Eastern Tent Caterpillars are Here

As a young boy growing up and visiting my grandparents, I can remember seeing little webbed tents in my grandfather’s apple trees. He would tie handfuls of sage grass into a torch and burn them out before they could defoliate his apple trees. If they were not controlled in time the could completely defoliate the trees. The trees could grow new leaves, but the defoliating would affect the apple crop. They also are found on wild cherry, crabapple, hawthorn, maple, peach, pear and plum trees.  I was warned not to handle the hairy worms because they might sting, but these were not stinging caterpillars. I was soon shown by the older kids how to hold and allow the caterpillars to crawl on my hands.

The caterpillars hatch from shiny, black egg masses that were glued to small pencil sized twigs. The egg masses encircle the branches and the caterpillars begin to hatch in early March. While feeding for 4 to 6 weeks the caterpillars grow to a length of 2 to 2 ½ inches.  The larvae are black with a white stripe down the back, brown and yellow bands along the sides, and a row of oval blue spots on the sides. As the caterpillars grow, they enlarge their web, eventually it will be more than a foot in length. The larvae remain within the tent during the heat of the day and during rainy weather. They emerge to feed during the early morning early evening and at night when it is warm enough to do so.

When they reach maturity, the larvae begin crawling on plants, sidewalks, drive ways and on the sides of houses. The phone calls begin. If the defoliation has not been excessive, the webs in the trees often go unnoticed. When the whole yard is crawling with black caterpillars with racing stripes, people notice. By this time the damage has been done, and the larvae are seeking a protected place to pupate. We also get calls about the tiny cocoons on shrubs, the side of houses, in flower beds and other sheltered places. The adult moths will emerge in about 3 weeks, they are about an inch long. They are reddish-brown in color with two diagonal pale strips across the fore wings. After emerging they mate and the females attach the egg masses to the branches, to begin the cycle the next spring.

Removing the egg masses during the winter is one of the best management tools. While the tents are still small in the early spring they are easy to remove and destroyed by hand. Larger tents may be wound upon the end of a stick and pulled from the tree. The webbing, shelters the larva from insecticidal applications and the tent must be torn open or saturated with water before the application can penetrate the web. Parasitic wasps are important predators of the tent caterpillars and greatly reduce the populations in some years. Other insect predators and a few diseases also help to regulate the eastern tent caterpillar populations.

Termite Swarming Season Is Here

The season has arrived when my office will be filled with small envelopes, medicine vials, fruit jars, cups and plastic bags containing very small winged insects. These containers will be brought by very nervous people who will want to know if their houses are threatened by these tiny insects. Termite swarming season is here, and tiny gossamer winged insects can be seen flying in small clouds. If you are unlucky these insects will be found flying within your house, emerging from tiny holes in your wall. More unnerving is to find small clumps or sprinklings of tiny insect wings upon the window sills of your home. Unfortunately if this is the case, it means that the termites have been active within the structure for three to five years. For termites to live is to eat and to eat means wood is being consumed and structural integrity is being threatened. Formosan Subterranean Termites colonies can consume up to a thousand pounds of wood a year due to the large number of termites within their colonies. Native subterranean termite colonies are much smaller and the damage they cause occurs at a slower rate.

     Confusion reigns because the ants that are swarming this time of year are very similar in appearance to termites. Both are of similar size and shape and color, both have four wings, six legs and antenna. Closer inspection will reveal differences that can be seen without a magnifying lens. Both have four wings, but the termites wings are of the same length and shape. The front wings of the ant are longer than the back wings. The body of an ant has a pinched waist with the same appearance of a wasp and the body of the termite is the same width for its entire length. The antenna give the final proof, the first segment of an ant’s antenna is long and is followed by much shorter segments. This arrangement gives the ant’s antenna an elbowed appearance that is very distinctive. The antenna of the termite is much like a string of pearls.

