Pests and Pesticides

The most annoying part of growing vegetables is coping with pests and diseases. Here are some tips on how to control them: If an insect problem is not excessive, picking the pests off the leaves or blasting them with water can be effective.

A. Look for new grasshoppers to hatch in March or April. They do not fly and can be killed in the early stages with an organic bait product (Grasshopper Attack, Grasshopper Control, Nolo Bait or Semaspore). The bait will also affect upcoming generations. Look for grasshoppers on spider and crinum lily and firebush particularly. An organic control for the very destructive lubber grasshopper is a mixture of hot pepper, soap and water sprayed on the leaves of the affected plants. This mixture will repel the grasshoppers. The big grasshoppers are best killed mechanically, as they become too large to be killed by commercial sprays. The large yellow lubbers do not fly like most of their relatives so are easier to catch and kill. They soon lay eggs and die off.

Q. My pinwheel jasmine and ponytail palms have black on their trunks and some leaves.

A. Your plants have sooty mold caused by sucking insects. Sucking insects like scale and whitefly create a honeydew secretion. The sooty mold grows on this and causes the blackened leaves. Organic gardeners can use Safer's Insecticidal Soap, but you must cover all affected areas with the soap, as it is a contact insecticide. You can also use Orthene to control. Retreat in 10 days.

Q. I have potted plants with ants in the soil. What can I do to get rid of them before bringing the plants inside?

A. Drench the pot with soapy water to drive the ants out. You may have to repeat the treatment several times.

Q. I have had a bad snail problem with my flowering plants. Do you have any organic controls? The bait is not very effective.

A. Many people report success by sinking saucers into the ground and filling them with beer. The snails and slugs drown in the beer; repeat the process until populations are reduced. Another trick is to surround the plants with diatomaceous earth or crushed shells from hard-boiled eggs. The eggshells and diatomaceous earth are sharp and puncture the snails/slugs so they dry out and die. The eggshells will need to be rinsed.

A. Funginex should control black spot. Keep foliage dry. Water in the morning only to minimize fungal problems. The roses should be in an open area, well spaced for maximum air circulation. Rake dead leaves from the ground around the plant to try to break the fungal space cycle. Orthenex is good if you want a combination of insecticide and funcigide.

A. The sweet potato whitefly has been attacking hibiscus and poinsettia. It is a very stubborn pest. Try a systemic insecticide like Orthene, which makes the whole plant poisonous. You will not have to worry about hitting every leaf as you do with a contact insecticide.

Q. I have a passion vine and hibiscus that produce buds, but the buds drop off.

A. You probably have thrips which damage new flowers, particularly roses, gardenias and hibiscus. They can be controlled with Orthene.

A. The stinkbug often punctures fruit, particularly thin-skinned types of citrus. Small brown scavenger beetles will clean out the interior of the fruit after it has been punctured. Occasionally a fruit rat will eat fruit, but then the hole is much larger in the fruit. Stinkbugs are very mobile, so spraying is not effective. Pick fruit early, just at ripening, to beat this pest.

Q. My impatiens have deformed curled tips. They are in pots and in the ground. I have sprayed Orthene, Di-syston, Cygon, Diazinion, and other sprays and cleaned the pots with alcohol before planting. I have a super strain of whitefly. My potted hibiscus and mandevilla are affected. I have used Orthene, Cygon, Thiodan, and Di-syston. The Thiodan and ultrafine oil spray was effective but not for long. The yellow sticky traps worked but filled up very quickly. What do you suggest?

A. It sounds like you have used everything but the atomic bomb on your plants. Insects can become superbugs with repeated sprays of insecticides as they build up resistance. Your impatiens and mandevilla are high on my DO NOT plant list as they have lots of problems. Hibiscus also have problems but usually are more manageable. They are usually big growers to 10 feet plus and resent confinement in a pot for more than two years for the standard landscape varieties. I would plant them in the ground and use something like desert rose as a substitute. If you insist on fiddling around with these troublesome plants you might try a mix of Organocide and Excel which is an organic oil and pyrethrum mix. That should stop the whiteflies. Another option is to choose less troublesome plants for your yard. Wax begonia can substitute for the impatiens and is infinitely less troublesome. A good vine substitute could be Henderson's allamanda.

Q. How can I tell if my plant has spider mites? What do they look like? How did I get them? Do they fly or crawl and are they going to affect my outside plants? How do nurseries protect themselves?

