1846.] Insects Injurious to Vegetation. 249 



localities, caterpillars were found which had devastated whole 

 fields. These caterpillars had their first abode near the ground, 

 in the first joint of the straw, where they were found in whole 

 families, in a sort of nest. The largest were about the length of 

 two lines. Their color was pale green, with a small black dot 



above The straw became dry at the first joint, and fell 



over or leaned on its neighbor. The upper part of the straw re- 

 ceived its nourishment from the atmosphere alone, and the ears 

 formed: but they continued in a sickly condition, and could only 

 produce small, shrivelled grains. The life of the caterpillars 

 (their duration as naked worms?) appeared to be from about 

 twenty-four to thirty days. As the straw ripened, the insects 

 changed their color into a brownish hue, shrivelled up, and finally 

 disappeared." 



M. Kcillar, who seems to have known nothing of the American 

 history of this insect beyond what he gathered from Mr. Say's 

 brief account, obtained some of the diseased straw from Germany, 

 in which, he says, " many of the brown pupae were found. I 

 opened the pupse-case, and was able to determine with great pro- 

 bability, partly from the form of the pupae, and partly from the 

 unchanged caterpillar in the pupae-case, that it must be a small 

 fly. I only ascertained this from the minute description and draw- 

 ing of the insect from Mr. Thomas Say, in a North American 

 journal, in which a stem of wheat, with the pupae within it, is 

 exactly represented as I have seen our wheat. 



Mr. Westwood, in a note appended to this account, says, it is 

 perhaps questionable whether the species, of which the above de- 

 tails are given by M. Kollar, is identical with Say's Cecidomyia 

 destructor. He even intimates a doubt whether the European 

 species is a Cecidomyia, for, from all that had been observed, this 

 genus in its pupae state, is naked, like the other Tipulidae, and 

 not enclosed in a case. Having himself received specimens from 

 Dr. Hammerschmidt of Vienna, and still in the straw near the 

 roots, he found the insect " enclosed in a leathery case," on open- 

 ing which, he discovered the larva shrivelled up and dead. Now 

 this nice point, so particularly noted, and so strikingly showing 



