330 MODERN CLASSIFICATION OF INSECTS. 



a secure habitation, but also a plentiful supply of food ; and in which 

 it subsequently undergoes its transformations until its arrival at the 

 perfect state, when it makes its escape by gnawing a small round hole 

 through the I'hind of the seed, the larva having previously eaten its 

 way to the inner surface of the seed, so that a thin pellicle alone 

 remains ; through which the larva makes a circular incision, leaving 

 only a very thin pellicle in that part, through which the imago easily 

 forces itself. One of these insects, Bruchus pisi, causes much in- 

 jury to the edible pea by eating the interior of the seed, and making 

 its escape about the period when the peas are ready for gathering. 

 This insect, which is probably an imported species in this country, 

 occasionally abounds to such an extent in some parts of North 

 America, as to cause the total destruction of the crops of peas, &c.* 



The Bruchus granarius Linn., is also in this country often very 

 destructive to the same vegetable, often depositing an egg in every 

 pea in a pod. In general, the insect remains in the larva state until 

 the following spring, but if the weather be very warm, the perfect 

 insect appears in the preceding autumn ; the larva has the curious 

 instinct to leave the most vital parts of the see-d until the last. The 

 larva (^^^.40. 7. larva of B. ruficornis after Germar) is a soft white and 

 fleshy grub, with a scaly head, and short strong jaws, with the legs 

 obsolete or but very slightly developed. They have nine spiracles on 

 each side of the body. 



I have published some notes on the economy of two species of 

 Bruchus, in the Trans. Entomol. Soc. (vol. i, p. xxiv.) and Gardeners 

 Magazine (No. 87- p. 287.). 



These insects are much more abundant in tropical climates than in 

 our northern country. They attack the grains of the Gleditsia, Theo- 

 broma, Mimosa, Robinia, Pseudoacacia, and many other plants. I 

 have also received specimens of the seeds of the Divi-divi (Ca:salpina 

 coriarea), a very valuable Brazilian plant, infested by a small species. 

 Germar has published a long notice of the economy of Bruchus rufi- 

 cornis, which resides solitarily in the cocoa nut {Mag. Entomol. t. iii. 

 p. 1. 7. tab, 1.); and M. Hummel has described another species, Br. 

 Faldermanni, which attacks the seeds of a species of Macuna (one of 

 the Leguminosae), as many as 14 having been found in a single seed 

 (Essais Entomol. No. vi. p. 10. 1827.). Latreille has also given an 



* See Kalm's Travels, vol. i. p. 173 



