THE LEPIDOPTERA 



267 



One part of this family consists of moths known as the Datanas. The larvae 

 of these insects feed on orchard, shade and forest trees, keeping together in 

 groups, and when resting or disturbed they bend the ends of the body nearly at 

 right angles to the middle part, in a very characteristic attitude. They feed 

 during July and August and when full-grown are about two inches long. One 

 species is common on the apple (Figs. 270, 271) : others occur on the oak, walnut, 

 hickory and other plants. The presence of 100 or 200 caterpillars feeding to- 

 gether on a single branch, and of 

 considerable size as they get older, 

 often disturbs the owners of infested 

 trees who unnecessarily fear serious 

 injury to their trees. 



The fact that the caterpillars feed 

 in groups renders control easy, how- 

 ever, either by removing the groups by 

 hand or by spraying the region at- 

 tacked, with a stomach poison, which 

 is very effective for these insects. 



Another Notodontid having similar 

 habits and found at the same season 

 is the Red-humped Apple-tree Cater- 

 pillar {Schizura concinna S. & A., 

 Fig. 272). The larva (Fig. 273) has a 

 red head ; a red hump a short distance 

 behind; a double row of black spineg 



Fig. 270. Fig. 271. 



Fig. 270. — Adult Moth of Yellow-necked Apple-tree Caterpillar {Datana minhtra 

 Dru.), slightly less than natural size. (Orifjinal.) 



Fig. 271. — Yellow-necked Apple-tiee Caterpillars on a branch, showing characteristic 

 attitudes assumed when disturbed. Natural size. (From Britton, Eighteenth Rept. Ent. 

 Conn. Agr. Exp. Sta. 1918.) 



along its back; and its body is narrowly striped with yellow, black and white. 

 Control is the same as for the Datanas. 



Family Dioptidae. — This family appears to have but one North American 

 representative, found only on the Pacific Slope. It is known as the California 

 Oak Worm {Phryganidia calif ornica Pack.), and the caterpillar feeds upon the 

 leaves of the hve oak and deciduous oaks. The adult moth (Fig. 274) is light 

 brown with darker veins and a wing-spread of about an inch and a quarter. 

 The eggs are laid on the leaves of the oaks and various other plants in October 



