• Hydorn, Susan B.
  University of Maine
  

A study to examine the effects of operational applications of spruce budworm insecticides, carbaryl (Sevin) and acephate (Orthene), on certain non-target forest invertebrates was conducted in central Penobscot County, Maine, in 1978. Caged spiders exposed to the insecticides, particularly acephate, demonstrated low survival; those surviving acephate treatment often evinced abnormal behavior. Analysis of arthropod densities in balsam fir foliage showed spiders to be the most numerous predaceous arthropods, followed by syrphid fly larvae. Treatment with the insecticides may have influenced density of arboreal spiders. Syrphid larvae were apparently unaffected by spraying.

Influence of spraying on soil surface arthropods was studied using pitfall traps. Data indicated lack of a severe effect of spraying on  terricolous spiders. Ants appeared to be unaffected by spraying. Carabidae, particularly Carabini, demonstrated a possible adverse response to treatment. Treatment with carbaryl apparently suppressed populations of harvestmen.