Nematodes enter the tree during beetle maturation feeding or oviposition, reproduce in the vascular tissue and cause wilt symptoms. Trees under stress are most attractive to beetles and susceptible to nematodes, and can be killed as quickly as 40 days, but more commonly within two years. The pinewood nematode is the most important forest pest in Japan, responsible for killing 8 million trees in 1978 alone. In the U.S., losses tend to be limited to ornamental Scotch, Austrian and Japanese black pines, especially when associated with salt, drought, or other stresses. This trouble is characteristic of white pines.
Needles turn reddish-brown more or less at the tips and give the tree a scorched appearance.
Insect Problems Aphids. There are several aphids that feed on the branches of various species of pine. Any of these aphids can be controlled by spraying with acephate or insecticidal soap, which are among the compounds registered for use against this pest in Connecticut. Imidacloprid can be applied as a systemic to be taken up by roots. Consult the labels for dosage rates and safety precautions.