Tent caterpillars: A threat to our trees!

largewhite_4069Tent caterpillars are moderately sized caterpillars, or moth larvae, belonging to the genus Malacosoma in the family Lasiocampidae.

The larvae of several moth and butterfly species are collectively referred to as tent caterpillars. These tent caterpillars multiply rapidly and can defoliate a large number of deciduous trees and shrubs in a short time. They are often seen on roadside trees and in neglected orchards. Besides defoliation, the larvae produce large unsightly webs, or tents, in the crotches of tree branches. These webs are used to protect the caterpillars from predators.

Tent caterpillars can be classified into different types as follows:

Eastern Tent Caterpillar: The eastern tent caterpillar is a native insect that was first reported in 1646. Eastern tent caterpillars prefer wild cherry, apple, and crabapple. They also feed on ash, birch, black gum, maple, oak, poplar, cherry, peach ,and plum etc. The caterpillar grows up to two inches long. They are black with a white stripe down the back. On either side of the stripe are blue spots and reddish or yellowish stripes.

Female moths lay egg masses of 100 to 300 eggs around a twig in mid-summer. The egg mass is very dark. The eggs overwinter and hatch the following spring. When the larvae (caterpillars) hatch, they are small. They immediately climb up the tree to a crotch of branches and build a silk tent. Eastern Tent Caterpillars use the tent for protection. They leave the tent during the day to feed and return to it at night. As the caterpillars eat and grow larger, the tent grows larger also. It can get to be about two feet long.

Western Tent Caterpillar: Western Tent caterpillars are troublesome in the northern and western portions of the United States and adjoining Canada. These hairy caterpillars are yellowish-brown in color and have a row of blue spots on their backs, with orange spots interspersed in between. Adult moths (1-1/2 inches long) are orange-brown in color with two narrow yellow lines on the wings. Willow, poplar, cottonwood, birch, apple, plum, cherry, roses and oak are favorite host plants of these pests. Hosts for these caterpillars include a wide range of tree and shrub species. In the central and the southern Rocky Mountains, quaking aspen is the preferred host. Other reported tree hosts include alder, cottonwood, crabapple, fruit trees, oak, poplar, and willow. Chokecherry is a host throughout its range. Other shrub hosts include bitterbrush, Ceanothus spp., mountain mahogany, nine-bark, serviceberry, sumac, wild currant, and wild rose.

Forest Tent Caterpillar:  The forest tent caterpillar is quite similar to the eastern tent caterpillar.  Despite its name, this pest does not spin a true tent; instead, it forms a silken mat on the surface of branches where they congregate. Larvae have a series of keyhole-shaped white spots running down their back instead of a solid line. Adults are light yellow to tan colored moths with two dark bands on their forewings. Host plants include wild cherry, aspen, maple, oak, and hawthorn.

The damage caused by the tent caterpillars is tremendous. The tent caterpillar feed on tree’s new foliage and they defoliate the trees if present in large numbers. Defoliation stunts the growth and vigor of trees. Because tent caterpillars feed in large groups, they can quickly destroy large sections of a tree’s canopy.

Larvae of a single tent caterpillar colony can strip the leaves from a small tree if allowed to develop and is more of a threat in nurseries or newly planted orchards. On larger trees they are only a serious problem if there are several colonies on the same tree. While fruits are not directly attacked, fruits on branches that have had leaves consumed will not develop normally. Moreover, heavy feeding during one year may reduce tree growth.

  • Tent Caterpillars Are Taking Over the Town In Livingston

By Kaitlin McCulley, April 01, 2016, abc13.com, Livingston, UK

Tent caterpillars are taking over the town in Livingston.

Their acrobatics may be fun to watch from a distance, but these creepy crawlers are getting up close and personal.

Amanda Fowler and her daughter Savannah want the circus act to hit the road.

“The webs go from the trees and connect to the house and they swarm the porches and you literally can’t step out your front door without having six or seven of them on you,” Fowler said.

Another type of damage that tent caterpillars cause is damage to electrical equipment, insulation etc.  leading to power blackouts.

Let us have a look at some news articles pertaining to this type of damage:

  • Tent caterpillar swarms causing power outages near Houston
    ByCarol Christian, July 30, 2015, Chron, Texas, USA

Tent caterpillars are so abundant in East Texas that some residents have been left in the dark. Sam Houston Electric Cooperative said that the colorful caterpillars have been hatching by the millions and covering homes, trees, and electrical equipment. Line technicians report that 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.”

There are few conventional solutions available to combat this 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 very effective and cannot provide a sure shot solution. Conventional insecticides which are toxic in nature are also proving to be ineffective and also have a significant share in environmental degradation.

C Tech Corporation offers a non-toxic and non-hazardous product, Termirepel™ to protect the trees and electrical equipment 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 solid masterbatches, liquid concentrate, and lacquer form.  Termirepel™ can also be incorporated in agricultural films and mulches for the protection of crops against these creatures. Also, the electrical equipment can be protected by incorporating our solid masterbatches while manufacturing them.