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ARS Home » Plains Area » Sidney, Montana » Northern Plains Agricultural Research Laboratory » Pest Management Research » Research » Publications at this Location » Publication #270245
Title: Alternative and integrated strategies for sugarbeet root maggot control

Author
item BOETEL, MARK - North Dakota State University
item SCHROEDER, ALLEN - North Dakota State University
item DREGSETH, ROBERT - North Dakota State University
item Jaronski, Stefan

Submitted to: Sugarbeet Research and Extension Reports
Publication Type: Research Notes
Publication Acceptance Date: 7/8/2011
Publication Date: 7/11/2011
Citation: Boetel, M., Schroeder, A.J., Dregseth, R.J., Jaronski, S. 2011. Alternative and integrated strategies for sugarbeet root maggot control. Sugarbeet Research and Extension Reports. 3 pgs.

Interpretive Summary: The sugarbeet root maggot (SBRM), Tetanops myopaeformis (Röder), is a threat for producers in up to two-thirds of the sugarbeet producing acres in the United States on an annual basis and is the most serious insect pest of sugarbeet in the Red River Valley growing area. Granular formulations of organophosphate and carbamate insecticides have been used to control this insect for over three decades. Although most granular insecticide applications in the RRV are carried out during sugarbeet planting, some infestations are sufficiently high to justify the need for additional postemeregence rescue applications of materials with the same mode of action. Thus, the development of insecticide resistance to these materials has been a concern for several years. Similarly, experimental bioinsecticide formulations, containing spores of the insect-pathogenic fungus, Metarhizium anisopliae, also have performed at only low to moderate levels against SBRM larvae. This experiment was carried out to assess the efficacy of M. anisopliae-based bioinsecticide granules (strain MA1200), insecticidal seed treatments, and combinations thereof for SBRM control. MA1200 fungus granules, applied at 20 lb product/ac using spoon placement, as well as the integrated program of beta-cyfluthrin/clothianidin seed treatment plus Metarhizium granules significantly reduced maggot feeding damage. Although combining beta-cyfluthrin/clothianidin seed treatment with Metarhizium granules appeared to have a slight additive benefit when compared with single applications of these tools, the integrated combination treatment consisting of both materials did not result in a significant increase in SBRM control when compared to the performance of either of these materials applied singly. Combining Metarhizium-based MA1200 granules with beta-cyfluthrin/clothianidin seed treatment produced an increase in gross revenue of $191 per acre when compared to that from plots protected solely by beta-cyfluthrin-clothianidin seed treatment. These data indicate there may be some value to the farmer in combining Metarhizium granules applied at planting with beta-cyfluthrin-clothianidin seed treatment.

Technical Abstract: Granular formulations of organophosphate and carbamate insecticides have been used to control the sugarbeet root maggot (SBRM), Tetanops myopaeformis (Röder), for over three decades; the development of insecticide resistance to these materials has been a concern for several years. This experiment was carried out to assess the efficacy of Metarhizium anisopliae-based bioinsecticide granules (strain MA1200), insecticidal seed treatments, and combinations thereof for SBRM control. Because previous research has shown that seed treatments and M. anisopliae-based applications have shown low to moderate efficacy in previous testing, we planned this experiment for a field site expected to have a moderate SBRM infestation rather than the typically high infestations used for most of our trials. The SBRM infestation that developed in this trial area was low. Treatments that provided significant reductions in SBRM feeding injury included the following 1) Metarhizium MA1200 fungus granules, applied at 20 lb product/ac using spoon placement; 2) thiamethoxam seed treatment; and 3) the integrated program consisting of beta-cyfluthrin/clothianidin seed treatment plus MA1200 granules. Although combining beta-cyfluthrin/clothianidin with MA1200 granules appeared to have a slight additive benefit when compared with single applications of these tools, the integrated combination treatment consisting of both materials did not result in a significant increase in SBRM control when compared to the performance of either of these materials applied singly. Significant increases in recoverable sucrose were achieved by applying the following treatments for SBRM control: 1) thiamethoxam seed treatment; 2) beta-cyfluthrin/clothianidin seed treatment + MA1200 granules; 3) thiamethoxam + MA1200 granules; and (4) terbufos banded at 7.5 lb product/ac. All of these treatments, in addition to the stand-alone entry of beta-cyfluthrin/clothianidin, also produced significant root tonnage increases over that of the untreated check. Combining Metarhizium-based MA1200 granules with beta-cyfluthrin/clothianidin seed treatment produced an increase in gross revenue of $191 per acre when compared to that from plots protected solely by beta-cyfluthrin/clothianidin. As observed with root injury rating data for this trial, combining MA1200 granules with thiamethoxam treatment did not provide a significant yield benefit or increase in revenue when this integrated strategy was compared with either of its component control tools applied separately.