- Author: Mark Bolda
- Author: Shimat Joseph
Former UCCE Entomology Advisor Shimat Joseph and I just had the linked paper below published in Crop Protection.
Excellent overview of the lygus problem in California strawberries and evaluation of a combination of bug-vac use and the insecticide sulfoxaflor (not registered yet, but useful for this study since it actually works) for management of this pest.
A few points out of the paper to take back to the farm:
1- The use of the bug-vac alone was not sufficient to reduce lygus populations to below that of the untreated check.
2- Treatments using the insecticide sulfoxaflor alone and in combination with the bug-vac reduced the numbers of lygus and the number of cat faced fruit.
3- Neither the bug-vac or sulfoxaflor had any effect on predaceous heteropterans and spiders compared to the untreated check.
The implication out of this work and paper is that the use of an effective insecticide will continue to be the best tactic for control of lygus and mitigation of its damage in strawberries.
Link is here, it will be active until the beginning of October:
https://authors.elsevier.com/a/1XWqVxPFYekQG
- Author: Mark Bolda
Shimat, Pete and I are holding a grower breakfast this coming April 14. Place is the UCCE auditorium at 1430 Freedom Blvd, Suite E in Watsonville. Format will be an open discussion - it's a great opportunity to speak with some of the best in the business on lygus.
And of course enjoy a fine breakfast, courtesy of UC Cooperative Extension!
- Author: Mark Bolda
One of the missing variables from the vacuum work over the past few years for management of lygus in strawberry has been the use of insecticides which inevitably accompany their use on the farm.
Wait no longer. Colleague Surendra Dara from Santa Maria with some serious grower support did a large study integrating a slew of insecticides, from microbials to botanicals to synthetic chemistries with the use of vacuums.
It's a lot to go through, but one thing which stands out is that the vacuum on its own does not appear to be the top performer. It looks like it's best to be used with some of the sprays tested here.
Link here:
http://ucanr.edu/blogs/blogcore/postdetail.cfm?postnum=19641
- Author: Mark Bolda
Colleague Shimat Joseph and I happened into CDPR head Brian Leahy at an ANR meeting in Sacramento this past week, and as expected we got to talking about what the hold up is with the sulfoxaflor (Sequioa) registration for control of lygus on strawberries. Readers of this blog know that this is a pretty good material for lygus, and it's been a bit frustrating to not have the registration be approved yet.
Brian helpfully clarified to us that the approval for sulfoxaflor (Sequioa) was vacated in a Federal ruling by the US Court of Appeals for the Ninth Circuit in San Francisco in September.
The ruling was in regards to a lawsuit filed in 2013 against the US EPA, which is responsible for the registration of pesticides in the US (California has an additional layer of regulation through the CDPR), by the beekeeping industry which challenged EPA approval of neonicotinoids, of which sulfoxaflor was ruled to be a subclass.
This last point is arguable, since while sulfoxaflor targets the same receptors in the insect as a neonicotinoid, it belongs to a different class of chemistry, the sulfoxamines.
With regards to future registration of this product, the court said that the EPA "must obtain further data regarding the effects of sulfoxaflor on bees... before it grants approval."
The EPA has yet to formulate a response to this decision.
- Author: Mark Bolda
A couple of pictures below from a farm call concerning unusual damage on the tips of growing raspberry. Some of the leaves are affected as in Photo #1, but others are pretty well aborted and not growing at all. Incidence wasn't more than 5%, but still this is disconcerting and I was over at the grower field within 15 minutes to take stock of the situation. No flowers or fruit yet on the plants.
No signs of frass or webbing that would be associated with leafrollers (some like to feed at the nitrogen rich tips), and I've checked this sort of thing in caneberries before and haven't found that viruses or nutrients are at cause either.
But we did find lygus and Photo #2 explains that we may have identified the cause. While some lygus were to be found wandering around on leaves, others were nestled in the growing point of the plant, which on the very young leaf can show up as a lot of damage later on when it fully expands. It's quite possible that this insect activity could be causing the tip to die entirely in a situation reminiscent of "black flagging" in cotton, which is the death of terminals in cotton caused by lygus feeding.