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ARS Home » Plains Area » Fargo, North Dakota » Edward T. Schafer Agricultural Research Center » Sugarbeet and Potato Research » Research » Publications at this Location » Publication #88976
Title: BIOLOGICAL CONTROL OF TETANOPS MYOPAEFORMIS (SUGARBEET ROOT MAGGOT) USING THE ENTOMOPATHOGENIC FUNGI BEAUVERIA BASSIANA AND METARHIZIUM ANISOPLIAE

Author
item Smith, Garry
item Eide, John
item Campbell, Larry
item SMITH, LARRY - UNIV. MINNESOTA CROOKSTON

Submitted to: American Society of Sugarbeet Technologists
Publication Type: Proceedings
Publication Acceptance Date: 3/3/1997
Publication Date: N/A
Citation: N/A

Interpretive Summary: Sugarbeet root maggot is the most serious insect pest affecting sugarbeets in the upper Midwest. Potential loss of chemical controls and variable results with chemical controls led us to examine biological control measures. Our previous laboratory studies have shown the efficacy of the entomopathogenic fungi B. bassiana and M. anisopliae on first and third instar sugarbeet root maggots (SBRM). Exposure of third instar larvae to M. Anisopliae resulted in 94% mortality 15 days post- inoculation. The fungi are also effective against adult flies. In our Fargo ARS laboratory studies, we found that six days after inoculation mortality rates were 100% for M. Anisopliae treated flies and 65% for B. bassiana treated flies. Based on our laboratory results and on a one-year field pilot study, a three-year field study was initiated to determine the persistence of M. anisopliae over seasons and rotations.

Technical Abstract: Our previous laboratory studies have shown the efficacy of the entomopathogenic fungi B. bassiana and M. anisopliae resulted in 94% mortality 15 days post-inoculation. The fungi are also effective against adult flies. In our Fargo ARS laboratory studies, we found that six days after inoculation mortality rates were 100% for M. anisopliae treated flies and 65% for B. bassiana treated flies. Based on our laboratory results and on a one-year field pilot study, a three-year field study was initiated to determine the persistence of M. anisopliae over seasons and rotations. Autoclaved barley (as a carbon source) inoculated with M. anisopliae was dried and applied in the spring immediately prior to planting, fall preceding planting, or fall plus spring in replicated field plots at Crookston, MN, in 1996. Sugarbeets inoculated in the fall plus spring had both significantly greater recoverable sugar per acre (8074 lbs. per acre) than the controls (6338 lbs. per acre). These plots also produced more recoverable sugar than Lorsban-treated plots, which averaged 7748 lbs. per acre. Since sucrose percentage was not significantly affected by any of the treatments, the increase in recoverable sugar is attributed to increased tonnage.