Control Winter Moth Larvae in Gardens – The winter moth (Operaophtera brumata), is a polyphagous insect, which means that it enjoys eating a wide variety of woody plants. Deciduous trees, fruit trees, berry bushes, roses as well as many other ornamental shrubs are on its menu.
However, if you know how to spot and deal with the gluttonous winter moth caterpillars, then controlling them should be a breeze.
In this post you can learn about
How to Get Rid of Winter Moth Larve Infestation
Regular, minor infestations can often be tolerated and are not worth the effort to control, especially for hobby gardeners where great yields are not required.
Encourage beneficial insects
Preventive plant protection is a common strategy these days, especially in natural gardens: Encouragement of beneficial insects and avoidance of insect-damaging sprays typically provides a variety of natural alternatives that prevent significant production losses.
In particular, installing nesting boxes is a wise investment. During the breeding season, good quality traps can consume up to 300 caterpillars every day.
The winter moth can be effectively controlled with glue rings, which are inexpensive and easy to use. By the middle of October, they’ve been fastened to the endangered trees’ trunks. It is also a good idea to ring nearby trees and support poles.
Later, the females who are creeping upwards will be attracted to the glue’s sticky surface. The ring must be fitted snugly in order to prevent the caterpillars from getting a foothold below it. Check the rings after a storm: The adhesive rings can become “bridged” over time by blown leaves or twigs. If you do this in spring, any helpful insects on the tree will be unable to get up the trunk.
Using Biological Bt Pest Control
However, if prevention methods have failed and an infestation becomes evident in spring, you may be able to take direct action against the moth. Bacillus thuringiensis Bt – containing preparations are ideal.
They only have an effect on butterfly caterpillars, and only if the caterpillars are fed on. When applied in warm weather (over 15°C), the caterpillars’ appetites are piqued and they readily absorb the substance. The spray should be used as early as possible to prevent feeding harm.
#Tip: A more serious infestation in the home garden can be confirmed if 10 out of 100 leaf tufts show caterpillars.
Identify Winter Moths
In the fall, scarlet winter moth eggs around half a millimetre in size can already be found if you check the buds of your woody plants. The caterpillars that emerge from the eggs are little and dark grey when they first hatch. They develop to a length of two and a half centimetres and turn a pale green colour.
Peeper caterpillars walk with a distinctive “hump” because they only have one pair of rear abdominal legs. Because the caterpillars want to feed undisturbed, they spin themselves between the leaves of the host plant, hence the name “spinner”.
Leaf skeletonization damage occurs when an infestation is so severe that the leaves are reduced to their skeletal state. However, in most cases, the harm appears to be more than it really is. Winter moth caterpillars enjoy “spoon-feeding,” which is half-eating young delicious cherry fruit.
From April until June, you’ll find the caterpillars on the leaves. Males and females among these winter moths are significantly different from one another because of this sexual dimorphism.
Male grubs are greyish-yellow to beige-brown in colour with brown-yellow, fringed wings that are a little wider than 1.5 centimetres, while female grubs are brownish-grey with only stunted, stubby wings that are the same colour as the males. It has a worthless proboscis and short hairy antennae and dies after a few days without eating.
Winter Moth Life-Cycle
The little winter moth (Operophtera brumata) is a butterfly that is found all over the world and can inflict considerable damage to deciduous bushes. Adult moths emerge around mid-October and early November, depending on soil temperatures.
On their route into the tree crown, the flightless females moths climb the trunk of the host tree and are mated by the winged males. Egg-laying happens preferentially near buds and towards the start of the winter season. A female is capable of laying up to 300 eggs.
When the winter is done, the caterpillars emerge from the eggs at the exact moment the fresh buds appear (in early spring) till the beginning of May. During their caterpillar stage, the moths consume buds, leaves, flowers, and even immature fruits. Once suitably developed, the caterpillars fall to the ground on a caterpillar silk thread and pupate in the earth, only to hatch as adult winter moths in October and reproduce the next generation.
The following information will help you recognize, prevent, and combat the winter moth so that your plants aren’t devoured by the voracious winter moth caterpillars.
#Note: The Mottled umber moth (Erannis defoliaria) is much less common in home gardens. Its biology is similar to that of the winter moth, although it is not the same genus.