Skip to Content

Whitefly Research Management

Published on 09/13/19

UGA CAES part of extensive research study aimed at whitefly management

By Clint Thompson for CAES News

Researchers from three research institutions are using a $3.2 million grant from the U.S. Department of Agriculture to fight whiteflies on vegetable crops.

Scientists from the University of Georgia College of Agricultural and Environmental Sciences (CAES), Fort Valley State University and the U.S. Department of Agriculture Agricultural Research Service (USDA-ARS) in Charleston, S.C., will combine their expertise to collaborate on finding short- and long-term solutions to fight the pest.

UGA’s team plans to use an integrated approach to solve Georgia’s whitefly problem in vegetables.

“We have seen significant buildup in the last two to three weeks, mostly in the Tift County and Colquitt County region, but I have had reports of isolated problems outside of the area as well,” said UGA vegetable entomologist Stormy Sparks. “The scientists that are part of this grant are studying all aspects of whitefly biology and management to try to find weaknesses that can be exploited for management.”

Sparks is one of the researchers on the UGA team, which includes entomologists, plant pathologists, virologists, breeders and vegetable specialists.

The scientists will rely on one another’s specialties for the duration of the five-year grant.

“My role involves finding resistance to the whitefly-transmitted virus complex in snap bean germplasm, advancing breeding lines and conducting research to find the genetic basis of resistance,” said Bhabesh Dutta, a UGA Cooperative Extension plant pathologist on the Tifton campus and member of the research team. “We’ll then give that information to the breeder so that they can introgress resistance into elite varieties.”

Whiteflies are responsible for transmitting multiple viruses, including cucurbit leaf crumple virus and cucurbit yellow stunting disorder virus. According to UGA crop loss estimates for fall 2017, these viruses caused between 30% and 50% crop loss in squash and cucumbers and nearly 80% crop loss in snap beans that year.

“This project gives us an opportunity to think long term. It’s not going to be a quick fix. We’ll take baby steps to understand the system, understand the problem, and then try to solve it,” Dutta said.

UGA entomologist Babu Srinivasan will focus on studying virus transmission by whiteflies and management.

“We’re trying to look at how these viruses interact with their host, how they interact with their vectors, and how they’re transmitted,” said Srinivasan, who’s based on the UGA Griffin campus. “Once we understand that, it will help us get closer to management.”

The severity, distribution and timing of whiteflies vary from year to year, but they remain a persistent problem for Georgia’s vegetable growers. They are especially problematic in the Tift and Colquitt County region where vegetables are produced year-round.

“It was a devastating event for us in 2017 and we certainly don’t need that again,” said Bill Brim, co-owner of Lewis Taylor Farms in Tifton, Georgia. “We need the university to work real hard on it and, hopefully, we’ll get some more funding next year for it as well.”

Whiteflies built up significant populations as early as May 2017. A warm winter that season did not help diminish the whitefly population. The pest normally becomes a problem in August or September, but the earlier they occur, the worse they become, according to Sparks.

“We cannot successfully manage this pest as simply a pest of fall vegetables. We have to look at the entire cycle and realize that what happens in one area impacts the others,” Sparks said. “Because this pest attacks so many different crops across the agro-ecosystem and cycles from crop to crop throughout the year, we have to understand how it survives and builds in our environment to determine the best strategies for control.”

Where and how whiteflies overwinter leads to populations in spring vegetables. This can have an effect on summer crops, which then impacts fall vegetables.

Following the 2017 epidemic, UGA formed a whitefly team on the Tifton campus. Those researchers are included in this grant project, along with researchers in Griffin, Athens, Fort Valley and Charleston.

“We might be able to fix the problem today, but how do we make sure it’s fixed to where it lasts through next year and the year after — and something even more permanent?” asked Allen Moore, UGA associate dean for research and principal investigator for the grant. “With sufficient resources that the federal government is providing, we ought to be able to do all of that. Rather than take 10 years to come up with something, we’re doing it a lot faster because we’re doing it all at once.”

The grant designates $560,000 to Fort Valley State University with the remaining money divided among the researchers at CAES and UDSA-ARS in Charleston.

Listed are the participating scientists and the areas of whitefly research in which they are involved:

Plant resistant traits: Babu Srinivasan (UGA), Bhabesh Dutta (UGA), Andre da Silva (UGA), Cecilia McGregor (UGA) and Somashekhar Punnuri (Fort Valley State).

Ecology, biocontrol, cultural practice: Phillip Roberts (UGA), Alton Sparks (UGA), Andre de Silva (UGA), Paul Severns (UGA), Jason Schmidt (UGA), Mike Toews (UGA), George Mbata (Fort Valley State) and Alvin Simmons (ARS).

