Published online by Cambridge University Press: 31 May 2012
A study of 2,500 adults of the California five-spined engraver, Ips confusus (Lec.), has shown that the sex of this beetle can be determined from a secondary sex character with an accuracy exceeding 99 percent. Insects often have secondary characters that indicite sex, and in species with concealed genitalia, reliable secondary characters are especially useful for rapidly separating the males and females. Where such characters are lacking, a dependable determination of sex can only be made by the laborious procedure of dissection for a check of genitalia.