Periplaneta fuliginosa, U.S.A., Pennsylvania (Roth and Willis, 1954b); Massachusetts (Roth and Willis, unpublished data, 1957).
Schmidt (1937) deduced that T. hagenowii was a primary parasite of eggs of P. americana because the parasitized oötheca was obtained from a cage covered with screen too fine to permit entry of a larger parasite, such as an evaniid. As noted above, we have reared T. hagenowii for more than 30 generations on cockroach eggs, none of which was ever exposed to parasitization by an evaniid. If T. hagenowii were ever hyperparasitic on Evania, this relationship would be accidental, the eulophid happening to oviposit into an oötheca already containing an evaniid, or vice versa.
Adult behavior.—The male mates soon after becoming adult; he mounts the female from behind, grasps her antennae with his own antennae, and vibrates his wings during copulation. Mating is accomplished in from "several" to 20 seconds (Takahashi, 1924; Edmunds, 1955). The adults are positively phototactic and are capable of hopping for some distance (Edmunds, 1955). The females feed on material that oozes through the oviposition puncture (Roth and Willis, 1954b). Females lived 10 days (Seín, 1923). Without food, females lived 7.8 days and males 3.4 days, but when fed dilute honey females lived 12.5 days (Usman, 1949). Females lived 5-11 days (Roth and Willis, 1954b). Fed water and sugar, the wasps lived 2-6 weeks at 65°F. (Cameron, 1955). Without food, 9 females lived an average of 3.5 days and 9 males an average of 1.7 days, but when fed on raisins, 9 females lived an average of 25 days and 9 males 15 days (Edmunds, 1955). In Formosa there were six generations from April to December (Maki, 1937).
In Hawaii, Severin and Severin (1915) caught 571 T. hagenowii in 10 kerosene traps that were set up to sample populations of Mediterranean fruitfly. Apparently the parasite is attracted by the odor of kerosene.
Oviposition.—The female wasp explores the surface of the oötheca with vibrating antennae (Edmunds, 1955). She bends her abdomen ventrad and repeatedly touches the surface of the oötheca with her valvae; when she finds an acceptable oviposition site, the wasp unsheathes her ovipositor and bores through the wall of the oötheca (Roth and Willis, 1954b). The wasp deposited her eggs in 2-5 minutes (Edmunds, 1955). Wasps oviposited (pl. [34], C) into young or old eggs of P. americana (Roth and Willis, 1954b). A single wasp parasitized more than one oötheca and more than one wasp oviposited into the same oötheca (Roth and Willis, 1954b; Edmunds, 1955). We found freshly laid wasp eggs in 34 empty but previously parasitized oöthecae from which the wasps had emerged (Roth and Willis, 1954b).
Development.—In Periplaneta americana: Development is completed in an average of 36 days (range 29-58 days) (Maki, 1937); 29-40 days (Lever, 1943); average of 23.6 days (range 22-26 days) at 62°-85° F. (Usman, 1949); about 3 months at 60°-65° F. (Cameron, 1955); 31-60 days at 70°-80° F. (Edmunds, 1955). We found that the wasps completed development in 23-56 days at about 85° F., but the period depended on the number of wasps in the oötheca; the larger the number of wasps (up to an average of about 70 wasps per oötheca), the shorter the time required to complete development. Wasps in oöthecae containing 70 or more parasites developed in an average of about 32 days (Roth and Willis, 1954b). Wasp larvae eat the contents of the cockroach egg in which they start development, then rupture the chorion and attack adjoining eggs (Cameron, 1955; Edmunds, 1955). All eggs are consumed when the parasite density is high, but if too few larvae develop per oötheca, some cockroach eggs survive and the embryos complete development (Roth and Willis, 1954b). However, a certain number of cockroach nymphs must complete development to enable the survivors to force open the crista and emerge from the oötheca; fewer than this number of surviving nymphs will be trapped and killed as effectively as if they had been eaten by the parasite. The adult parasites emerge from one to three holes cut through the wall of the oötheca (Usman, 1949; Roth and Willis, 1954b).
Number of offspring per female.—In Blatta orientalis: In the laboratory, 5 oöthecae were left with each of 25 female wasps for their entire lifespans; of the 125 oöthecae, 32 were parasitized. The average number of offspring per female was 66 (range 5-164) (Roth and Willis, 1954b). In Periplaneta americana: Each of 206 oöthecae was exposed to a single female wasp for 24 hours; the average number of offspring per female was 103 (range 50-139). Five oöthecae were left with each of 38 females for their entire lifespans; of the 190 oöthecae, 81 were parasitized. The average number of offspring per female was 94 (range 45-168 [from original data]) (Roth and Willis, 1954b).
Number of parasites per oötheca.—In Eurycotis floridana: In the laboratory, 3 oöthecae that had been exposed to 20 female wasps yielded an average of 648 parasites (range 606 [from original data] to 685) (Roth and Willis, 1954b). In Neostylopyga rhombifolia: One oötheca yielded 73 parasites (Pemberton, 1941). In Parcoblatta sp.: Two oöthecae yielded an average of 100 parasites (Edmunds, 1953a). In Periplaneta americana: 100 parasites per oötheca (Seín, 1923); 140 (Schmidt, 1937); 25 (Rau, 1940a); 7-38, average 33 (Usman, 1949); 71 (Wolcott, 1951); 4 oöthecae exposed to 20 female wasps yielded an average of 204 wasps (range 164 [from original data] to 261) (Roth and Willis, 1954b); average of 30-40 (Cameron, 1955); 39 oöthecae yielded an average of 93 parasites (range 12-187) (Edmunds, 1955). In Periplaneta australasiae: Oöthecae yielded an average of 40-50 adult parasites (Cameron, 1955); about 50 (Shaw, 1925).
Sex ratio.—3 ♀♀:1 ♂ (Usman, 1949); 4 ♀♀:1 ♂ (Cameron, 1955); 2-8 ♀♀:1 ♂ (Roth and Willis, 1954b); 1.2 ♀♀:1 ♂ (Edmunds, 1955). Parthenogenesis exists; the unfertilized eggs produced only males (Roth and Willis, 1954b; Edmunds, 1955).