|Authors: ||D.T. Johnson, M.E. Garcia, C. Rom, L. Freeman, Soo-Hoon Kim, B. Lewis|
|Keywords: ||Rubus, blackberry, raspberry, broad mite, spotted wing drosophila, pest management, miticide, exclusion|
Two pests were recently found in the USA causing yield reductions in blackberry and raspberry: spotted wing drosophila, Drosophila suzukii, broad mite, Polyphagotarsonemus latus (Banks). Field studies identified that unsprayed blackberry and raspberry plants (wild and commercial) had more than 72% of sampled ripe berries infested with spotted wing drosophila from late-June into October in Arkansas USA. Spotted wing drosophila egg laying increased with increasing Brix levels as wild blackberries matured from green (<7% Brix = 0% infested) to ripening (9.4% Brix 11% Brix = 100% infested). From June 4 to end of harvest 2014, a high tunnel had sides and ends screened with ProtekNet insect net (25 g m-2 mesh). The blackberry and raspberry plants in this screened high tunnel were not treated with insecticide but the adjacent plantings outside were sprayed with spinosad or pyrethrum insecticide during harvest on alternate weeks.
Baited traps in the screened high tunnel captured no spotted wing drosophila flies and had no fly-infested fruit compared to an excess of 10 flies per week per trap and greater than 10 spotted wing drosophila larvae per 30 ripe fruit sample.
Field trials conducted in late-October 2014 found three miticides effective against broad mites on blackberries: abamectin (Agri-Mek), spiromesifen (Oberon) and extoxazole (Zeal). On March 31, April 17 and 29 and May 15, densities of broad mites varied from 0 to 0.18 to 0.12 mites per expanded terminal primocane leaflet with 0, 0.3 and 0.3 predatory mites (Neoseiulus spp.) per leaflet, respectively.
In May 2015, blackberries inside a high tunnel had curled leaves that were found to be caused by cyclamen mites.
Future management projects for these pests will be discussed.
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