Black Cutworm Moths Arrive In Wisconsin

Pictured: Black cutworm moths. Photo by K. Hamilton DATCP.

Black cutworm moths arrived to Wisconsin in significant numbers for the second week in a row, according to the state Department of Agriculture, Trade and Consumer Protection.

The DATCP network of 50 traps collected 126 moths during the reporting period ending April 25. The team documented intense flights at three of the monitoring sites. An “intense” capture of nine or more moths in two nights indicates there was a large flight. It means that a corresponding increase in cutworm egg laying is on the way.

The first intense flight also marks the point to start counting degree days to forecast the peak seedling corn damage window. From the date of an intense capture, an average of 300 degree days (base 50°F) allows the black cutworm to develop from the egg stage to the damaging larval stage.

The black cutworm migrates northward each spring from overwintering areas near the Gulf of Mexico and Texas. When appropriate weather systems occur, the moths can reach Wisconsin from Texas in only two days.

The first moths were recorded in traps on March 31 this spring and the cumulative count as of April 25 is 296 moths. This total count compares to 166 moths captured by the same time last year. DATCP will forecast of the peak seedling corn damage window later this week.

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