies, sawflies, and scale insects.
Bottom Left: Big-eyed Bug.  The Big-Eyed Bug eats insect eggs of other pests, small caterpillars, fleas, beetles and mites.

Top Right: Minute Pirate Bug.  A true predator, the Minute Pirate bug feeds on eggs of other insects, as well as aphids, thrips, spider mites.  At less than 1/8” long, the Minute Pirate Bug feeds on the corn earworm eggs on corn plant.

Center: Assassin Bug.  By injecting it’s prey with saliva, the assassin bug liquefies the inside of it’s prey. Common insects like aphids, spiders, ants, and bees often become prey to the Assassin bug.  It feeds on other insect eggs and larvae. 

Bottom, Right:  The Potter Wasp, also called the Mason wasp.  the single cell mud next contains one egg of the female.  She also inserts a paralyzed moth caterpillar inside for her offspring to eat before it emerges from the nest.

These photos are some of the insects that can harm plant material. (References to Beneficial Insects that prey on them, is above.)
From Left to Right:  Aphids, Colorado Potato Bug, Scale, Small caterpillars, Cucumber Beetle, Mites, Thrips, Bean Beetle. 

This is some of the damage that these insects can cause to plants. image
From Top Left to right:  Bean leaf Beetle damage, spider Mites on tomato plant, Aphid damage, Beans ruined from Bean leaf Beetle, Flea Beetles damage, Bacterial wilt from Striped or Spotted Cucumber Beetle,  Beetle leaf damage, Beetle damage, Mite damage.

More evidence of insect damage.
Top left to right:  Corn damage from grasshoppers, Mites on Roses, Japanese Beetles, Cucumber Beetle Leaf Mosaic virus,  Elm Leaf Beetle.

As is evident from the damage on these plants, insect control is necessary for healthy production of ornamentals and food crops. And allowing Beneficial insects to do their job is difficult for many of us.  We want to call in the Calvary in the form of anything we can spray and kill these suckers!

Unfortunately, these same sprays and powders will kill ALL of the insects, including the Beneficial insects in slide 1.
After using a insecticide on pests, often times a secondary influx of pests occurs and then there are no natural predators to deal with the problem.  So we end up ‘spraying’ again!

Bringing Beneficial insects to the yard and plants that can keep pest insects at bay are called Insectary plants.  You can read more about them here.

Planting Insectary plants throughout the yard and garden will bring Beneficial insects to the area, and hopefully, pest damage will be negligible.

There are other organic ways to manage pests in the garden and some of these methods are describe in an article on Integrated Pest Management here.
Thanks for visiting, and I hope your garden thrives!

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