A. Spider mites are microscopic sucking insects related to the spider. They crawl or can be transported by the wind. Spider mites can be detected if you shake some affected branches over a white paper. If little eight legged dots are moving around, you probably have spider mites. Verify with a magnifying glass. Heavy infestations sometimes can be detected because the plants have webbing over the needles and branches. Mites are most active in the winter months. They are already outside and since rainfall on the leaves washes them off, they are mainly a winter problem. Nurseries have overhead watering systems, so they don't have a major problem with spider mites. Take your plants outside, under a tree and blast off the mites with a strong jet of water from the hose. Other controls include Safer's Insecticidal Soap or a miticide such as Kelthane. To avoid problems in the dry season, hose your plants off periodically in the morning

Q. We have a millipede invasion on our screened porch every fall. What can we do for control?

A. Millipedes live in the grass and normally are not a problem. After a wet summer, they often seek higher ground to avoid overly wet soil. If you water a great deal, like once a day or every two days, you are drowning your plants and inviting millipedes. Get a rain sensor for your irrigation system so it will shut off automatically when it rains. If we have no rain, water no more than two times a week. Remember, interior areas get about 10-15 inches more rain than coastal areas. You may wish to spray a band of Dursban just outside the screened area to form a barrier against the invaders.

A. Nematodes prefer sandy soils. Organic matter such as leaves, peat moss, etc. incorporated into the existing soil will discourage nematodes. Plantings of French marigolds also have a repelling effect if you turn them under the soil after blooming. Consider purchasing nematode-resistant plants to avoid the problem. Some varieties of plants are resistant to nematodes and many woody plants are grafted on resistant wood stock. In you are preparing new ground for planting and want to insure a nematode free area, solar sterilization of the garden plot over the summer is another possibility. Cover the garden tightly with clear plastic for two and a half months from the middle of June to the end of August. The soil will heat up to 130 _ 140 degrees, killing nematodes and other pests.

A. The only way to keep birds off your citrus would be to invest in bird netting. Netting is used up north for cherry trees and blueberry plants. Park's Seed and other major mail order houses carry the netting. You might also try hanging a replica of an owl. That seems to discourage many birds. However, you need to move it occasionally or the birds get wise and return when they realize the owl isn't real. I've also seen strips of foil or shiny aluminum pie plates attached to the branches with bits with string, thereby allowing them to flutter in the breeze, used as an avian deterrent.

Land crabs are scavengers and are mainly above ground and active during the warmer months from May through October. They stay in their burrows in cooler weather. These burrows can be 15-20 feet long and reach down to the water table. Moth balls, poisoned bread and sonic systems have little effect on them. No pesticides are currently recommended for their control. They can be caught with crab nets and are edible. People in the Caribbean Islands consider them a delicacy. They keep the crabs captive for two weeks and feed them cornmeal to clean out their systems. It should be possible to control a good part of the local population or at least conjure up a good meal during a crab roundup on one of the full moon nights when they mate.

Q. We just put in pentas around our pool and they disappeared over night, thanks to a hungry iguana. What can I do to stop him without killing him?

A. Try using pepper spray, a homemade mix that will discourage squirrels, rats, birds, insects and iguanas*. Add 2 teaspoons liquid Ivory soap to a spray jar. Put a coffee filter or cheese cloth over the jar mouth and add 2 tablespoons cayenne pepper and 1 tablespoon garlic powder. Add water and let the essence filter into the jar, then spray the foliage. It will not harm the plant or the iguana but it will taste terrible. When it rains the mixture will wash off.
* Since the book was published, iguanas have proliferated in south Florida and there is not much you can do to discourage them. We have used Neem oil which works for a while but once the oils dissipate the iguanas return in an herbivorous herd. They have devoured the hibiscus and eaten the orchids. We have a test garden along the waterfront to see what they will leave alone. So far they have not developed an appetite for the rosemary, crotons, native salvias, marigolds, citrus and milkweed.
For more information read: The Iguana Invasion pdf file

. Our condominium is having a rat problem. Are there plants that attract rats?

A. A number of plants can attract rats and snakes as they provide good shelter. Pampas grass harbors these pests and the pandanus or screwpine with its stilt-like roots is also a likely candidate. The screw pine, Pandanus utilis, grows in a tree form and is less likely to encourage vermin as it is very open growing. The shrubby clumping pandanus types are more likely to provide shelter as they are very dense. Keep tree and palm branches pruned away from the building, porches, roofs and catwalks to help minimize rat problems.

White footed ants are a new pest in Florida.
There is no recommended control here for them. Neil Reimer, entomologist for the Hawaii Department of Agriculture recommends a sugar water/boric acid bait for control.

Dursban, a chemical product, has recently been removed from the market and many homeowners are at a loss for what to do about insect control in their lawns.

Beneficial nematodes are an organic, living microscopic worm that preys on at least 24 lawn insect pests including sod webworm, army worm, chinch bug, lawn grubs and other lawn pests.

University of Texas conducted tests with beneficial nematodes and found that the beneficial nematodes killed 98% of fleas in the lawn. Most people spray for flea control and this is an effective product for that use.

