Evaluation of Biocontrol Agents for Colorado Potato Beetles (2000) - 3 pages
Defoliation of potatoes and other Solanaceous crops by Colorado Potato Beetles (CPB) may cause yield losses, with the extent of damage depending on insect populations and the vigor of the crop. Consistent chemical control of CPB is complicated by their rapid development of resistance to a range of pesticide chemistries. The application of biocontrol agents may represent an alternative to standard chemical control.
This trial evaluated the biocontrol agents Bacillus thuringiensis and Beaveria bassiana for their
ability to control CPB populations in an irrigated potato crop in Saskatchewan.
The trials were conducted on the Plant Sciences Department Potato Research plots in 1999 and 2000. Russet Burbank (1999) or Norland (2000) potatoes were grown using standard irrigated production practices. The long history of potato production in the plot area has provided ample opportunity for the establishment of a CPB population. In previous years, CPB numbers were sufficient to cause some yield loss. To increase the CPB populations in the test area, adult beetles captured in other areas were released into the plot in the first week of July. The final population of adults (ca 1/plant) approximates the economic damage threshold.
The treatments were ;
Control - no CPB control methods applied.
Chemical - Decis (deltamethrin) @ 150 ml/ha
Beaveria bassiana - Mycotrol® (Mycotech Corp.) @ 2.3 1/ha
Bacillus thuringiensis - Safers® BTKtm @ 3.3 l/ha in 1999 and B.t. tenebriones in 2000 The sprays were applied to the foliage of the crop beginning in late June 20 with the emergence of the first larva and repeated every two weeks until early August. Counts of CPB larvae and adults were done weekly. The crop was harvested in late September.