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Greenbug sexuales occurred in the greenhouse from November to the middle of April and were found only in Biotype C greenbugs, Schizaphis graminum (Rondani). Males were found periodically throughout this period, averaging about 17% of the alate population when present. Spermatozoa were observed in testes squashes. Oviparae were found consistently throughout the sexual season and averaged 15 to 25% of the apterous population. An average of 6.6 ova per female was observed by dissections, but on the basis of oviposition studies there were only about 2.5 to 3.5 ova per female. Small populations oviposited equally well on the plants and cages but heavy populations appeared to oviposit to a greater degree on the cages. Mating was observed but no premating behavior was detected. Some oviparae were found to reproduce both viviparously and oviparously. Squashes of ova detected rapidly dividing chromosome sets in ⅓ of the ova examined. None of the ova incubated at 2, 4, 18, 21, or 27°C hatched; however, 2 ova were found with developing embryos.