ET 4/99: Beneficial insects: voracious yet fragile friends

Beneficial insects: voracious yet fragile friends

by Don Trotter

ello fellow Earthlings, and welcome to the fascinating world of beneficial insects in the garden. This month we will be discussing these incredible creatures and the good that they do in controlling pest insect populations. So let's take a stroll through the insectary and discuss some of the more popular species of beneficial insects that can normally be found at better garden centers around the area or by mail order.

Ladybird beetles

These are probably the most widely recognized of all beneficial organisms, aside from earthworms. "Ladybugs," as they are often called, are predators of several different types of pest insects. Ladybugs feed on several species of aphids, mealybugs, spider mites, soft scales, and certain whitefly species. However, these insects are migratory, and if you don't give them something interesting to keep their attention, they will leave. Ladybugs can be purchased at many home centers and nurseries during the warmer part of the year. Ladybugs are considered "beneficial generalists" because they have a varied appetite for the critters that bug your garden. Releasing adult ladybugs should be done in the evening in moist conditions, or on a cool day. Lower temperatures lower their activity, so in cooler temperatures they will be less likely to fly away as soon as you release them.

Green lacewings

Green lacewings or just lacewings are also considered beneficial generalist insects. However the main difference from lacewing and ladybugs feeding habits are that adult lacewings are not predatory, while ladybugs are. The larvae of the green lacewing are voracious predators of aphids, mealybugs, spider mites, soft scales, most whitefly species, caterpillar eggs, and they will sometimes eat snail and slug eggs as well as each other, if there are no other pests to munch on.

The larva of the green lacewing are called "Aphid lions." This does not begin to describe how hungry these good guys are or how effective they are as a biological control for pests in the garden. Many garden centers carry green lacewings either in stock or as a mail away package direct to the insectaries where they are grown. This type of purchasing green lacewings ensures that you receive fresh insects directly to your mailbox.

The adult lacewing is a slender green or brown flying insect with large transparent wings and a kind of fluttering flight. Once recognized, you will see them everywhere. The adults feed mostly on pollen and nectar from flowers around the garden. Luring native lacewings to your garden is a very good reason to find some room in the garden for "companion plantings" that produce the type of flowers that are pollen- and nectar-rich.

Cryptolaemus beetles

These black beetles with red heads are directly related to ladybugs. Cryptolaemus beetles are also known by their common name "Mealybug destroyers." This is the truth! Both the adults and the larvae of this beneficial insect feed on mealybugs, some aphids, and soft scales. Cryptolaemus does prefer mealybugs, and are often used for controlling this pest indoors and in other areas where spraying is not possible.

The larva looks just like a large mealybug. However the cryptolaemus larva is more mobile than a mealybug, and their hairs are curly instead of straight, like they are on a mealybug. Cryptolaemus beetles also are normally sold direct from the nursery. They cost a little more than ladybugs, but they're worth it!

Delphastus beetles

Delphastus beetles are another relative of the ladybug that prefer to eat several species of whitefly. There are two fairly common species of the delphastus beetle at nurseries and garden centers. Delphastus pusillus is a predator of silverleaf whitefly and some of the other smaller species of whitefly. Delphastus catalinae is normally found in trees (arboreal), and they rarely come close to the ground to eat.

These two insects have been inaccurately sold to the public as an effective control for the giant tropical whitefly that seems to plague many of our tropical ornamentals and fruits during the summer. Delphastus will feed on the tropical whitefly, but do not keep up well with runaway populations of this pest, and they have difficulty negotiating the "floss" that the larvae of the tropical whitefly produce to protect themselves. Delphastus catalinae is often used by commercial avocado and citrus growers to control the tropical whitefly in their trees with good success. Delphastus can be very expensive, depending on the dealer.

Trichogramma wasps

Trichogramma wasps are parasites of many species of caterpillars. Don't let the "wasp" part scare you these beneficial insects are so small that even if they did want to sting you (and they don't) you couldn't feel it. Trichogramma are way too busy laying their eggs inside or on their hosts.

These insects are the most widely used beneficial insects used by farmers and growers to control damage that can be caused by hungry caterpillars. Trichogramma are often sold as parasitized moth eggs on flat pieces of plastic that can be hung close to where caterpillars are damaging plants so the adult wasps do not have to search too far for caterpillar eggs once they emerge from the egg. Adult trichogramma wasps feed on nectar and pollen. Keeping these beneficial insects in the garden is a good reason to put out some companion plantings of the flowers that they prefer to feed from. Trichogramma are also often sold as mail away packages. This ensures the buyer that you get fresh product that have not already emerged from their hosts.

These are just a few of the beneficial insects that are very effective at controlling pest populations in your garden. Many beneficial insect species are very sensitive to pesticides and don't recover well from the spraying of these chemicals. They should be employed as an alternative to spraying of potentially harmful chemical insecticides.

Next month, we will continue this discussion covering predatory snails, beneficial nematodes, and a couple of bacteria that work very well at controlling everything from mosquitoes to tomato hornworms. See you in the garden! HAPPY EARTH DAY!!!!