It is important to note that the beneficial nematode containers are stale dated so must be applied before the stale date.

They can be applied directly to the lawn through a hose-on sprayer. Follow directions on the label. The nematodes are effective for six to seven weeks.

Sources for beneficial nematodes include: Gore Nursery, 1611 SW 19th Ave., Fort Lauderdale, 954-463-4673, Garden Gate Nursery at Sears, Corner of Copans and Federal Highway, Pompano, 954-783-1189. Mail order source: Gardens Alive, 5100 Schenley place, Lawrenceberg, Ind., 47205, 812-537-8651

Pruned and hatracked ficus may be subject to a relatively new disease. I first noted this disease, Hypoxylon canker, on a historic strangler fig in Palm Beach in 1999. We also noted the disease on Ficus retusa and Ficus benjamina. I recently saw the same disease in Plantation, Florida.

The disease usually enters the tree through large wounds caused by pruning. If your ficus is dying back this disease could be the cause. Look for discolored dark areas in the wound area. Bark peeling with dark areas underneath are also characteristic. No control is available to my

knowledge.

A new rust disease was recently found on Syzygium paniculatum, the Australian brush cherry which is commonly used for topiary work in this country. Roger Brook's of Four B's wholesale nursery first noted the disease on some of his topiaries. A & L Southern Agricultural Laboratories in Pompano Beach identified the rust disease and noted some commercial controls for the problem. The best option for people who buy topiaries is to specify Syzygium paniculatum 'Globulus' which is a slower growing, much darker green variety used in topiary work. The 'Globulus' variety is hard to propagate and tissue culture is the best option. Plants are more expensive, but are immune to the rust disease which defoliates the topiary.

Florida Dept. of Agriculture & Consumer Services Memorandum states that Orange jasmine
(Murraya paniculata) has been added to the host list for Citrus Greening.

Orange jasmine is capable of being the host plant for the citrus psyllid which carries the Citrus greening disease from plant to plant. So, do not purchase any. They are being quarantined in Dade County with restrictions in place on the growers to grow them in screened approved enclosures.

Manatee and Hillsborough Counties are reporting the decline and death of our state tree in their areas. The fatal decline is caused by a phytoplasma, the Texas Phoenix palm decline which affects the Canary Island, Date, Wild Date, and Queen palms. The Sabal palms first show an excessive amount of dead leaves at the bottom of the tree. The next step is the death of the spear leaf and finally all the leaves die. The bud then decays and the top tips over. The insect spreading the decline is not known at this time.



