title: A rapid spectrophotometric method for the monitoring of embryonic development in ticks (Acarina: Ixodoidea).
abstract: A rapid spectrophotometric method for the monitoring of embryonic development in Boophilus decoloratus (Koch, 1844) is described. The method is based on a quantitative assessment of guanine, the prinicipal end-product of nitrogenous metabolism in ticks, which is gradually built up and stored in the rectal sac during embryonic development of the larvae. A study of the growth of tick embryos under constant temperature conditions and 6 different humidity conditions demonstrated that embryonic development was dependent on the water content of the eggs at the time of oviposition. When eggs lost more than 35% of their initial mass through evaporation, nitrogenous metabolism (as indicated by guanine production) was seriously affected and embryos died.
mesh_terms: D000818:Animals; D001699:Biometry; D005243:Feces / Q000032:analysis; D005260:Female; D006147:Guanine / Q000032:analysis / Q000378:metabolism; D006813:Humidity; D007814:Larva / Q000032:analysis; D008722:Methods; D010063:Ovum / Q000032:analysis; D012007:Rectum / Q000032:analysis; D013053:Spectrophotometry; D013987:Ticks / Q000032:analysis / Q000196:embryology* / Q000378:metabolism
chemical_list: D006147:Guanine