76 DR. HARRIS'S REPORT. April, 



proleg, or part which performs the office of a posterior foot, is sit- 

 uated in a semicircular space at the base of the last segment. They 

 are found under the bark of trees ; the perfect insects, in June 

 and July, in the same situation, and also upon flowers. 



In tlie Coleopterous insects which follow, all the feet have but 

 four articulations. 



The genus Bruchus, appears to be chiefly appropriated to the 

 Leguminous or Pea-flowering plants. The form of the body in this 

 genus is short and convex ; the head is produced or elongated be- 

 fore into a broad snout, and is suspended vertically below the thorax; 

 the antennae are composed of eleven nearly cylindrical joints, which 

 gradually increase in size to the last ; the elytra are short, and do not 

 cover the posterior extremity, which is pointed ; the posterior thighs 

 are thick. The perfect insects deposit their eggs upon the pods of 

 plants, the pulse of which affords nourishment to the larvae. These 

 are little whitish grubs, without feet, and one only is to be found 

 within a single seed, the interior of which is perforated by a hole, 

 which is covered only by the thin hull, on the outside, and through 

 which the perfect insect gnaws a passage sometime before it makes 

 its escape. This is not effected until about the time of the ger- 

 mination of the seed, so that the existence of the insect is extended 

 througli one year, during the winter months of which it remains, con- 

 cealed in the seed, in a state of torpidity. 



These insects are far more conmion than has generally been 

 imagined. The Gleditsia, Robinia, Mimosa, Cassia, and various 

 other native legumes have their distinct species. But the most re- 

 markable is the Bruchus pisi., or pea-bug of North America. This 

 insect has been introduced with American pease into England, and 

 a part of Europe, but is not known in the North of Europe. Kalm, 

 the Swedish traveller, tells us that he was greatly agitated on dis- 

 covering some of these insects in a parcel of pease brought by him 

 from America, lest he should be the instrument of introducing so fatal 

 an evil into his beloved country. Nor was his agitation unfounded ; 

 for this noxious insect was at one time so destructive to the pea in 

 our country as to put an end to its cultivation in many places. The 

 pea-bug must originally have fed upon some of our indigenous vege- 

 tables allied to the garden pea, which, however, it has deserted in 



