| Takecallis taiwanus Takahashis (Homoptera: Callaphidiae) is one of most important pest harming bamboo, has a wide distribution and does serious damage to the bamboo. So far, there are little better methods other than application of chemical pesticides for the control of the aphid. Chemical control would cause many negative effects as it did in other pests. Biological control may be a prospective solution for the integrated management of this aphid. However, very little on the aphid has been known at present. Therefore, I carried out detailed, quantitative studies on the biological characteristics of I taiwanus and the virulence of Beauveria bassiana against the aphid. The objective is to provide the necessary information for the biocontrol of this aphid. The major results are summarized as follows.The development, survival and reproduction of T. taiwanus were determined under seven constant temperatures ranging from 5 to 35 . Temperature affected the development rate, survivorship and life-span, fecundity and reproductive rate of T. taiwanus. Aphids could survive and reproduce from 5 to 30 , with maximum fecundity at 16 . Mean generation time decreased from 54 days at 5 to 9 days 30 . Adult longevity was the longest (33 days) at 10 , and shortened with descending or elevating temperature at below or over 10 . Development and doubling times were shortest, and intrinsic rate of increase highest at 25 . No nymph could survive to the adult stage at 35 .The development-span of T. taiwanus was determined under 5 constant temperatures ranging from 10 to 30 . The low-development threshold temperatures were estimated to be 12.76 , 9.24 ,.7.28 , 6.45 and8.1 , and the thermal constants were estimated to be 19.66, 19.88, 28.52, 36.49 and 115.82 day-degree for the development of the 1st, 2nd, 3rd, 4th instar nymph and whole nymph stage from new born to adult emergence, respectively. All these data could be served as reference when number of generations and timeof occurrence need to be forecasted at a particular locality.Virulence bioassay of the 5 isolates of Beauveria bassiana from 5 species of insects, respectively, against T. taiwanus were carried out. The result showed that all 5 isolates tested were capable of infesting T. taiwanus. Among 5 isolates, B12 and Bxs had the most virulent against this aphid, with accumulative mortality reaching as high as 100% and 96.4% respectively on the seventh day after inoculation. The Time-Dose-Mortality model (namely Complementary log-log model) was used for the analysis of the bioassay of the 5 isolates of 8. bassiana on f. taiwanus. Time-dependent lg(LC50) curves and dose-dependent LT5o curves were drawn respectively for each isolate of the fungus. According to the curves, the Ig(LCso) for every day after inoculation and LT5o at each dose for each isolate were estimated. For instance, for 612, Bxs, REBbOl, Zhe-B and F-263, the lg(LC50) by the 9th day after inoculation were estimated to be 4.0549, 4.4620, 4.6261, 4.9290 and 5.1580, respectively, and the LT50at an inoculate dose of 106 conidia/ml were estimated to be 3.63, 3.70, 4.31, 4.34 and 5.20 days, respectively.Three-dimension figures of cumulative mortality of T. taiwanus with the changes of time and dose were drawn, based on which, virulence of each isolate against T. taiwanus under different time and dose were evaluated and compared. The virulence of 5 isolates in a decreasing order was B12>Bxs>REBb01>Zhe-B> F-263.Virulences on the reproduction of T. taiwanus were also investigated for the three better performance isolates of 8. bassiana. As a whole cohort, infection by the pathogen could reduce the mean fecundity within observing . time due to some death of the infected adult aphids . However, as speaking of individual aphid, whether it has been infected or not infected by the pathogen, the number of progeny produced by the aphid remained the similar until the death occurred. After inoculation of 8. bassiana at gradient doses, the intrinsic rate of increase (rm) of T. taiwanus was reduced, but...
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