SPIDERMITES: I have a sneaking suspicion that spidermites are making their way into those fields that haven’t had rain in a while. We have had situations in the past where not only have they popped up in soybeans and were being disregarded as “drought stress” symptoms but also in seed corn, especially around or just after wheat has been harvested in the area. Be particularly careful in watching those fields that may have had a pyrethroid used recently for any other insect issues. Pyrethroids do not work on spidermites and can actually cause mite populations to flare up. For more info on spidermites and scouting, refer to: http://www.omafra.gov.on.ca/english/crops/pub811/13soybean.htm#spider
SOYBEAN APHIDS: As suspected, some fields are noticing a drastic decline in numbers, while others have seen a drastic increase. A significant soybean aphid flight took place this week (as captured by our suction traps) and some winged aphids left the early planted fields they started in this summer and have moved to later planted fields either nearby or in other regions entirely. But we also may have received aphids from neighbouring states and provinces so fields should be checked soon to figure out if you were one of the lucky ones or not.
WESTERN BEAN CUTWORM: We experienced an increase in moth captures this week, indicating that this is a good time to start scouting for egg masses, especially at trap locations that have been catching moths into the double digits. Since corn is still barely tasseling, the moths will prefer to lay their eggs in corn still. Trap capture maps for this week are at: http://www.cornpest.ca/default/index.cfm/wbc-trap-network/weekly-maps-of-wbc-trap-catches/
Information on how to scout for egg masses and larval activity can be found at: http://www.cornpest.ca/?LinkServID=3FD7CC42-65B8-8CF0-A092D60341F09626&showMeta=0 Make sure to click on the speaker notes at the top left of each slide for more detailed information.
Also here is an infosheet on WBC in corn: http://www.cornpest.ca/?LinkServID=D23DD4EE-188B-3AFA-0809F13CA830D6F4&showMeta=0
Have a Fantastic Long Weekend Everyone!