Orangestriped oakworm

Anisota senatoria (J. E. Smith) (Lepidoptera: Saturniidae)

Orientation to pest

Orangestriped oakworm, Anisota senatoria (J. E. Smith), is a native silkmoth that feeds mainly on the foliage of oaks (Quercus). It has as a wide distribution in eastern United States and southern Canada. Adults appear in the June or July in the northern part of its range and lay groups of eggs on the undersides of leaves of host trees. Young larvae feed in groups, skeletonizing leaves. Older larvae consume all but the main veins and are less gregarious. Mature larvae drop to the ground and wander before pupating in the soil, where they overwinter. Outbreaks occur infrequently. There is one generation per year in most parts of the range. Defoliation can be significant in some years, but little harm results unless trees are under additional stress from other factors.

Hosts commonly attacked

This species feeds primarily on oaks (Quercus).

Distribution

This species occurs in much of the eastern United States and southern Canada, west to Minnesota and Texas, although it is not common in the southeastern United States.

Images of orangestriped oakworm

John Wheatley, John B. Wheatley, Bugwood.org 768x512	John Wheatley, John B. Wheatley 768x512	Lance S. Risley, William Paterson University, Bugwood.org 768x512 / 1536x1024
Figure 1. Adult of orangestriped oakworm, Anisota senatoria	Figure 2. Eggs of orangestriped oakworm	Figure 3. Young larvae of orangestriped oakworm

Lacy L. Hyche, Auburn University, Bugwood.org 768x512 / 1536x1024	Erich G. Vallery, USDA Forest Service - SRS-4552, Bugwood.org 768x512 / 1536x1024
Figure 4. Close up of mature orangestriped oakworm caterpillar	Figure 5. Defoliation by larvae of orange striped oakworm

Important biological control agents related to this pest species

Parasitoids that have been reared in Virginia from orangestriped oakworm larvae or pupae include Hyposoter fugitivus (Say) (Ichneumonidae) (in larvae, 3.2 to 9.3%) and Lespesia anisotae (Webber) (Tachinidae) and Belvosia bifasciata (Fabricius) (Tachinidae)(in larvae at 10.7 and 0.7%, respectively).

Web links for information on orangestriped oakworm

• Fact Sheet | Connecticut Agricultural Experiment Station
  
• Guide on Species Recognition and Habits | L.L. Hyche, Auburn University
  
• Bulletin | Michigan State University Extension
  Bulletin E-6254; provides identification and management information

Articles

Coffelt, M. A. and P. B. Schultz. 1993. Population biology of orangestriped oakworm (Lepidoptera: Saturniidae) in southeastern Virginia. Journal of Entomological Science 28: 218-229.

Coffelt, M. A. and P. B. Schultz. 1993. Larval parasitism of orangestriped oakworm (Lepidoptera: Saturniidae) in the urban shade tree environment. Biological Control 3: 127-134.

Coffelt, M. A. and P. B. Schultz. 1989. Development of an aesthetic injury level to decrease pesticide use against orange-striped oakworm (Lepidoptera: Saturniidae) in an urban pest management project. Journal of Economic Entomology 83: 2044-2049.