32 MASS. EXPERIMENT STATION BULLETIN 353 



Spiny Oak Worm 



Anisota stigma F. 



This species is rare in the northern United States, but it often becomes as 

 injurious in the South as the closely related orange-striped oak worm, Anisota 

 senatoria, in the North. It has been reported as feeding on oak in September. 



The moths resemble those of A. senatoria but are more densely flecked with 

 dark spots. The mature caterpillar, which is about 2 inches long, is bright 

 tawny- or orange-colored with dark, inconspicuous stripes along the back and 

 sides and speckled with numerous tiny raised white dots. In addition to the two 

 long spines on the back of the second body segment, the third and following body 

 segments, unlike the other species of Anisota mentioned, have quite long, slightly 

 branched spines instead of short ones. 



If an outbreak occurs, an arsenical spray such as that recommended for A. 

 senatoria, is effective. 



Felt, E. P. N. Y. State Mus. Mem. 8(2) :527. 1906. 

 McDaniel, E. I. Mich. Agr. Exp. Sta. Spec. Bui. 243:57. 1933. 

 Packard. A. S. Fifth Rpt. U. S. Ent. Comm.. pp. 125-126. 1890. 



(M 



1. Spiny Oak Worm, Anisota stigma. (Note long barbed spines along body.) Actual size. 



2. Rosy-striped Oak Worm, Anisota virginiensis. (Note short spines along body.) Actual size. 



Brown Anisota or Rosy-striped Oak Worm 



Anisota virginiensis Drurj^ 



The range of this species is believed to be roughly most of the United States 

 east of the Mississippi River. Full-grown caterpillars are observed in greatest 

 numbers in late September. Although the insect is primarily a pest of oak, it is 

 also found on hazelnut and chestnut. 



The female moth is brownish-red, has a wingspread of about 1 3^ inches, a small 

 but distinct white spot on each front wing and an irregular darker line running 

 parallel with the margin of both front and hind wings. The male is somewhat 

 smaller than the female. 



The mature caterpillar is about 13^ inches long, and uniform brown with tiny 

 raised dots of pale yellow and regular rows of short, sharp, black spines. Two 

 spines just back of the head on the second body segment are conspicuously longer 

 than the rest and are slightly curved. The striping is not conspicuous. 



If an outbreak occurs, an arsenical spray such as that recommended for A. 

 senatoria will control it. 



Bailey, H. L. Vt. Dept. of Agr. Bui. 35:25. No date. 

 Houser, J. S. Ohio Agr. Exp. Sta. Bui. 332:251-252. 1918. 

 McDaniel, E. I. Mich. Agr. Exp. Sta. Spec. Bui. 243:56-57. 1933. 



