Well, the weather is still hot – very hot. Even when I try to work early or late in the day, I’m absolutely soaked within 5 minutes of being out. I guess it’s worth it though. Fresh, organically grown vegetables right from my garden are incomparable and well worth the effort.
My organic ethic has been a bit challenged this year. I have been inundated by stink bugs and they have ruined almost all of my tomatoes. I did, however, get some and they were really delicious, but I had to pick them the minute I saw the first trace of color. Fortunately, tomatoes ripen well off the vine as long as they have warmth. They don’t even need light, just warmth. So, tomatoes on the kitchen counter ripen quite nicely. That was the only way that I could get ripe tomatoes this year. I did not see many leaf-footed bugs this year after the first rash of juveniles that I managed to kill, but suddenly, I am seeing a bunch of large adults. In fact, yesterday I saw seven adults, six of them mating. Fortunately, when you do the Louisiana Stomp on them that stops their laying eggs. So hopefully, the next generation will be even smaller than this year’s was. I am also seeing more and more assassin bugs. The first year here, with the surrounding cane fields constantly doused with insecticides, I saw only two or three assassin bugs all year. After a year of no insecticide on my property, I saw a few more. Then, the cane farmer sold the field to a developer, so no more insecticide and the number of assassin bugs exploded. It was wonderful to see.
When the stinkbugs became too much, I did resort to using insecticides, but all of them were organic and, of course, I used Integrated Pest Management (IPM). With IPM, you do not just randomly spray every plant with a broad-spectrum pesticide. Instead, you first identify the insect that is causing the problem and then use the method that is the least damaging to the environment and your health to control that insect. This can start with hand picking and dropping them into soapy water (gloved hand or tongs, of course). If that is not possible, for instance because the insects are too numerous, or too small, or because they fly away, you can move to spraying the insect(s) with soapy water or water with a little oil added. This smothers the insect and in the case of flying insects, makes it difficult for them to fly, allowing you to hand pick them. If that is not working sufficiently and there is still too much damage to your crop, you can move to using a product that is very specific to the particular type of insect causing the damage, like Bacillus thurigensis, commonly called ‘Bt’ that is specific for certain insects, but is harmless to fish, birds, and mammals.
Bt is a naturally occurring, soil-borne bacterium commonly found throughout the world. It has been used since the 1950s for natural insect control and all subspecies are approved for organic gardens. It consists of a spore, which when consumed by certain insects, develops in the gut and poisons the insect, causing it to stop feeding. The gut of these insects is alkaline, which is what makes Bt work on them while remaining harmless to birds, fish and mammals, whose guts are acidic negating the effect of the bacteria. Adding to the safety profile, Bt biodegrades quickly in sunlight.
There are a number of subspecies of B. thurigensis that are toxic to certain insects at certain stages. Bacillus thuringiensis var. kurstaki (Bt-k) controls tent caterpillars, gypsy moth, cabbage looper, tomato hornworn and other leaf -eating caterpillars. It is most effective when applied during the 1st and 2nd instars. Bt-k is supplied under many trade names, like Monteray Bt.
Bacillus thuringiensis var. israelensis is highly specific for use against mosquito, black fly and fungus gnat larvae. It can be applied to water sources safely and is 95 - 100% effective on mosquito larvae within 24 hours of ingestion. This application is especially effective because it kills the larvae before they reach the adult, biting stage.
Bacillus thuringiensis var. san diego (Bt-sd) and Bacillus thuringiensis var. tenebrionis (Bt-t) are used against the Colorado potato beetle, which has developed resistance to multiple chemical insecticides. They are also considered the most effective control for leaf-eating beetle species. They can also be used to control elm leaf beetle and are used on potatoes, eggplant, tomato and elm. Again, this biological pesticide is most effective in the early larval stages. In fact, they are completely ineffective on adult beetles.
Finally, Bacillus popilliae is used against Japanese beetles in lawns, causing milky spore disease. Milky spore again affects the larval form of the Japan beetle. When mildy spore is applied to the lawn it infects the beetle larvae. When each infected larva dies and decomposes, billions of new spores are released into the soil. This is not a quick solution, but rather requires time for the bacteria and its spores to saturate the soil. Being a natural process though, only one application is required. The bacteria will continue to multiply on their own as long as larvae are present. When there are no more grubs to be found, the bacteria sporulate and go dormant, waiting for the next infestation of Japanese beetle larvae.
