7° 



SCIENCE- GOSSIP. 



disc on the margin of the hinder curve is not 

 circular but nearly square. The front edge of this 

 disc slightly overlaps the anterior curve (see 

 fig. 8). 



Locality.-— Near Lowestoft, 1896. 



87 Dryburgh Road, Putney, 

 May \Uh, 1901. 



NOTES ON SPINNING- ANIMALS. 



By H. Wallis Kew. 



(Continued from Vol. VII., page 265.) 



IX. — Larvae of Weevils. 



O PINNING of a remarkable kind is practised by 

 ^ the larvae of weevils of the genus Hypera. 

 They make small, elegant, silk-like cocoons, spun 

 with more or less wide meshes, through which the 

 larva and afterwards the pupa can often be seen. 

 The cocoons are attached, generally, to the leaves 

 and stalks of plants ; for these larvae, though leg- 

 less, are not buried in vegetable tissues, as are so 

 many of their kind, but live like caterpillars on the 

 external surfaces of plants. They travel by means 

 of ventral fleshy prominences, and are apparently 

 helped to retain their position by the viscous matter 

 with which their bodies are varnished. This is 

 excreted by a small more or less protrusile nipple, 

 found in the anal region on the upper surface of 

 the last segment of the body, near the union of 

 that segment with the preceding one. The genus 

 is extensive ; but, except to entomologists, its 

 members are not well known. Hypera punctata, 

 however, having proved injurious in clover fields 

 in North America, has obtained a certain notoriety. 

 The creatures are of but moderate size ; the larva 

 of H. viciae, for instance, measuring 10 mm. ; and 

 that of H punctata 14 mm. 



De Geer 1 (1775), who gives a history of the dock- 

 weevil {Hypera rumicis), states that the very pretty 

 cocoons are spun on the stalks of the dock, or 

 between the flowers or seeds at the top of the stalk. 

 They are nearly spherical, about the size of a pea, 

 and are made of yellow or white silk, spun in large 

 meshes in a single layer. The insect remains 

 visible through the walls, the tissue of which is 

 compared by the author to coarse gauze. The 

 component threads are rather coarse, but so elastic 

 that the cocoon, pressed with the finger, regains 

 its original form when released. In spinning, the 

 larva keeps its body curved in a semicircle, and 

 De Geer thinks that the cocoon owes its round- 

 ness to this circumstance, the body serving as 

 a mould. Since the time of De Geer many authors 

 have, no doubt, observed these curious cocoons. 

 Among others, Kirby and Spence refer to the beauti- 

 ful fine gauze-like cocoon of Hypera motor 

 found on stalks of spurrey (Spergiila mvensisf). 



(1) De Geer, "Memoires pour servir k l'Histoire des Insectes," 

 v. (1775), pp. 231-34. 



The pupa was visible through the cocoon, and r 

 on touching the plant, Kirby observed that the 

 pupa whirled round within the cocoon several 

 times with astonishing rapidity ( 2 ). Perris ( 3 ) has 

 written at length on the cocoons of H rumicis 

 and H viciae, the latter being found upon Apium 

 nodiflorum. He describes them as elegant spherical 

 structures, made of a network of irregular meshes 

 and of a tissue resembling tulle. They are 

 yellowish-white at first, becoming afterwards 

 yellow, then golden in H. rumicis and tawny in 

 H. viciae. The cocoons of the latter are usually 

 solitary ; but H. rwmicis sometimes groups its 

 cocoons at the extremities of dock-stems, from five 

 to eight having been found together. H. rumicis- 

 has been further observed by Osborne ( 4 ), in 

 Ireland, the cocoon being described by him as a 

 globular reddish network, appearing darker at the 

 circumference, where the meshes are massed 

 together, and permitting the animal to be seen 

 through its walls. He found the cocoons upon 

 both sides of dock-leaves, where they had a striking- 

 resemblance to the circular rust-stains common on 

 those leaves. He notes that the enclosed pupa is 

 active, becoming excited when brought near the 

 light, and making three or four revolutions on its 

 long axis in alternate directions. 



Lastly, we have notes by Eiley ( s ) on Hypera 

 cocoons observed in the United States. In infested 

 clover fields the cocoons of H punctata are found 

 on or in the ground. In captivity, however, they 

 were usually spun between leaves or stalks. They 

 were oval, pale yellow, of coarse tough threads in 

 irregular network. Eiley had previously reared 

 H. compta from Polygonum nodosum, to which 

 plant were attached the cocoons, of the usual net- 

 work appearance. H. eximia, says Popenoe, trans- 

 formed in similar cocoons on Mumex britannica. 



With regard to the manner in which these 

 cocoons are formed, De Geer believed the threads 

 to come, like those of lepidopterous caterpillars, 

 from a spinneret which he supposed he had seen 

 on the lower lip. Goureau ( 6 ), who saw the crea- 

 tures spin, also believed the spinneret to be oral \ 

 and Eiley states of Hypera punctata that the spin- 

 ning is clone with the mouth, the silk issuing " from 

 the spinneret in a very perceptibly liquid condition."" 

 He further notes that the creature touches the leaf 

 with its mouth, applying at the same time a drop 

 of the liquid, which is stretched out into a thread 

 until the mouth is touched upon another point. 

 The larva, he says, continues to work in this way 



(2) Kirby and Spence, " Introduction to Entomology," ii. 

 (1817), p. 298 ; iii. (1826), pp. 215, 224. 



(3) E. Perris, " Memoires de l'Academie Rationale de Lyon." 

 Sciences (n.s.), i. (1851), pp. 93-106. 



(4) .J.A.Osborne, "Entomologist's Monthly Magazine," xvi. 

 (1879), pp. 16-18. 



(5) C. V. Eiley, "American Naturalist," xr. (1881), pp. 

 912-14 ; "Report of the Commissioner of Agriculture," 1881 and 

 1882, pp. 171-79. 



(6) Goureau, quoted by Perris, I.e. 



