Production of Female Offspring by Virgin Females in the Greenhouse Whitefly, Trialeurodes vaporariorum, Under the Influence of High Temperatures

Abstract

Virgin [female] [female] of T. vaporariorum normally produce eggs that hatch into [male] [male]; fertilized eggs result in [female] [female] . Under the influence of high temp. (38[degree]-43 [degree]C), the virgin [female] [female] were induced to produce some [female] [female] . Multiple heat treatments were more successful in production of these exceptional [female] [female]. Low temp. failed to induce virgin [female] [female] to become thelytokous. Virgin [female] [female] that had been exposed to high temp. in the pupal stage failed to produce [female] [female] . Unfertilized eggs exposed to high temp. developed only into [male] [male]. Exceptional [female] [female] have the same diploid number of chromosomes, 22, as the stock (control) [female] [female] . Virgin exceptional [female] [female] produced only [male] [male] at 20[degree]C. Virgin [female] [female] were also permitted to feed on Colchicum autumnale, and in 2 of the 11 expts. 3 exceptional [female] [female] were found. The production of [female] [female] by virgin [female] [female] may be due to the retention of the diploid number of chromosomes in the egg under the influence of high temp. The 2d polar body may fuse with the egg nucleus or there could be a faulty separation of the chromosomes during one of the divisions in the maturation process.