

Insects. 5215 



Note on the Nests of Hydrophilus caraboides and Hydrous piceus. — Perhaps the 

 following notice, respecting the construction of the singular cocoon, or rather nest, of 

 two of our aquatic beetles, may not be unacceptable to the readers of the ' Zoologist,' 

 as I believe that no description of the process has hitherto been given. My observa- 

 vations were made upon insects living in a tank of glass, in my chambers in the 

 Temple, during the month of May last. I had then a pair of Hydrophilus caraboides, 

 whose proceedings I was enabled, to watch. The leaves of the lesser spear-wort (Ra- 

 nunculus Flammula), a plant of which was growing in the tank, were employed by the 

 beetles in the formation of their nest. I found that they cut the leaves in a trans- 

 verse direction near the stem, under water ; that the detached portion was bent, by the 

 joint efforts of the insects, till the point of the leaf approached the cut part, which 

 caused it to assume the form of the tilt or arched head of a waggon. During this 

 operation, and indeed until the whole was completed, the male was on the female's 

 back, firmly clasping the edges of her elytra with his last pair of legs, and bending 

 his head and thorax over hers. The hinder legs of the female were engaged in keep- 

 ing together the extremities of the severed portion of the leaf whilst she closed up the 

 openings with a light-coloured species of silk. This was a most curious and interest- 

 ing process. The insect protruded from the extremity of her abdomen a forked organ, 

 closely resembling two wasp stings, which moved with great rapidity, working a glu- 

 tinous secretion between its points, much as a confectioner spins melted sugar. This 

 gluten appeared to harden instantly, forming a close and tenacious web. As soon as 

 the little ark was completed, a singular appendage was added to the upper part of the 

 truncated end or stern, in the shape of what I shall call a flagstaff. This was slightly 

 spatulate at its extremity, but soon curved longitudinally under the sun's heat. The 

 concave side was always turned from the stern. The flagstaff itself was entirely com- 

 posed of the above-mentioned gluten, and was about half an inch high. I was unable 

 to observe the actual deposition of the eggs ; but the larvae were excluded in about a 

 week. I should add, however, that this was under a high temperature, not unfre- 

 quently upwards of 90 degrees; the tank being enclosed with glass. This pair of 

 beetles constructed no less than three of these nests, all floating freely on the surface 

 of the water. I afterwards placed a pair of Hydrous piceus in the same tank. These 

 also formed a nest, and one only. Of course I could not tell how many they might 

 have made before they came into my possession. The plant selected by these insects 

 was a Kanunculus with divided leaves, like a buttercup, which floated. The nest was 

 in the shape of a shallow bag, fixed to the under side of the leaf, which was not bent, 

 and allowed to remain, still growing, to the plant. It was also furnished with a flag- 

 staff, more bent backwards than that of the Hydrophilus, and not spatular. It was 

 of a dark reddish brown. No extraneous matter was interwoven with the web. The 

 manner of spinning it was the same as that adopted by the Hydrophilus, as was the 

 form of the spinning organ and the relative position of the male aud female. It is 

 not easy to give a clear idea of the form of these curious nests in words ; but my 

 sketches, which are left in Mr. Newman's hands, may perhaps convey a better. 

 About two hours were employed in the construction of each nest. — W. J. Bernhard 

 Smith; 1, Plow den Buildings, Temple, July, 1856. 



[I shall be most happy to show Mr. Smith's sketches to any entomologist desirous 

 of seeing them. — Edward Newman, ,] 



Capture of Ochina Ptinoides in Cumberland. — I took about a dozen of Ochina 



