. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 34 BULLETIN 427, U. S. DEPAETMENT OF AGEICULTUEE. DIBRACHYS BOUCHEANUS KATZ. This well-known and cosmopolitan secondary parasite (fig. 17) emerged from the tuber-moth material collected during 1912, 1913,, and 1914, and, as shown by dissection, from both Hahrohracon. a ' c * "" h Fig. 17.—Dibrachys boucheanus: a, Larva; 6, pupa; c, adult female; d, head of larva; e, antenna or male, highly magnified. Greatly enlarged. (After Howard.) joTiannseni and CJielonus sJiosJioneanorum, the former seeming to be its fav
. Bulletin of the Department of Agriculture. Agriculture; Agriculture. 34 BULLETIN 427, U. S. DEPAETMENT OF AGEICULTUEE. DIBRACHYS BOUCHEANUS KATZ. This well-known and cosmopolitan secondary parasite (fig. 17) emerged from the tuber-moth material collected during 1912, 1913,, and 1914, and, as shown by dissection, from both Hahrohracon. a ' c * "" h Fig. 17.—Dibrachys boucheanus: a, Larva; 6, pupa; c, adult female; d, head of larva; e, antenna or male, highly magnified. Greatly enlarged. (After Howard.) joTiannseni and CJielonus sJiosJioneanorum, the former seeming to be its favorite host. This species was reared from the egg in the laboratory,, where it attacked the mature larvse of its hosts after they had spun their cocoons. Where the cocoons were not too thick to prevent it from reaching its host the parasite would often feed at the wounds caused by its ovipositor. When reared under laboratory conditions thehyperparasites in- crease rapidly, bub under field conditions their numbers are not as large in proportion to the host as might be expected. During 1912 and 1913 the percentage of para- sitism ran as high as 50 per cent in the case of Habrobracon joTiannseni. With CJielonus sJiosJioneanorum the average was much lower, the highest running 29 per cent. During 1914 the percentages in both cases were much reduced, and while greater numbers of its two hosts were reared than in the previous year, DihracJiys boucJieanus was noted on only a few Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. Dept. of Agriculture. [Washington, D. C. ?] : The Dept. : Supt. of Docs. , G. P. O.
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