Stay A Step Ahead Of Psyllids

Lukasz Stelinski, UF/IFAS

Any scientist will tell you that nature doesn’t stand still. That’s certainly the case with the Asian citrus psyllid (ACP), according to Lukasz Stelinski, an entomologist with UF/IFAS. He and his colleagues’ research has shown the pest’s sensitivity to important pesticides is changing from year to year.
“I want to emphasize what we’ve found in research is not cause for alarm at this point,” he says. “But, it is an eye opener that changes are taking place in ACP populations, so we must be vigilant with rotations and good management practices for the pest.
“The point of our research is to keep a pulse of ACP populations, so if and when we have a problem, we can recognize it quickly and take the appropriate measures.”

Tolerance Evolving

Stelinski began monitoring ACP field populations for resistance to insecticides beginning in 2008. These pests were compared to a laboratory grown ACP population that is highly susceptible to all insecticides. The field populations are exposed to dosages of chemicals and compared to the vulnerable population over time.
In the test, mortality levels are monitored as well as enzymes the ACP produce to detoxify, and if mutations are being developed at the specific sites different insecticides target to cause mortality. Stelinski says the enzymes are important because as they build up, the ACP can become more tolerant to important tools in the fight against the pest.
“The 2009 trials provided the first baseline of what was happening in the field,” he says. “So, as early as 2009, we were finding changing sensitivities of ACP populations to important insecticide classes like organophosphates and carbamates.”

By 2010, trials were showing some level of reduction of sensitivities of ACP populations to major classes of insecticides across the state. However, the dosage rates being tested were very low and the field populations are being tested against highly susceptible lab ACP.
The data from 2011 provide more news — some bad and some good. Tests showed a marked reduction in sensitivity to a pyrethroid and organophosphate. While these reductions were demonstrated at below label rates, there is no evidence of product failure at the field level. Stelinski says this data shows that we don’t want the trendline to continue.
The 2011 trial data did provide some good news in that neonicotinoids showed no further decrease in sensitivity from the previous year. “These products are so very important to help us protect younger trees through systemic activity and helping to prevent ACP from transmitting HLB,” says Stelinski. “These things bounce around, so we must remain vigilant, but it was good not to see further reduction in sensitivity to critical neonicotinoid products.”

Top Tips

To extend the viability of key insecticides used in the fight against ACP, Stelinski offers five suggestions for growers to consider:
1. Any rotation is better than no rotation. Keep track of a product’s mode of action (MOA) and don’t follow the same MOA in sequential order of applications.
2. Cooperation works. The coordinated sprays under citrus health management areas (CHMAs) will help to slow the development of resistance and have been effective in controlling ACP populations over broad areas. “The more minds we have working together to guard against resistance the better,” says Stelinski.
3. Be aware of multiple MOAs. Stelinski cautions that the newer products coming onto the market can be a little more complicated because they often have more than one MOA. This makes them very effective for control of pests, but this should be noted to avoid following an application with the same MOA that is contained in the new products hitting the market.
4. Do not cut rates, especially with low-volume applications. “We are finding the ACP are building up tolerance because of these higher enzymes used to detoxify,” says Stelinski. “If you are applying the correct rate, very few of the ACP with the higher enzymes are surviving. By cutting the rate, more of these pests survive and go on to breed more tolerant ACP.
5. Young tree protection. Where growers are using multiple neonicotinoid applications to protect young trees, be sure to break up those applications with another MOA to avoid potential resistance problems with this essential class of chemistry.

