FSYCHE. 



MIMICRY IN HEMIPTERA. 



E. P. VAN DUZEE, BUFFALO, N. Y. 



The family lygaeldae presents us 

 with two examples of protective mim- 

 icry that seem well worth recording. 

 These cases which are very similar, 

 have doubtless been frequently observed 

 by collectors, but I have seen no pub- 

 lished account of them. I refer to the 

 adolescent stages of Cymus angiista- 

 tus and Oedancala dorsalis ; both live 

 on the various species of Carex and 

 Juncus growing in swampy places in 

 open woods and pastures. 



Cymus angustatus occurs princi- 

 pally on y uncus nodosus and allied spe- 

 cies, but is frequently found on the 

 smaller Carlces; it is extremely abun- 

 dant in the localities mentioned above, 

 and along roadside ditches, and in fact 

 wherever the yuncus grows. In this 

 vicinity it appears in May, and continues 

 until late in autumn ; copulation takes 

 place about the first of July, the imma- 

 ture insects are abundant through the 

 last of July, the imago appearing from 

 the first to the tenth of August. The 

 young, at least in the nymph state, bear 

 a striking resemblance to the capsules 

 and perigynia of the plants on which 

 they occur ; they are of a dull straw- 



color, ovate in form, compressed or 

 somewhat lenticulate, acute behind, 

 produced and blunt before, and with 

 the connexivvmi expanded and very thin. 

 When taken in tlie sweep-net with the 

 glumes and fruit of these plants, it is 

 all but impossible to detect them as long 

 as they remain quiet, which however, 

 fortunately for tlie collector, is never for 

 any considerable length of time. I 

 have frequently poked them aside with 

 my tweezers, never suspecting their true 

 character until they indicated it by 

 scrambling to their feet and running 

 otl', which they did with surprising 

 facility. 



Oedancala dorsalis is a larger spe- 

 cies and ratiier less abundant ; it occurs 

 wherever Carex vulpinoidea can be 

 found, but can frequently be taken on 

 other species of Carex and Cyperus. 

 In the nymph state it greatly resembles 

 the preceeding, but is larger, more 

 roimded in form, has a conspicuous 

 dark line on the dorsum, and is of a 

 much more sluggish disposition ; it is 

 equally difficult to detect, when on the 

 plant or mixed with the contents of the 

 sweep-net. The imago when senile is 



