Genome size of the northern walkingstick, Diapheromera femorata (Phasmida: Heteronemiidae)

The haploid genome size (C value) of the northern walkingstick, Diapheromera femorata (Say), was estimated to be 1C = 2.55 pg using Feulgen image-analysis densitometry of haemocyte and sperm nuclei. This relatively large genome is similar in size to the genomes of the few other phasmids studied so far, and is consistent with hypotheses regarding an upper limit to the size of many insect genomes imposed by the process of metamorphosis, which is relaxed among hemimetabolous orders. Comments on sperm morphology in D. femorata are also provided, and another possible relationship between genome size and the organismal phenotype in insects is suggested.