Caterpillars winter moth

Feeny P. 1970. Seasonal changes in oak leaf tannins and nutrients as a cause of spring feeding by winter moth caterpillars. Ecology 51 565-581. 

Deltamethrin is a crystalline powder, white or slightly beige in color. The formulations include emulsifiable concentrates, wettable powders, ultra-low volume and flowable formulations, and granules. There are no known incompatibilities with other common insecticides and fungicides. It is used as a contact poison to control apple and pear suckers, plum fruit moths, caterpillars on brassicas, pea moths, aphids (apples, plums, hops), winter moths (apples and plums), and codling and tortrix moths (apples). It also is used in control of aphids, mealybugs, scale insects, and whiteflies on glasshouse cucumbers, tomatoes, peppers, potted plants, and ornamentals.9-11... 

Tachinids parasitize winter moth caterpillars, codling moth caterpillars, noctuid moths, small ermine moths, beetle larvae. 

Bacillus thuringiensis is especially effective against winter moth caterpillars. 

Very deep damage, which becomes corky by autumn, is often found on fruit, as in the case of the winter moth. At harvesting time it is no longer possible to distinguish the damage from that caused by other caterpillars. 

Fig. 5.46. Winter moth caterpillar moving with typical looping action.

ENEMIES. Birds, especially coal-tits, are important enemies of winter moth caterpillars. The feeding requirements of these birds at brood time are very high (300 caterpillars/day for the brood). Coal-tits are capable of keeping winter moth infestation below the damage threshold. 

INSPECTION AND DAMAGE THRESHOLD. Winter moth Caterpillars are detected by visual inspection, with 100 blossom clusters being examined. The damage threshold is 10-15% of blossom clusters infested. 

Caterpillars of this moth tunnel into the leaves of leeks. The damage is worse in warm, dry summers. The adult moths spend the winter in plant debris. There can be several generations in a year. 

DEVELOPMENT OF THE SUMMER FRUIT TORTRIX. The Summer fruit tortrix moths overwinter as young larvae in a cocoon on the tree, usually under the remains of dead leaves. Before flowering the first caterpillars move from their winter hiding-places to the flower huds or rosette leaves and weh several leaves together in order to feed and grow there. They may also feed on the young fruit. The places where caterpillars have fed can later he seen on the fruit as scars of varying depth. 

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