GROUND-BEETLES THAT ATTACK LOCUST-EGGS. 289 



Piqya. — Pale-brown, ronnded at each eud, with the prothoracic spiracles and lips ante- 

 riorly, and the anal spiracles and lower tnbercles posteriorly, showing as minute points. 



Imago, $ . — Average expanse 0.48 inch. General color ash-gray with a ferruginous 

 hue, especially above, and a more or less intense metallic reflection. Face with white 

 reflections below; eyes smooth, brown, encircled by the ground color, and this behind 

 and on forehead bordered by a brown line; 2 similar lines at back of head from upper 

 corners of eyes and approaching to neck ; forehead dusky-brown, becoming bright 

 yellowish-red toward base of antennae, and the brown forking at right angles around 

 occiput. Trophi and auteunre black, the style simple and somewhat longer than the 

 whole antenna3. Thorax with three dusky longitudinal lines, obsolete behind; legs 

 black, with cinereous hue beneath; wings faintly smoky, with brown-black veins, 

 the discal cross-vein straight and transverse, the outer one bent and more oblique ; 

 balancers crumpled, yellowish. Abdomen with faint dusky medio-dorsal spots, broad 

 at base, tapering and obsolescing toward end of each joint. 



In the $ , aside from the larger eyes, stronger bristles, and narrower, less tapering 

 abdomen with its additional joint — all characteristic of the sex— the face is whiter, and 

 the medio-dorsal dark mark of abdomen continuous, and the hind tibiae are armed on 

 the inner side with a pectinate series of tine hairs. 



Described from 25 specimens of both sexes, reared from locust-egg-feeding larvae. 



The Common Flesh-fly {Sarcophaga camaria, L.). — The red-tailed 

 variety (sarraceniw) of this ubiquitous insect, described and figured 

 further on as preying on the locust, also attacks its eggs. It is a larger 

 maggot than the preceding, and contracts to a darker pupa, which is not 

 similarly rounded at each end, but has the hind end truncate, and the 

 front end tapering. It sucks the eggs, as does the Anthomyia larva, but 

 the parent fly is probably attracted principally to those which are addled 

 or injured, as the pods in which we have found it have very generally 

 been in a fluid state of decay. 



Ground-beetles and their larvae. — That many ground-beetles {Cava- 

 hid(e) feed upon the eggs as well as upon the locusts there can be no 

 doubt whatev^er, though few instances ha-ve been observed. One species, 

 however, the Agonoderes dorsaliSy^^ Lee. (Fig. 23), 

 has been observed to settle in swarms in fields 

 containing locust-eggs, and to busy itself devour- 

 ing them. The following letter from Mr. W. 

 Eobertson, of Olaytonville, Kans., under date 

 of April 28, 1877, refers to this little beetle, which 

 will be easily recognized from the figure, the colors 

 being yellowish-brown and black: 



On Sunday afternoon, April 15, the air was laden with 

 those beetles; they came with a warm northwest wind, 

 and I observed that they disappeared under the surface as 

 soon as they fell. 



sAus.' %mmo? rf^f r^ ^°^' ^ ^^^' ^^^^ afterward I went into a field that was plowed 

 last fall for wheat, and abandoned because of the immense 

 number of eggs it contained. I scratched a handful of earth to search for eggs, and 

 found more than a dozen of these little beetles. I examined this field very closely, but 

 found no beetles where I found no eggs. I also examined other fields and found the 

 same result. I went to that same field again to-day, and found only very few eggs, and 

 those few broken and half consumed. I could scarcely find a whole cocoon; the 

 beetles are only where the eggs are, and in walking over the ground you rarely see one. 



Hatipalus (?) Larva. — While few of the perfect ground-beetles have 

 been observed preying on locust-eggs, two larvte were quite commonly 



s2 Supposed to be the Carabus comma of Fabr. 

 19 G 



