Despite its name , the western bean cutworm is a pest of all form of corn — athletic field , sweet and seed — though it also appears on edible bonce ( except soybeans ) and , to a less extent , tomatoes and other nightshades . Unlike other cutworms that are true to their name , cut the industrial plant when untested , western bean cutworms feed on the fruit of the plant , such as the corn ears and bean pod .
Tracey Baute , a field crop bugologist and the program lead with the Ontario Ministry of Agriculture , Food , and Rural Affairs , is likely Canada ’s best expert on this blighter . In 2008 , for the first clip ever in Ontario , snare capture found westerly bean cutworm moth present , though no damage was documented .
“ WBC has institute itself , successfully overwinter and impacting yield and quality of maize in some regions of Ontario , ” says Baute , noting that damage has been found in dry beans too over the last few years .
The pest overwinters as larvae in soil chambers , and Baute says the grownup moth are well-off to identify : A white lot run for along the edge of each wing with signature synodic month and boomarang - comparable marks . They start to seem in early to mid - June in Canada ’s cool climate , when corn is in the whorl to pre - tassel level . They lay their eggs on the upper surface of the leaf , preferring the hybrid kind with upright leaves . Jocelyn Smith
“ Once the corn crop is in tassel or beyond , they prefer to position their eggs on dry bean plant crops , ” Baute says . “ Unfortunately , the larvae are very mobile and can dissipate from the original egg site to other plants in the vicinity , both up and across corn rows . High jeopardy theatre admit no - till subject area and W. C. Fields with arenaceous grunge .
The vernal burn - to - pinkish larvae munch on the tassel and silk , and once enceinte enough , they tunnel to the capitulum ’s kernels , where they feed . If you look closely , you may see their entry hole on the outside of the stalk , though they may also enter through the silk channels , in which case , their terms wo n’t be seeable . Because western noodle cutworms are not anthropophagus , multiple larva can feed on the same ear , leave small left to harvest .
Jocelyn Smith
“ estimation on yield loss from other jurisdiction indicate a field infestation of one larva per pinna can cause a 3.7 bu / ac loss , ” Baute suppose . “ Additional encroachment can be expect from ear rots and secondary pest that may go in and feed on damaged ears .
Controlling Western Bean Cutworms
Several born enemies provender on western bean cutworm ball masses and young larva , including :
old larva may be eat by bird and some vertebrates , such as , raccoon and skunks , but once in the ears of the corn or pod of the bean plant , they ’re protected from predation .
Scouting For Western Bean Cutworm In Your Fields
“ In corn , scout 20 plant in five domain of the field from the end of July to the end of August , ” Baute advises for northern domain , though you may want to check with your extension factor to find out when your area is most at peril . “ Focus on area in the pre - tassel stage and inspect the top three to four upper leaves of the flora . Look for egg masses and untested larvae . ”
If you line up white orchis masses , then that mean they are newly laid . Purple imply they ’ll be ready to concoct in one to two day . masthead plants with ashen slew , and return in a few days so you’re able to get a line when young larvae will be active . If you choose to apply pesticides to handle the infestation , this is the stage when it will be most efficient .
“ new hatched larva will ab initio climb to the top of the plant to feed on the tassel , but only for a short time before migrating down the plant life to feed on the ear , ” Baute say . If your software is time right , you may be able to curb the problem .
For more selective information on WBC , visit Baute’sblog .
