208 INSECTS. 



are black and yellow, legs partially tinged with reddish 

 Fig. 55. brown, wings more or less 



darkened, N. dimidiatus is 

 black and red, with white mark- 

 ings. The second genus, Gorytes, 

 possesses in some species the 

 latter peculiarity, but has the 

 stemmata arranged in a curve. 

 These genera contain some 

 Profile Outline of Nysson common species, black and 

 Spinosus. yellow. The fifth gen us, Melli- 



nus, has the stemmata in a curve, and the petiole of 

 the abdomen terminates in a knot. Mellinus arvensis 

 (PI. TIL, fig. 6) is one of the most common of the Sand- 

 wasps. It is usually banded and marked as in the plate, 

 but is subject to much variety in this particular. It is 

 about J inch in length. The wings have a long pointed 

 marginal cell, and four submarginal cells.* Of this 

 insect Mr. Smith writes as follows : " Having fre- 

 quently observed the habits of the Mellinus arvensis, 

 and reared it from the larva state, a few observa- 

 tions are here recorded. When the parent insect 

 has formed a burrow of the required length, and 

 enlarged the extremity into a chamber of proper dimen- 

 sions, she issues forth in search of the proper nutriment 

 for her young. This consists of various dipterous in- 

 sects ; species of various genera are equally adapted to 

 her purpose. Muscidce, Syrphidce, &c., are captured. 

 It is amusing to see four or five females lie in wait upon 

 a patch of cowdung until some luckless fly settles on it. 

 When this happens, a cunning and gradual approach 



* The fourth, which reaches to the tip of the wing, is not shown in 

 the plate, the nerve which bounds it falling short. 



