Aphid Monitoring Project Update - May 15th

Thursday, May 16, 2013

Monitoring plots have been set-up around the province and leaf and sticky trap samples are now being collected regularly. Egg hatch was underway last week on many farms and we are now finding aphids on new leaves. As noted in my earlier report, the majority of aphids that we are finding are Chaetosiphon species which are the vector for the two viruses that have caused so many problems over the past year. This is a concern and many growers are opting to apply a control as a precaution against virus increase and spread.

The leaf sampling procedure we are using involves collecting 60 random leaves from each field/block and conducting the aphid counts in our lab under 20-30X magnification. The leaf samples should be immature, partly unfolded leaves as these are the target for young aphids. The strawberry aphid is distinct from other species in that it has knobbed hairs on its body and the knob at the end of each hair often appears to glisten from light reflection (see photo below).

The good news is that we have not found any winged aphids yet but we did observe an aphid that was starting to grow its wings this morning. It was collected May 14th from an early matted-row field that had been covered by row cover for a month and was 2 weeks ahead of other fields. Perhaps this is an early warning as to when we might expect an aphid flight in matted row fields without row cover. Needless to say, winged strawberry aphids are a much higher risk for virus spread.
Once again, regarding aphid management options, please visit Perennia’s Strawberry Insect and Disease Management Schedule here!

OR you may wish to review Pam Fisher’s (Berry Specialist, OMAFRA) article on aphid management here.