	PESTS AND PESTICIDES The best advice is to stay away from insecticides unless you see a problem. Pesticides that drip into our waterways cause fish kills and other environmental problems. I recommend that you use organic controls whenever you can. Insects build up resistance to pesticides, creating superbugs. Use the safest product possible and make sure you have the problem correctly identified so you will not use the wrong pesticide. Less usually is better than more. I have sprayed only twice on my property in the past 17 years for a localized problem. General Suggestions Spray in the early morning or late evening when the temperature is below 85 degrees. Spraying when temperatures are over 85 degrees can burn leaves and cause leaf yellowing or leaf drop. Do not spray if it is windy as some sprays stain or could hurt adjacent plantings. Copper fungicide is an example as it can stain everything electric blue like your house or paving. Repeat treatment in 7-10 days to kill new pests hatching from eggs. Use a spreader sticker or a few drops of soap with your pesticide mix to help the spray adhere to the plant. Clearly many of the most frequently asked questions regarding insects revolve around tomatoes, those succulent orbs of earthy delight. As versatile as they are delicious, they can be grown in pots on a patio or planted in the yard. One bite will convince you that, whatever their problems, they are worth the effort. From letters and samples sent or presented to me at plant clinics, I present the condensed guide to growing tomatoes. They can drive you buggy! A woman has a small Baggie in her hand. Inside is a branch from a tomato plant. The leaves are green but oddly puckered. "What's wrong with my tomatoes?" she asks plaintively. The answer is aphids -small, soft-bodied insects that suck plant juices. The telltale sign is the twisted leaves. The remedy is a thorough spray with the garden hose or an application of insecticidal soap. The next person carries the patient, or a small piece of it, in a plastic dish. Again, it's a tomato plant. Yellow leaves, with small dark splotches. Hmmm. Could be blight or maybe leaf spot. Both are treatable, if not curable, with a copper sulfate spray or a weak solution of hydrogen peroxide. But it could also be fusarium or verticillium wilt, in which case the prognosis is poor. The gardener should have used a disease - resistant variety. You have to face it. Pests are the order of the day with tomatoes. Expect leaf damage, but don't let it drive you crazy. Some insects, such as leafminer, will make the leaves look awful, but they will not affect fruit yields. One of the reasons we grow our own food is to have some control over what chemicals go on it. It's best to avoid heavy doses of pesticides. Use commercial insecticidal sprays as a last resort. Beneficial insects are a good first line of defense. Ladybugs control aphids, mealybug, scale and other sucking insects. Praying mantis control larger insects such as grasshoppers, beetles and other chewing pests. Parasitic wasps lay eggs on caterpillars, such as tomato hornworm and other larvae. Give the good guys a few days to start working on the bad guys before you panic. Now, let's get more specific. Aphids Aphids come in many colors, from rosy pink to gray to pale green and they attack almost anything. Some have wings; others don't. If your plant is growing slowly, or if the leaves (especially the tender young ones) look twisted or puckery, check the underside for these little sap-sucking insects. Their sucking causes distorted foliage and poor growth. They may also spread tobacco mosaic virus, a disease fatal to tomatoes. A strong spray of water will wash them off, but you will have to repeat the treatment often. You also can use a commercially prepared insecticidal soap, available at garden centers, to suffocate them. Or put a couple of tablespoons of hydrogen peroxide in a gallon of water and spray the plant regularly. The good news? Aphids are a favorite food for ladybugs. Stinkbug An occasional problem on tomatoes and citrus, stinkbug is a shield-shaped bug about a half inch long. It can be green, black or brown and can leave a foul odor on your hands if it is handled. Stinkbug punctures the fruit and sucks out the juices. The fruit will change color where the stinkbug feeds and leaves a toxin behind; a tomato will turn white or yellow in the affected areas. The best control is to remove weedy areas where they hide close to the tomatoes. If you continue to have problems, dust the fruit with diatomaceous earth or spray with insecticidal soap. Cutworm Cutworm is a major problem for new tomato transplants. The caterpillar is about 1 to 2 inches long and is usually black or gray. Active only at night, they hide below the ground during the day. They chew new transplants off at the ground level and the plant topples over and dies. The easiest solution is to put a "collar" around the transplant after it is set in the ground. You can use almost any material _ cardboard, empty vegetable cans with both ends removed or empty toilet paper tubes. Make sure the collar is pushed down about an inch into the soil and is at least 2 inches high Tomato fruitworm Tomato fruitworm is active in south Florida. The caterpillar is about an inch and a half long and can be green, pink or brown. It enters the tomato at the stem end and feeds on the fruit, making it worthless. Nature can take care of these pests because they are often parasitized by trichiogamma wasps and tachnid flies. Or you can dust the fruit with diatomaceous earth or Dipel. Tomato hornworm The tomato hornworm is a big guy _ more than 4 inches long- but its dark green color makes it difficult to see in foliage. It gets its name because of a horn at the rear end of its body. One or two of these fellas can eat an entire plant. Leaves may be chewed to the stem; occasionally fruit also will be consumed. In most cases, they can be picked off by hand and dropped in a can of kerosene or ammonia. The best time to find them is at night using a flashlight, because they hide during the day. One warning: If you find a hornworm or other caterpillar with small white sacks on its back, leave it alone. The sacks contain the larvae of a small wasp that preys on the hornworm and other caterpillars. Blossom end rot Blossom end rot is a common problem on tomatoes. One end of the fruit rots making it unuseable. A calcium deficiency is the cause of this disorder. Try spraying 2 times a week with 4 tablespoons of calicium chloride mixed in 3 gallons of water. Spray 1 quart per plant. New Insect Pests – Dr. Catharine Mannion, ornamental entomologist at the Tropical Research Station in Homestead, reported on some new insect pests to watch out for in Florida. They have all started in the Miami area. A new thrip has been discovered on pink tabebuia’s in Dade County in 2001. It feeds on the trees leaves causing leaf distortion, folded, and curled leaves that may be covered with galls. The insect is best controlled with systemic insecticides. The lac scale was discovered in 1999 and is globe shaped with a waxy covering. Lac scale can be light to