Western bean cutworm is alive and well in central Michigan

Dry bean growers and crop consultants should begin scouting for damage this week.

August 15, 2019 - Author: ,

Western bean cutworm feeding
Photo by Fred Springborn, MSU Extension

Peak flight of western bean cutworm occurred largely over the week of July 28 – Aug. 5, 2019, in west central Michigan. This is a full week later than last year and several previous seasons. There were still a significant number of moths being captured in pheromone traps as of Aug. 12.

Several western bean cutworm pheromone traps have passed the mark of 150 total moths captured for the season, but it is important to remember the rest of the guidelines:

  • Greater than 150 moths captured in pheromone traps.
  • Neighboring pre-tassel corn fields have egg masses.
  • Blossom and pod feeding observed in dry beans.
8-15 wbc 4and5
Photos by Fred Springborn, MSU Extension

From my own observations and from what local agribusiness scouts are reporting, egg masses have been few in pre-tassel corn. With pre-tassel corn abundant throughout the flight period, western bean cutworm may have had lots of corn to deposit eggs upon, which may be diluting the population. Remember, it is not the moths that feed on dry beans, it is the larvae that hatch from the eggs produced by the moth.

Check dry bean fields periodically for signs of western bean cutworm larval blossom and pod feeding this week and through the rest of August. It will take time and patience to scout for this feeding, especially to find it early. You will not see it by driving by a field or flying over it with a drone. Growers of large seed dry beans such as kidney beans should consider an insecticide application if feeding is detected, especially if those beans are heading for a quality-sensitive market. Insecticide applications should begin at least seven to 14 days after peak flight has occurred. Be sure to observe pre-harvest intervals and read and follow label directions.

Montcalm County, Michigan, area trap counts 2019

Nearest town

July 23

July 30

Aug. 6

Aug. 12

Totals

Entrican

5

25

68

55

153

Stanton

16

91

127

4

238

Greenville 1

82

141

103

54

380

Greenville 2

28

35

62

23

148

Sidney

22

69

18

10

119

Trufant 1

54

87

200

60

401

Trufant 2

36

123

87

51

297

Coral 1

29

78

71

19

197

Coral 2

14

105

111

17

247

Tags: agriculture, corn, dry beans, integrated pest management, msu extension, western bean cutworm


Michigan State University Michigan State University Close Menu button Menu and Search button Open Close