. Bulletin of the Department of Agriculture. Agriculture; Agriculture. BULLETi:sr 1088, XJ. S. DEPARTMENT OF AGRICULTURE. Fig. 3.—Brown - tail moth caterpillars containing pu- paria of Zygobothria ni- dicola. THIRD-STAGE MAGGOT OF THE PARASITE. When the second-stage skin is molted it is pushed back upon the funnel, as was that of the first stage; the mouth hooks of the two instars at this time are easih^ seen on the mass of yellowish tissue that surrounds the chitinous funnel itself. The particular points of difference between the second and third stage maggots are the larger size of the
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. BULLETi:sr 1088, XJ. S. DEPARTMENT OF AGRICULTURE. Fig. 3.—Brown - tail moth caterpillars containing pu- paria of Zygobothria ni- dicola. THIRD-STAGE MAGGOT OF THE PARASITE. When the second-stage skin is molted it is pushed back upon the funnel, as was that of the first stage; the mouth hooks of the two instars at this time are easih^ seen on the mass of yellowish tissue that surrounds the chitinous funnel itself. The particular points of difference between the second and third stage maggots are the larger size of the latter and its much heavier mouth hook. The mouth hook is divided longitudi- jftt/k nally as in the second stage, but there are now '^''' two joints in the anterior part of the skele- |^|MJ|itt^ ton, one near the middle, corresponding to the ^^^^^^ single joint of the second stage, and another near the base of the very broad posterior plates. The anterior spiracles, opening be- tween the second and third body segments, are much more distinct than in the second instar. This stage is the shortest of the three, requiring only four or five days. The host larva is killed just before the end of this period, with the destruction of its vital organs, and the parasite forms its puparium in the integumental funnel inside the host. The pupariimi is about 8 mm. long and is dark brown- ish red in color; the posterior end is a little depressed, and the two anal stig- mata (Fig. 4) with- in the depression are slightly elevated. Dead caterpillars that contain puparia of Z. nidicoJa (Fig. 3) are easily detect- ed; they are greatly shortened, being scarcely longer than the puparia within, and are slightl}^ inflated. The period spent in the puparium averages from 25 to 30 days,, after which the flies appear, some 8 to 16 days prior to the hatching. Fig. 4.—Anal stigmata of puparium of Zygobothria Please note that these images are extracted from scanned page images that may have bee
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