These products come under many trade names like Dipel, Thuricide, Milky Spore, Monteray Bt, Mosquito Dunks and more. The important thing is to look for ‘Bacillus thuringiensis’ in the Active Ingredients. If you absolutely need an insecticide that is broadly effective against many insects, I recommend one containing spinosad. This should not, of course, be your first choice when reaching for an insecticide, but it is an effective, organic choice. Spinosad is relatively new. It is a combination of two compounds produced by the fermentation of certain microbes found in soil. It is considered ‘broad-spectrum’ because it is toxic to a wide variety of insects, but it is relatively non-toxic to mammals and beneficial insects. Part of the reason it is not toxic to beneficials is that the product must be ingested to be toxic, unlike many chemical insecticides that are toxic on contact, even to the dry residue. Most beneficials eat other insects or their eggs rather than leaves or other parts of plants, so they do not take in spinosad. Nonetheless, I prefer to apply an insecticide product containing spinosad late in the day, after the pollinators, like bees, have returned to their nests. I also try to inspect the plant that I am treating to insure that there are no other beneficials, such as mantises, lacewings, ladybugs, assassin bugs, OR THEIR LARVAE, on the plant. Please excuse the shouting, but the larvae of most of these insects are truly the workhorses, eating many more harmful insects than the adults do. You should be able to identify the larval stage of each of these beneficials. Hint, they look nothing like the adult.
It’s also helpful to identify the eggs of the good and the bad bugs. If you can eliminate the eggs of the bad bugs, you will never have to bother buying insecticide. Some products containing spinosad are Fertilome Borer, Bagworm, Tent Caterpillar & Leaf Miner Spray, Captain Jack’s DeadBug Brew Concentrate, Southern Ag Conserve Naturalyte Insect Control, and Bonide Colorado Potato Beetle Concentrate.
It’s still time to plant here in southern Louisiana. Through early September, plant Limas, both bush and pole, Brussels sprouts, broccoli, cauliflower, English peas and cucumbers, as well as bush beans, cabbage, Irish potatoes, pumpkins and tomato plants. Through September you can plant beets, carrots, celery, Swiss chard, Chinese cabbage, collards, kohlrabi, lettuces, mustard, radishes and turnips.
My organic ethic has been a bit challenged this year. I have been inundated by stink bugs and they have ruined almost all of my tomatoes. I did, however, get some and they were really delicious, but I had to pick them the minute I saw the first trace of color. Fortunately, tomatoes ripen well off the vine as long as they have warmth. They don’t even need light, just warmth. So, tomatoes on the kitchen counter ripen quite nicely. That was the only way that I could get ripe tomatoes this year. I did not see many leaf-footed bugs this year after the first rash of juveniles that I managed to kill, but suddenly, I am seeing a bunch of large adults. In fact, yesterday I saw seven adults, six of them mating. Fortunately, when you do the Louisiana Stomp on them that stops their laying eggs. So hopefully, the next generation will be even smaller than this year’s was. I am also seeing more and more assassin bugs. The first year here, with the surrounding cane fields constantly doused with insecticides, I saw only two or three assassin bugs all year. After a year of no insecticide on my property, I saw a few more. Then, the cane farmer sold the field to a developer, so no more insecticide and the number of assassin bugs exploded. It was wonderful to see.
When the stinkbugs became too much, I did resort to using insecticides, but all of them were organic and, of course, I used Integrated Pest Management (IPM). With IPM, you do not just randomly spray every plant with a broad-spectrum pesticide. Instead, you first identify the insect that is causing the problem and then use the method that is the least damaging to the environment and your health to control that insect. This can start with hand picking and dropping them into soapy water (gloved hand or tongs, of course). If that is not possible, for instance because the insects are too numerous, or too small, or because they fly away, you can move to spraying the insect(s) with soapy water or water with a little oil added. This smothers the insect and in the case of flying insects, makes it difficult for them to fly, allowing you to hand pick them. If that is not working sufficiently and there is still too much damage to your crop, you can move to using a product that is very specific to the particular type of insect causing the damage, like Bacillus thurigensis, commonly called ‘Bt’ that is specific for certain insects, but is harmless to fish, birds, and mammals.
