Moths, a magnificent microscope (scanning electron microscope) and friendly scientists--what could...
One of the odd things about this production year is the lack of Macrophomina showing up in strawberry in comparison to the amount of Fusarium. While I've been called out on a good number of fields that ultimately turned out to be Fusarium (thank you Steven Koike and your diagnostic lab staff!), I haven't been called out to a single one that's been found to be Macrophomina.
Recall that both of the diseases caused by these two pathogens look very similar in the field - plant collapse associated with a discolored crown.
Now for some of the work that Steve has been doing for his DNA testing for plant pathogens, he's been eager to get his hands on Macrophomina material. I've submitted a sample from a field off of Old Stage which had it last year and so the assumption is that it does this year too, and indeed plants are starting to go down.
I dutifully submitted a sample to Steve, and told him that if it wasn't Macrophomina I'd eat my hat. It just has to be Macrophomina, but then again with the current spate of all Fusarium calls, who knows?
Is it or isn't it?
Argentine Ant is a very aggressive invader that disrupts native ant populations and at the same time disrupts biocontrol agents that help control, such pests as scale, aphids and mealy bugs in citrus and other tree crop species. They defend these sugar producing sources of energy from attack by predators and parasites, like parasitic wasps and predatory assassin bugs and lady bugs. They increase the threat of Asian Citrus Psyllid and HLB by protecting the psyllid from attack by parasitic Tamarixia.
A careful, well placed chlorpyrifos spray has been used to control Argentine ants. A trunk spray and/or spray on irrigation lines has disrupted their activity with minimal impact on beneficials. This protectant spray keeps the Argentine ants out of the canopies and allows the beneficials access to the pests. Controlling this one species, can have significant impact on biocontrol and the whole need for controlling pests.
Chlorpyrifos is a pesticide that might lose registration and other materials and techniques have been examined over the years as a replacement. A recent procedure has been proposed and used successfully on Santa Cruz Island to control introduced Argentine ants. The ant has caused tremendous disruption in biocontrol and it appears to have been controlled by this new technique. We are in the process of evaluating it's use in citrus. The application technique, costs and materials would need to be modified for use in citrus orchards. The current procedure would not be considered an organic practice since the pesticide material is not registered organic. It might be possible to use an organically registered material in the future.
Protocols for Argentine ant eradication in conservation areas
L.Boser1,C.Hanna2,D.A.Holway3,K.R.Faulkner4,I.Naughton3,K.Merrill5,J.M.Randall1,C.Cory1,D.-H. Choe6 & S. A.Morrison
Journal of Applied Entomology
The Argentine ant (Linepithema humile) is a widespread, abundant and ecologically disruptive invader that is present throughout major portions of coastal California and on half of the California Channel Islands. On Santa Cruz Island, the Argentine ant had invaded about 2% of the island's area in four distinct locations as of 2012. Given the negative ecological effects resulting from Argentine ant invasions,we sought to develop a cost-effective method of eradication. Here, we describe the results of large-scale, field-tested methods for Argentine ant eradication and post-treatment detection. Our eradication protocol employs a novel toxicant-delivery system: an aqueous solution of sucrose and 6 ppm of thiamethoxam mixed with hydrating polyacrylamide beads. Ants feed on the solution present on the bead's surface for about 24h after which time bead dehydration prevents feeding. We distributed hydrated beads by helicopter over 74 ha of infested areas plus a 50-m buffer on 14 occasions between June 2013 and September 2014. Treatments reduced Argentine ant activity to subdetectable levels within four months. In 2014, we conducted a high-intensity detection protocol using lures (n = 55 363) in areas treated in 2013.This effort did not detect Argentine ants. In 2015, we conducted a medium-intensity detection protocol using lures (n=2250) in areas treated in 2013 and 2014 but not searched in 2014; this sampling effort did not detect Argentine ant activity except for a single remnant infestation (c.0.3ha in area),which was retreated in2015.Thec ost of treatments was approximately $1400 per ha; this cost is comparable to other ant eradication efforts. The cost of our preferred detection method, which used lures spaced every 10m,was $500 per ha.These results demonstrate sufficient protocol efficacy to justify expansion of treatments to other infested areas in ecologically sensitive areas.
Photo: Argentine ant and scale
It was not a good way to welcome an admiral. The Red Admiral butterfly, that is. The Vanessa...
University of California Agriculture and Natural Resources (UC ANR) is a division of the University with scientists based on three UC campuses and in UC Cooperative Extension offices serving all California counties. UC ANR conducts research and shares research-based information with the public about wildfire, agricultural production, environmental stewardship, water policy, youth development and nutrition.
UC ANR Cooperative Extension weed specialist at UC Riverside
Management of invasive plants that introduce or alter fire regimes
UC ANR Cooperative Extension specialist at UC Berkeley
Land change science including fire and land use planning
Mike De Lasaux
UC ANR Cooperative Extension natural resources advisor for Plumas and Sierra counties
Wildfire fuel reduction on small forest parcels, forestry and watershed management
UC ANR Cooperative Extension natural resources advisor for Los Angeles and Ventura counties
Plant arrangement, building design and maintenance to reduce fire risk, invasive weeds and pests contributing to fire risk
UC ANR Cooperative Extension natural resource monitoring specialist
Geographic information science, mapping forests
UC ANR Cooperative Extension natural resources advisor in the Central Sierra
Fire adapted communities, fire hazard mitigation in forests, post fire restoration
“Living with Fire in the Tahoe Basin” website, http://www.livingwithfire.info/tahoe/
UC ANR Cooperative Extension natural resources advisor
Desert species, invasive plants and fire
Professor of earth sciences, UC ANR Agricultural Experiment Station, UC Riverside
Fire ecology of Southern California, Baja California, and temperate Mexico; exotic plant invasions, climate change.
UC ANR Cooperative Extension wildfire specialist in the Department of Environmental Science, Policy and Management at UC Berkeley. He is located in Santa Barbara County.
Wildland fire, fire modeling, fire effects, shrubland ecosystems and spatial patterns of fire disturbance, climate change adaptation
Associate professor of Forest Ecology, UC ANR ecologist
UC Cooperative Extension Area fire advisor - Northern California
Fire ecology and management
Plant pathology professor, UC ANR pathologist
Fire and infectious disease
UC ANR Cooperative Extension natural resources advisor
Public participation in resource management
Environmental science professor at UC Davis and UC ANR ecologist
Forest plot mapping
UC ANR Cooperative Extension area natural resources wildlife specialist for Southern California
Conservation of wildlife, wildlife management at the urban-wildland interface, and response of plants and animal species to fire
Professor of fire science and co-director Center for Fire Research and Outreach at UC Berkeley, UC ANR fire scientist
Fire ecology, fire behavior, wildfire, fuels treatments, forest mortality, fire policy
UC ANR Cooperative Extension forestry specialist in the Department of Environmental Science, Policy and Management at UC Berkeley and co-director Center for Fire Research and Outreach
Economics of fire prevention and fire suppression programs
UC ANR Cooperative Extension forest advisor in Humboldt and Del Norte counties and member of the Northern California Fire Science Consortium hub
Home and landscape design considerations for wildfire, prescribed fire, forest health and prescribed fire, wildfire and fuels in redwood, Douglas-fir and tanoak forests, fire education