May 13, 2003

There is quite a bit of excitement and discussion about the arrival of Entrust, the organically-approved version of spinosad (Success). There are a couple of considerations that I want to point out. First, we don’t have a lot of information about how well Entrust will work in the field, although we do expect it to control codling moth to some degree. During the development of Success, we did quite a bit of codling moth work in high pressure situations, and found that there was an effect. However, that effect was not close to the ‘standards’, Guthion and Imidan. So we haven’t looked at Success under more ‘normal’ pressure, as it wasn’t as good as alternatives at the time.

Which brings me to the second, more important point. Unless you are an organic grower, there is simply no need to use Entrust for this first flight, and I would not recommend it. There are many soft alternatives (the IGRs in particular) that we have experience with, and confidence in how they work. Therefore, unless you are working within the constraints of organic production, Entrust use is not warranted, just as Success has not been used for codling moth control (its leafroller activity is fantastic, though). Instead, I would recommend that you wait until we have further results on the efficacy of this product in research contexts.

-jd

May 12, 2003

We caught codling moths in Peshastin Creek over the weekend--please refer to the News & Notes page within the PCG section for trap catch data for Monday morning.

-tm

May 9, 2003

This cool weather has slowed everything down. Pear psylla is still developing very slowly. So is codling moth. So is grape mealybug. So is my suntan. But I am not looking forward to a quick change to hot weather. Then things get burned.

Codling moth is just sitting there waiting for favorable weather. We have been threatening to begin sampling for resistance in the Yakima area for two weeks now, but the weather refuses to comply (ahhhh Comply® ahhhhhhhh). We have plenty of sites to sample throughout the state at this point, but if you feel you have a orchard that most certainly has resistant codling moth, send an email.

Because of the cool temperatures, the IGR program timings for both codling moth and pear psylla that I mentioned last week (below) are really shaping up well. Codling moth is at about 110 +- degree days in Wenatchee and Yakima, while pear psylla are generally still younger than third instars. A Dimilin or Esteem application will help control both of them (but only consider them for codling moth if you are also using mating disruption, or have extremely low pressure).

-jd

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May 2, 2003

Apple Blossom Weekend (why not a Pear Petal-fall Festival?)

It’s time to treat for codling moth in most areas, if the tactic of choice is an insect growth regulator (IGR). IGRs that are effective for codling moth control include Intrepid, Esteem, and Dimilin (Dimilin only on pear; it is not registered on apple). Esteem and Dimilin should be applied as egg-laying occurs, whereas Intrepid should be applied later, around the typical Guthion timing. Esteem and Dimilin affect the eggs, preventing proper development of the embryo. Intrepid is directed at the first instar (the neonate), the same as Guthion, Imidan, and the like; Intrepid must be eaten before it disrupts the development of the larva.

Using either Esteem or Dimilin will provide some additional benefits for pear psylla control. With the relatively late development of pear psylla populations, the control of pear psylla may be helped considerable even when applying them for codling moth. Intrepid, on the other hand, only affects the moths. Nevertheless, all three of these IGRs are considered very soft or selective, in that they affect the pest insects and do not have detrimental effects on beneficial natural enemies.

-jd

May 1, 2003

Things still look fine and dandy in the Upper Wenatchee Valley. Pear psylla pressure is remarkably low, with most orchards having only a few eggs here and there, and fewer nymphs. Nymphs of both pear psylla and grape mealybug are generally first and second instars, so petal fall applications should be very effective, targeting the most susceptible stages. In the Cashmere to Monitor area, as well as north along the Columbia, pressure is a bit higher, and the need for petal-fall applications is more apparent. Nymphs are generally no older than second instar, however a few third instars do show up.

So, there are more options for the petal-fall applications, particularly in the upper valley (where petal-fall timing will begin next week some time). Where nymphs are hard to find and are only firsts or seconds, growers should be able to go with softer programs. These would include materials such as Esteem, Dimilin, or azadirachtin (Aza-Direct or Neemix), all with oil of course. The caveat for the soft pear psylla control, however, is that there won’t be secondary effects on pear rust mite, spider mites, or grape mealybug.

Where nymphs (PP or GMB) are easily apparent, and third instars can be found, a conventional approach is likely the best course. If GMB is present, then a chloronicotinyl is probably the best option, particularly Actara (saving the Assail for a timing when codling moth can be affected). If there is no GMB, and treatment is necessary for pear psylla (there aren’t nearly as many orchards in this category as a few years ago), then the old standby Agri-Mek is the best choice. The Agri-Mek will also give control of pear rust mites and push back the development of spider mites to mid-summer.

