178 THE ENTOMOLOGIST. 



THE METAMORPHOSES OF QALERUGA NYMPH JEA, Linn. 

 By H. E. Quilter. 



While out by the side of Groby Pool, one Saturday afternoon 

 early in July, 1886, I noticed and admired the show of Polygonum 

 amphibium, L., which was then in bloom. I was thinking over 

 the modifications the plant must have undergone to adapt itself 

 to being amphibious, as at the same time the year before, owing 

 to the drought, the water had gone down, and the plant was 

 flowering on a dr}^ beach. 



My attention, however, was soon attracted by the fact that 

 upon the upper surface of the long floating leaves — so charac- 

 teristic of this plant — were numerous insect larvae. An examina- 

 tion soon convinced me that they were the larvae of a coleopterous 

 insect. Noting also that they were preparing to pupate, I took 

 home a quantity upon the leaves. They wei-e generally clustered 

 together upon the upper surface, but some had crawled upon 

 the stalks of grass growing out of the water. Placing them 

 in a box with a glass lid, I had the pleasure of watching the 

 insect through the later stages of its metamorphosis. Owing to 

 the difficulty, generally, of observing the changes undergone by 

 beetles, the observation of them, even in the commoner species, 

 is of interest ; but when the beetle is uncommon, as in this 

 instance, the interest and utility is augmented. 



The earlier stages of this beetle are as yet, so far as I am 

 aware,* unknown ; when and where the parent insect deposits its 

 eggs, so that the larvfe upon leaving the egg can feed upon an 

 aquatic plant, is somewhat puzzling, especially when we recollect 

 that the insect is not an inhabitant of the water. I may perhaps 

 be allowed to suggest that, from what I saw of the* habits of the 

 perfect insect, the parent deposits its eggs at the roots — which 

 are generally left dry or partially so about that time of the year — 

 of the plant upon which the larvae subsequently feed, and that the 

 larvaB are consequently aquatic, coming up out of the water, as 

 already noted, to pupate upon the leaves and stalks of aquatic plants. 

 I have before mentioned that when the larvae were found they were 

 preparing to pupate. They were not eating, and were motionless. 



The larva is about five-sixteenths of an inch in lengtli, and 



[* De Geer described and figured the earlier stages of this beetle upwards of 

 a hundred years ago (Memoires, v. 405, pi. x., figs. 3-6; 1781), and cf. Westwood's 

 Introduction, i. 382.— E. A. F.] 



