1910] Girault and Sanders — Chalcidoid Parasites 17 
puparia, of which they made use for purposes of oviposition, whereas 
those having access to but one or two host puparia, especially those 
of the smaller host, Musca domestica, produced the least progeny. 
These experiments were performed at various times in the laboratory 
and are by no means conclusive, that is, do not establish the range or 
average of fecundity. 
Tape III. ProGeny or SINGLE FemMALes or Nasonia brevicornis. 











Progeny of single | ¢ g 
Female} Date, Hae | eae: Hpaae AoE ENO eevee 
No. | 1908: ost. ex- |, Hosts B| 8] & 
posed. infested. ee HE eS 
uss O’s. | Total. | = | = |e 
| 
1 Sept. 25 | Musca 1 1 1 6 7 
2 1 1 4 6 10 
3 Bane! 1 5 6 fas. | 
4 Phormia | 1 1 a7)" 
5 2 2 38 +1 
6 4 4 39 
a Sept. 28 | Musca 4 4 2 ily / 19 
8 1 1 1 2 3 3 
9 | Sept. 30 1 1 2 4 6 | 
10 Oct. Phormia 5 4 9 18 PAE a 
11 Oct. 1 if 1 2 8 10 
12 Oct. 20 Many — ‘a 12 19 
i183 | Many — 4 22 26 
14 130 17 21 57 78 
15 | 86 22 38 65 103 103)100 
16 Chrysomyia| 1U7/ ie. 31 53 84 








It is thus seen that in one instance, a female was able to parasitize 
successfully 22 host puparia and another 17, when quite a number 
were available. The observations do no more than indicate the 
probabilities and possibilities of fecundity for the species. Apparently, 
all of the females concerned were fertilized. From the fact that single 
ovipositions take so much time, as well as for other reasons, we strongly 
suspect polyembryony in this connection. 
H. Proportion of the Sexes. he following results, recorded in 
table IV, comprise actual counts of over seven thousand specimens, 
including practically every individual of this parasite reared or ob- 
served by us during the period of breeding, excepting one thousand 
individuals of mixed sexes released for experimental purposes. 
1 All from one of the puparia; the numerous larvae in the other died and were not 
counted, 