Viruses/transmission dynamics: Babu Srinivasan (UGA), Sadeep Bag (UGA), Paul Severns (UGA), Somashekhar Punnuri (Fort Valley State) and Alvin Simmons (ARS).

Molecular tools/biotech: Trish Moore (UGA), Bhabesh Dutta (UGA), Cecilia McGregor (UGA), Somashekhar Punnuri (Fort Valley State), George Mbata (Fort Valley State) and Alvin Simmons (ARS).

Insecticide resistance/biorational control products: David Riley (UGA), Jason Schmidt (UGA), Alton Sparks (UGA), Phillip Roberts (UGA), George Mbata (Fort Valley State) and Alvin Simmons (ARS).

Clint Thompson is a news editor with the University of Georgia College of Agricultural and Environmental Sciences based in Tifton.

Silverleaf Whitefly Update

Sep 26, 2018 | Written by                                                                               Silverleaf whitefly populations have increased in many areas in the last few weeks and will likely continue to increase as we stay above average temperatures. When we start to cool off at night, the population increases should slow down. We have been fortunate that we have not seen population explosions like we had last year. Part of this is likely the impact of a fungus that attacks whitefly. We saw a lot of it last year after the hurricane and are seeing impacts in many areas this year. When present, you will see fuzzy, white, dead adults stuck to the leaves. High humidity (which we have had even without rain) helps fungal attack on whitefly and other pests (unfortunately it also helps fungi attack plants). Hopefully we will experience cooler weather with some rain in the near future and help suppress the whitefly population growth.

Insecticide trials have mostly shown good efficacy with most of the products we usually use. We have seen reduced performance with imidacloprid (Admire Pro) and thiamethozam (Actara) – these two neonicotinoids are very similar and resistance has historically been worse with these as compared to other neonicotinoids. Coragen has also shown less efficacy than expected but is still providing some control. Insecticide resistance is always a threat and rotation of modes-of-actions is highly encouraged.

Whitefly-transmitted viruses in vegetable crops

Sep 26, 2018 | Written by                                                                                           We are currently detecting a variety of whitefly-vectored viral diseases in vegetable crops. The two of greatest concern are cucurbit leaf crumple virus and tomato yellow leaf curl virus. Both have been detected in multiple counties in southern Georgia but are generally at low levels to date; unfortunately, this could change rapidly. Current levels of virus infection are similar to late spring (in normal years) but with the obvious difference of large whitefly populations to spread these viruses. The only good news with this is that infection is occurring much later in the season than the last two years and will have less impact on overall yield.

In test on station, I noted obvious leaf crumple virus in less than 5 percent of young squash plants but terminal growth with questionable symptoms was likely in the 25 to 50 percent range. Again, with the relatively high whitefly population we have in Tifton, even a low level of virus can spread rapidly.

Tomato yellow leaf curl virus has also been detected, but generally at lower levels (with the exception of one field reported to be near 100 percent). Again, under conditions with high whitefly populations, any whitefly-vectored virus can spread rapidly.

Bermudagrass Stem Maggot Control Options

Chemical Control

Many of us county agents are working with Dr. Lisa Baxter who is helping look for new products with BSM efficacy. Still today the use of a pyrethroid labeled for forage use around 10 days after the previous cutting appears to be the best strategy for control. Sometimes a second application 10 days later will be beneficial, especially if the forage is growing slowly. UGA Extension Forage Scientist Dr. Dennis Hancock adds that some formulations add residual control for fall armyworm, but residual insecticides (chlorantraniliprole, dimilin, spinosad, etc.) have proven ineffective at preventing the BSM. They are great for FAW, though. So, consider formulations or tank mixes with them when we start seeing more FAM show up.

Physical Control

With some who missed the first cutting and damage is showing up (6 to 8 inches tall), the best option is to cut or graze the field now and encourage regrowth. It’s better to cut early and accept the loss than have low-yielding, damage crop harboring fly populations. This also prevents shading of any regrowth. The maggot does not remain in cut stems. It exits the stem to the soil and adult flies escape to field margins and other fields. A prompt treatment gives best reduction in damage.

Varieties with smaller stems and leaves seem to be more susceptible to damage. Below is a table from the updated publication Managing Bermudagrass Stem Maggot.

