106 MODERN CLASSIFICATION OF INSECTS. 
willows by another species (Nematus gallicola Westw., Steph. ; N. 
saliceti Fallen, Dahlb.; Tenthredo Galle foliorum salicis Zinn, 
Frisch, Ins. Germ., vol. iv. p. 22. tab. 4.; Réaumur, tom. ili. pl. 37. 
f. 1—5. 8.). These galls are irregular in shape, and often of a red 
colour. They extend on both sides of the leaf, and are of a spongy 
substance. They are at first solid, but by degrees a cavity is formed 
in the centre, by the feeding of the inclosed inhabitant ; which, when 
full fed, quits the gall and descends to the earth. 
I have traced the natural history of this third kind of gall-making 
Nematus *, and have ascertained that it is attacked by a beautiful 
species of Eulophus (E. Nemati W.), the female of which pierces the 
substance of the young gall. (See also Rosel, Insect. Belust. vol. ii. 
Bomb. et Vesp. tab. 10., wherein are figured these two leaf-gall- 
making species in their different states; and Swammerdam, Book of 
Nature, pl. 44., in which N. gallicola is represented in its different 
states.) Euura Cynips Newman (Ent. Mag. No. 18.), allied to N. 
gallicola, also resides in galls in the larva state. 
The 22-footed larvee of the genus Lophyrus are social (each family 
consisting of from 50 to 100 individuals), and devour the leaves of 
various species of firs; they also gnaw the young twigs, forming 
channels of some depth: they commonly repose along the leaves, 
having their heads inclined on one side. When touched they emit 
from the mouth a drop of clear fluid, of a resinous smell. The 
females are much larger than the males, and may be distinguished by 
this character in all their stages. De Geer (Mém. tom. ii. tab. 35. 
f. 24—27., and tab. 36. f. 1—30.) has represented the details of two 
species of this genus, L. rufus and L. Pini. The cocoon is simple, and 
never made in the earth; it is of very small size compared with that of 
the larva by which it is formed, and which is compelled to lie in a 
curved direction within. Curtis states that one of Dr. Leach’s cater- 
pillars of L. pallidus, remained in its cocoon unchanged for two years. 
Scheeffer has given the history of one of the species of this genus under 
the name of Die Tannensagfliege (Abhandl. von Ins. vol. ii. tab. 8.), 
with figures. In the first vol. of the Gardener’s Mag. (1826) is con- 
tained a notice of an 8vo vol. by D. E. Miller, on the ravages com- 
mitted by the caterpillars of Tenth. Pini, Pinastri, Juniperi, and 
erythrocephela, by which several thousand acres of pines were entirely 
destroyed in Franconia. (Ueber den Afterraupenfrass, §c. Aschaften- 
* The details of these observations, with the history of its parasite, will form the 
subject of a separate memoir. 
