ENTOMOLOGY 201 



passed in the larval stage and pupation occurs early in the spring. 

 The caterpillar is greenish-white or pale yellow without markings, 

 with a brown head, and sixteen legs. It is about one-fourth of an 

 inch long. The adult moth is brown. Spring plowing (done before 

 the end of April) or fall plowing will destroy the third generation. 

 Early cutting of the first crop, as is recommended for the seed- 

 midge, should destroy the first generation, and where this is common 

 practice it is unlikely that the head caterpillar will become very 

 serious. 



Clover Thrips. At any time before the middle of the summer, 

 a clover head, if torn apart, is likely to reveal a number of tiny red 

 or black creatures, which run quickly about in attempts to hide. 

 They are thrips. The immature thrips are bright blood-red, becom- 

 ing darker as they grow older, the adults being black. The general 

 appearance is quite similar to that of the oats thrips. These little 

 creatures are so small and are provided with such feeble mouth- 

 parts, fitted for scraping only, that individually they are capable of 

 doing only a slight amount of injury. In the aggregate it is rea- 

 sonable to assume that they must blight quite an appreciable num- 

 ber of heads or parts of heads, but thus far no one has devised a 

 practical method of controlling them. Fortunately they are most 

 plentiful early in the season at a time when it does not make so 

 much difference. All thrips thrive best in hot, dry weather. 



Crimson Clover-Seed Chalcid. "When crimson clover was intro- 

 duced into America, it was hoped and believed that we had a sub- 

 stitute for red clover that would at least be free from the enemies of 

 red clover. The trial proved, however, that crimson clover seed 

 was preyed on by a pest, more troublesome than those of red clover 

 seed, and further that the new pest was liable to spread from the 

 crimson to the red clover. A close examination of the seed showed 

 the kernels to be hollowed out by the tiny creatures, each infested 

 seed containing a tiny, black, wasp-like winged insect, belonging to 

 a family most of the members of which are parasitic in their habits. 



There are two broods each year. The tiny chalcids are slightly 

 more than one-sixteenth of an inch in length, and jet black in 

 color. The hulls from which they emerge show each a little, round 

 hole through which the insect has come. If this were the whole story 

 no one would grieve much, but, unfortunately, Dr. A. D. Hopkins, 

 then of the West Virginia Station, reports that they work in devel- 

 oping seeds of red clover as well. It is not at all impossible that on 

 some of the occasions where the red-clover crop has failed, this 

 newer pest has been to blame. The writer has searched many times 

 and has had many samples of clover seed sent in from all over the 

 state for the purpose of finding the cause of such failure, but thus 

 far has been unable to find the characteristic hulls, possibly because 

 they are so light as to be blown out by the separator. 



Dr. Hopkins reports that the insect winters in seed left in the 

 open field, evidently in the larval stage. This would suggest fall 

 plowing when the presence of the pest in a given field is established 

 and when such practice is practicable. Prof. F. M. Webster sug- 



