Blueberry Tip Midge Control, 2015

This experiment was conducted on lowbush blueberry to evaluate the effectiveness of five insecticides against blueberry tip midge (TM). Materials were applied to 7 × 20-ft plots in a vegetative-year blueberry field at Jonesboro, ME. There were four treated plots for each material plus four untreated check plots. All treatments were applied in 25 gal of water-mixture per acre using a CO ₂ -propelled, 80-inch boom sprayer (76-inch swath), with four, flat spray 8002VS TeeJet nozzles operating at 35 psi. Rimon 0.83EC (novaluron), Movento SC (spirotetramat), Exirel SE (cyantraniliprole), Sivanto 200SL (flupyradifurone), and Assail 30SG (acetamiprid) were applied on 27 May. A second application of each material was made on 5 Jun. Blueberry stems were scattered and < 1 inch tall on 27 May and 1–1.5 inches tall on 5 Jun. Larval infestation was assessed on 12 and 25 Jun by counting the number of blueberry stems with and without tip midge damage as evidenced by curled leaves from each of three, sq ft samples per treated plot. No symptoms of phytotoxicity were apparent in any of the plots.

Analysis of Variance (ANOVA, RCB) and LSD ( P  ≤   0.05) were used to compare mean number of curls among the treatment plots. Subplots were pooled within main plots.

Data were transformed by arcsine to stabilize variance prior to analysis. Rimon, Exirel, Sivanto, and Assail were all effective, at least initially, in suppressing tip midge populations. Significantly fewer damaged stems were found in the treated plots compared with the non-treated checks on the first sample date on 12 Jun ( F_(5,15,)  = 19.31 _,P  = < 0.0001). However, by the second sample date on 25 Jun numbers of damaged stems in the treated plots increased resulting in no significant difference in numbers of damaged stems in all treated plots compared with the non-treated checks; ( F_(5,15)  = 0.56, P  = 0.7260) ( Table 1 ). This research was supported in part by industry gift(s) of pesticides and/or research funding.

Author notes