     Native subterranean termites are tied to the ground by their need to live within a high moisture environment. This is a weak point in their biology that can be exploited to control them. Most termite treatments involve putting a barrier of insecticide on the ground that will prevent the termites in the ground from entering the house. Termites trapped within the structure are cut off from their moisture supply and will soon perish. Termites gain entrance to house through cracks and crevices or by building mud tubes up the outside of the concrete slab upon which the house is built. These are easy to spot and when broken open the active termites are exposed going up and down the tube. The mud tubes will generally be the size of pencils and will cross the outside of the concrete slab toward some opening in the brick or exposed wood. These tubes may be obscured by tall grass, vines, ornamentals, mulch, or debris. All of these things should be kept away from the slab to prevent termites from entering the house unnoticed. Cracks in the slab may be an undetectable point of entry. The square cut out in the slab that lies beneath most bathtubs is the most common place for infestations to begin. There should be an inspection plate in a closet or wall behind the tub that allows inspection of the pipes entering the house. Once termites have entered a house they not only eat the wooden studs they will also feast on the paper covering of the gypsum boards. They will tunnel through the boards and eat the paper underneath the paint on the walls then cover the hole with mud. Wiping a white cloth across the wall will result in streaks when the mud is removed revealing holes in the wall.   

     To protect your property you should visually inspect the outer walls of your slab each year along with all the hidden areas that are accessible to visual inspections. Continue to be alert for and tell tale signs of mud on the walls of your home that may mean termites are already present and damaging your home. Even after your house has been properly treated it is necessary to continue to inspect your house for termites. Broken pipes, digging animals, cracked slabs and other unforeseen circumstances can again put your house at risk to termite infestation.

Varroa destructor

With a name like Varroa destructor you would expect the organism to be a problem causer, and it is. This mite virtually single handedly wiped out all feral honey bee colonies in many areas of the United States. These small (0.06 inches wide) mites feed on both adult bees and developing honey bee larvae. Adult mites lay eggs in the cells of the developing bee larva resulting in the death, deforming or seemingly no visible affect on the larva. After the bee matures the mites will also ride the adults feeding on the hemolymph. The mites also serve as transmitters of several virsuses that may kill the bees or compromise their immune systems.
Economic thresholds for mite infestations have been set for different sampling methods. If 10 mites are found on 200 bees by the sugar shake method control measures need to be taken. The sticky board method measures mites that fall to the bottom of the colony and become suck there, the boards are removed after 24 hours and the mites are counted. Colony size will then determine if the number of captured mites requires control measures be taken when counts exceed 60 to 190 mites.
Much work has been done on control measures and new alternatives are now available. Pesticide strips hung between the wax combs have provided high levels of control, but in some circumstances the mites are becoming resistant. Mechanical control measures do not use chemicals and may not be as effective in ruducing mite numbers but they do not use chemicals to control the mites. Screened bottom boards are benefical in reducing numbers of mites within the colony, but are not a stand alone treatment. Using drone-brood as a trap crop can dramatically reduce mite populations. Mites prefer feeding on the larger drone larva, and special combs with drone sized cells may be inserted within the hive then removed before the mites emerge. Covering the adult bees with powdered sugar can cause mites to loose their grip and fall off their host.
To me the most exciting advances are in honey bee genetics. Particular strains of honey bees are more tolerant to the mite because of a different behavior or physiological trait. Russian bees have been exposed to the mite for a number of generations and are more than twice as tolerant of the mites as the typical U.S. strains. Queens are being selected that show high levels of hygienic behavior toward varroa-parasitized pupae. The bees bred for brood-nest cleanliness significantly reduce the need for control methods.
Biopesticides are being registered for the control of the varroa mite. These naturally occuring organisms or their by-products are showing control efficacy equal to conventional chemical controls. One product uses a combination of essential oils within a vermiculite tablet to treat both varroa and trachael mites. Another is derived from tobacco plants and is sprayed on the adults as they emerge from the brood comb. Formic acid has been used by beekeepers in Canada and Europe for years to control mites during cooler weather (under 79 degrees) and when honey isn't flowing. Care must be taken with smaller hives, lest the bees be overwhelmed by the fumes.
Synthetic insecticides are still capable of giving up to 100% control of the varroa mites, but continual use can lead to resistance. State Departments of Agriculture have approved lists of products that may be safely used within the hives and only these should be used.

