5583e313_rol_Plant_Pests_on_Your_Garden__escription_and_damage_symptoms
[Management] Check your plants regularly for aphids--at least twice weekly when plants are growing rapidly. Many species of aphids cause the greatest damage when temperatures are warm but not hot (65° to 80°F). Catch infestations early. Once aphid numbers are high and they have begun to distort and curl leaves, it is often hard to control them because the curled leaves shelter aphids from insecticides or natural enemies. Many aphid species prefer the undersides of leaves, so turn them over to check them. On trees, clip off leaves from several areas of the tree to check for aphids. Also check for evidence of natural enemies such as lady beetles, lacewings, syrphid fly larvae, and the mummified skins of parasitized aphids. Look for disease-killed aphids as well: they may appear off-color, bloated, or flattened. Substantial numbers of any of these natural control factors can mean that the aphid population may be reduced rapidly without the need for treatment. Biological Control. Many predators also feed on aphids. The most well known are lady beetle adults and larvae, lacewing larvae, and syrphid fly larvae. Naturally occurring predators work best, especially in a small backyard situation. Commercially available lady beetles may give some temporary control when properly handled, although most of them will disperse away from your yard within a few days. Aphids are very susceptible to fungal diseases when it is humid. Whole colonies of aphids can be killed by these pathogens when conditions are right. Aphids are small, soft-bodied insects with long, slender mouth parts that they use to pierce stems, leaves, and other tender plant parts and suck out plant fluids. Almost every plant has one or more aphid species that occasionally feeds on it. Many aphid species are difficult to distinguish; however, identification to species is not necessary to control them in most situations. Where aphid populations are localized on a few curled leaves or new shoots, the best control may be to prune these areas out and dispose of them. In large trees, some aphids thrive in the dense inner canopy; pruning these areas out can make the habitat less suitable. High levels of nitrogen fertilizer favor aphid reproduction. Never use more nitrogen than necessary. Use less soluble forms of nitrogen and apply it in small portions throughout the season rather than all at once. Or better yet, use a urea-based, time-release formulation (most organic fertilizers can be classified as time-release products as compared to synthetically manufactured fertilizers). Another way to reduce aphid populations on sturdy plants is to knock them off with a strong spray of water. Most dislodged aphids will not be able to return to the plant, and their honeydew will be washed off as well. Using water sprays early in the day allows plants to dry off rapidly in the sun and be less susceptible to fungal diseases. Chemical Control. Insecticidal soap, neem oil, and narrow-range oil (e.g., supreme or superior parafinic-type oil) provide temporary control if applied to thoroughly cover infested foliage. To get thorough coverage, spray these materials with a high volume of water and target the underside of leaves as well as the top. Soaps, neem oil, and narrow range oil only kill aphids present on the day they are sprayed, so applications may need to be repeated. Many other insecticides are available to control aphids in the home garden and landscape, including foliar-applied formulations of malathion, permethrin and acephate (nonfood crops only). While these materials may kill higher numbers of aphids than soaps and oils, their use should be limited because they also kill the natural enemies that provide long-term control of aphids and other pests. Repeated applications of these materials may also result in the development of resistance to the material by the aphid.
Aphids Aphids are small, soft-bodied insects with long, slender mouth parts that they use to pierce stems, leaves, and other tender plant parts and suck out plant fluids. Almost every plant has one or more aphid species that occasionally feeds on it. Many aphid species are difficult to distinguish; however, identification to species is not necessary to control them in most situations. Aphids may be green, yellow, brown, red, or black depending on the species and the plants they feed on. A few species appear waxy or woolly due to the secretion of a waxy white or gray substance over their body surface. All are small, pear-shaped insects with long legs and antennae. Most species have a pair of tubelike structures called cornicles projecting backwards out of the hind end of their bodies. The presence of cornicles distinguishes aphids from all other insects. Generally adult aphids are wingless, but most species also occur in winged forms, especially when populations are high or during spring and fall. The ability to produce winged individuals provides the pest with a way to disperse to other plants when the quality of the food source deteriorates. Although they may be found singly, aphids often feed in dense groups on leaves or stems. Unlike leafhoppers, plant bugs, and certain other insects that might be confused with them, most aphids do not move rapidly when disturbed. Life Cycle. Aphids have many generations a year. Most aphids in California's mild climate reproduce asexually throughout most or all of the year with adult females giving birth to live offspring (often as many as 12 per day) without mating. Young aphids are called nymphs. They molt, shedding their skins about four times before becoming adults. There is no pupal stage. Some species mate and produce eggs in fall or winter, which provides them a more hardy stage to survive harsh weather. In some cases, these eggs are laid on an alternative host, usually a perennial plant, for winter survival. When the weather is warm, many species of aphids can develop from newborn nymph to reproducing adult in 7 to 8 days. Because each adult aphid can produce up to 80 offspring in a matter of a week, aphid populations can increase with great speed. Low to moderate numbers of leaf-feeding aphids are usually not damaging in gardens or on trees. However, large populations cause curling, yellowing, and distortion of leaves and stunting of shoots; they can also produce large quantities of a sticky exudate known as honeydew, which often turns black with the growth of a sooty mold fungus. Some aphid species inject a toxin into plants, which further distorts growth. A few species cause gall formations.
Plants & Garden: The Ways to Control Plant Pests on Your Garden
Name, description and damage symptoms