Abstract:

Experimental studies were conducted to determine the reproductive compatibilitybetween the newly invaded B biotype and a non-B biotype (China-ZHJ-1 population) of Bemisia tabaci from Zhejiang, China, and to compare their morphological and biological characteristics, including development duration, the ability to cause squash silverleaf and host plant adaptability. Males and females of the two biotypes placed together in various inter biotype crosses exhibited courtship behavior, but no copulation occurred, and all the offspring were males produced parthenogenetically, whereas the average numbers of copulation event in the first 72 h after emergence for males and females within the B biotype and the non-B biotype were 4.4 and 1.0, and the female/male ratios of the offspring produced by the B biotype and the non-B biotype were 2.8∶1 and 1.0∶1, respectively. The two biotypes showed obvious difference in pupal morphology. The width of anterior and posterior wax fringes of the non-B biotype ZHJ-1 population were 2.5～2.7 times and 1.8～2.1 times wider than that of the B biotype. There was no significant difference in development duration between the two biotypes on cotton except that the B biotype had slightly longer development duration for the 1st instar than that of the non-B biotype. From 2nd instar onwards, the body of the non-B biotype was consistently longer than that of the B biotype. Within the same biotype, the body of 4th instar female was significantly longer than that of males of the same age. On several host plants tested, the survival of the B biotype was significantly or substantially higher than that of the non-B biotype. This comparative study on the biology of the B biotype and the non-B biotype ZHJ-1 population provided some basic information for further investigating the two biotypes of B. tabaci in China, especially the invasion biology of the B biotype.

Key words: Bemisia tabaci, biotypes, reproductive isolation, morphological characteristics, biological characteristics, host plant adaptability