If it quacks like a duck...

Well it may not look like a duck and it certainly does not sound like a duck or a stink bug either, but it certainly smells like a stink bug. Leaffooted bugs are important fruit, nut, seed, and vegetable pests. Stink bugs and leaffooted bugs have similar life cycles and similar feeding preferences. They also resemble assassin bugs in size and shape. They  are generally brown with white markings on the wings, body and legs and are from .75 to 1 inch in length. They get their name from the flared and flattened leaf like lower portion of their hind legs.They over winter as adults and emerge in the spring to begin feeding in the spring. They have piercing sucking mouthparts and feed on plant juices. They use their saliva to penetrate and dissolve the contents of their chosen food and then suck up the digesting mixture. The saliva damages the surrounding cells and leaves a somewhat corky or spongy mass of silvery white cells. The healthy cells continue to grow around the damaged areas forming an injury known as catfacing.
Eggs are laid in rows and the bright orange-red colored soft bodied immatures congregate in masses to feed on the host plant. The young nymphs cause much of the feeding damage.  Not only will the eggs be laid in the vegetable gardens they may also be deposited on Jimson weed, goat weed and various grasses. Their ablility to feed on a wide variety of plants makes controlling them a problem. 
To protect themselves from predators the bugs are able to secrete foul-smelling, foul-tasting fluids from their bodies. Birds, spiders, assassin bugs and other predators will feed on them inspite of the foul fluids. This foul odor becomes more of a problem to us in the late summer and fall when the leaffooted bugs begin looking for overwintering sites. They consider our houses a well protected site, suitable for overwintering, when they can find a suitable crack or crevice into which to wedge themselves. Under the bark of fire wood is another common place to find these insects, and when the log is added to the fire it is soon evident that there was a hitchhiker aboard the fire wood.

The Others

All summer we have been concerned about the aphids, whiteflies, scale insect, stink bugs, june bugs, leaf miners and caterpillars. They have been eating our plants, damaging the way the plants look and even killing them or causing sooty mold to grow over all the leaves. The end is in sight, fall is coming. Some of the leaves are even changing color if they didn't just turn brown and fall off in the first good breeze. Football weather is here and the tailgate parties have begun, schools are in session and the kids are enjoying themselves on the playgrounds. And now the others have come.  All season they have been helpful, they have been feeding on caterpillars that were eating holes in our foliage that we tended and fertilized and watered. They fought with the spiders that were building pesky webs around the house and making the eaves look unkempt and unclean. They fed on flies that no one likes and crickets that drive everyone crazy with their chirping. They would chew up these specimens then feed them to their young within the nest and even share the food with other adults within the colony. Now the colonies have ceased to grow and no longer need large quantities of protein. The queen is no longer laying eggs and she and the colony no longer need large quantities of protein.

The queen and workers are more concerned about obtaining sweets and carbohydrates. The will often be found around human food and drinks. And will be found in numbers at outdoor activities where these are found. A canned drink is an almost irresistable attraction to these wasps, and they will fly or crawl in to feed on the liquid within the can. Unwary people have been stung on the lips, in the mouth and even in the throat. You must keep a watchful eye upon your food and drinks at tailgating parties and picnics and even at break on the school playgrounds. Garbage cans should be kept covered and not allowed to become too full for the lid to close. Large amounts of sugars are need to maintain the queen and workers at this time so the numbers of foragers can be quiet large at any one time, especially until temperatures drop below 60 degrees.

Some studies have been done to determine if wasps get part of their protein requirement from pollen. Diessection has shown that wasps do ingest pollen when feeding on nectar, and since pollen ranges from 5% to 40% protein this source can satisfy part of the nutritional need. The question was raised when wasps were observed visiting flowers, on a recent visit to Restoration Park this activity was quiet evident. 

