The development and longevity of Nosopsyllus laeviceps kuzenkovi (Yagubyants), a major plague vector among sylvan and campestral rodents in Inner Mongolia, China, was studied under controlled laboratory conditions of 11, 14, 17, 20, 23, 26, 29, and 35 C at 76% relative humidity (R.H.), and 32, 53, 76, 87, and 100% at 23 C. Development from egg to adult was shortest (21-23 days) under favorable conditions of 26 C at 76% R.H., but maximum survival to adulthood (84%) occurred at 23 C. Average longevity was 13.25 days (13.70 in females and 12.80 in males) at 17 C and 76% R.H.; it was longer at cooler and shorter at warmer temperatures. Findings provided experimental data that helped clarify seasonal fluctuations, summer mortality, generation cycles, and survival of compared flea species from Russia, Azerbaidzhan, and China.

The gerbil flea Nosopsyllus laeviceps (Wagner) (Siphonaptera: Ceratophyllidae) is an important Palaearctic vector of enzootic plague among sylvan and campestral rodents. Laboratory blood-feeding experiments with the subspecies N.l.kuzenkovi (Yagubyants) from Inner Mongolia, China, using three rodent species including the natural host Meriones unguiculatus (Milne-Edwards), demonstrated a positive relationship between per cent feeding and time allowed for feeding, particularly for female fleas. Also the bloodmeal size was proportional to sucking time and was significantly greater in females, which are larger, than in males. However, on all four strains of host tested, there was no significant correlation between the feeding success rate of the fleas and the amount of blood they imbibed. Fleas fed better on active compared to confined M.unguiculatus. These findings agree with studies of other flea species.