Poor orchard hygiene (i.e. fruit left on and under trees) and poor hygiene around packing sheds is a major cause of the beetle surviving and increasing in early spring, to the point where the beetle is a major pest by early summer.
Management (continued from last month)
Fallen fruit should be destroyed. Sweeping fruit from under drip lines and mulching is an option, especially fruit under trees.
This has the effect of breaking the life cycle of the beetle.
Traps and their effectiveness
There is a wide variation in susceptibility of different stone fruit varieties to Carpophilus, the ‘Carpophilus Catcha Trapping System’ attract-and-kill traps are used to treat only the most susceptible fruit tree varieties.
Carpophilus populations often tend to build up in the untreated, less-susceptible varieties and then migrate to ripening, more-susceptible varieties in neighbouring areas.
This compromises the ability of attract-and-kill traps to control the pest in the treated orchards.
Work by Mofakhar S. Hossain et al demonstrated that 2 traps per hectare gave good results when large areas were treated instead of just susceptible varieties.
Starting early is the key to control
We have found the key to control is to start early.
Placing traps in the orchard in September will trap beetles on warm days when they are active.
As with all pest control, keeping the population low and trying to prevent the population from increasing is the key to control.
Even though the system is not a perfect solution to the beetle problem, starting early can markedly delay the need to start using foliar insecticides.
Overall control in a season is better, and there is a likelihood of fewer mites and mite flare from insecticides used for control of beetle.
Traps can be used for monitoring
One trap per 5 hectares, together with fruit inspections, gives an indication of the population size and the activity of the beetle.
Fruit and beetles need to be monitored as the fruit approaches maturity and becomes susceptible to attack.
Sprays are applied to cover the fruit and foliage before the beetles can reach damaging levels. Decisions to respray trees should be based on monitoring and label recommendations. Insecticides do not give long-term protection against the adult beetles that can migrate into the area.
Life cycle
(continued next month)
See this article in Tree Fruit Feb 2017
