Abstract
The chromosomes of Orthocephalus funestus Jakovlev (Miridae: Heteroptera) were studied in male germ cells according to the acetic orcein squash method. The chromosomes of the species are 2n=30, MI, 16, MII, 15 and the sex-determining system is of the X-Y type.
Fragment chromosomes were observed in four bugs (5.3%) out of seventy-six in 1970, while the other seventy-two bugs (94.7%) had normal chromosome complements. The number of the first-spermatocytes observed in the remaining four bugs is one hundred and twenty-six. The chromosome complements of seventy-six cells (60%) out of one hundred and twenty-six are normal and the remaining 50 cells (40%) have fragment chromosomes.
