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
CitrusFarm Bureau Supports Bill To Halt Controversial WOTUS Rule
April 21, 2015
 Legislation would force EPA and the U.S. Army of Engineers to withdraw Waters of the United States proposal. Read More
CitrusRecord Number Of Organic Producers In U.S.
April 21, 2015
USDA’s Agricultural Marketing Services says domestic production has increased by 250% across all markets since 2002. Read More
Captain Citrus running through an orange grove
CitrusFlorida Citrus Gaining Leverage For Next Growth Spurt
April 21, 2015
Amid the battles, moments of real and sustainable hope have emerged this season. Read More
citrus black spot symptoms
Insect & Disease UpdateCitrus Black Spot Rears Its Ugly Head Again In Southwest Florida
April 20, 2015
Recent confirmed findings of the fungal malady forces USDA-APHIS to expand regulated area. Read More
Natalie Parkell and Kevin Osburn of Vertical Horizon Farms
CitrusSmall Family Farms Can Survive [Opinion]
April 17, 2015
It is reassuring amid the corporate climate the agriculture industry has experienced in more recent times that there is still room for the little guy, and — more importantly — a need. Read More
Golden Rice
CitrusMore Social Commentators Changing Their Views On GMO Crops
April 15, 2015
Could public opinion be swayed by evolving narration on genetic modification? Read More
CitrusFlorida Agriculture Rings Up Record $4.2 Billion In International Sales
April 13, 2015
Accomplishment represents third year in a row that Sunshine State exports have topped the $4 billion mark. Read More
The Latest
Havana, Cuba view
CitrusRenewed Relations With Cuba A Concern For Florida Growe…
April 23, 2015
It might be said Sunshine State producers are worried if wider trade is opened as the potential for competing winter crops is real. Read More
CitrusFarm Bureau Supports Bill To Halt Controversial WOTUS R…
April 21, 2015
 Legislation would force EPA and the U.S. Army of Engineers to withdraw Waters of the United States proposal. Read More
CitrusRecord Number Of Organic Producers In U.S.
April 21, 2015
USDA’s Agricultural Marketing Services says domestic production has increased by 250% across all markets since 2002. Read More
Captain Citrus running through an orange grove
CitrusFlorida Citrus Gaining Leverage For Next Growth Spurt
April 21, 2015
Amid the battles, moments of real and sustainable hope have emerged this season. Read More
Natalie Parkell and Kevin Osburn of Vertical Horizon Farms
CitrusSmall Family Farms Can Survive [Opinion]
April 17, 2015
It is reassuring amid the corporate climate the agriculture industry has experienced in more recent times that there is still room for the little guy, and — more importantly — a need. Read More
Golden Rice
CitrusMore Social Commentators Changing Their Views On GMO Cr…
April 15, 2015
Could public opinion be swayed by evolving narration on genetic modification? Read More
CitrusFlorida Agriculture Rings Up Record $4.2 Billion In Int…
April 13, 2015
Accomplishment represents third year in a row that Sunshine State exports have topped the $4 billion mark. Read More
Florida citrus packinghouse
CitrusLatest Florida Orange Crop Outlook Puts Brakes On Downw…
April 9, 2015
Updated numbers from USDA reveal count continuing to hover just above the 100 million box mark. Read More
CitrusForecasters Predict Historically Weak Atlantic Hurrican…
April 9, 2015
Extended range outlook cites El Niño as culprit in what could be one of the least active seasons in recent memory. Read More
One World Challenge Wall
CitrusToday’s Youth Set To Sustain The World [Opinion]
April 9, 2015
A select group of University of Florida students are thinking of innovative ways to meet the challenges of supporting 9+ billion people on Earth by 2050. Read More
Summer Foley, Miss Florida Citrus 2015
Citrus6 Questions With Miss Florida Citrus 2015
April 7, 2015
Pageant's much-anticipated comeback brings with it a breath of fresh air. Read More
non-gmo label leafy greens
CitrusNational Farmers Union Supports Mandatory GMO Labeling
April 3, 2015
Organization calls on Congress for unified standards to bridge several pending labeling proposals. Read More
CitrusRainfall Relief Welcomed Across South Florida
April 3, 2015
Below-average precipitation for the region during March helps lower high water levels from what has been a rather wet Dry Season. Read More
CitrusEPA Says It Is Unlikely To Approve New Neonicotinoid Ou…
April 3, 2015
The agency is waiting until new bee data has been submitted and pollinator risk assessments are complete. Read More
FFVA Emerging Leaders Class 4 visits Tallahassee
CitrusMarch On Tallahassee A Fruitful Exercise For Florida…
April 2, 2015
Road trip to the state capital beneficial for Florida Fruit & Vegetable Association's board of directors and Class 4 of its Emerging Leader Development Program. Read More
CitrusCalifornia Snowpack Is Virtually Gone
April 2, 2015
With the lowest water content since 1950, the governor orders first-ever mandatory water reductions in cities and towns, and growers face tighter regulations. Read More
CitrusMake Every Day Ag Day
March 31, 2015
Another National Ag Day came and went on March 18. Did you do anything to promote it this year? Even Read More
Laboratory beakers
CitrusGrowing Demand For Magnesium Nitrate Spurs TradeMark Ni…
March 30, 2015
Via enhancements made to its manufacturing plant, Florida company is able to provide more of its product to various fertilizer distributors and retailers throughout the country. Read More