Cooperative Extension
Arrow
MG Manual Home
Arrow
Entomology
Arrow
Logo    

ENTOMOLOGY: INSECT PESTS [continued]

Previous Previous


  MG Manual Reference
Ch. 3, pp. 52 - 53
[ Insect Pests: ipm | landscape; foliage, sap, trunk, root | turf grass; root, leaf, sap, nuisance | household; structures, living quarters, products | outdoor | citrus | fruits | gardens ]


Orange Dog Caterpillar
Orange Dog Caterpillar

CITRUS PESTSTop

Lepidoptera

Orange Dog Caterpillar
Orange dog caterpillars feed on citrus. They are mottled dark grey to light brown, and are said to look like "bird droppings." If disturbed, two orange, horn-like projections emerge from the head and the caterpillar produces a pungent lemony odor. When mature the caterpillar is about 1 1/2 inch long. The adult is beautiful black and yellow butterfly called the giant swallowtail.
Orange dogs are potentially harmful to young trees only, older trees can easily withstand the loss of a few leaves. Orange dogs can be controlled on small trees by finding and crushing eggs and caterpillars. Most are controlled naturally by parasites and other natural enemies.
Cotton Aphid Nymph
Cotton Aphid Nymph
Homoptera

Aphids
The cotton or melon aphid may occasionally become a pest in citrus, particularly in young trees. It may transmit a virus of citrus known as tristeza virus. To control aphids, encourage natural enemies such as lady beetles or lacewings. Parasitic wasps attack aphids and cause them to form rigid brown or tan structure called "mummies." Leave any mummies you see alone, because a parasitic wasp will emerge from them and attack more aphids.
Cottony-cushion Scale
Cottony-cushion Scale
Cottony-cushion Scale
Mature females have bright orange-red, yellow or brown bodies about 1/2 inch long, often covered with ridges of yellow or whitish wax. The eggs and newly hatched immatures are bright red. Cottony-cushion scales may feed on citrus, acacia, grape, ironwood, pittosporum, and other ornamentals.
This pest was introduced and became a serious pest of citrus in the 1880's. In one of the classical success stories for biological control, cottony-cushion scales were completely controlled by the introduction of a ladybeetle called the vedalia beetle. Where the beetle is not found, infested branches should be cut out and destroyed immediately.
Citrus Thrips
Citrus Thrips

Flower Thrips
Flower Thrips
Thysanoptera

Citrus Thrips
Thrips are slender, tubular insects about 1/20 to 1/16 inch long. Their wings are narrow with a fringe of hairs.
Citrus thrips begin to feed on new leaves, green twigs, and small fruit of citrus in late February and March. This causes leaves to curl and may cause scarring of fruit. However, the damage is mostly cosmetic and does not effect the internal quality of the fruit. To check for thrips, turn a leaf or flower onto a piece of white paper and tap gently. The insects will show up as tiny slivers on the white background.
Another type of thrips, flower thrips, may be feeding on blossoms at the same time as citrus thrips. The flower thrips are about twice as long as citrus thrips and slightly darker in color. They may also cause cosmetic damage to fruit, but may be predaceous as well.
Six-spotted thrips feed on spider mites and are therefore beneficial. They may be distinguished from other thrips because they have three dark spots on each forewing (a total of six spots).
Citrus Red Mite
Citrus Red Mite
Class Arachnida

Citrus Mites
Mites are difficult to see without the aid of a hand lens. They have rounded bodies with eight legs. Mite damage is usually more apparent than the mites themselves. They produce yellow stippling (tiny spots) on the leaves. Some types leave a fine webbing on the underside of leaves or between fruit. Mites are often associated with water stress and dust. Keep trees well irrigated, particularly in the late summer and early fall when monsoon winds can kick up dust storms.

Next Next
Search Index Comment

This site was developed for the Arizona Cooperative Extension, College of Agriculture, The University of Arizona.
© 1998 The University of Arizona. All contents copyrighted. All rights reserved.