Aphid infestations on blueberry plants can destroy crops and cause a secondary viral problem. While aphid infestations are only an occasional problem, their destructive capacity begs for preventive attention. Familiarize yourself with how to care for your blueberry plants and what to look for should an infestation occur as a means of keeping a healthy home garden.
Blueberry plant aphids (Illinoia pepperi) are a threat to blueberry plants both as young and mature pests. Young aphids display yellow or green bodies and are so tiny that identification is aided by a microscope. The adult blueberry aphids display light green bodies with two tubes that project from their backsides. Antennae and legs are a darker hue than their bodies, according to the Michigan State University Extension.
Aphid infestations are dangerous not simply because aphids remove plant tissue fluids, but because of the harmful virus they carry and transmit from one blueberry plant to the next. Aphids are "sucking" bugs that remove plant sap by inserting their mouths into soft plant tissue. As aphids feed, the virus present in sap remains in aphid saliva for as long as 10 days and is transmitted to another plant when the aphid feeds again. The disease, blueberry shoestring virus, is incurable and is often asymptomatic for up to four years, according to the Michigan State University Extension.
Symptoms and Damage
Aphids gather beneath leaves and secrete honeydew when they feed. Honeydew, a sugary substance, creates an ideal environment for the development of the fungal disease sooty mold which creates a blackish mold on plants. If aphids have transmitted blueberry shoestring virus, your plant will produce narrow leaves that look like shoestrings, as the name suggests. Leaves often curl and turn red and blossoms take on a reddish hue while abnormal red lines appear on stems. This diseases stunts plant growth and destroys fruit crops, according to the Michigan State University Extension.
Remove aphids from plant surfaces with a strong stream of water or overhead irrigation and clean any tools used on a blueberry plant before moving to the next plant to prevent transfer of aphids, according to the Michigan State University Extension. Additionally, release parasitic wasps of the Praon and Aphidius species into the home landscape as these parasites kill aphids. Or, release predatory insects like ladybeetles that hunt and kill aphids as a natural management strategy.
Particularly in cases of severe infestation, chemical control is an effective management method. Saturate the lower shoots of your blueberry plants with an insecticide with the active ingredient Imidacloprid or Acetamiprid, according to the Michigan State University Extension. Though these insecticides will not cure viral infection, they spread through plant foliage and provide lasting, effective control of aphids.