Adelgids or Wooly Conifer Aphids are a family of insects, closely related to Aphids. They are sap-sucking insects with complex life cycles, which usually involve living on different plants in the summer and winter. They're very similar to aphids, but they feed on evergreens such as conifers. Like aphids, they deposit a white-waxy cotton-like secretion, making them look 'woolly'. Common host plants include Spruces (Picea sp.), Douglas Firs (Pseudotsuga sp.) Larches (Larix sp.) and Pine Trees (Pinus sp.).
These insects can spread plant diseases.
Food for other wildlife!
Adults: These insects can vary from grey-black to brown depending on what host plant they colonise. In the garden, they associate in large aggregations on the host plant. They are most likely to be seen active on young shoots and branches or sometimes on the trunks of conifers, pine, or spruce tree. Each individual can be between 3-6mm.
Heavy infestations can turn leaves yellow and dry. Produce clear sticky honeydew. Honeydew may attract mould and ant infestations. Some species can cause plants to produce plant galls.
Damage caused by adelgids is often minimal and infestations tend to be tolerable.
Adelgids can be difficult to control chemically due to the waxy secretions they are able to secrete. These waxy coatings act as a layer of protection. Likewise, host plants are often too large to treat completely, so chemical treatment can be ineffective and expensive for a little pay-off. It's thought that this insect should be tolerated due to the minor risks it imposes on garden plants. Chemical alternatives available for home use vary in the degree of persistence and strength. These include organic sprays containing natural pyrethrums; winter washes containing natural plant oils; and lastly, the more persistent chemicals which incorporate synthetic pyrethroids. Please consider if chemical control is necessary. If a chemical option is sought, check with your local garden centre and please take care to follow the manufacturers' instructions. Check with your local regulating body for guidance on active ingredients and their authorisation for use.