dark reddish brown in color. It attacks new stems but not leaves. Oil products like Organocide should offer good control. This scale has been noted on wax myrtle, cocoplum, buttonwood, and sand live oak in the native plant group. Exotic black olive, and weeping fig are also affected. A Sri Lanka weevil has been found on lychee and mango trees in Dade County. This weevil has a wide host of plants that it will feed on. It could cause serious damage. Weevils chew foliage and roots. The strangest pest of all is a spider which does not prey on the plant itself. It makes heavy horizontal webs which can completely cover a plant cutting light off. The plant will eventually die from lack of light. The spider should be killed to stop nest building but it is important to have the spider properly identified before any spraying is done. The pink hibiscus mealybug is the latest pest to visit south Florida. It was identified on 2 hibiscus plants in Pembroke Pines. This bug can attack over 200 different plant species. It is spread by wind and ants. Florida Department of Agriculture staff are trying to eradicate the pest. If it escapes eradication a small Puerto Rican wasp offers hope for control. This mealybug was last seen in southern California in 1999 where it was eliminated. It has the potential to weaken and even kill some plants here. The Lobate Lac scale now is attacking 120 Florida plant species including 39 native species such as wax myrtle, cocoplum, buttonwood, strangler fig, myrsine, red bay, and wild coffee. Exotics like black olive, Indian laurel fig and Benjamin fig are also attacked as are edible fruit trees like mango, lychee, and starfruit. Ficus benjamina has been under recent attack with the lac scale whose voracious feeding turns the ficus leaves black with sooty mold. A new thrip is now attacking Ficus benjamina. The thrip curls and distorts the leaves and the pest has been found in Dade and Broward counties so far. The damage is similiar in appearance to the thrip that has attacked Ficus retusa foliage for years. Ortho Systemic Insecticide and Bayers Tree and Shrub insecticide will control this pest. Gore Nurseries, Bob Betz told me about this new insect pest. The gall or bud midge is a new pest attacking hibiscus blooms. The flower buds drop after this pest attacks. Thrips were the other pest attacking the buds causing bud drop. Ortho Systemic Insecticide will control this pest. Ortho Systemic Insecticide has a danger label so follow label directions exactly. A biological control offers the best long term cure but a soil drench of systemic Merit or Bayer's Lawn and Garden Care will offer quick control. Follow label directions exactly. Remember that systemic insecticides will also poison the fruit so these products are not recommended for fruit trees. My 'Knockout' rose had pale stippled foliage and I decided to see what the problem was. The leaves on this otherwise healthy rose were almost white in color. It turned out that the problem was the Chilli thrip. This pest is particularly bad on the 'Knockout' rose. It can also affect many other plants with documented attacks on yeddo hawthorn, Viburnum suspensum, and Rhododendron species. It can attack many different plants. I treated the rose with Bayer's Tree and Shrub Care soil drench and the problem cleared up within a few days. The old leaves dropped off and the new growth and flowers look good. This product should protect the plant for at least a year if label directions are followed. We were almost invaded recently by the giant harlequin beetle. This pest has the ability to kill mango and cashew trees by burrowing into the trunk and branches eventually killing the tree. This long horn beetle has big antennae which help to identify it. The bettle can also blemish fruit. Department of Agriculture plant inspectors found the pest walking on the deck of a freighter from Honduras. The beetle was captured and fortunately did not make it to our shores. More New Insect Pests added 1-08 Red Palm Mites are the newest pest on palms in South Florida. These mites attack coconuts first but also feed on date and areca palms. They have been found on 32 different types of palms. Insecticidal soap or oils like Organocide offer control for homeowners. Merit should work for commercial applications. Damage would be most apparent in the dry season. Stippling is the initial appearance on foliage and eventually spots spread to form brown leaves and defoliation. Palms can die under heavy attack. Ficus Whitefly is causing extensive damage on ficus hedges and trees in Dade County. Leaves yellow and hedges and trees become bare if not treated. Treat with Organocide at weekly intervals for 3 weeks to give control. Trees and hedges grow back if treated. Ficus benjamina is a favored host but this whitefly also attacks other ficus. Dade County has released natural predators to control the outbreak before it spreads. Palm Weevil borers attack newly planted or stressed palms and causes the top of the palm to lean over and eventually to fall off. Date and sabal palms are favored hosts. More New Insect Pests Added 1-09 A new soft scale is recent addition to the exotic pest population of South Florida. The croton is a preferred host plant but this scale can also attack guava, strangler fig, mysore fig, mango, firebush, wild coffee, marlberry, and satinwood. The female scales are greenish-yellow with dark striations. Male scales have a glassy appearance. This new pest does not have any natural enemies at present. Pesticides like Organocide, and Safer’s Insecticidal Soap should offer control on the open growing croton. Apply when the temperatures are below 85 degrees and when there is no wind. Reapply in 10 days to kill hatching eggs. Added 8-11-2009 Laurel Wilt is a new disease threatening avocado trees in South Florida. This disease was first noted in North Florida where many native red bay trees were dying. The disease was just discovered in South Florida at the University of Florida's Tropical Research and Education Center in Homestead in Miami-Dade County. The county has over 6500 acres in commercial avocado production and the crop is valued at 40 million dollars by commercial growers in the area. Laurel Wilt poses a serious hazard for homeowners who are growing the tree for their own consumption. The disease is spread by the red ambrosia beetle which bores into the tree and spreads the disease through its mouthparts. The beetle attacks living trees, pruned and injured trees, stumps, and severed branches. Trees can die from 21 days to 3 months depending on tree condition. The disease is spread by movement of infested wood, wood chips from infested trees, illegal dumping of infested wood, using landfills that do not burn or bury infested wood, and moving plants of red bay and avocado that might be infested. Trees will wilt, leaves will turn to dark green/brown and hang on the tree, Stems and trees will die back, and trees will have boring holes with whitish sap and the inner sapwood will have dark streaks. Sapwood normally is white without dark streaking. Call 1-888-397-1517 if you suspect activity on your avocado or red bay.



