The cocoon in this genus is double; the outer being reticulated, and the inner compact and close, but paler coloured.

Amongst the smaller species, with 22-footed larvæ, which do not emit a fluid from the pores of the body, those of Allantus tricinctus Fab., Hart., Dahlb., which feeds upon Lonicera caprifolia (Tenth. vespiformis St. Farg., T. rustica Fourc.), have been observed by De Geer (Mém. tom. ii. tab. 34. f. 9-19.), and Hartig (tab. 5. f. 39.); likewise those of Allantus pulveratus Retz. (leucozonius Hartig, Ibid. tab. 34. f. 20-25.).

The 22-footed larva of Allantus scrophulariæ Linn. is described by Bouché (Naturg. Ins. p. 138.), and figured, with the details of the transformations of this species, by Réaumur (Mém. tom. v. pl. 13. f. 12-23.). The insect does not form a regular cocoon, but merely constructs an earthen cell at the foot of the Scrophularia. It is also figured in the Entomol. Mag. (vol. i. pl. 1. f. 2, 3.), varying in colour very considerably after the penultimate moulting of the skin of the larva. An allied species, A. flavicornis Kl., luteicornis Fab., has been figured, in its different states, by Lyonnet (Mém. Posth. pl. 15. f. 13-18.). The larvæ of Emphytus cinctus and rufo-cinctus Klug (T. pavida St. Farg.) are found upon the rose in the autumn. The latter species is figured, in its different states, by De Geer (pl. 35. f. 14—18.). The former, when full grown, quits the leaves, and burrows into the pith of the stem to the depth of several inches, closing the aperture with its excrement, and thus forming a safe retreat for itself. (Réaumur, tom. v. p. 163. pl. 10. f. 1, 2, 3.; Bouché, Naturg. Ins. vol. i. p. 139., by whom the transformations of Emphytus perla are also described, Ibid. p. 140.)

The preceding species have smooth-bodied larvæ. Those of Selandria ovata Linn., forming (with some other species) the section named Eriocampa by Hartig (p. 279.), are 22-footed; but have the segments of the body clothed with small patches of white woolly matter, giving them still more the appearance of certain caterpillars. (De Geer, Mém. tom. ii. pl. 35. f. 1-13.) This matter is easily rubbed off, and is not found after the final mouiting of the caterpillar, which is found upon the alder. The cocoon is double.

The larvæ of Selandria bipunctata are 22-footed; but they are distinguished by having each segment of the body armed with strong spines, forked at the tip, but which do not exist after the penultimate moult of the larva. De Geer has represented one of these

larvæ (Mém. tom. ii. pl. 35. f. 19, 20., adding figures of simple, bifurcate and 4-furcate spines); he was, however, unable to rear it. Hartig has figured another similar larva, found on the oak (tab. 5. f. 27-30.), and which he gives as that of Tenthredo bipunctata (p. 262-277.), forming it (with some others) into the subgenus Hoplocampa, from the spines with which the larvæ are armed. Réaumur (Mém. tom. v. pl. 12.) has figured two species of these armed larvæ, found upon the oak and Prunus domestica; Lyonnet has also described one of these species of spined larvæ, found upon the oak (Mém. Posth. pl. 15. f. 1-12.), which he succeeded in rearing to the perfect state, and which De Haan doubtingly gives as the Dolerus hæmatodes of Klug.

De Geer (tom. ii. pl. 38. f. 11-13.), Réaumur (tom. v. pl. 12. f. 17, 18.), and Dahlbom, have figured a very curious 20-footed larva, found upon the alder, having the body flattened, and greatly resembling the larvæ of the butterfly genus Thecla, or the flattened Aselli. Neither of them were able to rear it, nor has Hartig been able to point out the group to which it belongs; he, however, introduces it into his great genus Tenthredo, copying De Geer's figure (pl. 5. f. 41.).

Lyonnet (Posth. Mém., pl. 14.) has given complete details of the various states and structure of an undetermined species of Dolerus ? * of which the larva is 22-footed.

The 20-footed larvæ of Selandria cerasi Linn. (Æthiops Fab.), which feed upon the leaves of plum and other fruit trees, are remarkable for the entire covering of greenish black viscid matter with which they are clothed, and which exudes from the sides of the body. By day they remain quiet upon the surface of the leaves, with the head withdrawn into the prothoracic segment, and the latter distended; the legs are also concealed, so that the insect has not the least appearance of animation, and looks more like a small portion of slime (fig. 71. 8.). (De Geer, tom. ii. tab. 38. f. 16–24.; Réaumur, tom. v. plate 12. f. 14.; Bouché, Naturgesch. Ins. p. 137.; Westwood, in Gardener's Mag. No. 92. November, 1837.) This, together with some allied species, has thence been formed by Hartig into the subgenus Blennocampa. (See his pl. 5. fig. 31.)

To this subgenus also belongs the "slug worm" of North America, which occasionally commits so much injury on the cherry, pear, plum,

⚫ The antennæ are described as only 7-jointed, but are represented as 8-jointed; but evidently incorrectly, as no species of the family has yet been described with eight joints.

and quince, in the United States. Its history has been completely detailed by Professor Peck, in the memoir above noticed, and who reared one of the Encyrti (?) from it.

The 22-footed larva of Athalia spinarum, according to Dahlbom and Drewsen (Clav. Nov. Hym. Syst. p. 16.), is gregarious, and feeds upon various species of Brassica, which it completely strips of its leaves, leaving only the stronger nerves. There are two generations in the course of the summer; and the larva does not form any cocoon, but merely encloses itself in an oval cell in the earth, of which it plasters the sides with a glutinous secretion, mixed with the earth.

