INSECTS INJURIOUS TO CLOVER AND ALFALFA 203 



20 to 80 per cent of the seed is often destroyed. Both red and 

 crimson clovers are attacked, and a recent bulletin * from the 

 Department of Agriculture states that the insect is actually 

 threatening to destroy the alfalfa seed industry in certain sections 

 which formerly produced it in quantity. 



Life History. The winter is passed by the fully grown larvae 

 in seed on the ground. The adults emerge in the spring, the maxi- 

 mum appearing about June 10th in central Illinois, according to 

 Dr. Folsom, to whom we are indebted for the most careful study 

 of the pest. The females deposit their eggs in the soft seed, just 

 as the floret is withering, being unable to penetrate the seed after 

 it has hardened. The egg is whitish, about .01 inch long, and 

 with a peculiar tail-like appendage (Fig. 169). The maggot-like 

 larva feeds upon the seed, gradually hollowing it out, and when 

 full grown is about one-twelfth inch long, stout and footless, 

 with a small head. The pupal stage is passed within the seed 

 and a second generation of adults emerges about the middle of 

 August. These lay their eggs in the second growth, and some 

 of the adults from these appear the same season and the rest 

 not until the following year. There seem to be at least three 

 generations a year in central Illinois, but the life history is com- 

 plicated, by the irregularity in the time of development, though 

 the greatest numbers of adults appear about June 10th and 

 August 10th, just as the clover-seed is green. 



Control. Mr. T. D. Urbahns, in the bulletin mentioned, 

 recommends cutting the seed crop promptly and stacking it as 

 soon as possible, using well cleaned seed, destroying burr-clover 

 and cleaning up of waste land as we.ll as destruction of screenings 

 from the thresher and winter cultivation as being practices likely 

 to reduce the damage from the chalcis. He particularly recom- 

 mends that infested crops be harvested, even if they are of no 

 value for seed, since, if they are left standing and pastured they 

 will infest a whole locality. 



The Clover-seed Caterpillar f 



"In its ability to diminish the seed crop, this pest ranks with 

 the seed-midge and the seed-chalcid. Attacking a clover head 

 that is green or partly in bloom, the little caterpillar eats out a 



* Farmers' Bulletin 636, U.JS. Dept. Agr. 



t Enarmonia interstinctana Clem, Family Grapholithidce. 



