30 



FARMERS BULLETIN 843. 



larva. Tlie larvte upon hatcliiiig from eggs, wliich are deposited in 

 masses (fig. 35) on the underside of the leaves, feed at first only on 

 the underside of the leaflets, but later they devour the entire foliage 

 except the stems and petioles. Small pecan trees, especially nur- 

 sery stock, sometimes are defoliated completely, and it is not uncom- 

 mon to see large branches on bearing trees stripped of their foliage. 

 The larvae feed in colonies (fig. 36), and in molting the larger 

 caterpillars invariably leave their feeding place and crawl to the 

 trunk or larger limbs, where in a mass they shed their skins, wliich 

 may adhere to the bark for several weeks or longer. After molting 

 they ascend the tree to continue their feeding depredations, and 

 when fully gro^^^l crawl down the trunk and immediately enter the 



soil to a depth of a 

 few inches. Here, 

 in a day or two, pu- 

 pation takes place. 

 In the North tliis 

 insect has only one 

 generation 3'early, 

 but evidently at 

 least two genera- 

 tions occur in the 

 South. 



According to Bur- 

 reau of Entomology- 

 records the mot lis 

 (see fig. 37) develop- 

 ing from overwin- 

 tering pupa? emerge 

 from April 15 to 

 July 15, and shortly after emergence egg laying takes place on the 

 underside of the leaflets. Tlie eggs, wliich are laid in masses usually 

 numbering from about 100 to 150 each, hatch in a httle less than a 

 week and the larvse feed for 25 days or longer before completing their 

 growth. Tlie caterpillars enter the soil to transform to bro^^^l pupa?, 

 in wliich state they remain about 18 days for the summer generation. 

 In the case of the fall generation the winter is passed as pupa^ (fig. 

 38) in the ground and the moths do not emerge until the f ollo^^-ing 

 spring or early summer. The second-brood larva- enter the soil 

 from the middle of September until the last week in October. 



Fig. 3J —The walQut caterpillar (Datana integcrrima): Egg mass, 

 largcd. 



CONTROL MEASURES. 



AYhenever the egg massed or colonies of the caterpillars are dis- 

 covered they should be destroyed promptly. Growers often may 

 discover the larger larvae massed on the tree trunks in the act of 



