Aphid control: Identification and treatment recommendations.

While shopping at my local garden center I noticed some beautiful gardenia plants with small unopened buds sticking up. Upon closer inspection, I saw that the flower buds were all brown and covered with aphids! Aphids are an important pest in greenhouses as well as in nursery and ornamental settings. Many different species of aphids occur in greenhouses, and one or more of them attacks almost every species of ornamental plant grown. Aphids are soft-bodied, pear-shaped insects less than 1/10 inch long, but can differ somewhat in size, appearance, host preference and the color of their bodies. Some are green, others brown, reddish or black in color, while wooly aphids are covered with a white, cottony substance. They may be winged or wingless. Winged forms are more common when aphid population density is high. But they all have basically the same biology and behavior, preferring to feed on tender, new plant growth. Under greenhouse, southern nursery, and in temperate zone summer conditions the life histories of aphids are similar, although the development time varies from species to species. Under these conditions all aphids are female and generation after generation produces females that upon maturity give birth to live young without the need to mate. These environmental conditions are similar to those in tropical and subtropical regions; thus, the true sexes do not appear nor does reproduction occur through eggs until temperatures drop in the fall. In temperate areas eggs are the overwintering stage, hatching into nymphs the following spring. Aphids are homopteran insects. They feed by sucking the sap from tender plants, often causing plant deformation, curling and shriveling...