I have yet to see any surprises or any real problem orchards (isn’t Surround a wonderful tactic?). So far, this appears to be a good year to continue to use soft pest management.

-jd

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April 29, 2003

Follow the bugs, not the plant

As bloom progresses up the valley, the pear psylla situation reminds us once again that timing the control tactic to the pest is key. The trees are once again ahead of the insects, and pear psylla is slow relative to tree phenology. So instead of having second and third instars out during clusterbud, it appears that petal fall is when things are happening. So applications at petal fall are important for pear psylla control (nothing new, just figured it was worth mentioning - pressure is low thanks to prebloom control anyway).

Codling moth activity has definitely slowed down over the past week, with the cooler (and wetter) weather. While this may give growers and fieldmen a short breather before the first codling moth cover sprays, it also makes for better conditions for pear rust mite. Don't overlook the rust mites, particularly as other products are used at petal-fall instead of Agri-Mek. (see the note from last week below).

I am hearing more people noticing the relatively slow activity of the chloronicotinyls (Actara, Assail, and Provado) on the pests, particularly grape mealybug. These materials tend to take a while before the nymphs start dying, so give it time. Five days should be the minimum time before reevaluation, and mortality will continue to show up readily for about ten days. Be patient, let the material work. One possible reason for this relatively slow death (can you hear them screaming, Bob?) is the anti-feeding action - the insects may ingest a sublethal dose of the chloronicotinyls, stop feeding, resume feeding, get a little more intoxicated, etc., until lethality. Anyway, the death is slow in the lab as well, so it's nothing to worry about, just something to be aware of.

-jd
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April 22, 2003

In case you haven't heard yet, the first codling moth catches in the WSU-TFREC research orchards occurred over the weekend (catches on both 4-19 and 4-20). Fortunately, Mike Doerr has a low threshold for ignoring the weather, and hung traps Saturday evening (the sunburn he got at his kids' Little League games Saturday afternoon served as a painful reminder that the weather was warmer than normal). So, moths are beginning to fly in the warm areas of northcentral Washington, and the official setting of biofix should be soon. With the weather forecast calling for further moderately nice weather, highs in the low 60s for most of the next week, mating disruption should already have applied.

Pear rust mite will be a problem again this year if not managed well. In orchards where rust mites were high last year, populations appear to have the potential to cause damage again. If facing a potentially damaging population (five rust mites per fruit) even after a prebloom control program (sulfurs, Thiodan, Pyramite, etc.), there are still several option to use at petal fall to prevent russeting. Agri-Mek should provide control, and is generally the industry standard for this timing (the additional pear psylla and spider mite control from an application at this time make it cost-effective). Alternatives include Carzol (very effective but disruptive to natural enemies, and use restrictions can be an issue) and Pyramite (effective against PRM, but a higher rate must be used to get pear psylla control, is also very effective against European red mite, although for two-spotted spider mite it's more effective later in the season).

-jd

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April 21, 2003

I apologize for being a bit slow on the news and notes section so far. Hopefully that will change. Check out the Peshastin Creek Areawide Organic Project Maps and Sampling page for sampling data that is updated as it comes in. If we get feedback that this sort of thing is useful, we may post 'live' data from the Areawide II Project All-IGR-All-the-Time Program and other trials.

This season looks to be going well for pear psylla management thus far. The prebloom Surround treatments once again did the job, and adult counts are generally very low. Spur samples for nymphs also are showing very low counts in most orchards (again, you can check out the PCG pages for examples of the type of pressure this year). The nymphs are coming out slowly relative to the pear trees, which are pushing fast (cherry and pear blooming a day apart - come on now!). This is the same sort of season that we have experienced the past three years.

So, with the nymphs being behind on the tree phenology curve, petal fall applications should be very effective. Combine this with the reduced overall pressure from successful prebloom programs, and this season's pear psylla management is shaping up nicely.
-jd

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April 10, 2003

We are well into the beginning of the 2003 field season. We have begun sampling on many of our field spray trials, as well as monitoring pear pests and predators in the Peshastin Creek Areawide Organic Project for members of the Peshastin Creek Growers Association and in both Yakima and Wenatchee as part of the Areawide II project. This year we have increased the number of sites we are monitoring in the PCG Areawide Organic Project, to make our work more useful by increasing precision and reflecting the orchardists' treatments. We will be posting insect monitoring data on this site and at a bulletin board we have yet to build by Dennis Nicholson's fruit stand. We hope to provide weekly updates of our counts to the co-operators in this program through this web site and on the bulletin board. The new features of the website are almost complete.

-tm

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