Latin Name: Mindarus abietinus Koch.
Common Names: Balsam Twig Aphid
In Nova Scotia, the balsam twig aphid is known to occur regularly every three to six years in high numbers. It primarily attacks balsam fir, with Christmas tree plantations being a prime target. The insect is not known to kill trees but its damage lowers the value of the tree.
The aphid has between three and four generations within May and June. It overwinters in the egg stage and the nymph emerges in the spring to feed on the old needles. This stage is known as the fundatrix, and causes very little damage. In early June, these nymphs mature into wingless adults and each female produces the offspring of the second generation.
These nymphs feed on the new shoots by sucking the sap from the needles. It is at this stage that the aphids are most noticeable with a woolly covering and the secretion of large quantities of waste called honeydew.
In late June, this generation (or the third if the climate permits) transforms into naked, winged (all female) adults. The aphids disperse by flying, wind, birds, and mammals. Once a new host has been located, the adults produce the live young of the next generation. This generation is again wingless and includes both males and females. Like the first generation, this generation causes little damage. At the end of June, the adult females lay one or two black eggs near the buds, where the eggs remain dormant until the following spring.
Look for twisted, short, and deformed needles from the current year's growth. During the height of the infestation in June, the aphid's woolly wax and droplets of sticky honeydew are evident. Large numbers of ants may be attracted by the honeydew. Black sooty mould is another symptom often seen later summer, growing where the honeydew dripped on the foliage.
Close observation early in the spring to detect the first generation is very important. Treat with a contact insecticide when approximately 20% of the buds have begun to flush.
CAUTION: Read and follow the instructions on the label when using any control agent. Proper application and use of recommended personal protective equipment are essential for the safe use and effectiveness of any pesticide.
DISCLAIMER: Control options are suggestions only. Actions taken for pest control are the sole responsibility of the applicator in full compliance with any Federal, Provincial or Municipal Acts, Regulations or Bylaws.