Pests and Diseases Viewer




Usually appear in

Spring to Autumn.

Back to Pests and Diseases

Caused By:-     Various Adelgid insects


Hemlock Woolly Adelgid
Adelgids are aphid-like insects in the family Adelgidae that primarily feeds on pines(Pinus), Spruce(Picea), Larch(Larix), DouglasFir(pseudotsuga menziesii) and Silver Fir(Abies). Adelgids feed by sucking their host plants sap. Infestations can cause yellowing of the leaves, gall production, branch dieback, growth deformation and in severe outbreaks even death of the host plant. Entire forests can be killed by certain adelgids such as the Hemlock Woolly Adelgid if left without control measures. Adelgids tend to be host plant-specific and can be important pests in landscapes, plant nurseries, plantations and forests. Picture from Wikimedia Commons.


Control measures depend on the kind of Adelgid and each type needs individual control measures. Therefore the first problem is to identify the Adelgid.
Waxy coated Adelgids are very difficult to control with spray-type insecticides. The best control strategy is to treat the young, unwaxed, stages with an overhead insecticidal soap spray then treat waxed stages with a systemic insecticides. Insecticidal soap may also work with unwaxed Adelgids. Washing them off with a strong water jet may also be possible.

P_adelgids P_adelgids2

Click picture to see larger view and more information   

Back to top