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The leaf crumpler is a leaf eating caterpillar that feeds on a wide range of host plants that include several cotoneaster species and cultivars, as well as crataegus, cydonia, malus, pyracantha and pyrus species. The leaf crumpler can be found in the eastern half of the United States and Canada, Texas, the states bordering the Mississippi River, especially the Upper Mississippi Valley and all of the Pacific Coast states. The caterpillar is dark brown, hairy and about 1/2" long. It overwinters in cocoons made of crumpled dead leaves and silk which is attached to a twig or branch. In the spring, the caterpillars loosen their cases and begin feeding. Pupation takes place in May and June. The moths are brown with white mottled wings and a wingspread of about 3/4". They lay their eggs along the veins on the underside of new leaves. Larvae hatch in 2-3 weeks and make curved, cornucopia shaped cases in which they feed for the remaining part of the season and then use for overwintering. There is 1 generation in the north and 2 generations in warmer climates. For control, the fly Nemorilla pyste is a internal parasite of the larva.
Leafcutters are caterpillars that neatly cut out sections of a leaf as they feed or for building their homes. Some common leaf cutters are the Maple Leaf Cutter, also called the Maple Casebearer, which is a native pest of the sugar maple. The Morning Glory Leaf Cutter which not only affects morning glory plants but other perennials as well and the Waterlily Leaf Cutter, which strangely enough, has larvae that are aquatic and breath through gills.
The Leaf Folder is a caterpillar much like the Leaf Rollers and Leaf Tiers. There is only one species, the Grape Leaf Folder and it is generally found east of the Rocky Mountains or in California, on both wild and cultivated grapes, virginia-creeper and on redbud. In the eastern part of the country damage is generally no more than ragged foliage, but in California, late maturing grape plants can be severely damaged by larvae feeding within the grape bunches causing fruit to decay. The moths are black with white markings, with a wingspread of about 3/4"-1" and may emerge from inside the folded leaf for a summer brood. The 1" long, larvae are glossy, translucent yellow-green on their sides and darker above with a brown head and feed within the folded leaves. In California the leaves are rolled tightly instead of being folded. There are 2-3 generation in warmer climates and only 1 in New England where pupation takes place in the soil.
Leafhoppers are sucking insects that belong to the same order and suborder as aphids and treehoppers, but belong to the Cicadellidae family. They can be found throughout the world with some 2000 species alone in our country. Most of them are small, not over 1/2" long and feed on all types of plants, both wild and cultivated. Adults have a long, wedge shaped appearance and the top of the head is either triangular or broadly curved. Overwintering adult females will lay eggs in leaves and stems in the spring when leaves first begin to appear. Eggs will hatch in 10-14 days. Nymphs resemble adults, but lack wings. Most species have 2-5 generations per year, overwintering either as adults or eggs, but some species do not survive winters in the north and migrate from the south every summer. They have piercing sucking mouth parts and generally feed on the undersides of the leaves sucking plant juices, they will hop away quickly when disturbed. When large populations are actively feeding, plants will lose vigor and become stunted, while the foliage loses color and becomes whitened, stippled or mottled. Some species, in particular the potato leafhopper causes the tips of the leaves to brown as if they had been scorched, this is referred to as hopperburn and may be due to a toxin which is injected during the feeding process. Leafhoppers also act as vectors of various virus diseases such as aster yellows, elm phloem necrosis, curly top on sugar beet and other plants, Pierce's disease on grapes, yellow dwarf on potatoes, peach yellows and many others. Control with a contact insecticide.
Leafminers are the larvae of various flies, moths, sawflies or beetles that feed between the upper and lower surfaces of a leaf. These larvae, as they feed on leaf tissue create blisters, serpentine tunnels or hollow mines within the leaf. Plants affected include many kinds of ornamentals and vegetable crops. The life history of each kind of leafminer must be known in order to control them since they are protected within the leaf most of their life. Timing is essential for their control, either to get the adult insect before she lays her eggs or to get the adult insect when it emerges from the leaf.
Caterpillars that protect themselves while they feed, by rolling themselves up in a leaf or in several leaves of their host plant.
Leaf skeletonizers are caterpillars much like leaf rollers, except that instead of feeding within the confines of a rolled up leaf on the host plant, they feed more openly on the leaf. The larvae feed on the tissue between the larger veins, on the underside of the leaf, leaving the upper leaf surface (known as the epidermal layer) intact. While most leaf skeletonizers feed on the underside of the leaves, the Grape Leaf Skeletonizer feeds only on the upper leaf surface leaving the lower leaf surface intact. There are several species of leaf skeletonizers. Some commonly affected plants are apple, birch, cherry, grape, hawthorn, hollyhock, maple, oak, palm, plum and quince.
Like leaf rollers, leaf tiers are caterpillars that tie up several leaves with strands of silk and within these protective confines, they feed. Some commonly affected plants are beech, American holly, hydrangea, oak, sweetgum, celery and other vegetables, strawberries and various perennials. |
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Leafminers -