A. A. Girault and G. E. Sanders.
The Chalcidoid Parasites of the Common House or Typhoid Fly and its Allies.
Psyche 17:9-27, 1910.

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19101 Girault and Sanders - Chalcidoid Parasites 9 THE CHALCIDOID PARASITES OF THE COMMON HOUSE OR TYPHOID FLY (MUSCA DOMESTICA LINN.)
AND ITS ALLIES?
The University of Illinois.
Habits in General and Biology.
A.
Oviposttion.
This appears to be the only function of the female.
When thus engaged she is not easily disturbed and the function is normally performed even in small capsules or vials, and in the insectary at various times, females were often observed attempt- ing to gain entrance to breeding-cages containing their hosts; in the case of large cages they were quite often successful and under certain conditions it was impossible to keep them out. The following detailed, though fragmentary observations were made on ovipositing females. (1)
Sept. 12, 1908.- The female often faces towards the caudal end of the host puparium when engaged in ovipositing - on this date, in the cases of 8 host puparia (Phormia regina), apparent oviposition was observed once in four cases and twice in the other four - the times of these ovipositions were between 9:55 A. M. and 1: 20 P. M. and the time required to deposit a single egg varied from 14 minutes to 16, averaging 73 minutes; the particular spot on the host puparium into which the ovipositor of the female was inserted was usually in the region of the 4th and 5th segments, but varied to the 6th and 7th or 7th and 8th. The hole made by the ovipositor was not distinct afterwards, but in many cases it became covered with a white mycelium-like growth the nature of which we have not determined. (2) On Sept. 29, 1908, at 11 : 30 A. M., in the case of three virgin females ovipositing into the puparia of Phormia regina, the ovipositor was inserted for its full length for 3, 7 and 8 minutes respectively. (3) On Sept. 13, 1908, a female was watched while ovipositing into a hard puparium of the Phormia. The puparium was pierced by rotating the ovipositor and pressing it down, the force of the pressure often causing the organ to bend, when the rotary motion was more easily seen; this continued 'Continued from Vol. XVI, p. 132
Pu&e 17:9-27 11910). http//psychr enlclub.me/17/17-WI him)



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10 Psyche [February
for 11 minutes; the abdomen, during this time, was inclined upward, its tip applied to the surface and the ovipositor appearing as a per- pendicular rod issuing from the venter slightly beyond the proximal third. After drilling through the crust of the puparium, the rotary motion was considerably lessened but not entirely discontinued and 10 more minutes were consumed in working the ovipositor back and forth, apparently in order to enlarge the aperture, the edges of which were frayed. The ovipositor was then pushed farther into the aperture, the abdomen moving up and down slightly and gradually being triangularly or conically produced at the base of the ovipositor, and as the latter entered farther, approaching nearer and nearer to the surface of the puparium, until after 30 seconds the ovipositor was fully inserted.
The female then remained motionless for 31 minutes, when the ovipositor was partially redrawn and reinserted two or three times, and finally wholly withdrawn from the host, assuming its usual concealed position within the valves along the venter. Upon the withdrawal of the ovipositor, the female immediately left the host. The time that she was engaged in the whole operation was 25+ minutes. (4) Observations made on three females depositing eggs into puparia of the Phormia, on Sept. 29, 1908, showed in three instances that the ovipositor was fully inserted for 70, 90 and 95 seconds respectively. (5) On Sept. 18, 1908, a female of this parasite was confined in a small homeopathic vial with a quantity of muscid puparia of varying ages - some three or four days old, some but several hours. The female chose an "old" puparium, formed about two days, and ap- parently deposited three eggs into it, one following the other. At first, she chose a place for inserting the ovipositor by examining closely the entire surface of the host; the ovipositor was then guided to the spot by bending the abdomen, the whole body convexly bent, the head turned as though the insect was watching the operation; as soon as placed, the ovipositor was released from the valves along the venter and the abdomen assumed its usual position. Piercing the shell of the puparium required 14 minutes; the ovipositor was then inserted for its entire length, without other delay, and as quickly withdrawn, fifty seconds being occupied in enlarging the hole. After this short period of time, the ovipositor was pushed in again for its entire length, remaining so for forty-five seconds, during which time, apparently, the egg was deposited. After the ovipositor was withdrawn, the parent parasite carefully examined the puncture with the antennae