Update on Stored Grain Protectants

News Release (7/16/2018)

For Immediate Dissemination

Contact: Dr. Michael Toews, UGA Extension Specialist on Grain Storage (mtoews@uga.edu)

Update on Stored Grain Protectants:

Empty Bin Treatments

Centynal EC. This is a good product for treating empty bins and elevator boots.  Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical.

Defense SC (labeled for empty bin use only).  This is a good product for treating empty bins and elevator boots, but is not labeled for application directly to grain.  Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical.

Suspend SC. This is a good product for treating empty bins and elevator boots.  Note that the active ingredient in Centynal EC, Defense SC and Suspend SC are identical.

Tempo SC (labeled for empty bin use only). Tempo is a good product for treating empty bins and elevator boots, but is not labeled for application directly to grain.

 

Direct Application to Shelled Corn and Grain Sorghum

 

Actellic 5E. This product has long been the standard for use on corn and grain sorghum. A full rate will provide protection from weevils for 9-12 months.  Reducing the rate will decrease the longevity of the protection.  UGA data suggest that Actellic is susceptible to heat degradation in the drier when grain temperatures exceed 120 F.

Centynal EC.  Centynal EC is a new formulation that will provide 3 to 6 months of protection from weevils.  This material is heat stable in the drier (tested up to 150 F).

Diacon IGR.  Diacon IGR is an insect growth regulator that is effective for killing nearly all immature grain moths and beetles, except weevils.  The 4 oz per 1000 bu rate is sufficient for tank mixing.

Diacon IGR PLUS. This product is a premix of Centynal EC and Diacon IGR.

Malathion. Although widely used in the past, this product is no longer recommended due to well documented resistance in many stored grain insect populations. Expect malathion to break down in the drier.

Sensat. This product is new to the market, but has been in our evaluation program for several years.  Test results show excellent weevil control for up to 12 months.  No dryer stability data at this time.

Storcide II. Storcide II is labeled for use on wheat and grain sorghum, but not corn.  Protection will degrade with heat and time.

Suspend SC.  This product is an older formulation that must be completely suspended before measuring and requires frequent agitation.  It provides 3 to 6 months of protection from weevils.

Three-way tankmix (only tested on corn).  UGA tests from 2014-2018 showed that a three- way tank mix of Centynal (8.5 oz) plus Diacon IGR (4 oz) plus PBO-8 Synergist (13.5 oz) per

1000 bu will provide 6-9 months of protection from weevils.  This is a moderately priced option for growers in markets where other products are unavailable or cost is a limiting factor.

Regardless of the product used, be mindful that grain protectants are not a silver bullet.  Shelled corn should be dried to a maximum of 15.5% moisture content before dropping into the storage bin and must be immediately aerated to further reduce moisture content. Chemical applications should only be made to clean grain that will be stored for more than 3 months.  Apply protectants at the bottom of the auger in a course spray to maximize coverage as the kernels are moving up

to the top of the bin.  Long-term grain storage requires moisture content below 14%, proper housekeeping, use of a spreader when filling bins, and managed aeration.

 

Additional information is available in the 2018 Georgia Pest Management Handbook or in a recent Extension Publication (http://www.aces.edu/pubs/docs/I/IPM-0330/IPM-0330.pdf) that was published with colleagues at Auburn University.

Kissing bugs in Georgia

Kissing bugs in Georgia not cause for

Chagas’ disease worry

By Nancy Hinkle, UGA Professor of Entomologist, Jule-Lynne Macie,

UGA ANR Program Development Coordinator, & Heather N. Kolich, UGA Cooperative Extension Agent

November 25, 2015

 

Between media coverage of Texas kissing bugs transmitting

Chagas’ disease to people and a recent news article reporting that a “deadly” kissing bug was found in Georgia, people are worried. Fortunately, here in the Southeast, these insects are not a public health concern.

Kissing bugs are not a public health concern in Georgia.

 

Kissing bugs are in the insect family Reduviidae, which includes several different species, such as beneficial assassin bugs and large, menacing looking wheel bugs (Arilus cristatus). While these insects can deliver a painful bite if handled, they’re not the Genus of insect that carries the Trypanosoma cruzi parasite that causes Chagas’ disease.

Wheel bugs (above) are often mistaken for kissing bugs.

Although kissing bugs have been present in the Southeast for many decades, the Centers for Disease Control and Prevention, located in Atlanta, has never recorded a case of Chagas’ disease caused by the parasite

some of the insects may carry. Blood-feeders, kissing bugs in Georgia tend to live in the nests and burrows of their animal hosts, typically raccoons, opossums, skunks and armadillos. Furthermore, the parasite doesn’t pass from insect to mammal through a bite. Instead, if the trypanosome

parasite is present, it is shed through the feces of infected

 

insects. Humans can become infected by ingesting or inhaling the feces, or by getting it into their eyes or into a cut or break in the skin.

