Bean Leaf Beetle Problems Build in Slow-growing Soybean
By Wayne Bailey

Numbers of bean leaf beetle adults continue to increase in northern and central Missouri counties. Slow soybean germination and growth due to drought conditions allow for increased damage by beetles migrating into soybean fields by overwintering adults. The economic threshold of 5 beetles per foot of row and 30 percent defoliation is a starting point, but drought conditions and mortality of soybean seedlings also must be considered. If an insecticide application is necessary to reduce adult BLB numbers, use one of the recommended insecticides listed in the following table. This table contains a correction from an earlier version of the table published in the newsletter. FMC has a label change for Mustang Max use on bean leaf beetle in soybean which reduces the rate to the levels listed in this table. Be sure to follow all label directions, precautions, and restrictions when using insecticides.

Chemical Name	Product Name	Rates: Amount of Product /acre (unless otherwise noted)
permethrin	*Ambush	3.2 to 6.4 fl oz
esfenvalerate	*Asana XL	5.8 to 9.6 fl oz
cyfluthrin	*Baythroid 2	0.8 to 1.6 fl oz
dimethoate	Dimethoate; Dimatesee	see specific label
methomyl	*Lannate LV	0.75 to 1.5 pts
methomyl	*Lannate SP	0.25 to 0.5 lb
thiodicarb	*Larvin 3.2EC	18 to 30 fl oz
chlorpyrifos	*Lorsban 4E	1 to 2 pts
zeta-cypermethrin	*Mustang Max	2.0 to 2.8 fl oz
chlorpyrifos	*Nufos 4E	1 to 2 pts
methyl parathion	*Penncap-M	2 to 3 pts
permethrin	*Pounce 3.2EC	2 to 4 fl oz
gamma-cyhalothrin	*Proaxis	1.92 to 3.2 fl oz
carbaryl	Sevin XLR Plus	1 to 2 pts
lambda-cyhalothrin	*Warrior	1.92 to 3.2 fl oz
* indicates Restricted Use

Wayne Bailey
Entomology
573-864-9905 cell