PEST PROFILES: APHIDS
Crape Myrtle Aphid
Click on image to view larger. Aphids
Aphids are small, from 1/16 to 1/8 inch long. They are soft-bodied and vary in shape and color. Their body shape may be pear-like, globular, oval, spindle-like, or elongate, and they may appear black, gray, red, orange, yellow, green, brown, blue-green, white-marked, or wax-covered. Adult aphids may be winged (alate) or wingless (apterous). Winged forms are usually triggered by environmental changes (e.g., decreasing photoperiod or temperature, deterioration of the host plant or overcrowding). On the back of the fifth abdominal segment, a pair of tube-like structures called 'siphunculi' or 'cornicles (on Oleander Aphid) are present on most aphid species. These structures secrete a defensive fluid.
Simple metamorphosis; parthenogenic. Most aphids reproduce sexually and develop through gradual metamorphosis (overwintering diapause egg, nymphs and winged or wingless adults) but also through a process called 'parthenogenesis' in which the production of offspring occurs without mating. These aphids may even bear live young, instead of laying eggs. The average lifespan of an adult is approximately one month with sexual maturity reached in four to ten days. Under good environmental conditions, aphids' reproductive period is approximately three weeks. Aphids can be quite prolific and can reproduce faster than any other insect.
Type of feeding: Piercing and sucking. Aphids draw sap from plant tissues using mouthparts adapted for piercing and sucking. .
Habitat and food source(s):
They feed on all plant parts (image is Oleander Aphid). Foliage, twigs, limbs, branches, fruits, flowers or roots may be affected, and after some time, cast whitish skins from the aphids' developmental stages will accumulate on infested plant parts.
Aphids injure plants by: 1) causing plant stress by directly removing plant juices (sap from phloem tissues); 2) reducing the aesthetic quality of infested plants by secreting a sugary liquid (excess plant sap called "honeydew") on which a black-colored fungus called "sooty mold" grows, discoloring the foliage and further stressing the plant from preventing sunlight from reaching plant cells for photosynthesis; and 3) possibly transmitting plant diseases, particularly viruses.