Symptoms, Characteristics, and Control Methods of Orchid Aphid Infestation

Many aphids (such as the green peach aphid, cotton aphid, etc.) can harm orchids. Aphids mainly damage tender leaves, buds, flower buds, and other young organs, piercing plant tissues with their piercing-sucking mouthparts and absorbing large amounts of sap nutrients, causing nutritional deficiency in the plant. Taking the green peach aphid as an example: it is distributed throughout China. The green peach aphid produces 20 to 30 generations per year. In cold regions, it overwinters as eggs; in warm regions, wingless viviparous aphids overwinter in the heart leaves of plants. The following year, they begin to reproduce from April, with a peak in reproduction from April to May. In dry springs, this pest occurs more severely. In November, aphids begin to lay eggs in the tips and cracks of peach branches to overwinter; in some regions, wingless viviparous aphids overwinter on some herbaceous flowers. On some herbaceous flowers such as chrysanthemums, pansies, and snapdragons, the parasitic aphids are green in body color. These pests congregate on tender leaves to suck sap, causing leaf yellowing and delayed growth. The pest's secretions are honeydew, which in large amounts can even cover the plant surface and affect photosynthesis. They frequently induce sooty mold. More seriously, this pest can transmit various viral diseases.

Control methods: During the aphid damage season, spray with 20% fenvalerate at 2000 times dilution, or laundry detergent at 150 times dilution. During the dormant period of fruit trees such as peaches and pears, spray with 3 to 5 degrees Baumé lime sulfur mixture to kill eggs. For branches with large numbers of pests and severe damage, they can be cut off and destroyed. Natural enemies such as various ladybugs, green lacewings, hoverflies, and aphidiid wasps can be used to control their occurrence.