2022 Codling Moth Biology & Behavior
Several months I posted about the importance of recognizing the effects of weather on codling moth behavior, and how that can result in flight curves that deviate from the phenology model. The bizarre weather we’ve been experiencing in the PNW this spring has given us a unique (I hope) opportunity to track and observe this.
We’ve been closely monitoring codling moth trap catch and comparing biofix based on trap catch with WSU’s fixed biofix model.
Through last Sunday, May 15, we’ve set biofix from trap catch at 90 individual sites representing 47 distinct geographical areas from just across the Oregon border up to the Canadian border. These data have revealed some interesting trends.
In EVERY SINGLE CASE, we had codling moth flight / trap catch on the very first evening with favorable flight conditions following 175 CMDD from January 1 (the fixed biofix from the WSU model).
At some locations this happened the same evening that we reached 175 CMDD. For those places, we should see flight curves synchronous with model predictions. At other sites, though, we didn’t have favorable flight weather at dusk for several days – in some cases up to 28 days later. Those are the sites that will show either a delayed or an abnormal, front-loaded flight curve.
Below is a snapshot of 25 sites comparing biofix based on trap catch to the fixed biofix of 175 CMDD. A couple of interesting data points that really drive home the effects of weather on codling moth behavior –
Wallula and Plymouth both had trap catch / biofix occur at 206 CMDD. In both cases, analyzing weather data at dusk confirmed that this occurred on the first evening with favorable flight conditions after 175 CMDD. This was after a prolonged period of very cold weather where daily CMDD accumulation was at or near zero for a couple of weeks.
Where this gets interesting is that at Wallula, they had reached 175 CMDD just before it got cold, had almost no development for 2 weeks, and then had catch once the weather improved. This resulted in a 15 calendar day spread between 175 CMDD and flight.
At Plymouth, though, they didn’t reach 175 CMDD until after the weather started to warm up. So while they also had trap catch at 206 CMDD, there was only a 7 day spread between 175 CMDD and flight here.
领英推荐
Another interesting site is an orchard south of Desert Aire. At that location, 175 CMDD was reached on April 5 – again just before the really cold weather set in. There was no flight / trap catch recorded there until 28 calendar days later. This seems a bit improbable, but a check of the dusk weather conditions confirmed that every single evening from April 5 until May 3 was either too cold, too windy, raining, or some combination of those 3 limiting factors.
I think there are 3 important take-home messages from these data:
1.???The WSU fixed biofix of 175 CMDD from January 1 is accurate. No doubt whatsoever that the WSU model is accurately representing codling moth biology. So far this spring it has been spot on at 90 individual sites.
?2.???The effects of weather on codling moth behavior will certainly result in flight curves that deviate from the model. Again, there is a difference between codling moth biology and codling moth behavior – and BOTH must be considered when developing a management strategy.
3.???Developing management strategies at locations where there is a 20- or 28-day spread between 175 CMDD and flight requires the skillset of an experienced team of consultants that has the insight and the context to interpret that specific data for that specific site.
Just because you don’t catch moths until 112 CMDD after 175 doesn’t necessarily mean that you should base subsequent management strategies on that delayed behavior. It certainly can in some situations, but not all. Following the wrong strategy can get you in trouble in a hurry.
?One valuable addition to WSU’s Decision Aid System this year is a chart that shows the combined and individual effects of temperature, wind, and rain on reducing codling moth flight. This is similar to the honeybee foraging model in that it generates a number that represents the percent of optimum flight. For DAS subscribers, this is a great visual of weather effects on codling moth behavior and well worth the nominal subscription price.
Marketing and Sales Executive in Agriculture
2 年Although I can’t always follow his science without him dumbing it down for me, Byron is my scientist hero. Better than the best!
Key Account Manager at Wilbur-Ellis
2 年It’s posts like this that show why it is a privilege to work with you. Any practitioner of applied horticulture or pest management will be better at their craft if they are able to spend time with you.?Your dedication to the art and science of growing tree fruit is unmatched worldwide. It’s just refreshing to read a post from someone that is 100% committed to what they can give to an industry and not what they can take. In a time of massive disinformation campaigns and transparent efforts to promote oneself as a thought leader, I long for the days when our industry was governed by scientific discipline. ?Your posts are never about boastful self-promotions, the number of acres that you bought your way onto, or funds generated through misrepresentation of the great work scientists, pest control advisors, agronomists, and growers have done for generations. Your efforts to gather information and disseminate it to the tree fruit community is a treasure. You have never feigned “partnerships” in an industry and then tried to regulate what your partners can or cannot say to protect a marketing campaign or your personal brand. I am honored to call you a friend and our industry is lucky to have you. I look forward to your next post!
Assistant Research Professor, Oregon IPM Center, Oregon State University
2 年Hi Byron, thanks for sharing your research. Do you have a link to the DAS chart that shows the effects of temp/wind/rain on CM flight? I'd really appreciate it for my own work. Thanks!
Horticulture Specialist at Wilbur-Ellis
2 年Thanks Byron!
Horticulture Tech and Data Products
2 年Nice analysis, Byron. Thanks for sharing the data. Really important to highlight the effect of local weather conditions on trap catches. Growers shouldn’t give up on the no-biofix model based on the timing of trap catches this year! But from a stats perspective, I’d suggest that your conclusions might stretch a bit. When there are long periods of flight-inhibiting weatger confitions, it is not possible to know when adults might have emerged and taken flight if NOT for the inhibition. To evaluate the accuracy of the no-biofix model across diverse orchards and microclimates, you would need to compile this kind of data in a year when flight conditions are relatively good. I know of at least one counter example from the Columbia gorge with an orchard-specific weather station where the first trap catches came a week prior to 175 CMDD.