The bean leaf beetle adult is a beetle similar in size to rootworm beetles or ladybird beetles. It can range in color from green to dark red and always has a dark triangle on its back directly behind the head. It may or may not have four dark spots on the back and a dark line running the length of the body on each side. There are two generation produced annually in Missouri with beetles feeding on soybean foliage and larvae feeding on roots and stem below the soil surface. Economic thresholds are based on soybean growth stage, beetle numbers and visible plant damage. Typical defoliation damage by beetles is characterized by oval holes chewed in plant leaflets which do not go through leaf veins and by holes chewed into soybean pods later in the season.

This soybean pest overwinters as adults in leaf litter and plant debris in border areas of crop fields. In spring, beetles move from overwintering sites to soybean fields where they feed on foliage, mate, and lay eggs in the soil. Adult beetles will feed on seedling soybean foliage for several weeks and eventually die. These beetles can damage to seedling soybean if they reach or exceed the seedling economic threshold of five or more beetles per foot of row and defoliation exceeds 30% or if an average of 1 or more plants are killed per foot of row. Although not common, beetles from the overwintering generation occasionally require management with an insecticide application. Problems with early season soybean defoliation or plant death is most common in years when springs are cool and dry, resulting in slowed seedling growth. Fields most at risk this spring are those planted earliest in an area. Bean leaf beetle adults are good fliers and will fly relatively long distances to infest early season soybean fields. If treatment is necessary, use one of the recommended insecticides.

Updated table: http://ppp.missouri.edu/newsletters/ipcm/archives/v16n11/ipmltr1.htm

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	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	2.8 to 4.0 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,
573 864-9905 (cell)