Black cutworm flocks to Indiana; scouting critical

decrease font size  Resize text   increase font size       Printer-friendly version of this article Printer-friendly version of this article

Record numbers of black cutworm moths have descended upon Indiana fields, and after a week of warm temperatures and rainfall now is a critical time to scout, a Purdue Extension entomologist says.

Pheromone trap cooperators throughout the state monitor for the insect's arrival, which has the potential to cause significant economic damage to field crops. A round of storms originating in southern states in March brought not only rain to Indiana, but cutworm populations not previously seen. Since that time additional captures have had the trappers very busy counting.

According to John Obermeyer, the key to successfully controlling the insect is to scout early and often and to apply insecticides when larvae are small - especially because large larvae are difficult to control.

"Producers may have a false sense of security with the seed-applied insecticides or Bt-corn," he said. "As many learned the hard way last year, these technologies don't stand up to severe infestations, which certainly are a possibility this year."

Infestations and black cutworm development are first determined by the moth trapping network, then by monitoring heat units once critical catches are recorded. Heat units are calculated as the difference between the average daily maximum and minimum temperatures and a critical developmental threshold temperature. For black cutworm, that threshold is 50 degrees, meaning it takes about 300 heat units from egg hatch to the time when larvae begin to "cut" or severely damage plants.

In the southern part of the state, accumulated heat units already are well above 300 and are rapidly approaching that number in the central and northern parts. With most of the state's corn crop already in the ground, Obermeyer said scouting now is crucial.

"Scout by inspecting 20 consecutive plants in each of five areas of a field for cutworms and feeding activity," he said. "Be sure to check areas that had an accumulation of weedy growth before or at the time of planting."

Obermeyer also said growers need to collect black cutworm larvae to determine the average instar, or development stage.

"A foliar, rescue insecticide may be necessary if 3 percent or more of the plants are damaged and black cutworm's average larval instar is 4-6," he said.

A larval instar guide is available inside the front cover of the Purdue Extension Corn and Soybean Field Guide, available for $7 through Purdue Extension: The Education Store at https://mdc.itap.purdue.edu/

Pheromone trap reports and updated heat accumulation graphics are available in Purdue Extension's Pest and Crop Newsletter at http://extension.entm.purdue.edu/pestcrop/index.html


Buyers Guide

Doyle Equipment Manufacturing Co.
Doyle Equipment Manufacturing prides themselves as being “The King of the Rotary’s” with their Direct Drive Rotary Blend Systems. With numerous setup possibilities and sizes, ranging from a  more...
A.J. Sackett Sons & Company
Sackett Blend Towers feature the H.I.M, High Intensity Mixer, the next generation of blending and coating technology which supports Precision Fertilizer Blending®. Its unique design allows  more...
R&R Manufacturing Inc.
The R&R Minuteman Blend System is the original proven performer. Fast, precise blending with a compact foot print. Significantly lower horsepower requirement. Low inload height with large  more...
Junge Control Inc.
Junge Control Inc. creates state-of-the-art product blending and measuring solutions that allow you to totally maximize operating efficiency with amazing accuracy and repeatability, superior  more...
Yargus Manufacturing
The flagship blending system for the Layco product line is the fully automated Layco DW System™. The advanced technology of the Layco DW (Declining Weight) system results in a blending  more...
Yargus Manufacturing
The LAYCOTE™ Automated Coating System provides a new level of coating accuracy for a stand-alone coating system or for coating (impregnating) in an automated blending system. The unique  more...
John Deere
The DN345 Drawn Dry Spreader can carry more than 12 tons of fertilizer and 17.5 tons of lime. Designed to operate at field speeds up to 20 MPH with full loads and the G4 spreader uniformly  more...
Force Unlimited
The Pro-Force is a multi-purpose spreader with a wider apron and steeper sides. Our Pro-Force has the most aggressive 30” spinner on the market, and is capable of spreading higher rates of  more...
BBI Spreaders
MagnaSpread 2 & MagnaSpread 3 — With BBI’s patented multi-bin technology, these spreaders operate multiple hoppers guided by independent, variable-rate technology. These models are built on  more...


Comments (0) Leave a comment 

Name
e-Mail (required)
Location

Comment:

characters left


X-TENDED REACH GRAIN CARTS

YOUR BEST HARVEST IS NOW WITHIN REACH J&M introduces their patented line of X-tended Reach grain carts, featuring a frontfolding single ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form