(L3) BLUEBERRY: Vaccinium angustifolium Aiton, 'Lowbush' BLUEBERRY FLEA BEETLE CONTROL IN THE LABORATORY, 2005 J. A. Collins Dept. of Biological Sciences 5722 Deering Hall University of Maine Orono, ME 04469 Phone: (207) 581-2868 Fax: (207) 581-2969 E-mail:
[email protected] F. A. Drummond Dept. of Biological Sciences 5722 Deering Hall University of Maine Orono, ME 04469 Phone: (207) 581-2989 Fax: (207) 581-2969 E-mail:
[email protected] Blueberry flea beetle (FB): Altica sylvia Malloch Each treatment was applied on 2 Jun in 25 gpa with a CO2-propelled, 80-inch boom sprayer (76-inch swath) equipped with four, flat-spray 8002VS TeeJet nozzles operating at 35 psi and at a slow walking speed. Speed was regulated using a metronome. The materials were allowed to dry on the foliage. Field-collected, FB larvae were placed in plastic cups with petri dish lids. There were four replications of five FB each. One treated stem was cut and placed in each cup. The cups were held in a growth chamber at approximately 21°C and assessed for mortality at daily intervals for five days. Untreated blueberry foliage was added to each cup as needed. The Product-Limit Survival (Kaplan-Meier) Method and Gehan-Wilcoxon Mean Separation were used to compare the mean days to death of each treatment to the untreated check. Logistic Regression was used to compare percent survival among the treatments. All the materials were significantly different from the untreated check (Table 1). The most effective materials were Assail 30SG and SpinTor 2SC; 50% of the larvae fed foliage treated with these materials were dead within one day. Table 2 shows percent survival of larvae treated with each material. Assail 30SG, Avaunt 30WG, Novaluron 10EC, and SpinTor 2SC were all highly effective and significantly reduced percent survival in comparison with the untreated check by the third day of the trial. Table 1. Treatment/ formulation Assail 30SG Avaunt 30WG Avaunt 30WG Novaluron 10EC SpinTor 2SC Untreated check
Rate amt product/acre
Mean a days to death
Prob X ≤ 0.05
5.3 oz 4.0 oz 6.0 oz 9.6 fl oz 6.0 fl oz --
1.00 3.00 2.00 3.00 1.00 b --
< 0.0001 < 0.0001 < 0.0001 0.0003 < 0.0001 NA
2
c
a
Biased estimate due to censored observations (live larvae) at end of study. Not possible to estimate because of > 50% survival. c Pair-wise comparison with untreated check. b
Table 2. Percent survival on day after application Treatment/ formulation Assail 30SG Avaunt 30WG Avaunt 30WG Novaluron 10EC SpinTor 2SC Untreated check
Rate product/acre
1
5.3 oz 4.0 oz 6.0 oz 0.6 oz 6.0 oz --
5.0d 65.0b 85.0a 95.0a 20.0c 95.0a
2 0.0c 65.0b 10.0c 80.0ab 0.0c 95.0a
3
4
5
0.0c 0.0c 0.0c 30.0b 0.0c 90.0a
0.0c 0.0c 0.0c 30.0b 0.0c 85.0a
0.0c 0.0c 0.0c 25.0b 0.0c 85.0a
Mean percent survival within each sample day, followed by the same letter(s), are not significantly different (Logistic Regression).
