Control of abundance of Colorado potato beetle and potato tuber worm.
Results are given of investigations on the population dynamics of Phthorimaea operculella in the Ukraine carried out in 1982-92 using pheromone traps, and laboratory and field-plot tests on control of this and Leptinotarsa decemlineata using hormonal and biological preparations. Field-plot tests were carried out on the latter species in 1988-90 and on both in 1992. Numbers of P. operculella were maximal during development of the 3rd generation (in September), larvae of the 4th generation overwintering. Following successful laboratory tests, field treatments were applied using 400 litres liquid/ha. An Alsystin [triflumuron] w.p. at 0.5 kg, Bitoxibacillin [Bacillus thuringiensis subsp. thuringiensis] (BTB-K at 2 kg or a BTB w.p. at 2 or 4 kg) or trifluron + Bitoxibacillin at 0.25 + 1 kg/ha gave 87-99% control of 1st-generation larvae of L. decemlineata and 59-97% control of those of the 2nd, with substantial yield increases.