- Author: Sandipa Gautam
USDA-APHIS Approves New Fuller Rose Beetle Mitigation – a Voluntary Option to Reduce Pesticide Applications
By
Sandipa Gautam, Area Citrus IPM Advisor UCCE
James R Cranney, President CCQC
At the request of the California Citrus Quality Council (CCQC) USDA's Animal and Plant Health Inspection Service (APHIS) has approved a new sampling protocol that growers can use to reduce pesticide applications for control of Fuller rose beetle (FRB), a quarantine pest in South Korea.
Fuller rose beetles are brown, flightless, snout beetles that have one generation in a year (Figure 1). Three-fourths of their life cycle is spent under the ground where they feed on roots and go through development. Adults emerge from the ground year-round, but the major emergence in the San Joaquin Valley occurs July-September, with 53% of beetles emerging in August. All beetles are females and adult females do not require mating to begin reproduction. Beetles climb to the tree canopy and feed on citrus leaves and lay eggs on cracks and crevices including the under the sepal (Figure 2). Eggs can be present at the time of harvest, thereby making this beetle a quarantine concern for Korea's Animal and Plant Quarantine Agency.
Figure. 1. Fuller rose beetle adult (right there, centered in the triangle).
Figure 2. Fuller rose beetle egg masses, live eggs (A) – note yellowish and plump eggs; dead or hatched eggs (B) – dried out egg mass.
Current Practices for FRB Management
Growers have been using a system's approach which combines cultural and chemical methods to target FRB, since 2010. The goal of FRB management is to reduce the beetle population and egg laying. Current regulatory requirements for managing FRB are
a) Skirt Pruning sufficient to prevent tree skirts from contacting the ground
b) Weed control sufficient to prevent forming a bridge from ground to tree skirt
c) Two insecticide treatments to control Fuller rose beetle using only University of California recommended pesticides from the UCANR IPM Guidelines web page at http://ipm.ucanr.edu/PMG/r107300311.html
In recent years, most growers and pest control advisors have reported that they no longer detect beetles in most citrus groves. Furthermore, the USDA APHIS interception rate from phytosanitary inspections, where 600 fruits per container are sampled for FRB egg masses, FRB was found in only 0.05 percent of all containers. This indicates that FRB populations are very low in citrus groves.
Since FRB populations in citrus groves are historically low, CCQC has proposed an additional voluntary option for the Korea FRB Protocol to reduce pesticide use:
- Trees must be skirt pruned to minimize branches touching the ground.
- Herbicide treatments should be made to eliminate weeds that could be a pathway into the tree.
- Either option a or option b
a) Growers must make two pesticide applications to control FRB using pesticides recommended on the University of California Citrus IPM website https://ipm.ucanr.edu/agriculture/citrus/fuller-rose-beetle/
b) Growers must use the FRB sampling protocol (below), keep records and if no more than two FRB-infested trees per sample are detected they may eliminate the first application and make one application, preferably before October 31 with pesticides recommended on the citrus IPM website.
Fuller Rose Beetle Sampling Protocol:
- Growers should conduct Fuller rose beetle (FRB) sampling from Aug. 7 – Aug. 31 since that is the peak period of emergence.
- Conduct a random sample in each citrus block.
- Divide the block into four quadrants and sample 18 trees that are spread equally apart in each quadrant. A total number of trees sampled is 72 trees.
- Growers or Pest Control Advisors (PCA) should:
i. Check suckers inside the tree for signs of FRB leaf chewing and if beetles are detected the tree is considered infested.
ii. If no beetles are found in the interior, shake two large outside branches over a light cloth and inspect for FRB. If beetles are found, the tree is considered infested.
- Growers must keep records on the results of the sampling including (i) block identification, (ii) inspection date, (iii) name of inspector, and (iv) number of trees infested with beetles out of 72 trees inspected.
- If no more than two infested trees are found, growers may eliminate the first FRB pesticide application. If two infested trees are found, growers must make a pesticide application in August or early September.
- If no more than two infested trees are found, growers are still required to make one pesticide application to control FRB, preferably before October 31.
How will the new protocol help?
- Reduced pesticide use could reduce grower costs to manage FRB.
- Fewer pesticide applications should improve biological control in citrus groves by preserving beneficial insects. Many PCAs and growers attribute severe mealy bug outbreaks to increased pesticide use to control FRB and Asian citrus psyllid.
- Reducing pesticide use to control FRB will help California citrus growers adopt more sustainable production practices and align the industry with the California Department of Pesticide Regulation's Sustainable Pest Management Roadmap.
References:
UCIPM 2017. Citrus Pest Management Guidelines: Fuller Rose Beetle. https://ipm.ucanr.edu/agriculture/citrus/fuller-rose-beetle/
UC Riverside scientists are on the hunt for a chemical that disrupts “evil” weevils' mating and could prevent them from destroying California's supply of avocados.
Avocado weevils, small beetles with long snouts, drill through fruit to lay eggs. The weevil grubs or larvae bore into avocado seeds to feed, rendering everyone's favorite toast topping inedible.
“They're extremely hard to control because they spend most of their time deep inside the fruit, where they're very well protected from insecticides and natural enemies,” said UCR entomologist Mark Hoddle.
Not only are the insects reclusive, they are also understudied, making information about them hard to come by. “All books on avocado pest management will tell you these weevils are bad. They're well recognized, serious pests of avocados, but we know practically nothing about them,” Hoddle said.
