THE SAN FRANCISCO CHRONICLE - April 4, 1994
Author: KENNETH HOWE, Chronicle Staff Writer
In the war on bugs, there's plenty of room for dirty tricks. Biotech companies are spending millions of dollars to expose insects to bug diseases, muck up their sex lives and induce them to eat poisonous plants.
One of the most successful methods to battle bugs is germ warfare, specifically the bacterium Bacillus thuringiensis (Bt). First developed in France in the late 1920s to control the flour moth, this insect pathogen is a spore-forming microorganism that, while harmless to invertebrates, produces proteins that, when eaten by the pest, destroy the insect's stomach.
The more than 30 subspecies of Bt can be easily applied as a powder or a liquid and are used to kill caterpillars, beetles, flies and mosquitoes.
Novo Nordisk Entotech, a Davis-based biotech firm, is working on a form of Bt that will kill corn root worms, a pest that does about $200 million in agricultural damage a year.
Viruses and fungi also hold promise for controling bugs, said Pam Marrone , Entotech's president, ``but so far we haven't cracked the technical problems.''
For one thing, viruses can take several days to kill an insect, time enough for the bug to devour a considerable amount of crop. As for fungi, scientists are still uncertain about how external factors like humidity and temperature change their effectiveness.
So far the biggest hurdle facing so-called microbial insecticides has been getting them registered. Currently, state and federal laws treat these environmentally friendly microbes as ordinary pesticides. That means they must undergo the same lengthy scrutiny as their chemical forbearers.
But Lynn Goldman, assistant administrator for toxic substances and pesticides at the Environmental Protection Agency, said her office is developing ``a faster track'' for biological control agents. ``We have to come up with a shorter and less-burdensome process for regulation,'' she said.
That regulatory shortcut also would apply to pheromones -- chemicals emitted by insects to communicate. The most common pheromones used to control pests are the sex attractants. The natural chemicals can be used for mass trapping of insects. But mostly they have been wielded to interrupt the mating process of bugs, including the pink bollworm, the Oriental fruit moth and the tomato pinworm.
For many in agriculture, the future lies in genetic engineering. By adding a certain hormone or enzyme, for example, an insect- killing virus can become more effective by killing the target bug quicker.
Taking another approach, some researchers are cloning a Bt gene into tomato plants. Instead of dusting the crop with the bacteria -- and hoping enough insects ingest the germ -- scientists are putting the bioinsecticides inside the plant. A couple of bites and the bug is dead.
But creating potent new viruses is raising public concern about safety and creating a plant that carries its own insecticide raises the specter of accidentally spawning a super bug, immune to Bt.
--------------------------
Some Commercially Available ``Beneficial'' Bugs and What They Do.
Good Bug
Fly Parasites, (Muscidifurax zaraptor, Nasonia vitripennis and many others).
.
Bad Bugs:
The housefly, Musca domestica and other flies found around farm animals.
.
The Battle:
These small parasitic wasps, harmless to humans, are used to control various manure-breeding flies in feedlots, dairy farms and chicken houses. The wasps inject their eggs into fly maggots and the offspring eat their way out of the ``hosts,'' emerging as adult wasps.
Good Bug:
Green Lacewing (Chrysoperla carnea)
.
Bad Bugs:
Aphids, thrips, mites, etc.
.
The Battle:
In its larval stage, the green lacewing, also called the aphid lion, is a voracious predator that snacks on insects that devour orchard and row crops as well as ornamental plants. A single lacewing in its two-to-three-week larval stage can consume as many as 11,000 spider mites.
Good Bug:
Convergent Lady Bettle (Hippodamia convergans)
Bad Bugs:
Aphids and other small insects.
.
The Battle:
The lady beetle is a popular predator because it eats a wide range of insects that plague farms and gardens, eating more than a thousand aphids in two or three months. But it is a migratory insect so is often ineffective at controling pests in a particular area.
Good Bug:
Predatory Mites (Phytoseiulus persimilis, Metaseiulus occidentalis, etc)
.
Bad Bugs:
Spider mites and other types of mits.
.
The Battle:
These carnivorous mites prey on their cousins, the leaf-sucking spider mites, that can damage the leaves, and in turn the fruit of strawberries and orchard crops.
Good Bug:
Trichogramma
Bad Bugs:
Caterpillars and worms
The Battle:
One of the most widely used parasitic wasps, it attacks the eggs of caterpillars including tomato fruitworms (also called corn earworm and boll weevil), loopers and hornworms that munch tree, fruit and vegetable crops.
Good Bug:
Whitefly parasite (Encarsia species)
Bad Bug:
Whiteflies
.
The Battle:
Another parasitic wasp, this one lays eggs inside the nymphs of the greenhouse whitefly, which destroys a range of flowers and vegetables.
Good Bug:
California red scale parasite (Aphytis bifasciata)
Bad Bug:
Red scale
.
The Battle:
A parasitic wasp used widely in citrus orchards, it attacks red scale, which sucks on the fruit and twigs of oranges and, in a heavy infestation, can kill a tree.
