Hello Peter,
We have had only a few years to have gained experience with SWD, but what we
have learned has not often lined up well with the pre-2008 literature. We have
learned that this is a pest that we need to take seriously, especially so far,
the berry and cherry industries.
SWD gets through our eastern Oregon and Washington winters very well,
especially if they are milder than usual. Below zero F seems to slow the
problems in the next spring. We were hoping that they would die out every
winter and would have to fly over from Western Washington and Oregon every
spring, that didn't turn out to be the case. Temperatures in the winter of
2012 -- 2013 didn't get much below 12 to 14 F.
Despite catching relatively few adults in the orchards this year, we continued
to have significant fruit infections in some cherry orchards. There doesn't
seem to be a good correlation between trap catch and percent fruit infection.
Timothy Smith
Regional Extension Specialist
Washington State University
Wenatchee
From: apple-crop-boun...@virtualorchard.net
[mailto:apple-crop-boun...@virtualorchard.net] On Behalf Of Peter J. Jentsch
Sent: Sunday, July 14, 2013 6:04 PM
To: Apple-crop discussion list
Cc: jon.cleme...@umass.edu
Subject: Re: [apple-crop] Stone fruit SWD injury
Dean,
A Penn State Extension Article on SWD Natural History summaries and references
studies on basic biology of the insect found at
http://pubs.cas.psu.edu/freepubs/pdfs/xj0046.pdf. Here's a quote from the
article that discusses aspects of temperature on insect biology.
SWD prefers environments with moderate temperatures and high humidity. Adults
are most active at temperatures around
70°F, and their activity is greatly decreased when temperatures are only 15
degrees colder or warmer. Adults need shelter when temperatures drop below
about 50°F and begin hibernation at 40°F. Female adults exposed to cold
temperatures lay very few eggs, and the eggs and larvae are killed by several
days of exposure to temperatures just above freezing. Thus, seasonal
populations are likely to start out extremely low in each spring, increase as
temperatures warm, decline during hot spells, and then increase very rapidly
during early fall when temperatures become more ideal. Regardless of whether
SWD can overwinter in a region, it can be readily reintroduced in fruit that is
shipped from warmer regions.
Peter J. Jentsch
Senior Extension Associate - Entomology
Department of Entomology
Cornell University's Hudson Valley Lab
P.O. Box 727, 3357 Rt. 9W
Highland, NY 12528
Office: 845-691-7151
Cell: 845-417-7465
FAX: 845-691-2719
E-mail: p...@cornell.edumailto:p...@cornell.edu
http://hudsonvf.cce.cornell.edu/bmsb1.html
http://web.entomology.cornell.edu/jentsch/links.html
From:
apple-crop-boun...@virtualorchard.netmailto:apple-crop-boun...@virtualorchard.net
[apple-crop-boun...@virtualorchard.net] on behalf of Dean Henry
[d...@berrypatchfarm.com]
Sent: Sunday, July 14, 2013 8:40 PM
To: Apple-crop discussion list
Cc: jon.cleme...@umass.edumailto:jon.cleme...@umass.edu; Apple-crop
discussion list
Subject: Re: [apple-crop] Stone fruit SWD injury
Are there any clues from temperature effects on egg laying? I read that the swd
has preference, thus the need for trap location in shade. Do they oviposit
daytime or night?
Regards, Dean, Sent from my iPad
On Jul 14, 2013, at 6:59 PM, Peter J. Jentsch
p...@cornell.edumailto:p...@cornell.edu wrote:
We sampled a range of peach varieties maturing at different dates throughout
the season last year. Although we did see one sample with a single adult SWD
emerge from incubated sound fruit held for two weeks, we didn't see what we
would consider to be economic injury, again the caveat being, 'of sound fruit'.
However, damaged fruit from suture splits, bird pecks, insect damage from
earwigs or Japanese beetle to create openings in the skin are a different
matter. In these cases SWD will infest fruit as do other Drosophlia sp. A few
of our growers thought the fly was causing increased brown rot in peaches but
we didn't find SWD emergence evidence to support the claim. Certainly that
could be the case in late cherry with reduced fungicide use. We did see late
cherry varieties in the lower HV with significant egg laying injury this year
in a site where SWD was captured in low numbers. One monitored site in Dutchess
County in early July suffered 100% ovipositional injury. A second site in
Orange County experienced 70% ovipositional injury during the first week of
July. However, we have yet to rear out adults from these samples.
This year in the Hudson Valley, as in most monitored sites throughout the
region, we did capture flies earlier then in 2012, possibly because of the
addition of yeast/sugar combination floating in apple cider vinegar (ACV) or
simply because we were looking more intensely. We'll need to again collect
stone fruit and grape