	*HOW TO COMBAT PESTS* The most annoying part of growing vegetables is coping with pests and diseases. Here are some tips on how to control them: If an insect problem is not excessive, picking the pests off the leaves or blasting them with water can be effective. Insecticidal soap is useful for sucking insects. Follow label directions and spray on the underside of the leaves before 10 a.m. or in the evening; repeat spray a week later. Never spray if pollinating bees or wasps are working the flowers. Beneficial nematodes kill many soil-borne insects, including cutworms and beetle and weevil larvae that can chew foliage and roots of many plants, including tomatoes. Spray them in the garden with a hose and water. Bacillus thuringiensis (also called B.T.) is marketed as Thuricide, Dipel, or Biotrol. It's an organic specific stomach poison for use on caterpillars such as hornworms and fruitworms. New strains have been developed for grasshoppers and other insects. Diatomaceous earth is composed of ground-up fossilized one-celled creatures from prehistoric times. The powder can be sprinkled around the base of plants to stop slugs, snails and other insects from crawling up plants and feeding. Q. Could you tell me about grasshopper control? A. Look for new grasshoppers to hatch in March or April. They do not fly and can be killed in the early stages with an organic bait product (Grasshopper Attack, Grasshopper Control, Nolo Bait or Semaspore). The bait will also affect upcoming generations. Look for grasshoppers on spider and crinum lily and firebush particularly. An organic control for the very destructive lubber grasshopper is a mixture of hot pepper, soap and water sprayed on the leaves of the affected plants. This mixture will repel the grasshoppers. The big grasshoppers are best killed mechanically, as they become too large to be killed by commercial sprays. The large yellow lubbers do not fly like most of their relatives so are easier to catch and kill. They soon lay eggs and die off. Q. My pinwheel jasmine and ponytail palms have black on their trunks and some leaves. A. Your plants have sooty mold caused by sucking insects. Sucking insects like scale and whitefly create a honeydew secretion. The sooty mold grows on this and causes the blackened leaves. Organic gardeners can use Safer's Insecticidal Soap, but you must cover all affected areas with the soap, as it is a contact insecticide. You can also use Orthene to control. Retreat in 10 days. Q. I have potted plants with ants in the soil. What can I do to get rid of them before bringing the plants inside? A. Drench the pot with soapy water to drive the ants out. You may have to repeat the treatment several times. Q. I have had a bad snail problem with my flowering plants. Do you have any organic controls? The bait is not very effective. A. Many people report success by sinking saucers into the ground and filling them with beer. The snails and slugs drown in the beer; repeat the process until populations are reduced. Another trick is to surround the plants with diatomaceous earth or crushed shells from hard-boiled eggs. The eggshells and diatomaceous earth are sharp and puncture the snails/slugs so they dry out and die. The eggshells will need to be rinsed. Q. What can do about black spot on my roses? A. Funginex should control black spot. Keep foliage dry. Water in the morning only to minimize fungal problems. The roses should be in an open area, well spaced for maximum air circulation. Rake dead leaves from the ground around the plant to try to break the fungal space cycle. Orthenex is good if you want a combination of insecticide and funcigide. Q. I have white fly on my poinsettia. What can I use to kill them? A. The sweet potato whitefly has been attacking hibiscus and poinsettia. It is a very stubborn pest. Try a systemic insecticide like Orthene, which makes the whole plant poisonous. You will not have to worry about hitting every leaf as you do with a contact insecticide. Q. I have a passion vine and hibiscus that produce buds, but the buds drop off. A. You probably have thrips which damage new flowers, particularly roses, gardenias and hibiscus. They can be controlled with Orthene. Q. Something is putting holes my fruit. What might it be? A. The stinkbug often punctures fruit, particularly thin-skinned types of citrus. Small brown scavenger beetles will clean out the interior of the fruit after it has been punctured. Occasionally a fruit rat will eat fruit, but then the hole is much larger in the fruit. Stinkbugs are very mobile, so spraying is not effective. Pick fruit early, just at ripening, to beat this pest. Q. My impatiens have deformed curled tips. They are in pots and in the ground. I have sprayed Orthene, Di-syston, Cygon, Diazinion, and other sprays and cleaned the pots with alcohol before planting. I have a super strain of whitefly. My potted hibiscus and mandevilla are affected. I have used Orthene, Cygon, Thiodan, and Di-syston. The Thiodan and ultrafine oil spray was effective but not for long. The yellow sticky traps worked but filled up very quickly. What do you suggest? A. It sounds like you have used everything but the atomic bomb on your plants. Insects can become superbugs with repeated sprays of insecticides as they build up resistance. Your impatiens and mandevilla are high on my DO NOT plant list as