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
Freeze protected peach trees in Florida
Citrus
January 19, 2017
New Technology Could Take Weather Intel to the Extreme for Farmers
Scientists aiming to make difficult climate-based production decisions easier for growers. Read More
the sunset on a hot day
Citrus
January 18, 2017
NASA, NOAA Concur 2016 Was World’s Warmest Year on Record
For the third time in three years, the bar is raised on surface temperature statistics. Read More
'Gold nugget' seedless tangerine
Varieties & Rootstocks
January 18, 2017
5 Florida Citrus Nursery Trends Worth Watching
Gleanings from recent grower gatherings expose opportunities and possibilities in new variety development and management. Read More
Mobile technology farming
Citrus
January 17, 2017
The Future of Agriculture is in Your Hands — Literally [Opinion]
Can farmers actually reach the point of having too much information? Read More
Citrus
January 16, 2017
First Bee in Continental U.S. Listed as Endangered Species
Rusty patched bumble bee receives protection from activities that could cause it to go extinct. Read More
Example of how farmers can use iPads to track data around his operation
Citrus
January 16, 2017
Precision Agriculture and Big Data Gaining Traction Fast
Specialty crop adoption of hort tech to usher in new efficiencies and transparency. Read More
Urban vegetable farm in rural Cuba
Citrus
January 15, 2017
New Transitional Certification Program to Foster Organic Growth Receives USDA Approval
The program will be based on standards developed by the Organic Trade Association. Read More
The Latest
Citrus
January 20, 2017
Farming Will Always Have a Place in Flor…
Growers are resilient and agriculture will survive in our state and elsewhere. It has to, if we want food on our plates. Read More
Citrus
January 19, 2017
Trump Taps Sonny Perdue for Secretary of…
Ag leaders applaud pick to head up USDA. Read More
Citrus
January 19, 2017
New York Representatives Introduce Bill …
Legislators say the move aligns the program in the department to better fit the needs of agriculture businesses. Read More
Citrus
January 19, 2017
New Technology Could Take Weather Intel …
Scientists aiming to make difficult climate-based production decisions easier for growers. Read More
Citrus
January 18, 2017
NASA, NOAA Concur 2016 Was World’s Warme…
For the third time in three years, the bar is raised on surface temperature statistics. Read More
Citrus
January 17, 2017
The Future of Agriculture is in Your Han…
Can farmers actually reach the point of having too much information? Read More
Citrus
January 16, 2017
First Bee in Continental U.S. Listed as …
Rusty patched bumble bee receives protection from activities that could cause it to go extinct. Read More
Citrus
January 16, 2017
Precision Agriculture and Big Data Gaini…
Specialty crop adoption of hort tech to usher in new efficiencies and transparency. Read More
Citrus
January 15, 2017
New Transitional Certification Program t…
The program will be based on standards developed by the Organic Trade Association. Read More
Citrus
January 13, 2017
Vilsack Bids Fond Farewell in Early Exit…
With no clear-cut replacement in sight, U.S. agriculture secretary leaves one week before his term officially ends. Read More
Citrus
January 12, 2017
Season’s First Slip Seen In Latest Flori…
Despite slight drop in Valencias, silver linings found. Read More
Citrus
January 10, 2017
Was 2016 the Worst Weather Year Ever?
Near all-time records in average temperature and costly climate-related disasters make a strong case for dubious distinction. Read More
Citrus
January 9, 2017
Longtime Florida Citrus Grower Earns Cha…
Hugh English recognized for his support of UF/IFAS research. Read More
Citrus
January 3, 2017
Soil Health Institute Launches Web-Based…
The tool allows users to connect soil health problems, management actions, and desired outcomes with research addressing a user’s particular situation. Read More
Citrus
January 3, 2017
Research Shows Limited Sign of Soil Adap…
Studies indicate that soils will typically respond strongly to increasing temperature by releasing more carbon dioxide. Read More
Citrus
January 2, 2017
New Organic Farming Cost Share Options A…
Organic growers may apply for certification cost share reimbursements; expanded eligibility for transition and state certification costs. Read More
Citrus
January 1, 2017
FSMA Training Strategy Available
Aid to help growers understand role in new food safety rules released. Read More
Citrus
December 29, 2016
Are Today’s Agriculture Regulation…
Donald Trump has been clear that he is no fan of burdensome rules that stifle productivity. Read More