SOURCE: Pests of the Garden and Small Farm Flynt, M.L. 1990
Edition: FINALOne of the most successful methods to battle bugs is germ warfare, specifically the bacterium Bacillus thuringiensis (Bt). First developed in France in the late 1920s to control the flour moth, this insect pathogen is a spore-forming microorganism that, while harmless to invertebrates, produces proteins that, when eaten by the pest, destroy the insect's stomach.
The more than 30 subspecies of Bt can be easily applied as a powder or a liquid and are used to kill caterpillars, beetles, flies and mosquitoes.
Novo Nordisk Entotech, a Davis-based biotech firm, is working on a form of Bt that will kill corn root worms, a pest that does about $200 million in agricultural damage a year.
Viruses and fungi also hold promise for controling bugs, said Pam Marrone , Entotech's president, ``but so far we haven't cracked the technical problems.''
For one thing, viruses can take several days to kill an insect, time enough for the bug to devour a considerable amount of crop. As for fungi, scientists are still uncertain about how external factors like humidity and temperature change their effectiveness.
So far the biggest hurdle facing so-called microbial insecticides has been getting them registered. Currently, state and federal laws treat these environmentally friendly microbes as ordinary pesticides. That means they must undergo the same lengthy scrutiny as their chemical forbearers.
But Lynn Goldman, assistant administrator for toxic substances and pesticides at the Environmental Protection Agency, said her office is developing ``a faster track'' for biological control agents. ``We have to come up with a shorter and less-burdensome process for regulation,'' she said.
That regulatory shortcut also would apply to pheromones -- chemicals emitted by insects to communicate. The most common pheromones used to control pests are the sex attractants. The natural chemicals can be used for mass trapping of insects. But mostly they have been wielded to interrupt the mating process of bugs, including the pink bollworm, the Oriental fruit moth and the tomato pinworm.
For many in agriculture, the future lies in genetic engineering. By adding a certain hormone or enzyme, for example, an insect- killing virus can become more effective by killing the target bug quicker.
Taking another approach, some researchers are cloning a Bt gene into tomato plants. Instead of dusting the crop with the bacteria -- and hoping enough insects ingest the germ -- scientists are putting the bioinsecticides inside the plant. A couple of bites and the bug is dead.
But creating potent new viruses is raising public concern about safety and creating a plant that carries its own insecticide raises the specter of accidentally spawning a super bug, immune to Bt.
--------------------------
Some Commercially Available ``Beneficial'' Bugs and What They Do.
Good Bug
Fly Parasites, (Muscidifurax zaraptor, Nasonia vitripennis and many others).
.
Bad Bugs:
The housefly, Musca domestica and other flies found around farm animals.
.
The Battle:
These small parasitic wasps, harmless to humans, are used to control various manure-breeding flies in feedlots, dairy farms and chicken houses. The wasps inject their eggs into fly maggots and the offspring eat their way out of the ``hosts,'' emerging as adult wasps.
Good Bug:
Green Lacewing (Chrysoperla carnea)
.
Bad Bugs:
Aphids, thrips, mites, etc.
.
The Battle:
In its larval stage, the green lacewing, also called the aphid lion, is a voracious predator that snacks on insects that devour orchard and row crops as well as ornamental plants. A single lacewing in its two-to-three-week larval stage can consume as many as 11,000 spider mites.
Good Bug:
Convergent Lady Bettle (Hippodamia convergans)
Bad Bugs:
Aphids and other small insects.
.
The Battle:
The lady beetle is a popular predator because it eats a wide range of insects that plague farms and gardens, eating more than a thousand aphids in two or three months. But it is a migratory insect so is often ineffective at controling pests in a particular area.
Good Bug:
Predatory Mites (Phytoseiulus persimilis, Metaseiulus occidentalis, etc)
.
Bad Bugs:
Spider mites and other types of mits.
.
The Battle:
These carnivorous mites prey on their cousins, the leaf-sucking spider mites, that can damage the leaves, and in turn the fruit of strawberries and orchard crops.
Good Bug:
Trichogramma
Bad Bugs:
Caterpillars and worms
The Battle:
One of the most widely used parasitic wasps, it attacks the eggs of caterpillars including tomato fruitworms (also called corn earworm and boll weevil), loopers and hornworms that munch tree, fruit and vegetable crops.
Good Bug:
Whitefly parasite (Encarsia species)
Bad Bug:
Whiteflies
.
The Battle:
Another parasitic wasp, this one lays eggs inside the nymphs of the greenhouse whitefly, which destroys a range of flowers and vegetables.
Good Bug:
California red scale parasite (Aphytis bifasciata)
Bad Bug:
Red scale
.
The Battle:
A parasitic wasp used widely in citrus orchards, it attacks red scale, which sucks on the fruit and twigs of oranges and, in a heavy infestation, can kill a tree.
SOURCE: Pests of the Garden and Small Farm Flynt, M.L. 1990
Caption: PHOTO
The larva of the Green Lacewing attacked an aphid / BY JACK KELLY CLARK, UC DAVIS/SPECIAL TO THE CHRONICLE
The larva of the Green Lacewing attacked an aphid / BY JACK KELLY CLARK, UC DAVIS/SPECIAL TO THE CHRONICLE
Section: BUSINESS
Page: D5
