THE ROLE OF HALTICA SP. (COLEOPTERA: HALTICIDAE) AS BIOLOGICAL CONTROL AGENT OF POLYGONUM CHINENSE

Abstrak

The role of Haltica sp. (Coleoptera: Halticidae) with emphasis on host specificity and damage potential in controlling Polygonum chinense was evaluated under laboratory condition. Starvation test of the weevil on 33 weeds and 14 crop plant species indicated that only 6 weed species were attacked: Polygonum chinense, P. nepalense, P. barbatum, P. longisetum, Ludwigia octovalvis and L. parennis with P. chinense as the most preferred host plant. Preliminary damage potential test indicated that a population of 0, 1,2 and 3 pairs of adult weevil reduced the  percentage  of  fresh  weight  increment  of  P.  chinense  by    0;  46.2;  74.7  and  75.5%  respectively.  Field observations indicated that the larvae as well as adult weevils are potential biological control agents of P. chinense. Further studies are, however, on the host-range of this weevil.