HOW TO KNOW THE IMMATURE INSECTS 



33a. Front reaching less than half way to vertex; crochets triordinal. 

 Fig. 458 FamUy COSSIDAE 



Fig. 458. a, Leopard moth, Zeuzera pyrina L.; b, trior- 

 dinal crochets. 



The caterpillars are mostly borers in the heartwood of various kinds 

 of woody plants. The leopard moth, Zeuzeia pyrina (L.), the larvae 

 bore in the branches and stems of apple, beech, birch, cherry, currant, 

 elm, maple, oak, pear, plum, walnut, etc. The life cycle needs two 

 years to be completed. 



33b. Front reaching more or less two 

 thirds way to the vertex, and end- 

 ing in on attenuate point; crochets 

 uniordinal or biordinal; small spe- 

 cies. Fig. 459 34 



Fig. 459. Crochets: a, uni 

 ordinal; b, biordinal. 



34a. Crochets of prolegs biordinal. Fig. 460. 



35 



Fig. 460. Bior- 

 dinal crochets. 



34b. Crochets of prolegs uniordinal. Fig. 461. 



36 



Fig. 461. Uni- 

 ordinal crochets. 



163 