they have lots of problems. Hibiscus also have problems but usually are more manageable. They are usually big growers to 10 feet plus and resent confinement in a pot for more than two years for the standard landscape varieties. I would plant them in the ground and use something like desert rose as a substitute. If you insist on fiddling around with these troublesome plants you might try a mix of Organocide and Excel which is an organic oil and pyrethrum mix. That should stop the whiteflies. Another option is to choose less troublesome plants for your yard. Wax begonia can substitute for the impatiens and is infinitely less troublesome. A good vine substitute could be Henderson's allamanda. Q. How can I tell if my plant has spider mites? What do they look like? How did I get them? Do they fly or crawl and are they going to affect my outside plants? How do nurseries protect themselves? A. Spider mites are microscopic sucking insects related to the spider. They crawl or can be transported by the wind. Spider mites can be detected if you shake some affected branches over a white paper. If little eight legged dots are moving around, you probably have spider mites. Verify with a magnifying glass. Heavy infestations sometimes can be detected because the plants have webbing over the needles and branches. Mites are most active in the winter months. They are already outside and since rainfall on the leaves washes them off, they are mainly a winter problem. Nurseries have overhead watering systems, so they don't have a major problem with spider mites. Take your plants outside, under a tree and blast off the mites with a strong jet of water from the hose. Other controls include Safer's Insecticidal Soap or a miticide such as Kelthane. To avoid problems in the dry season, hose your plants off periodically in the morning Q. We have a millipede invasion on our screened porch every fall. What can we do for control? A. Millipedes live in the grass and normally are not a problem. After a wet summer, they often seek higher ground to avoid overly wet soil. If you water a great deal, like once a day or every two days, you are drowning your plants and inviting millipedes. Get a rain sensor for your irrigation system so it will shut off automatically when it rains. If we have no rain, water no more than two times a week. Remember, interior areas get about 10-15 inches more rain than coastal areas. You may wish to spray a band of Dursban just outside the screened area to form a barrier against the invaders. Q. What is the best way to get rid of nematodes? A. Nematodes prefer sandy soils. Organic matter such as leaves, peat moss, etc. incorporated into the existing soil will discourage nematodes. Plantings of French marigolds also have a repelling effect if you turn them under the soil after blooming. Consider purchasing nematode-resistant plants to avoid the problem. Some varieties of plants are resistant to nematodes and many woody plants are grafted on resistant wood stock. In you are preparing new ground for planting and want to insure a nematode free area, solar sterilization of the garden plot over the summer is another possibility. Cover the garden tightly with clear plastic for two and a half months from the middle of June to the end of August. The soil will heat up to 130 _ 140 degrees, killing nematodes and other pests. Q. How can I keep birds off my citrus trees? A. The only way to keep birds off your citrus would be to invest in bird netting. Netting is used up north for cherry trees and blueberry plants. Park's Seed and other major mail order houses carry the netting. You might also try hanging a replica of an owl. That seems to discourage many birds. However, you need to move it occasionally or the birds get wise and return when they realize the owl isn't real. I've also seen strips of foil or shiny aluminum pie plates attached to the branches with bits with string, thereby allowing them to flutter in the breeze, used as an avian deterrent. Q. How do I get rid of land crabs? Land crabs are scavengers and are mainly above ground and active during the warmer months from May through October. They stay in their burrows in cooler weather. These burrows can be 15-20 feet long and reach down to the water table. Moth balls, poisoned bread and sonic systems have little effect on them. No pesticides are currently recommended for their control. They can be caught with crab nets and are edible. People in the Caribbean Islands consider them a delicacy. They keep the crabs captive for two weeks and feed them cornmeal to clean out their systems. It should be possible to control a good part of the local population or at least conjure up a good meal during a crab roundup on one of the full moon nights when they mate. Q. We just put in pentas around our pool and they disappeared over night, thanks to a hungry iguana. What can I do to stop him without killing him? A. Try using pepper spray, *a homemade mix that will discourage squirrels, rats, birds, insects and iguanas.