CLASS I. INSECTA: ORDER 3. HYMENOPTERA. 
669 
SECT, Cynips gallce tinctorice. The females of tliese puncture the leaves, buds, and other parts 
of plants and trees, depositmg an egg in the wound, accompanied probably by some irritating- 
fluid, which causes a diseased growth in the part, and thus produces the excrescences known as 
galls. Within this domicile the larva lives, feeds, and attains its maturity. Here it also under- 
goes its transformations, and it is not until its arrival at the perfect state that it eats its way out, 
and becomes a free denizen of the air. 
The forms of the galls vary according to the plant on which they are found, and the species 
of gall-fly by whose puncture they are caused. The oak is especially subject to the attacks of 
these insects. The leaves are often covered with small round galls, produced by the Oynips 
quercus-folii, and several other species attack those organs; while the well-known oak-apples 
are produced by a species — Cynips terminalis — which deposits its eggs in the extremities of the 
shoots. Other species of oaks are equally infested by these creatures, one of which, noticed 
above, produces the well-known and important galls of commerce, often called Nut-Galls, 
and used for making ink and as a chemical test. The Bead Sea Apples, which have been 
the subjects of frequent controversy, are also galls, produced by the puncture of a small insect 
described by Mr. Westwood under the name of Cynips insana. The spangles of the oak-leaves 
are also produced in this manner. These excrescences usually contain only a single larva ; but 
in some cases a large family of grubs are concealed in a single gall. A few species are parasitic 
in their habits. 
THE SECUEIFEEA. 
Under this name are included a large number of insects — the Phyllophaga, known as Saw- 
Flies, and the Xylophaga, or Wood-Gnaioers^ known as Tailed Wasps. The females of the former 
have the ovipositor in the form of a fine, sharp 
saw ; with this she cuts numerous minute slits 
in the stems or leaves of plants, in each of 
which she lays an egg, accompanied by a drop 
of fluid, which prevents the closing of the 
wound, and in some cases the irritation thus 
induced causes the formation of a gall, within 
which the larvas live and feed. As a general 
rule, the larvse, when hatched, leave their shelter 
and feed upon the leaves of plants. The species 
are generally confined to certain kinds of plants, 
to which, when they are produced in great num- 
bers, they often do immense mischief. Thus 
the larvaj of the Athalia centifolice, known to 
farmers as the Nigger or Blade Caterpillar, have 
occasionally done incredible damage to turnips 
in Europe; and those of another species, the 
Nematus g^'ossularioB, are not less destructive to 
gooseberry-bushes. The larvae of other species 
infest fruits, living and feeding in the interior, 
and causing them to fall off" while still immature. 
They are almost always furnished with pro-legs 
in addition to the thoracic members. The Cim- 
bex ulmi is an American species, frequenting elm-trees. 
In the Tailed Wasjos, Horntails, or Wood Wasps, also often called Borers in this country, 
the ovipositor projects from the abdomen, and is composed of serrated bristles, with which they 
perforate timber. On the continent of Europe the Sirex gigas often appears in immense num- 
bers, and does great damage in this way. The Pigeon Tremex of Harris, Sirex cinctus, is one 
of the American species; this sometimes completely riddles the trunks of maples, button- 
woods, &c. 
YoL. n.— 72 
THE SIREX GIGAS. 