One strategy for controlling pests is to introduce other insects that feed on them. However, that is unlikely to work in this case. “Natural enemies of these weevils seem to be extremely rare in areas where this pest is native,” Hoddle said.
To combat avocado weevils in Mexico, an area where they are native, and to prevent them from being accidentally introduced into California, Hoddle is working with Jocelyn Millar, a UCR insect pheromone expert. They are leading an effort to find the weevil's pheromone, with the goal of using it to monitor these pests and prevent them from mating in avocado orchards.
Pheromones are chemicals produced and released into the environment by an insect that can be “smelled” by others of its species, and affect their behavior.
“We could flood avocado orchards with so much pheromone that males and females can't find each other, and therefore can't reproduce,” Hoddle said. “This would reduce damage to fruit and enable growers to use less insecticides.”
Alternative control strategies could include mass trapping, using the pheromone as a lure, or an “attract-and-kill” approach, where the pheromone attracts the weevils to small sources of insecticide.
The work to identify, synthesize and test this pheromone in the field is supported by grants from the California Department of Food and Agriculture, as well as the California Avocado Commission.
An initial phase of the project sent Hoddle to a base of operations three hours south of Mexico City, an area with large weevil populations. Using a special permit issued by the USDA, Hoddle brought weevils back to UCR's Insectary and Quarantine facility.
Hoddle and Sean Halloran, a UCR entomology researcher, captured the chemicals that avocado weevils release into the air. Possible pheromone compound formulas were identified from these crude extracts and are now being synthesized in Millar's laboratory.
“Weevil pheromones have complicated structures. When they're made in a lab, they can have left- or right-handed forms,” said Hoddle. Initially, Millar's group made a mixture of both forms to see if the blend would work as an attractant, as it is far cheaper to make the blend than the individual left- or right-handed forms.
Field work in Mexico with the pheromone cocktail by Hoddle, his wife Christina Hoddle, an associate specialist in entomology, and Mexican collaborators did not get a big response from the weevils, suggesting that one of the forms in the blend could be antagonizing the response to the other.
As the next step, the researchers plan to synthesize the individual forms of the chemicals and test the insects' response to each in Mexican avocado orchards.
Because the levels of avocado imports from Mexico are increasing, the risk of an accidental weevil invasion is rising as well. Hoddle is hopeful that the pheromone will be successfully identified and used to lower the risk this pest presents to California's avocado growers.
“We've been fortunate enough to be awarded these grants, so our work can be implemented in Mexico and benefit California at the same time,” Hoddle said. “The tools we develop now can be used to make sure crops from any exporting country are much safer to import into California.”
/span>/h4>- Author: Ben Faber
There have been recent reports of a beetle infesting downed avocado fruit in Ventura County. This scolytid weevil was first reported in San Diego in 2010. Gary Bender found it in a high density planting where fruit was lying on the ground.
The reports in Ventura have been of fruit that has found on the ground. It's a “B” rated pest that previously had only been reported from the Andes through Central America and Mexico into North Carolina. The main threat is to stored corn. The weevil is about the size of a sand grain. The photo below is by Alana King.
The beetle burrows into the fruit where the larvae tunnel the flesh.
Image - Aimee Smith
Image: Alana King
The avocado reports here have involved some superficial tunneling into the fruit flesh, although its various names include seed weevil. This is not the seed weevils Helipus or Conotrachelus which cause so much damage in Mexico
This insect probably is not a major threat to avocado, but just demonstrates again how easily pest infestations occur.
- Author: Ben Faber
UC Ag Expert talks about Fuller rose beetle
Date: January 23, 2019
Time: 3:00 PM - 4:00 PM
Contact: Petr Kosina pkosina@ucanr.edu
Sponsor: UC Ag Experts Talk
Location: Webinar
Event Details
Register in advance for webinar at
https://ucanr.zoom.us/webinar/register/WN_RIYGPBgkTo6o_hPooWlfmg
Participants of this webinar will receive 1 DPR hour of 'Other' CE units and 1 CCA hour of IPM CE units
Note: This webinar has no fee.
Dr. Beth Grafton-Cardwell, citrus IPM specialist and research entomologist, will discuss the lifecycle, damage to citrus, monitoring, methods of control and export issues associated with Fuller rose beetle. Participants can use the chat function of the webinar to ask questions.
Event Reminder
/h2>/h2>/h1>- Author: Ben Faber
UC Ag Expert talks about
Fuller rose
beetle (weevil)
Date: January 23, 2019
Time: 3:00 PM - 4:00 PM
Contact: Petr Kosina pkosina@ucanr.edu
Sponsor: UC Ag Experts Talk
Location: Webinar
Event Details
Register in advance for webinar at:
https://ucanr.zoom.us/webinar/register/WN_RIYGPBgkTo6o_hPooWlfmg
Participants of this webinar will receive 1 hour of 'Other' CE units
Note: This webinar has no fee.
Dr. Beth Grafton-Cardwell, citrus IPM specialist and research entomologist, will discuss the lifecycle, damage to citrus, monitoring, methods of control and export issues associated with Fuller rose beetle. Participants can use the chat function of the webinar to ask questions.
http://ipm.ucanr.edu/PMG/r107300311.html
http://entnemdept.ufl.edu/creatures/orn/beetles/fuller_rose_beetle.htm