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|• research topics|
|• host plants|
|• list of natural enemies|
Gilletteella cooleyi (Gillette, 1907) - (Cooley's spruce gall adelgid)
This adelgid is native to western North America but has been introduced into eastern parts of the continent in the mid 19th century, as well as into Europe. It can cause damage to its secondary host, Pseudotsuga, where infestations of young trees can result in chlorotic needles, deformations and stunting.
G. cooleyi normally has a life cycle over 2 years involving 2 host plants. Spruce is the primary host, where galls are formed in spring in which the gallicolae form develops into winged females. These migrate to Douglas fir trees in the summer, the secondary host. On Douglas fir, G. cooleyi overwinters and reproduces parthenogenically for several generations. Winged forms develop in the following year which migrate back to spruce in late spring or early summer. On spruce males and females develop and reproduce sexually. The nymphs emerging from the eggs overwinter near the tip of the branches and induce the formation of galls in the following spring.
|• English:||Cooley's spruce gall adelgid|
|• Français:||puceron de l'épinette de Sitka|