NOTES ON INSECTS OF THE ORDER STREPSIPTERA, WITH DESCRIPTIONS OF NEW SPECIES. By W. Dwight Pierce, Of the Bureau of Entomology , U. S. I ')< [xirl. mint of Agriculture. INTRODUCTION. The appearance of a considerable number of publications on the order Strepsiptera since the publication of the Monographic Revision in Bulletin 66 of the U. S. National Museum, calls forth this summary of the recent additions to our knowledge of the group. A number of corrections to the preceding paper must be noted and a considerable number of new or unpublished records are here to be added. In view of the approaching publication of the Genera Insectorum on this group a number of new species are here added. No attempt will be made at this time to indicate generic c h a ages or arrangement, as these matters will all receive due attention in the forthcoming paper. Special assistance in making the corrections to Bulletin 60 has been received from Mr. Karl Ilofeneder of Innsbruck, Austria, and Prof. T. D. A. Cockerell of Boulder, Colorado. Material has been received from the former and also from II. L. Adams (Pennsylvania), W. L. McAtee (District of Columbia), J. D. Mitchell (Texas), V. I. Satro (Louisiana), Prof. L. Brunei-(Nebraska), Charles Robertson (Illinois), Prof. Henry Comstock (New York), Dr. E. D. Ball (Utah), William Cockle (British Columbia), Dr. E. Zavattari (Italy), E. E. Green (Ceylon), and Lt. Col. C. G. Nurse (England). Considerable material has also been found in the collections of the U. S. National Museum. Determinations of the host insects have very kindly been made by Messrs. Cockerell, Crawford, Heidemann, Robertson, Rohwer, and Viereck. BIOLOGY. ACTUAL RELATIONSHIP OF PARASITE TO HOST. POLISTES METRICUS Say. Wheeler (1910&) records studies of 1,000 wasps collected at Cole-brook, Connecticut, in August. On these wasps the following data were obtained, as tabulated: 137 male wasps; 112 unparasitized, 25 parasitized. 863 female wasps; 637 unparasitized, 226 parasitized. 1, 000 wasps; 749 unparasitized, 251 parasitized. 13.7 per cent of the wasps were males, 86.3 per cent females. 9.9 per cent of the parasitized wasps were males, 90.1 per cent females. 81.7 per cent of the male wasps were unparasitized, 18.3 per cent parasitized. 73.8 per cent of the female wasps were unparasitized, 26.2 per cent parasitized. 74.9 per cent of all the wasps were unparasitized, 25.1 per cent parasitized. Proceedings U. S. National Museum, Vol. 40— No. 1834. 487