Leave a Reply

Citrus Stories

Grapefruit & SpecialtyFlorida Grapefruit Growers Feeling Good About Early Crop Forecasts
November 14, 2014
Producers, packers, and suppliers view initial USDA outlooks as positive predictor for future. Read More
Insect & Disease UpdateScientists Track Scent To Successful Citrus Psyllid Control
November 14, 2014
New research identifies odors that could help in the fight against HLB. Read More
CitrusFlorida Citrus Forecast Stands Firm Through Season’s First Month
November 10, 2014
Latest USDA outlook unchanged for oranges and grapefruit. Read More
Varieties & RootstocksCitrus Research And Development Foundation Seeks Grower Cooperators
November 10, 2014
Five HLB-tolerant rootstocks to be evaluated in three main growing regions of Florida. Read More
Citrus Achievement AwardGroundwork Set For Fruitful Future In Florida Citrus
November 1, 2014
Progress in research, significant government funding, and new plantings have 2014 Citrus Achievement Award winner Mike Sparks feeling positive. Read More
CitrusForecast: South Florida Dry Season May See Fair Share Of Damp Days
October 31, 2014
Outlook calls for possible above-normal precipitation around region for fall and winter months. Read More
CitrusUSDA To Provide $4 Million For Honey Bee Habitat
October 29, 2014
The funds will go toward helping growers implement conservation practices to improve honey bee health. Read More

The Latest

CitrusRamped-Up Predatory Mite Production To Benefit Growers
November 21, 2014
Biologics company Beneficial Insectary now rearing two species in its California facility. Read More
CitrusWomen’s Impact On Agriculture Impressive [Opinion…
November 18, 2014
Florida Agriculture Commissioner Adam Putnam says the long-term sustainability of farming depends on our youth. Read More
CitrusPrograms Burgeon To Promote Citrus Plantings
November 17, 2014
Processors and USDA step up to support growers who are putting new trees in the ground. Read More
CitrusFlorida Citrus Forecast Stands Firm Through Season’s …
November 10, 2014
Latest USDA outlook unchanged for oranges and grapefruit. Read More
CitrusForecast: South Florida Dry Season May See Fair Share O…
October 31, 2014
Outlook calls for possible above-normal precipitation around region for fall and winter months. Read More
CitrusUSDA To Provide $4 Million For Honey Bee Habitat
October 29, 2014
The funds will go toward helping growers implement conservation practices to improve honey bee health. Read More
CitrusModern Agriculture Is A True Centerpiece Of Thanksgivin…
October 27, 2014
FFAA's Mary Hartney says take time during this holiday season to give thanks where thanks is due. Read More
CitrusNOAA’s Winter Weather Outlook Runs Hot And Cold
October 27, 2014
Repeat of last year’s extreme cold and snow events east of the Rockies unlikely. Read More
CitrusFlorida Citrus Growers Get Box Tax Relief
October 23, 2014
Citrus Commission votes to put dollars back in producers’ hands to spur reinvestment. Read More
CitrusEPA Launches Program To Reduce Pesticide Drift
October 22, 2014
The voluntary star-rating program aims to protect people, wildlife and the environment. Read More
CitrusMcCrometer Introduces New Ag Management Mobile App
October 22, 2014
The app displays data on weather, ET, soil moisture, water flow, and more. Read More
CitrusAgriculture, Interior Departments Partner To Measure Co…
October 22, 2014
Goal is to provide science-based information for watershed wellness. Read More
CitrusIt’s Time For Young Farming Leaders To Engage [Op…
October 21, 2014
Florida Grower editor Frank Giles says there are capable and talented youths in the ag field ready to step up and take the reins. Read More
CitrusBayer CropScience Launches New Award To Recognize Produ…
October 21, 2014
Award recognizes innovation that enhances the role of produce in creating better lives. Read More
CitrusReport: Major Food And Agriculture Employers Can’t Fi…
October 21, 2014
Current shortage of young farming professionals means ample employment opportunity for the next generation. Read More
CitrusGrowers Need To Take The Ball And Run — Now! [Opi…
October 18, 2014
Help yourself, your farm, and fellow colleagues by becoming more involved in your industry. Read More
CitrusLegendary Florida Citrus Grower And Advocate Passes
October 17, 2014
Joe L. Davis Sr. will be remembered for his straight talk and sage advice. Read More
CitrusDiversification Is King For Small Farm’s Success
October 16, 2014
Being flexible and adapting to the times critical for Central Florida's Vo-LaSalle Farms. Read More