274 Benj. D. Walsh on the Insects inhabiting the Galls 



HETEROPTERA.— INQUILINES. 



Family Lyg^id^. 

 Anthocoris [Redvmus] insidiosus Say (= Anthocoris pseudo- 

 chinche Fitch.) Both larva and imago occur very abundantly on S. bras- 

 sicoides in the summer, and more sparingly on S. rhodoides and S. 

 strobiloides, all three galls being Cecidomyidous and of the same year's 

 growth. I have also noticed a few larvae and imagos on S. senigma, 

 and a single larva, Aug. 1, on a leaf covered by S. semen; the above 

 two galls being Acaridous and of the same year's growth. This insect 

 is very common, and sometimes occurs under the husks of the ears of 

 maize in the autumn, in company with the notorious Chinch-bug; CMi- 

 cropus leucopterus Say;) for which, to my personal knowledge, it is 

 sometimes mistaken by Agriculturists, although it is only half as large 

 and very differently shaped. Dr. Fitch mentions that, in one instance, 

 it had actually been sent him by a correspondent as the Chinch-bu?, 

 whence his specific name. (N. Y. Rep. I, p. 29-4.) Say's descrip- 

 tion is defective in not stating, that the hind legs are entirely brown- 

 black. What Fitch calls the " variety semiclarus " of his pseudo-chinche, 

 i. e. with the posterior half of the hemelytral membrane fuliginous, is 

 possibly Anthocoris [reduvius] muscuhs Say, a very similar but larger 

 and proportionally longer insect, with the hemelytral tips normally 

 fuliginous, and with the tips of antennal joints 2 and 3 and the whole 

 of joint 4. brown-black, the rest of the antenna being pale. The anten- 

 nal joints, it may be added, are proportioned as in insidiosus. Say's spe- 

 cimen of this last species had lost its antennae, and consequently they 

 are as yet un described. 



The study of the various Families of gall-producing insects is pecu- 

 liarly interesting and peculiarly important just now, because it throws 

 considerable light upon the great questions of the day — What is a spe- 

 cies ? Wherein, if at all, do species differ from varieties ? How is 

 one species essentially distinguishable from another? And what was 

 the origin of species ? Ordinarily, when we compare together two 

 closely-allied animals, we can only compare them in regard to the dif- 

 ferent states, that intervene between the earliest embryo and the com- 

 pletely developed adult. This is a strictly zoological test. But in the 

 case of the gall-making insects we have, in addition, a botanical test of 

 the highest value ; for the characters of the gall are frequently of far 

 more practical importance for the distinction of species, than those of 

 the egg, larva, pupa and £ £ imago all put together. For example, 



