| For the Jacksonville Florida Times-Union USA TODAY NETWORK
In the past few weeks we have seen two insect outbreaks in northeast Florida. The two insects are the eastern grasshopper and the tufted moth caterpillar. Both insects are abundant and showy this spring. Both insects cause damage by chewing on fallen leaves.
What is special about them is that one continues to cause problems if not controlled in the landscape, and the other disappears on its own without permanent damage.
It has been reported that tufted moth caterpillars chew on oak leaves throughout the region and in some cases defoliate them. Tussock moth caterpillars have a red head with two tufts of hair on the head, short tufts of hair on the body and a long tuft of hair in the back.
The complaints we get from tussock moths are threefold. First, they tend to fall out of the tree in long, silky strands, similar to an invading force abseiling from helicopters. This can break up a quiet cup of coffee or a glass of wine on the back patio. The second complaint is that they create large cotton cocoons on your walls and under your eaves, on patio furniture, and even on your boats. The third is that the hair on the caterpillars can cause an itchy allergic reaction in some people.
The good news is that this “invasion” will soon go away on its own. Feeding the oak trees does not affect a healthy tree. The leaves will reappear. The caterpillars that crawl on your house and lawn furniture will not consume your valuable patio plants. When they come down from the trees, they have stopped eating and are looking for places to cocoon.
If they crawl on your house, you can easily kill them by sweeping them in a bucket of soapy water. The cocoons can be removed quickly by slipping tweezers between the cocoon and the wall, garden chair, or boat. You may want to wear a long-sleeved shirt while doing this, as the cocoon fibers can irritate the skin on your forearm. Another calming fact that calms your mind is that up to 50 percent of the time, the cocoons are inundated with parasites that infest the developing larvae. In a week or two, you will hardly see any signs that they were there.
At this time of year the number of locusts from the east also increases. I once heard them described when they seemed to “gush” out of the ground. The difference between the grasshoppers and the caterpillars is that the “lubricants”, as they are commonly called, can cause significant damage to your landscaping plants.
The adult eastern grasshopper can be up to 3 inches long and yellowish green in color. The adults have wings but do not fly. An adult female Lubber can lay up to 400 eggs, which emerge in March. The rubbers can be found in the landscape from March to November. They have very few natural enemies due to a toxic secretion that birds and lizards have learned to avoid.
The stage of the gums that we see now is called the nymph stage. They can be seen in clusters of hundreds near the tops of small plants and shrubs first thing in the morning. They don’t look like the adults and are often mistaken for other grasshoppers. Nymphs are almost entirely black with an orange stripe. Lubbers (especially nymphs) have an insatiable appetite for landscaped plants and quickly remove all leaves.
The nymph stage is also the easiest stage to control. Insecticides are less effective as the gums mature into adults. Insecticides such as carbaryl, bifenthrin, and permethrin are effective for combating nymphs. The insecticides must come into direct contact with the insects in order to control them. Often times, gardeners go looking for heaps of nymphs with their spray bottles in hand every morning. It is very important to read and understand the label of any insecticide that you may be using.
Once they grow up, it is impractical to control them with insecticides. Physical removal is the best way to get rid of them. A bucket filled with rubbing alcohol held under the eating locust can be effective if you can tap the plant and slam the unsuspecting lubricant into the bucket. It’s not uncommon for volunteers here at the expansion office to paint the grounds with buckets of dead locusts.
The lesson from these two insect infestations is that it is important to understand when it is best to control them and when it is best to let nature take its course. Now control the locusts while you can.
It is best for the tussock moth caterpillars to let them do their thing and move on. For more information on Florida’s insects, visit the University of Florida entomology website at: http://entnemdept.ufl.edu/creatures/.
Larry Figart is an urban forestry representative at the University of Florida / IFAS.
