absence of ribosomal dna amplification in the meroistic telotrophic ovary of the large milkweed bug oncopeltus fasciatus dallas hemiptera lygaeidae in the typical meroistic insect ovary the oocyte nucleus synthesizes little if any rna nurse cells or trophocytes actively synthesize ribosomes which are transported to and accumulated by the oocyte in the telotrophic ovary a morphological separation exists the nurse cells being localized at the apical end of each ovariole and communicating with the ooocytes via nutritive cords in order to determine whether the genes coding for ribosomal rna rrna are amplified in the telotrophic ovary of the milkweed bug oncopeltus fasciatus the percentages of the genome coding for ribosomal rna in somatic cells spermatogenic cells ovarian follicles and nurse cells were compared the oocytes and most of the nurse cells of o fasciatus are uninucleolate dna hybridizing with ribosomal rna is localized in a satellite dna the density of which is 1712 gcm3 the density of mainband dna is 1694 gcm3 the ribosomal dna satellite accounts for approximately 02 of the dna in somatic and gametogenic tissues of both males and females rnadna hybridization analysis demonstrates that approximately 003 of the dna in somatic tissues testis ovarian follicles and isolated nurse cells hybridizes with ribosomal rna the fact that the percentage of dna hybridizing with rrna is the same in somatic and in male and female gametogenic tissues indicates that amplification of ribosomal dna does not occur in nurse cells and that if it occurs in oocytes it represents less than a 50fold increase in ribosomal dna an increase in total genome dna accounted by polyploidization appears to provide for increasing the amount of ribosomal dna in the nurse cells