. The Cambridge natural history. Zoology. 554 HYMENOPTERA have an ovipositor three or four inches in length, and are parasitic on species of the family Siricidae, which, as we have previously described, live in solid wood. In order therefore to deposit the egg in a suitable place, the wood must be pierced by the Ichneumon. The ovipositor is not only of extreme length, but is also furnished with serrations on its apical part, so that it forms a very effective boring apparatus. It is brought into use by being bent on itself over the back of the Insect (Fig. 362), so as to bring the tip verticall
. The Cambridge natural history. Zoology. 554 HYMENOPTERA have an ovipositor three or four inches in length, and are parasitic on species of the family Siricidae, which, as we have previously described, live in solid wood. In order therefore to deposit the egg in a suitable place, the wood must be pierced by the Ichneumon. The ovipositor is not only of extreme length, but is also furnished with serrations on its apical part, so that it forms a very effective boring apparatus. It is brought into use by being bent on itself over the back of the Insect (Fig. 362), so as to bring the tip vertically down on to the wood, through which it is then forced by a series of efforts; the sheaths do not enter the wood. The egg is laid anywhere in the burrow of the Sirex ; the young larva seeks its prey, and lives on it as an external parasite (Fig. 342,D). Erne, however, states^ that the young larva of Bhyssa persuasoria enters its victim, and remains within the latter till its death occurs. This happens when the young Bhyssa is two or, three lines in length, and it then makes its exit from the interior of the body and gradually eats it up. Should the larva it has attacked be of large size, it of itself affords sufficient food for the comple- tion of the growth of the Bhyssa. Should the Bhyssa, however, have attacked a small larva, this does not furnish it with sufficient food, and it con- sequently dies without seeking another larva. Erne says, indeed, that it will not eat another if offered to it, so that. Tig. 3b'2.—Thalessa lunator. (After Riley.) Oviposition. in order to rear the Bhyssa in captivity, the victim it has first attacked must always be given to it. The same observer states that the Bhyssa larva is sometimes transported by the Sirex deep into the wood, so that when it has completed its metamor- phoses the Ichneumon-fly may find itself buried in solid wood to a depth of about two inches. In that case it excavates the wood with its mandibles, and should it fail to
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Keywords: ., bookcentury1800, bookdecade1890, booksubjectzoology, bookyear1895
