David Daehnke

gardeningguru@juno.com
Mahwah, NJ
United States

Pine Sawflies - Check pines for second generation sawfly eggs. Look for rows of yellow spots on needles, which indicate the presence of eggs. Look for yellow, curled, half-eaten needles indicating the presence of larvae. Light infestations on small pines may be hand picked and destroyed. Use horticultural oil on larvae. Improve cultural conditions. Stressed plants may attract sawflies.

Fall Webworm - More than 100 species of deciduous forest and shade trees may be attacked by the native tiger moth caterpillar, particularly mulberry, walnut, hickory, elm, sweetgum, poplar, willow, oak, linden, ash, apple and other fruit trees. The caterpillars produce a web over terminal growth in which they feed. Prune out webbed terminals as detected, or use Bacillus thuringensis var. Kurstaki, horticultural oil or horticultural soap to control young larvae in large infestations.

Magnolia Scale - This native soft scale feeds only on magnolia, preferring cucumber, star, lily and saucer magnolias. Oil sprays in the dormant season or residual insecticides in spring or early summer should reduce the populations. In August and September, eggs are present under females and sprays are ineffective. A residual insecticide in October should eliminate most crawlers.

If you have any specific IPM questions, please e-mail me at IPMQuestions@Gardeningguru.org or The Q & A Message Board to see if it has previously been asked.