First Signs

I had a gentleman walk into the office today to talk about problems he was having with his oak trees. He was having them pruned and termites were found within one tree. We talked about treatment options and he scheduled an appointment with the forrester to discuss general tree maintainance. If you are concerned about termites the first thing you need to look for is dirt or mud in places that is does not naturally occur. Subterranean termites like high humidity and use mud to seal their tunnels to maintain the moisture levels that they require within their colony. When they move into a different area they pave the way with mud tunnels and this is one of the easiest signs to look for.

When infesting trees in over ninety percent of the cases the tunnels will be found outside the bark of the tree.

Having said that you must remember there will be a small percentage of the time when the termites will come up the inside of the tree. They can do major damage with few or no outward signs. The first sign of trouble may come after a wind storm.

When the tree or parts of the tree are blown down due to lack of support caused by the feeding of the termites. You can greatly reduce your possibility of loss by monitoring your trees and structures for signs of feeding or the building of mud tubes. Insecticidal barriers are a deterent to the termites, but they are driven by hunger to constantly seek out ways around these barriers to new sources of food. Breaks in the insecticidal barrier cause by digging animals, broken plumbing, planting of ornamentals too close to the house, or cracks in concrete slabs pose threats to your home. Louisiana provides many of the necessities of life for subterranean termites: moderate temperatures, plenty of water, and numerous sources of cellulose(wood). When cracks in concrete slabs offer them entry points not visible from the outside termites can begin feeding before outward signs are visible. They will eat the paper off the inside of gypsum board then tunnel though the gypsum to eat the paper on the outside. When they break through the paint on the inside of the room they will seal this opening with mud. By taking a white cloth and rubbing it acoss a wall suspected of harboring termites you will wipe off the mud leaving streaks on the cloth and pin prick holes in the wall revealing the work of the termites. Until everyone has access to a termite sniffing dog or infrared devices that detect hot spots inside the walls of our house caused by large numbers of termites feeding, we are limited to using our eyes to detect the presence of termites.

Termites and Trees

I have been asked, why are there termites. The simplest answer is termites are here to recycle wood. The problems start when they want to recycle our houses and trees. Most all termites will attact trees that are damaged in someway; a lightening strike or an area weaken by fungus. Unfortunately Formosan Subterranean Termites will also attack living trees causing significant damage and rendering the trees unsafe. Over 300 trees were reported blown down in New Orleans by the winds of Katrina and most of those were found to have contained active Formosan Subterranean Termites colonies. The infestation not only resulted in the loss of the tree with all of it's intrinsic value, but trees in an urban setting can cause considerable damage when they fall.
After hurricane Gustov, one of the beautiful old oaks on the Forsythe Park golf course was found split in two. Closer examination found the interior of the tree riddled by Formosan Subterranean Termites. Infested trees can be treated and this one had, but older trees are harder to treat successfully due to their larger bulk. Treating tree involves trenching the exterior of the tree and applying the appropriate insecticide and using a foaming insecticide mix on the interior of the tree to fill all of the voids caused by the feeding of the termites.
When Formosan Subterranean Termites infest a tree in over 90 percent of the cases mud tubes will be found on the exterior of the tree. If an infested tree is cut or suffers a broken limb the termites will seek to mud over the break in the tree.

They are trying to maintain the high moisture levels they require inside their tunnels. This picture is of a tree that was blown over in a windstorm in West Monroe. The tree damaged the roof of a near by house and the fallen tree was cut back to remove limbs from the roof. I examined the tree the next day and found that the termites had sealed this opening with mud. If the tree had still been standing this part of the tree would have been about 30 feet off the ground, which means that the termites were actively feeding in the tree above this point. Other trees suffering similar damage have fallen in the garden district of Monroe. In all cases the trees were removed and destroyed. Trees in urban settings need to be continually examined for signs of termite activity to prevent damage and loss of the trees. Fire ants can actually be of benefit in this scouting. Fire ants eat termites and will build their mounds against or into the base of trees to be closer to their termite food source.