Tent Caterpillars are moderately sized species in the genus Malacosoma and in the moth family Lasiocampidae. Species occur in North America, including Mexico, and in Eurasia. Twenty-six species have been described, six of which occur in North America. Some species are considered to have subspecies as well. They are often considered pests due to their habit of defoliating trees. They are among the most social of all caterpillars and exhibit many noteworthy behaviors.
Tent caterpillars are readily recognized because they are social, colorful, diurnal and build conspicuous silk tents in the branches of host trees. Some species, such as the eastern tent caterpillars, Malacosoma americanum, build a single large tent which is typically occupied through the whole of the larval stage, while others build a series of small tents that are sequentially abandoned. Whereas tent caterpillars make their tents in the nodes and branches of a tree’s limbs, webworms enclose leaves and small branches at the ends of the limbs.
Full-grown caterpillars (2 inches long) are sparsely hairy and black in color with a row of pale blue spots on each side. They have a white stripe down the center of their backs that makes them easy to identify. Adults (1-1/2 inches long) are reddish brown moths with two white bands running diagonally across each forewing. Host plants include cherry, apple, and crabapple, but may be found on a variety of shade trees as well.
They damage plants by chewing on leaves, flowers, shoots, and fruit and sometimes by boring into wood. Caterpillars in fruit or wood can be difficult to manage. They are hidden most of their life and can cause serious damage even when numbers are low.
In agricultural production, the preferred hosts of this pest are cherry, cabbage, kale, collards, broccoli, cauliflower, crabapple, and apple. They also occasionally attack other deciduous ornamental shrubs, shade, and forest trees. The silky tents spun by the caterpillars make landscape trees unsightly, and the caterpillars are annoying when searching for food or a suitable place to spin their cocoons. When tent caterpillars are abundant, they frequently eat all the leaves on a tree which weakens it, but seldom kills it. The foliage on the host tree may be stripped from all the twigs within a distance of three feet from the nest.
Tent caterpillars can be fast- feeding and ruthless pests to have in your crop. The damage they can cause can be severe to the point of total crop loss through complete defoliation. Most medium-sized to large trees can handle two to three consecutive years of defoliation, but most of the crops produced by growers do not fall into this category. To most growers, a large infestation can spell doom.
Recently tent caterpillars are proving to be the newest threat to the electric industry. Dozens of power outages have been reported in recent times due to these caterpillars. Sam Houston Electric Cooperative’s line technician Virgil Cain said on the utility’s blog “The caterpillars can completely cover a piece of electrical equipment; they can actually disrupt the insulating ability of the equipment and cause a power outage”. “Members are seeing them all over their homes, on outbuildings and all over our power poles, transformers, and other equipment,” said Mary Kate Pedigo, communications specialist for Livingston-based Sam Houston EC.
“Line techs are seeing swarms so thick along the neutral that you can’t even see the line,” said Pedigo. “In recent years we’ve had to remove hundreds of thousands of dead trees from our sights of the way because of the drought, and we expect to see even more as a result of caterpillar damage.” In the northeast of Houston, undulating masses of moth larvae have coated transformers, utility poles and insulators, causing system faults, tripping breakers and sizzling fuses into failure mode. Line technicians have been changing out damaged components across several counties of the co-op’s service territory.
The following article will explain just how detrimental tent caterpillar can be:
Tent Caterpillars Cause Power Outages in East TexasTop of Form
Published at 10:55 AM CDT on Apr 8, 2015
Over the past week, Sam Houston Electric Cooperative members have experienced dozens of power outages caused by “tent caterpillars.” The caterpillars can actually disrupt the insulating ability of electrical equipment and cause a power outage
Spring means bluebonnets are popping up across Texas, but that also means insects are back. Tent caterpillars are so abundant in East Texas that some residents have been left in the dark.
Sam Houston Electric Cooperative said the colorful caterpillars have been hatching by the millions and covering homes, trees, and electrical equipment. Line technicians report the caterpillars can engulf transformers, resulting in blown fuses.
“The caterpillars can completely cover a piece of electrical equipment,” said Sam Houston Electric Cooperative line technician Virgil Cain. “They can actually disrupt the insulating ability of the equipment and cause a power outage.”
The caterpillars not only swarm equipment they also feed on leaves, particularly of oak trees.
According to Texas A&M Agri Life, they can defoliate a tree causing permanent damage. The damage could cause trees to fall on power lines causing power outages.
Eventually, the caterpillars will emerge from cocoons as brown and yellowish moths with a one-inch wingspan. They no longer feed on vegetation but they do lay eggs and the life cycle starts all over again.
Tent caterpillars are not usually very difficult to detect. Regardless of size, color and area of activity all of which are easily identifiable for what they are and can be simple to control if multiple and aggressive steps are taken quickly.
There are very few solutions available to combat a modern-day plague of tent caterpillars. Damage can be reduced by removing and destroying tents and caterpillars as soon as they are noticed, but this technique is not always effective. Insecticides are used to control tent caterpillars, but this method is hazardous and may cause long-lasting consequences to the crops and humans who consume them.
C Tech Corporation offers a non-toxic and non-hazardous product, Termirepel™ to protect the crops and cables from these ravenous insects. It is an environmentally safe product that works by repelling the insects without causing any harm to the target or non-target species. Termirepel™ is available in concentrate and lacquer form. It can also be used as a liquid solution. Termirepel™ can be safely incorporated into the PVC insulation of wires and cables or coated on surfaces to keep tent caterpillars away from the application. Termirepel™ can also be incorporated in agricultural films and mulches for the protection of crops against these creatures.