Bean leaf beetle active in Kentucky soybeans

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

Bean leaf beetle (BLB) damage is being reported in scattered areas across Kentucky. Though they are active in all the soybean production areas, the most significant damage seems to be in the central Kentucky counties. These beetles will be pests from plant emergence throughout the season. They are present in most fields every year. In some years seedlings will be heavily damaged. You should have intensive scouting from emergence through the first trifoliate then from pod set through pod fill.

Figure 1. Bean leaf beetle colors and patterns. Bean leaf beetle can come in several colors and patterns (Figure-1). However, they will always have a backward pointing black triangle just behind the head. Adults are about 1/8” – ¼” long. The body is slightly convex and the beetle is longer than wide. Color is variable, ranging from light brown to dark red, spots and/or stripes may be present or absent.

Bean leaf beetles feed on cotyledons, leaves and pods. Leaf feeding consists of very distinctive almost circular holes. Feeding on cotyledons and pods usually appears as scoop-out divots or holes in the surface.

Scouting in early season: look for stand reduction (cotyledon stage) and heavy leaf feeding while crossing the fields. If damage is noticed, try to establish that BLB is the problem by looking for them on the plants. Control should be considered if 30 percent stand loss (cotyledon) –OR- 30% defoliation (true leaves) is present.

This early season damage is caused by “overwintering” BLB adults that survived the winter in perennial crops and weeds, then move back into soybean fields. In addition to the feeding they will lay eggs in the soil around plants. These eggs will hatch into small worms which will complete their development in the soil.

BLB will have two more adult generations during the soybean season. The 1st generation adults will emerge in midseason and will feed on leaves. We generally do not have problems with this generation. However, economic populations are possible. They will also lay eggs in the soil eventually resulting in the 2nd BLB adults. 2nd generation adults emerge during reproductive or pod filling time and feed on leaves, flowers and pods. This population can be more important than the 1st generation, as these beetles are feeding directly on the yield. When soybeans begn to mature these 2nd generation beetles will move out of soybeans and into surrounding perennials (alfalfa etc.) and other weed plants through the fall then overwinter for the following year. It is possible to have a 3rd generation, but that is more likely to occur much further south.

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 

e-Mail (required)


characters left

1325 Bushel Grain Cart

Equipped with a 22” computer balanced auger with 5/16” flighting,the unloading speed is 50% faster than smaller grain carts with ... Read More

View all Products in this segment

View All Buyers Guides

Feedback Form
Feedback Form