Kissing bugs will bite humans, especially if they are handled; however, in Georgia, we have certain advantages over areas of Central and South America where Chagas’ disease is endemic. First, our homes tend to be well-sealed, which limits opportunities for the nocturnal insects to visit us as we sleep. Second, the kissing bugs present in Georgia behave differently than those in other regions of the world. In Central and South America, kissing bugs tend to defecate immediately after feeding, leaving potentially parasite-infected feces next to the feeding wound, where it may be scratched into the

broken skin. In Georgia, kissing bugs usually move away from the host before defecating. Since the

parasite is transmitted through the insect’s feces, not through the bite, the victim is much less likely to be exposed to it.

Homeowners with concerns about kissing bugs can take measures to keep insects from entering the house. Repair damaged window screens, replace weather-stripping around doors and windows, and install door sweeps to seal small openings. These measures will also keep out cold air, making the home warmer and more energy efficient this winter.

 

 

Thrips Monitoring 2018

UGA  peanut  entomologist  Dr. Mark Abney shares some information on thrip  monitoring,  he has seen across the state and offers recommendations for treating. Peanuts are being planted, and tobacco thrips are moving in Georgia. Trap captures increased significantly at four of our six monitoring locations last week. This means that peanuts emerging over the next couple of weeks will be at relatively high risk for infestation. Using an at-plant insecticide with proven efficacy will usually be sufficient to keep thrips injury low, but growers are still strongly encouraged to scout fields for thrips activity. Growers who are not using an at-plant insecticide should be prepared to make foliar applications (usually acephate) for thrips if they want to avoid injury. Remember that phorate (Thimet) in-furrow is the only insecticide that has been proven to reduce the risk of tomato spotted wilt disease in peanut.  We are in the first two weeks of thrips dispersal, and we do not know how long flights will continue or how large populations will be. We will continue to post weekly updates of trapping data as the planting season progresses.

These data are being provided for informational purposes only and may not be representative of thrips dispersal at your location. Peanut fields should be scouted regularly to quantify actual thrips populations.

If you have questions about thrips or thrips management please contact your local county Extension agent.

Lorsban in Sweet Potatoes

Lorsban 24C Label for 60 Day PHI in Sweet Potato

 

While it has taken several years, Georgia does now have a 24C registration to allow for the use of Lorsban in Sweet Potato with a 60 day pre-harvest interval (PHI).

Lorsban is still labeled for pre-plant incorporated application only.

Cotton Production Meeting Tomorrow

We will be having our Cotton Production meeting tomorrow night at 6 with Dr. Whitaker, cotton agronomist and Dr. Roberts, cotton entomologist. We will also be offering a Pesticide One on One Training. This will benefit applicators who will be spraying the new technology. The presentation will be short and anyone attending can earn an extra pesticide credit for the meeting. Please call the office if you have any questions at 229-333-5185.

DIAMONDBACK MOTH CONTROL UPDATE

If you are a brassica grower, retailer or have brassica in a greenhouse, I highly encourage you to go to a diamondback moth update that is being held in Moultrie on February 23rd. Below is the schedule. Please RSVP to either of the numbers given so they can have a head count.

Colquitt County Extension Office

350 Veterans Parkway North

Moultrie, GA 31788

9:30 AM 10:00 AM Registration and Refreshments

10:00 AM 10:10 AM Welcome and Opening Comments

Jenna Brock, UGA Extension ANR Agent

Donna McMikle, DuPont

10:10 AM – 11:00 AM Diamondback Moth Control Update

Dr David Riley, UGA Vegetable Research Entomologist

Dr Stormy Sparks, UGA Vegetable Extension Entomologist

11:00 AM 11:10 AM BREAK / DRAWING

Jenna Brock, UGA Extension ANR Agent

Donna McMikle, DuPont

11:10 AM Noon DuPont Best Management Practices for Controlling DBM

Jeff Meredith, DuPont Product Dev Mgr

Stanley Royal, DuPont Dev Rep

NOON Closing Remarks

Jeff Meredith

DRAWINGS

Jenna and Donna

LUNCH

PESTICIDE CREDITS WILL BE AVAILABLE

PLEASE RSVP SO WE CAN PLAN ACCORDINGLY FOR LUNCH

JENNA BROCK (229) 921-1992 jkickli2@uga.edu

DONNA MCMIKLE (229) 881- 1171 donna.h.mcmikle@dupont.com