Bt is a naturally occurring, soil-borne bacterium commonly found throughout the world. It has been used since the 1950s for natural insect control and all subspecies are approved for organic gardens. It consists of a spore, which when consumed by certain insects, develops in the gut and poisons the insect, causing it to stop feeding. The gut of these insects is alkaline, which is what makes Bt work on them while remaining harmless to birds, fish and mammals, whose guts are acidic negating the effect of the bacteria. Adding to the safety profile, Bt biodegrades quickly in sunlight.
There are a number of subspecies of B. thurigensis that are toxic to certain insects at certain stages. Bacillus thuringiensis var. kurstaki (Bt-k) controls tent caterpillars, gypsy moth, cabbage looper, tomato hornworn and other leaf -eating caterpillars. It is most effective when applied during the 1st and 2nd instars. Bt-k is supplied under many trade names, like Monteray Bt.
Bacillus thuringiensis var. israelensis is highly specific for use against mosquito, black fly and fungus gnat larvae. It can be applied to water sources safely and is 95 - 100% effective on mosquito larvae within 24 hours of ingestion. This application is especially effective because it kills the larvae before they reach the adult, biting stage.
Bacillus thuringiensis var. san diego (Bt-sd) and Bacillus thuringiensis var. tenebrionis (Bt-t) are used against the Colorado potato beetle, which has developed resistance to multiple chemical insecticides. They are also considered the most effective control for leaf-eating beetle species. They can also be used to control elm leaf beetle and are used on potatoes, eggplant, tomato and elm. Again, this biological pesticide is most effective in the early larval stages. In fact, they are completely ineffective on adult beetles.
Finally, Bacillus popilliae is used against Japanese beetles in lawns, causing milky spore disease. Milky spore again affects the larval form of the Japan beetle. When mildy spore is applied to the lawn it infects the beetle larvae. When each infected larva dies and decomposes, billions of new spores are released into the soil. This is not a quick solution, but rather requires time for the bacteria and its spores to saturate the soil. Being a natural process though, only one application is required. The bacteria will continue to multiply on their own as long as larvae are present. When there are no more grubs to be found, the bacteria sporulate and go dormant, waiting for the next infestation of Japanese beetle larvae.
These products come under many trade names like Dipel, Thuricide, Milky Spore, Monteray Bt, Mosquito Dunks and more. The important thing is to look for ‘Bacillus thuringiensis’ in the Active Ingredients. If you absolutely need an insecticide that is broadly effective against many insects, I recommend one containing spinosad. This should not, of course, be your first choice when reaching for an insecticide, but it is an effective, organic choice. Spinosad is relatively new. It is a combination of two compounds produced by the fermentation of certain microbes found in soil. It is considered ‘broad-spectrum’ because it is toxic to a wide variety of insects, but it is relatively non-toxic to mammals and beneficial insects. Part of the reason it is not toxic to beneficials is that the product must be ingested to be toxic, unlike many chemical insecticides that are toxic on contact, even to the dry residue. Most beneficials eat other insects or their eggs rather than leaves or other parts of plants, so they do not take in spinosad. Nonetheless, I prefer to apply an insecticide product containing spinosad late in the day, after the pollinators, like bees, have returned to their nests. I also try to inspect the plant that I am treating to insure that there are no other beneficials, such as mantises, lacewings, ladybugs, assassin bugs, OR THEIR LARVAE, on the plant. Please excuse the shouting, but the larvae of most of these insects are truly the workhorses, eating many more harmful insects than the adults do. You should be able to identify the larval stage of each of these beneficials. Hint, they look nothing like the adult.
It’s also helpful to identify the eggs of the good and the bad bugs. If you can eliminate the eggs of the bad bugs, you will never have to bother buying insecticide. Some products containing spinosad are Fertilome Borer, Bagworm, Tent Caterpillar & Leaf Miner Spray, Captain Jack’s DeadBug Brew Concentrate, Southern Ag Conserve Naturalyte Insect Control, and Bonide Colorado Potato Beetle Concentrate.
It’s still time to plant here in southern Louisiana. Through early September, plant Limas, both bush and pole, Brussels sprouts, broccoli, cauliflower, English peas and cucumbers, as well as bush beans, cabbage, Irish potatoes, pumpkins and tomato plants. Through September you can plant beets, carrots, celery, Swiss chard, Chinese cabbage, collards, kohlrabi, lettuces, mustard, radishes and turnips.
MaryAnn Armbruster, Ph.D.
MaryAnn Armbruster, Ph.D. is a certified Advanced Master Gardener and member of the Lafayette Parish Master Gardeners.
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