Bean leaf beetle

Insects generally do not cause yield loss in organic soybeans. Occasional browsing by grasshoppers, leafhoppers, and bean leaf beetles rarely... 

An issue of growing importance, however, is the relationship between the bean leaf beetle and a host of soybean seed diseases. 

Plant yellow and stunted, wilts during hot days and recovers at night. Causes Wire-worms bean leaf beetle larvae root knot nematodes. If you suspect any of these pests, pull up a plant and examine the roots. Wireworm larvae are up to 1 A", yellow to reddish brown, slender, tough-bodied, segmented grubs. Adults are A" long, dark-colored, elongated click beetles. Apply parasitic nematodes to the soil to control. 

Slender white grubs up to A" long feeding on roots are bean leaf beetle larvae. See Leaves with large holes on page 36 for more information. 

Large holes in leaves. Cause Bean leaf beetles. Adults feed above ground larvae eat roots plants may turn yellow and wilt. 

Direct effects on soybean seed and grain quality are typically associated with pod or seed feeders, which include various stink bugs, corn earworm, bean leaf beetle, grasshoppers, several armyworms, and occasionally high population densities of soybean looper and velvetbean caterpillar (Steffey et al., 1994 Turnipseed, 1976 Hammond et al., 1991 Zeiss Klubertanz, 1994). 

Obopile, M. R.B. Hammond. Effects of delayed harvest on soybean seed quality following bean leaf beetle (Coleoptera Chrysomelidae) pod injury. J.Kansas Entomol. Soc. 2001, 74, 40—48. 

Soybean Soybean weevil Bean leaf beetle... 

Imidacloprid (1) provides additional control of Cokopteran spp. (e.g., rice water and tobacco weevil, Colorado potato beetle, rice leaf beetle, wrreworms, grubs and other soil beetles) and Dipterans spp. (e.g., fruit fly, beet fly, bean and onion fly) and of selected micro-lepidopteran species (e.g., citrus, apple and potato leaf miner), ants Hymenoptera spp.), termites Isoptera spp.), cockroaches, grasshoppers and crickets Orthoptera spp.) [53]. 

In addition to the leafhoppers and Mexican bean beetle there are other insects which, when their damage is taken collectively, constitute an important loss in bean production. These insects are the apion pod weevils, Apion spp., Dmbrotica spp., white flies, Trioleurodes spp., and leaf miners, Chalepus signaticollis Baly. It has been found that when the proper insecticides are applied correctly to a good stand of beans the use of insecticides is profitable to the grower. 

On the other hand, laboratory tests showed that it was not necessary to cover both sides of the leaf. There was no difference between tests in which only one surface of the leaves was dusted, and those in which leaves had been thoroughly treated on both sides. Since the caterpillars ate the entire thickness of the leaf, this was not surprising however, the same results were found with the Mexican bean beetle larvae, an insect which feeds primarily by rasping the surface of the leaf. Either the larvae were eating a trace of the opposite, treated side of the leaf and being affected by that small amount, or the compound was being absorbed, or penetrated, through the thickness of the leaf. 

It is more difficult, if not impossible, to collect excreta of insects with highly dilute or watery feces. The Mexican bean beetle, Epilachna varivestris, usually excretes droplets of feces that adhere to the foliage on which they feed. The Colorado potato beetle, Leptinotarsa decemlineata, also excretes watery fecal material that tightly adheres to leaf tissue when dry. For such species, estimates of excreta as a function of uric acid concentration (Bhattacharya Waldbauer 1970, see below) has been suggested (Kogan 1986) but has not been widely used. 

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