Some Effects of Storage at Different Temperatures on the Lipids of the American Roach and on the Resistance of This Insect to Heat1

Abstract

If nymphs of Periplaneta americana are held at temps. between 17 and 27[degree]C their total lipids have an iodine number of about 72; between 27 and 32[degree]C the lipid iodine numbers fall to around 60 and decline little with further rise in temp. Such changes in saturation move rapidly in either direction and are nearly complete in 2 weeks; the reaction is not "triggered." Groups of roaches with lower iodine numbers are not more resistant to temps. sufficiently high to be lethal than are roaches with more unsaturated lipids.