Aphid Monitoring Project Update - May 7th

Tuesday, May 7, 2013

This is a brief update on the “strawberry aphid monitoring project” that is underway for this growing season.

Overall the project is proceeding very well. Student biologists have been hired and are located at Perennia’s Bible Hill and Kentville offices respectively.  Also, an aphid identification training session was held on Monday April 30th at the Kentville Research Station, led by Dr. Deb Moreau of AAFC and with excellent support from Erika Bent and Rachael Cheverie.

Monitoring plots have been established at most targeted sites around the province with the remaining ones being set-up over the next two days. Samples have also been collected from most sites and some counts have already been conducted.

Interestingly, we have already learned quite a bit of new information. Firstly, we did not know if there would be any overwintering nymph or adult aphids and surprising to me we have not found any. In contrast we have found an abundance of overwintering aphid eggs, with much variability in numbers from field to field and farm to farm. So, for this year at least aphids appear to be overwintering primarily as eggs. In my opinion this is a good thing because with the late spring, hatch has been delayed and thus population build-up is going to be delayed. This gives us time to plan our aphid management strategies and in turn our virus management should be optimized this season.

What about the aphid egg hatch? Well, our first confirmation of newly hatched nymphs came from an ‘Annapolis’ block in Central NS that was covered in row cover and this was on Friday, May 3rd. Our first confirmation of nymphs in uncovered matted row system was in an early ‘Wendy’ block on a sandy soil in the Annapolis Valley and this was on Monday, May 6th. Several other aphids were observed while setting up plots today in the Annapolis Valley so the spring hatch is underway here in the Valley. We are uncertain how long the hatch period may be but I would expect it to occur fairly rapidly on a given site because it is largely based on heat accumulation and this should be fairly uniform in a given field.

Finally, what about aphid species?  Unfortunately, the bulk of the aphids found thus far, from the Annapolis Valley and Central NS, have been ‘strawberry aphid’, the vector that transmits the viruses that were identified in the province last year. Other species have been found as well but the majority of aphids counted thus far have been the strawberry aphid and this is a concern as surveys from the 1960’s reported very few strawberry aphids at that time. Things have definitely changed and we need to monitor and manage this new pest if we are to prevent the spread and increase of the problem viruses.

Individual farm monitoring results will be communicated by phone or email. No news is good news but if you can’t wait please feel free to contact me at my cell number 902-670-4892.

Regarding aphid management options, please visit Perennia’s Strawberry Insect and Disease Management Schedule here!

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

Stayed tuned for my next monitoring report on Monday, May 13th.