Armyworm look-alike in wheat

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

click image to zoomSawfly larva on wheat. Small, caterpillar-like larvae have been reported in East Central Indiana wheat fields just before fungicides were to be applied. These are not caterpillars at all, but are sawfly larvae, probably grass sawfly (Pachynematus sp.). Adult sawflies are insects with four wings that are distant relatives of the honey bee, but they do not have a stinger. The larvae are usually plant feeders and a few are pests of home gardens (rose sawfly, for example).

The sighting of foliage feeding sawfly larvae in wheat fields is infrequent in the Midwest. And although this species was feeding on the leaves, it was minor and economic damage is not expected. This is more of a curiosity than anything else, and an opportunity to learn the differences between different insect larval types – always fun! Full size larvae, about 1.25 inches, may feed on stems causing head clipping much like armyworm. Another closely related insect, the wheat stem sawfly, occasionally causes problems in northern regions of the United States. This species, as the name implies, feeds only in the stem causing lodging of small grains.

click image to zoomSawfly and armyworm differentiation. Unlike armyworms, which feed at night or on dark, cloudy days, sawfly larvae feed throughout the day. Another difference takes close inspection – caterpillars have three pairs of true legs just behind the head and another five pairs of prolegs on their abdomen. Sawflies also have the three pairs of true legs up front, but also have six or more pairs of prolegs further back on the abdomen. Because sawflies’ coloration blends into the vegetation, a sweep net would be useful to determine their presence. If populations of 10 or more larvae per 100 sweeps are found, plants should be examined more closely. By shaking undisturbed plants in multiple locations in the field, count and calculate the number of larvae per foot of row that fall to the ground. Populations as low as 0.4 larvae/foot of row have been suggested by the University of Delaware as the treatment threshold. That is not many, but it would be very surprising if any Indiana fields topped that threshold – it’s extremely unlikely that treatment will be required.


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