Got questions? Fax the Doc at (760) 632.8175 or Email him at Curlymill.net. Don Trotter's columns on natural gardening appear nationally in environmentally sensitive publications. Look for Don's book, Natural Gardening A to Z, coming in July from Hay House Publishing

Beneficial insects: voracious yet fragile friends
by Don Trotter
	ello fellow Earthlings, and welcome to the fascinating world of beneficial insects in the garden. This month we will be discussing these incredible creatures and the good that they do in controlling pest insect populations. So let's take a stroll through the insectary and discuss some of the more popular species of beneficial insects that can normally be found at better garden centers around the area or by mail order.
Ladybird beetles
	These are probably the most widely recognized of all beneficial organisms, aside from earthworms. "Ladybugs," as they are often called, are predators of several different types of pest insects. Ladybugs feed on several species of aphids, mealybugs, spider mites, soft scales, and certain whitefly species. However, these insects are migratory, and if you don't give them something interesting to keep their attention, they will leave. Ladybugs can be purchased at many home centers and nurseries during the warmer part of the year. Ladybugs are considered "beneficial generalists" because they have a varied appetite for the critters that bug your garden. Releasing adult ladybugs should be done in the evening in moist conditions, or on a cool day. Lower temperatures lower their activity, so in cooler temperatures they will be less likely to fly away as soon as you release them.
Green lacewings
	Green lacewings or just lacewings are also considered beneficial generalist insects. However the main difference from lacewing and ladybugs feeding habits are that adult lacewings are not predatory, while ladybugs are. The larvae of the green lacewing are voracious predators of aphids, mealybugs, spider mites, soft scales, most whitefly species, caterpillar eggs, and they will sometimes eat snail and slug eggs as well as each other, if there are no other pests to munch on. The larva of the green lacewing are called "Aphid lions." This does not begin to describe how hungry these good guys are or how effective they are as a biological control for pests in the garden. Many garden centers carry green lacewings either in stock or as a mail away package direct to the insectaries where they are grown. This type of purchasing green lacewings ensures that you receive fresh insects directly to your mailbox. The adult lacewing is a slender green or brown flying insect with large transparent wings and a kind of fluttering flight. Once recognized, you will see them everywhere. The adults feed mostly on pollen and nectar from flowers around the garden. Luring native lacewings to your garden is a very good reason to find some room in the garden for "companion plantings" that produce the type of flowers that are pollen- and nectar-rich.
Cryptolaemus beetles
	These black beetles with red heads are directly related to ladybugs. Cryptolaemus beetles are also known by their common name "Mealybug destroyers." This is the truth! Both the adults and the larvae of this beneficial insect feed on mealybugs, some aphids, and soft scales. Cryptolaemus does prefer mealybugs, and are often used for controlling this pest indoors and in other areas where spraying is not possible. The larva looks just like a large mealybug. However the cryptolaemus larva is more mobile than a mealybug, and their hairs are curly instead of straight, like they are on a mealybug. Cryptolaemus beetles also are normally sold direct from the nursery. They cost a little more than ladybugs, but they're worth it!
Delphastus beetles
	Delphastus beetles are another relative of the ladybug that prefer to eat several species of whitefly. There are two fairly common species of the delphastus beetle at nurseries and garden centers. Delphastus pusillus is a predator of silverleaf whitefly and some of the other smaller species of whitefly. Delphastus catalinae is normally found in trees (arboreal), and they rarely come close to the ground to eat. These two insects have been inaccurately sold to the public as an effective control for the giant tropical whitefly that seems to plague many of our tropical ornamentals and fruits during the summer. Delphastus will feed on the tropical whitefly, but do not keep up well with runaway populations of this pest, and they have difficulty negotiating the "floss" that the larvae of the tropical whitefly produce to protect themselves. Delphastus catalinae is often used by commercial avocado and citrus growers to control the tropical whitefly in their trees with good success. Delphastus can be very expensive, depending on the dealer.
Trichogramma wasps
	Trichogramma wasps are parasites of many species of caterpillars. Don't let the "wasp" part scare you these beneficial insects are so small that even if they did want to sting you (and they don't) you couldn't feel it. Trichogramma are way too busy laying their eggs inside or on their hosts. These insects are the most widely used beneficial insects used by farmers and growers to control damage that can be caused by hungry caterpillars. Trichogramma are often sold as parasitized moth eggs on flat pieces of plastic that can be hung close to where caterpillars are damaging plants so the adult wasps do not have to search too far for caterpillar eggs once they emerge from the egg. Adult trichogramma wasps feed on nectar and pollen. Keeping these beneficial insects in the garden is a good reason to put out some companion plantings of the flowers that they prefer to feed from. Trichogramma are also often sold as mail away packages. This ensures the buyer that you get fresh product that have not already emerged from their hosts. These are just a few of the beneficial insects that are very effective at controlling pest populations in your garden. Many beneficial insect species are very sensitive to pesticides and don't recover well from the spraying of these chemicals. They should be employed as an alternative to spraying of potentially harmful chemical insecticides. Next month, we will continue this discussion covering predatory snails, beneficial nematodes, and a couple of bacteria that work very well at controlling everything from mosquitoes to tomato hornworms. See you in the garden! HAPPY EARTH DAY!!!!
Got questions? Fax the Doc at (760) 632.8175 or Email him at Curlymill.net. Don Trotter's columns on natural gardening appear nationally in environmentally sensitive publications. Look for Don's book, Natural Gardening A to Z, coming in July from Hay House Publishing