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19101 Girault and Sanders - Chalcidoid Parasites 11 and mandibles and apparently also by means of sight. (6) The
deposition of an egg observed at 9: 45 P. M., Sept. 14, required 16 minutes; the host was Phormia regina. Another observation made at 10: 15 A. M. the same day, showed that the'act required 8 minutes; the host puparium was that of Musca domestics; in the latter case, the ovipositor was inserted into the 9th segment of the host. A female was observed to deposit an egg in confinement at 7: 30 A. M. to-day. (7) A female confined at 9: 20 A. M., Sept. 10, deposited into puparia of the Phormia at 9: 32 A. M. and 1: 20 P. M. the same day. One confined at 10 A. M. the same date with 2 puparia of the same host oviposited at once.
(8.)
In the cases of 4 females confined separately in vials each with 4 (in one case 8) puparia of Cynomyia cadaverina Desv., April 29, 1909, oviposition occurred with one female at 10 : 25 P. M., April 30, and again at 9 P. M., May 1; no other observations were recorded. (9.) Nine males and twenty females confined at 11 : 20 A. M., April 29, with 10 puparia of the same host commenced oviposition about noon, or sooner, and oviposition was observed at nearly every hour between 9 A. M. and 11 P. M., for several days. B. Nature of the Parasitism. Examinations made of parasitized hosts, showed that in all cases, the parasite is "social" or gregarious and does not attack the host until after the formation of the puparium, preferably after the latter has been formed for at least twenty-four hours. Puparia of Phormia regina examined, were in some cases filled entirely with the larvae of the parasite which had totally consumed the host pupa; for example, from one puparium 47 larvae of the parasite were removed; from another 8 larval parasites were removed, together with a shriveled pupa of the host - none of the parasitic grubs had entered the body of the latter, which indicates that the parasites are external as far as the host pupa is concerned, obtaining their nourish- ment by means of absorption; in the case just cited, one of the parasitic larvae was attached to the head of the host pupa over the eye, one to the thorax and six to the abdomen. In a third Phormia puparium, there were found 21 larval parasites, the host pupa being totally con- sumed; in four more single cases there were 8, 13, 13 and 16 larvae of the parasite respectively. In another, 27 parasitic pupae were found, from a single puparium of Sarcophaga sp. " e " 22 8 c?' and 4 Q Q of the parasite were taken. As a rule, the remains of a parasitized host - the fully formed pupa - is a flat, scale-like mass apparently con- sisting of the ventral shell of the pupa and that of the head; for



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12 Psyche [February
example, the thecae of the eyes, legs and wings are discernible, and the remains are not much shrunken, so far as the original length is concerned. In the case of Cynomyia cadaverina, in one pupa- rium infested with 21 larvae of the first spring generation, the parasites were all attached to the dorsal surface of the host from the pronotum to the tip of the abdomen; these parasitic larvae were nearly full-grown. But in another puparium of the same host, in which 13 larvae were found, their attachment to the host appeared to be hap- hazard, and the host pupa was considerably shrunken, especially in width. It is evident, from their appearance, and from the fact that the larger larvae are found attached externally to the host - between it and the inner walls of the puparium - that the larval parasites obtain their nourishment through the body wall of the host pupa, leaving the integument intact. In both of the latter cases, the host pupae were nearing the final ecdysis when they were attacked by the parasites.
Although gregarious, the host is not as completely destroyed as by Spalangia, M~cidifu~rax or Pachycrepoidezis, which though solitary parasites, reduce the host to a mere flat unrecognizable shell. In addition to the foregoing, Mr. Maurice C. Tanquary has kindly collated the following records from our rearing notes: TABLE I.
NUMBER AND SEX OF PARASITES (Nasonia brevicornis) ISSUING FROM PUPARIA OF Phormia regina.
Males Females Larvae. Total. 1 Males.
0
0
5
9
1
6
0
16
0
2
1
3
3
7
6
1
3
Females.
5
1
0
6
6
16
5
5
7
12
4
9
8
12
4
10
9
Larvae. Total.
5
1
5
15
7
22
5
21
7
14
5
12
11
19
10
11
12




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19101 Girault and Sanders - Chalcidoid Parasites 13 Males.
5
7
1
17
2
4
4
1
3
2
2
5
11
1
17
38
6
1
1
4
15
6
5
5
11
5
0
9
6
2
15
8
1
2
7
8
9
0
7
12
4
0
9
7
1
3
Females.
4
1
10
0
7
11
10
6
7
11
3
11
0
9
5
4
10
2
2
7
4
0
1
5
0
14
4
11
5
1
12
8
7
1
9
12
3
6
9
7
12
3
13
11
9
8
Larvae. Total.
9
8
11
17
9
15
14
7
10
13
5
16
11
10
22
42
16
3
3
11
19
6
6
10
11
19
4
20
11
3
2 7
16
8
3
16
18
12
6
16
19
16
3
22
18
10
3 14
Males.
9
9
7
10
4
0
11
11
11
1
5
2
2
0
3
5
10
3
13
5
4
1
2
22
3
3
9
9
8
0
2 3
4
4
9
6
9
7
1
3
3
Females.
13
10
5
9
5
4
8
4
18
0
4
0
6
4
1
1
11
4
4
10
2
10
8
6
2
8
6
3
5
2
11
2
5
3
9
3
1
2
7
3
Larvae.
5
8
6
6
4
6
2 3
Total.
22
19
12
19
9
4
19
15
29
6
9
2
8
4
4
6
2 1
7
17
15
6
11
10
28
5
11
15
12
13
2
34
6
9
12
15
12
8
3
10