The 22-footed larva of Athalia centifolia has periodically, in this country, proved to be one of the most obnoxious of our insect enemies. It is of a greenish black colour, whence it has obtained the name of the nigger, or black caterpillar, of the turnip, to which plant it is chiefly detrimental, by devouring the leaves, and thus totally destroying the crop in an incredibly short space of time. Albin, in his Nat. Hist. of English Insects, 1720, pl. 62., first figured this insect in its different states, observing that whole fields were occasionally destroyed by it; and an instance is recorded in the Philos. Transact. for 1783 (vol. lxxiii. p. 317.), by Mr. Marshall, in which their destruction was so great that many thousand acres were obliged to be ploughed up. In 1835, 1836, and 1837, it was exceedingly abundant and injurious. The appearance of the blacks is preceded by that of the imago, a pretty yellow and black species, which first appears about the middle of May or beginning of June, depositing its eggs within the parenchymatous tissue of the leaf, introducing her saw between the edges of the cuticle; and from which, in five or six days, the larvæ are hatched.

These are very voracious, and shed their skins several times. When full grown, they descend into the ground, forming an oval cocoon of agglutinated earth, at the depth of several inches, the interior of which they plaster with a white shining secretion, and in which the earlier produced individuals remain but a short time; but the late broods do not make their appearance in the winged state till the following

season.

Hand-picking, and the employment of ducks to eat the grubs, are the most serviceable remedies hitherto suggested for the destruction of these obnoxious insects.

Rusticus, in Entomol. Mag. vol. iii. p. 339.; Yarrell, in Trans. Zool. Soc. vol. ii. p. 67. pl. 14.; Westwood, in Gardener's Mag. No. 86. May, 1837; W. C., in Saturday Mag. vol. vi. p. 181.; Curtis (Brit. Ent., October, 1836); W. W. Saunders, in Trans. Ent. Soc. vol. i. p. 76. App.; and especially Mr. Newport, in his admirably elaborate prize essay (1838), have given ample details of the history, &c., of this species.

M. Brullé has published an account of the transformations of Cladius difformis Klug (Annal. Soc. Ent. de Fr. 1832, pl. 11. f. 11, 12.), the larva of which is found upon the leaves of Rosa centifolia and Bengalensis. Curtis also reared this species from larvæ found on the under side of the leaves of the China rose, eating small holes through them. Dahlbom once observed it upon Salix viminalis: it is slender, subcylindrical, clothed with slender upright hairs, and 20-footed. Curtis says that the anal feet do not assist them in walking. They are fullfed on the 28th of July, and the imago appears on the 11th or 12th of August, and they form a double cocoon of a very irregular shape amongst the leaves. Hartig has figured the larva and imago of Nematus (Pristiphorus) albipes, with numerous details (pl. 2. f. 16 -26.). The larva is 20-footed, and closely resembles that of Cl. difformis; it feeds upon the under side of the leaves of the cherry. The larva of Nematus (Pristiphorus) Brullei Dahlb. (Priophorus B.) is very similar to the preceding, and inhabits the Rumex and Rubus fruticosus; it is 20-footed, and forms a double cocoon, composed of a glutinous secretion, mixed with very fine silken threads.

One of the most destructive insects in the family inhabits the gooseberry, upon which the larvæ are found in society; from 50 to more than 1000 being sometimes observed upon a single tree, of which they devour all the leaves in the beginning of the summer, so that

the fruit cannot ripen. There are two generations in the course of a year. The larvæ are of a glaucous colour, with numerous transverse rows of black shining piliferous warts; they are furnished with 20 feet. The insects also undergo their transformations in society, one attaching the end of its cocoon to the end of the next. The species has been named Nematus grossulariæ by Dahlbom, who has given the history of the species in the Vetenskaps. Acad. Handl. for 1835, and who considers it as identical with the insect represented by Réaumur (tom. v. pl. 10. f. 4, 5.), which feeds upon the "groselier;" but that author states that his insect had 22 feet. Bouché (Naturgesch. p. 140.) describes the insect as the Tenthredo ventricosa Klug (Nematus v. Hartig, p. 196.). The Caledonian Horticult. Society has published a number of plans for the destruction of these caterpillars. (See also E. S. in Mag. Nat. Hist. No. 13.; vol. v. of the New Series of the Manchester Memoirs; Hort. Mag. 1831.) Stephens has described an allied species (Nematus Ribesii), the larva of which feeds upon the red currant.

At the end of June, 1838, I observed that nearly the whole crop of the young apples in the garden of my residence at Hammersmith had fallen to the ground, being then about the size of small walnuts; and, on opening some of them, I found the interior devoured by one or more larvæ of one of the Tenthredinidæ (probably a Nematus), having 6 thoracic, 12 abdominal, and 2 anal feet; the body not pilose, with thick lateral wrinkles. Its appearance in the perfect state will not take place until the next spring, when I hope to be able to add the name of this curious and destructive species. When alarmed, this larva emitted an odour like that of Cimex lectularius. The larva of Nematus dimidiatus feeds upon the poplar; it is yellow, with a black head, and large lateral black spots; it is figured in the Entomol. Mag. vol. i. pl. 1. f. 1., and is stated to have 14 abdominal legs.

The 20-footed larvæ of Nematus ochraceus Hartig (p. 218.), found upon the willow, in society, generally attach themselves to the edges of the leaves, the prolegs being placed on the opposite sides. Here they continue to feed incessantly, with the hind part of the body elevated in the air, and which, when disturbed, they throw about in various directions. De Geer has figured the history of this species (Mém. tom. ii. pl. 37. f. 1—11.). Réaumur also appears to have intended this, or a closely allied species, in his vol. v. tab. 11. f. 3-6. De Geer has also figured another very closely allied species, N. melanocephalus