Posts Tagged: lygus
Emily Bick's AAUW Grant: Targeting the Lygus Bug
Watch out, lygus bugs! Agricultural entomologist Emily Bick is targeting you. Lygus hesperus, a...
Agricultural entomologist Emily Bick doing field work in Denmark before the lockdown due to the coronavirus pandemic precautions..
Emily Bick (right) in an engagement photo with her fiance, Nora Forbes. Bick is an agricultural entomologist and a postdoctoral fellow in the lab of Lene Sigsgaard at the University of Copenhagan and Forbes is a statistician at the Danish Medtronic office.
You are welcome.
We finally have a label for the insecticide Sequoia. It will be a good one to have in our roster of insecticides in strawberry, not only because it is pretty darn effective in controlling lygus, but also because it can be rotated in with the remaining usable materials we have and keep them effective that much longer.
It does come with the caveat of only being 12 months long, but there always is the possibility of renewal plus the regular Section 3 label is being worked on at the Federal level. Use directions for the Section 18 for Sequoia attached below as a pdf file.
The only way to get these labels in California is to have the efficacy from the field to prove that the insecticide actually does what it is supposed to do. This was a job led out of this office of UCCE, and it was a major commitment that stretched over something like 5 years. My colleagues and I get up well before daybreak to beat the wind and do the sprays, are out there week after week to collect the samples, and spend many hours at the microscope counting the lygus, beneficials and other bugs. This was a ton of work over many years and effort put in by some very committed people, in particular Shimat Joseph and Monise Sheehan of UC Cooperative Extension and Hillary Thomas at the time with the CSC, but at the end of the day the effort very much worth it because we got you your Sequioa label for lygus in strawberries.
I am very grateful to Dow Chemical, now Corteva Agrisciences, Jean-Mari Peltier who sheparded the application through the CDPR and all the growers who collaborated with us for the tremendous support they gave us over the years to get this label to you.
Growers, this is a Section 18, so as always you have to get it on your restricted use permit.
Questions about efficacy? Lots of studies on this site, type in lygus or sulfoxaflor in the search box and you'll see plenty of information on it.
You are welcome.
Sequoia Strawberry Sec 18 Final Label 10.30.18
Paper: Evaluating the Utility of an Electrostatic Sprayer and a Tractor Mounted Vacuum for Lygus Management in Strawberry
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
I-HM-LDES-NM
2016 Insecticide Efficacy Trial for Lygus Bug Control in Central Coast Strawberry
Lygus bug (Lygus hesperus) (Fig. 1) is a major pest of strawberry in the Central Coast. Lygus bug populations develop on weed hosts surrounding the strawberry fields such as wild radish, common groundsel, lupines, and mustards (Zalom et al. 2012). Time to time, adults migrate into the strawberry fields and lay eggs. Eggs hatch, and molt through five nymphal stages before molting into adults. Lygus bug feeding on the developing embryos affects the normal development of tissues surrounding the embryo (Handley and Pollard 1993) and affected fruits are misshapen often referred as “catfaced fruit” (Fig. 2) which are deemed unmarketable. Although both nymphs and adults can cause catface injury, nymphs are considered more destructive than adults. The young fruits up to ~10 days after petal fall are considered vulnerable to economic injury from lygus bug feeding (Zalom et al. 2012).
Chemical control continues to be an effective tool for lygus bug control and growers are always seeking effective and softer insecticides for its control. A replicated trial comparing the efficacy of insecticide treatments against lygus bug was conducted in first-year strawberry ‘San Andreas' in Watsonville, CA in 2016. The details on insecticide products and rates used in the trial are shown in Table 1. The insecticides were applied twice at 10 day interval using commercial tractor mounted sprayer. The water volume used for both the applications was 150 gal per acre and was applied at 140 psi. Dyne-Amic (surfactant) was added at 0.25% v/v to all the treatments. Insect samples were collected using regular sized Rubbermaid container by hitting 20 flowering strawberry plants with lid. In addition, 60 fruits were sampled from each plot to determine catface injury.
Pre-count sample did not show any difference in number of adult and nymphal lygus bugs among treatments (Figs. 3 and 4). Overall, all the insecticide treatments reduced the number of lygus bug adults and nymphs compared with untreated plants. The combination treatments using pyrethroid insecticides such as Danitol and Brigade suppressed lygus bugs and general predators such as bigeyed bug, minute pirate bug, and damsel bug as well as spiders (Figs. 5-8). Data show that reduced-risk insecticides, Rimon and Beleaf suppressed lygus bug nymphs as well. Sequoia, not yet registered on strawberry, provided a decent lygus bug control. Sivanto initially provided a good suppression of adults and nymphs but could not adequately sustain the control for more than a week. Two rates of Avaunt (unregistered insecticide on strawberry) was included in this experiment and were comparable to other effective insecticides in this experiment.
Insecticide use certainly reduced catface injury on strawberry fruit. Number of fruits with catface injury was lower in all the insecticide treated plants than untreated except the lower rate of Avaunt (Fig. 9). Catface injury on fruits treated with Sequoia was lower than untreated but not different from other insecticides (except lower rate of Avaunt).
References
Handley, D. T., and J. E. Pollard. 1993. Microscopic examination of tarnished plant bug (Heteroptera: Miridae) feeding damage to strawberry. J. Econ. Entomol. 86: 505-510.
Zalom, F. G., M. P. Bolda, S. K. Dara, and S. Joseph. 2012. Strawberry: Lygus bug. UC Pest Management Guidelines, UC ANR Publication 3468.http://www.ipm.ucdavis.edu/PMG/r734300111.html
Figure 1: Lygus bug adult.
Figure 2: Catfacing of strawberry fruit.
Table 1
Figure 3. Mean number of lygus bug adults collected by week from treated plants.
Figure 4. Mean number of lygus bug nymphs collected by week from treated plants.
Figure 5. Overall mean number of lygus bug adults collected from treated plants.
Figure 6. Overall mean number of lygus bug nymphs collected from the plants.
Figure 7. Overall mean number of predatory bugs collected from treated plants.
Figure 8. Overall mean of spiders collected from treated plants.
Figure 9. Percentage fruit with catface (lygus bug feeding) injury.
A Big Cheer for a Crab Spider
What happened in our pollinator garden on June 3 probably would have promoted a standing ovation...
A crab spider nails an agricultural pest, a lygus bug. (Photo by Kathy Keatley Garvey)