Source: Texas A&M Forest Service
Spring and warm weather are finally here, bringing new growth and life. But they also bring increased forest pest activity.
Now is the time for landowners to check their trees to inspect for any signs of pests and/or pest damage.
One common Texas spring time pest seen in pine trees is the pine sawfly – a defoliator. Signs of sawfly infestation may be the unexpected shedding of needles. Typically, sawflies infest single or small groups of trees but if conditions are favorable, larger areas may be affected. Loss of tree growth is common, though repeated attacks for two or more years may cause mortality.
Pine sawfly caterpillars which, depending on the species, can be either yellowish-green or olive green colored, begin to feed on pine needles in late spring. Wilted, browning or missing needles warrant a closer inspection to determine if sawflies are active.
Usually, no control is warranted as infestations are typically localized and quickly controlled by natural predation, weather and disease organisms. Sawfly control methods, if desired, are most effective during the caterpillar stage.
High-pressure water jets may remove large clusters of larvae, though this technique may require some specialized equipment to reach larvae high in the tree.
Insecticides such as cyfluthrin, permethrin, insecticidal soap and spinosad can be effective but are usually only used to protect high-value trees and then only after repeated defoliations. Always follow the directions on the label of the pesticide to make sure that the chemical is labeled for use against sawflies and to ensure that the application will be effective. Remember: The Label Is The Law.
Contact your local Texas A&M Forest Service office at https://tfsweb.tamu.edu/contactus/county-search/ for assistance or more information regarding forest and tree pests.
You may also learn more about pine sawflies at https://tfsweb.tamu.edu/uploadedFiles/TFSMain/Manage_Forest_and_Land/Landowner_Assistance/Stewardship(1)/Pine_Sawfly.pdf