. Bulletin of the Department of Agriculture. Agriculture. BULLETIN 766, U. S. DEPARTMENT OF AGRICULTURE. Iii the description of the larva Bouche neglected to speak of a very important point, the anal hooks of the first-stage larva?. This character has been found only in one other tachinid first-stage larva, that of the closely allied genus Dexodes. It is very easy to deter- mine this stage by these hooks and to verify the fact that Comp- silura parasitizes early-stage brown-tail moth larva; in the fall, as has been found from various dissections. Pantel describes and illu- trates these ho
. Bulletin of the Department of Agriculture. Agriculture. BULLETIN 766, U. S. DEPARTMENT OF AGRICULTURE. Iii the description of the larva Bouche neglected to speak of a very important point, the anal hooks of the first-stage larva?. This character has been found only in one other tachinid first-stage larva, that of the closely allied genus Dexodes. It is very easy to deter- mine this stage by these hooks and to verify the fact that Comp- silura parasitizes early-stage brown-tail moth larva; in the fall, as has been found from various dissections. Pantel describes and illu- trates these hooks in " La ; (Fig. 1.) There are three of these peristigmatic hooks; two prestigmatic and one retrostigmatic. It is with these hooks that he larva attaches itself to the peri- trophic membrane just previous to molting into the second stage. As the larva grows, the molt skins are pushed down on to this fun- nel until just previous to emerg- â-a -b â Â¥ Q. Fig. 1.âCompsilura concinnata: Posterior stigmata and peristigmatic hooks of first-stage larva, a, Prestigmatic hooks, paired; b, stigmatic plate; c, retrostig- matic hook; d, sensory terminations, finger-like or as punctate areas ; AâB, horizontal line along which the skin folds over the stigmata as two grasping lips. Highly magnified. (Redrawn from Pantel.) ing, when the full-grown third- stage maggot breaks loose and forces itself out of the dead host. This is done in the following manner: The anterior end of the parasite, assisted by the mouth hooks, makes a small opening in the integument of the host and by a gradual process of extending and retracting the anterior part of the body the larva finally suc- ceeds in passing out. If the hoct is one that has spun a cocoon, the parasite larva will pupate within this, but if not, it will drop to the ground or pupate near the host. The time between emergence of the larva and pupation is governed by such things as temperature and location, whether on a tree
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