** Add 2 teaspoons liquid Ivory soap to a spray jar. Put a coffee filter or cheese cloth over the jar mouth and add 2 tablespoons cayenne pepper and 1 tablespoon garlic powder. Add water and let the essence filter into the jar, then spray the foliage. It will not harm the plant or the iguana but it will taste terrible. When it rains the mixture will wash off. * Since the book was published, iguanas have proliferated in south Florida and there is not much you can do to discourage them. We have used Neem oil which works for a while but once the oils dissipate the iguanas return in an herbivorous herd. They have devoured the hibiscus and eaten the orchids. We have a test garden along the waterfront to see what they will leave alone. So far they have not developed an appetite for the rosemary, crotons, native salvias, marigolds, citrus and milkweed. For more information read: The Iguana Invasion pdf file . Our condominium is having a rat problem. Are there plants that attract rats? A. A number of plants can attract rats and snakes as they provide good shelter. Pampas grass harbors these pests and the pandanus or screwpine with its stilt-like roots is also a likely candidate. The screw pine, Pandanus utilis, grows in a tree form and is less likely to encourage vermin as it is very open growing. The shrubby clumping pandanus types are more likely to provide shelter as they are very dense. Keep tree and palm branches pruned away from the building, porches, roofs and catwalks to help minimize rat problems. White footed ants are a new pest in Florida. There is no recommended control here for them. Neil Reimer, entomologist for the Hawaii Department of Agriculture recommends a sugar water/boric acid bait for control. Combine 3 cups of water with 1 cup of sugar and 3 teaspoons of boric acid powder. Place the liquid in containers. He recommends film canisters ( like Kodak film comes in) Make small holes on the sides of the canisters just below the lid. Fill the canisters with the bait and snap on the top. Turn the canisters upside down and locate by the ant trails. Worker ants will die off in a few days. A few workers will continue to feed the queen ants. Allow 3 weeks for the bait to complete the job. Dursban Removed from Market Dursban, a chemical product, has recently been removed from the market and many homeowners are at a loss for what to do about insect control in their lawns. Beneficial nematodes are an organic, living microscopic worm that preys on at least 24 lawn insect pests including sod webworm, army worm, chinch bug, lawn grubs and other lawn pests. University of Texas conducted tests with beneficial nematodes and found that the beneficial nematodes killed 98% of fleas in the lawn. Most people spray for flea control and this is an effective product for that use. It is important to note that the beneficial nematode containers are stale dated so must be applied before the stale date. They can be applied directly to the lawn through a hose-on sprayer. Follow directions on the label. The nematodes are effective for six to seven weeks. Sources for beneficial nematodes include: Gore Nursery, 1611 SW 19th Ave., Fort Lauderdale, 954-463-4673, Garden Gate Nursery at Sears, Corner of Copans and Federal Highway, Pompano, 954-783-1189. Mail order source: Gardens Alive, 5100 Schenley place, Lawrenceberg, Ind., 47205, 812-537-8651 Hypoxylon canker Pruned and hatracked ficus may be subject to a relatively new disease. I first noted this disease, Hypoxylon canker, on a historic strangler fig in Palm Beach in 1999. We also noted the disease on Ficus retusa and Ficus benjamina. I recently saw the same disease in Plantation, Florida. The disease usually enters the tree through large wounds caused by pruning. If your ficus is dying back this disease could be the cause. Look for discolored dark areas in the wound area. Bark peeling with dark areas underneath are also characteristic. No control is available to my knowledge. A new rust disease was recently found on Syzygium paniculatum, the Australian brush cherry which is commonly used for topiary work in this country. Roger Brook's of Four B's wholesale nursery first noted the disease on some of his topiaries. A & L Southern Agricultural Laboratories in Pompano Beach identified the rust disease and noted some commercial controls for the problem. The best option for people who buy topiaries is to specify Syzygium paniculatum 'Globulus' which is a slower growing, much darker green variety used in topiary work. The 'Globulus' variety is hard to propagate and tissue culture is the best option. Plants are more expensive, but are immune to the rust disease which defoliates the topiary. Florida Dept. of Agriculture & Consumer Services Memorandum states that Orange jasmine (Murraya paniculata) has been added to the host list for Citrus Greening. Orange jasmine is capable of being the host plant for the citrus psyllid which carries the Citrus greening disease from plant to plant. So, do not purchase any. They are being quarantined in Dade County with restrictions in place on the growers to grow them in screened approved enclosures. New problems for the Sabal/Cabbage palm, our state tree Manatee and Hillsborough Counties are reporting the decline and death of our state tree in their areas. The fatal decline is caused by a phytoplasma, the Texas Phoenix palm decline which affects the Canary Island, Date, Wild Date, and Queen palms. The Sabal palms first show an excessive amount of dead leaves at the bottom of the tree. The next step is the death of the spear leaf and finally all the leaves die. The bud then decays and the top tips over. The insect spreading the decline is not known at this time.