It’s in your nature: Eastern tent caterpillars
Eastern tent caterpillars build “webby tents” in the forks of cherry tree varieties, their preference, which hold and protect the caterpillars when they are not feeding. BARRY REED/SPECIAL TO THE TIMES NEWS
When pruning your fruit trees in February or March, look for these tent caterpillar egg cases, with a varnished look, and remove them.
Fall webworms begin appearing in late summer, and unlike tent caterpillars, are found on the end of branches. They prefer many ornamentals such as this flowering crabapple.
This chokecherry tree was stripped by the voracious larva. Some people mistakenly identify these as gypsy moth caterpillars.
The past few weeks you probably have noticed roadside trees with a white webby nest or nests in the forks of the trees. On closer inspection, you will notice that most of that tree’s foliage has been devoured. These “tents” are from the Eastern tent caterpillar. The caterpillars are voracious eaters and will often defoliate almost the entire tree. Their favored host trees are a variety of cherry species (in particular the chokecherries you see on roadsides) and also apple trees.
The good news is that apparently since they eat the young leaves in spring, the tree usually replaces them soon after. However, if you were a backyard orchard hobbyist, they can devour even the blossoms and almost no fruit will be produced.
To avoid another spraying just to kill the tent caterpillars, I usually manually tear into the “tent,” pulling the tent and nearly all the caterpillars from the tree. I then crush the “tent” which protects the caterpillars. Some people have told me that they use a small propane torch to burn them. (You’ll probably do more damage to your tree with that method than the caterpillars would.) Another avenue to control them on your fruit trees is to remove the egg cases when you prune your trees. The case encircles the branch and appears varnished. That egg case will hold 150 to 300 eggs.
There are some natural predators on the caterpillars. When partly grown I have seen robins and grackles eating them. However, the two cuckoo species in our area will eat them at all sizes. These are the black-billed and yellow-billed cuckoo. In fact, birding buddy Dave and I note that on years of larger infestations of these caterpillars, we record more cuckoos. The mature caterpillars, almost 2 inches long, are usually seen crossing your sidewalks or streets when they travel to another area to pupate (make their cocoon).
In later summer, another common and similar species of caterpillars attacks fruit trees. These are the fall webworms. This “tent” is often larger than the tent caterpillar’s but not quite as dense. These webs are not found in the fork of a tree but on the end of branches. These caterpillars are a pale (whitish/light yellow) and are not as harmful. Your ornamental crabapples (or other ornamental trees) lose their attractiveness with these present though.
These “webs” will cling to the trees often after leaf fall and can still be seen into winter. If these caterpillars begin feeding on my fruit trees, I employ the same tactic by reaching into the “web” and tearing it from the affected tree.
Spraying with a common home orchard spray will kill both of these species. So remember, tents in the forks of trees in spring, tent caterpillars; while webs on the branches in later summer/fall, fall webworms.
Test your outdoor knowledge: Which bird will defend its nest by vomiting on an intruder? (Including humans) A. rock dove B. house wren C. turkey vulture D. barn swallow E all of these
Last week’s trivia answer: The house, winter, Carolina, and marsh wrens could all be found in Pennsylvania.
Contact Barry Reed at email@example.com.