|
This pine tree plant disease is caused by one of two species of spittlebugs. The pine spittlebugs, or aphrophora parallela which may cause serious injury7 to white or scotch pinesor the saratoga spittlebugs, a. saratogensis which typically kills off only the branches of red and jack pines. These insects may kill branches or the entire tree if infestation is strong.
Pine spittlebugs at maturity are grayish brown, wedge-shaped insects which can be up to 1/2 inch in length. They may first be noted by the frothy spittle which surround their body. This is caused by drops of undigested sap that then mix with air, being excreted by the insects as they suck sap from twigs and the main body of the trunk. Often these frothy bubbles of spittle can be seen also on the twigs and near the base of individual needles or needle clusters. Needles often turn yellow and drop off while black mold that has a sooty appearance will begin to appear on nearby branches.
Female pine spittlebugs lay their eggs in late summer at the base of needle buds. Eggs winter and hatch the following May when young insects emerge to feed on the sap. As they feed, they form spittle. It is when this spittle drips down onto branches beneath their feeding area that the black sooty mold is formed as the sap becomes colonized by fungus. Female saratoga spittlebugs lay their eggs on plants beneath the pine trees rather than at the base of buds. The rest of their life cycle follows a similar path with adults migrating to feed on trees in late June rather than May, and then returning to the low growing plants beneath the trees to lay eggs again in the fall.
At the first sight of spittlebugs or spittle, spray the infested area with acephate containing insecticide. For pine spittlebugs, repeat applications of insecticide in late May and then again in July, depending on when you first noted the infestation. For the saratoga spittlebug, spray in late June and then again in July, again depending on the time you noted infestation. It is best to use a high pressure sprayer with these insects as the spittle can sometimes protect the insect from the insecticide.
|
| |
