- Author: Ben Faber
Argentine Ant is the great protector of many pests found on plants. Without the Argentine, many pests would not be so much of a problem. In many crops, like cherimoya and passionfruit, mealy bug can become so severe that fruit will stop growing and fall off the tree. Controlling Argentine, makes it possible for predators and parasites to do their thing in bringing them under control. Watch these two videos to see how hoverflies (syrphids) can help biocontrol and how Argentine Ant control can help that biocontrol
Citrus Psyllids Bribe Ants With Strings Of Candy Poop | Deep Look - YouTube
How Hoverflies Spawn Maggots that Sweeten Your Oranges | Deep Look - YouTube
Cherimoya fruit and stems covered with mealy bug.
- Author: Ben Faber
It might seem like common sense that a starving animal is more likely to take dangerous risks to obtain food than one with a full belly. But new research from UCLA shows that groups of Argentine ants, who forage boldly when they're well fed, exercise far more caution when they've been deprived of carbohydrates and the risks from competitors are high.
This counterintuitive foraging strategy might contribute to the success of these insects, known as Linepithema humile, an invasive species that displaces native ant populations in California and elsewhere and has become a significant agricultural pest, the researchers said.
Their findings, published in the journal Current Zoology, suggest that the unwillingness of Argentine ants to expose themselves to danger when weakened by hunger could possibly give them a competitive edge over other species by helping to preserve their colonies' foraging capabilities.
“While not foraging may lead to a reduction in food stores when those stores are already low, foraging in a high-risk environment exposes the colony to potential loss of foragers,” said the study's senior author, Noa Pinter-Wollman, a UCLA professor of ecology and evolutionary biology. “So reduced foraging could be interpreted as individual foragers not taking unnecessary risks.”
To support the energetic requirements of daily life, all ants require carbohydrates, which they obtain from a variety of plant and animal sources. They also need protein, which they generally get from dead animals, to nourish their larval offspring. Ant colonies adjust their foraging strategies according to the availability of these food sources, the presence of competing ant species, and the threat of predators or other dangers. Well-fed ants will forage for carbohydrates even in the presence of other ant species or danger cues.
First author Bryce Barbee, who conducted the research as a UCLA undergraduate, expected that starving Argentine ants of either carbohydrates or protein would only increase their willingness to forage for those foods in high-risk environments because they had little to lose and everything to gain.
Together with Pinter-Wollman, Barbee designed a series of laboratory experiments that involved feeding ants normally, depriving them of either carbohydrates or protein, and depriving them of both, then allowing them to forage as they normally would in either low-risk or high-risk environments.
The researchers created the impression of high-risk environments with formic acid, a chemical marker produced by ants, to signal the presence of competitors.
When the risk was low, starving ants did indeed forage more vigorously for the food of which they had been deprived. But when the risk was high, starving ants surprised the researchers by becoming more cautious, not less, in their foraging strategies.
In both high- and low-risk foraging scenarios, the ants were more willing to forage for carbohydrates than protein, which they only need to raise their brood. Since no eggs or pupae were present in the laboratory colonies, this finding might not be surprising, but it could also indicate that starving ants put their own energetic needs ahead of raising offspring, the researchers said.
Scientists who study animal behavior have advanced two ideas to explain foraging strategies. The first, known as the asset-protection principle, holds that hungry animals have less to lose than satiated animals and will therefore behave more assertively to get food. The second, the state-dependent safety hypothesis, holds that animals in good condition are more likely to take risks because they are more likely to survive dangers they encounter.
“Our work upheld the state-dependent safety hypothesis but not the asset-protection principle,” said Barbee, now a doctoral student at UC Santa Barbara. “The findings suggest that factors such as activity level and energetic costs of starvation are important for Argentine ant foraging decisions.”
The work points toward an avenue of research that could lead to better efforts to control the spread of Argentine ants and mitigate their detrimental impact on agriculture, the researchers said.
https://academic.oup.com/cz/advance-article/doi/10.1093/cz/zoac089/6825390
Ant species across five subfamilies exchange milk-like substances. Jasius via Getty Images
- Author: Ben Faber
You wanted to see where all those ants are coming from? Well here is the site to see what ants are where with their descriptions and images.
The ant fauna of California comprises 8 subfamilies, 44 genera and approximately 300 species (of which 30 are introduced). About 25% of the native species are endemic to the state or to the California Floristic Province (including northern Baja California and southern Oregon).
https://www.antweb.org/adm1.do?name=California&country=United+States
Prominent California ants include seed-harvesting species in the genera Veromessor, Pheidole and Pogonomyrmex; honeypot ants in the genus Myrmecocystus; a diverse array of species in the genera Camponotus ("carpenter ants") and Formica; native fire ants (Solenopsis spp.); velvety tree ants (Liometopum spp.); and the introduced Argentine ant (Linepithema humile). This last named species is particularly common in urban and suburban parts of California, where it establishes dense populations and eliminates most native species of ants.
This web site provides color images and identification information for most of the species of ants known to occur in California. For identification of pest ants you may find it useful to consult the key to common household ants of California developed by the UC Statewide IPM Program.
Specimens: 15,612
Images: 655
Imaged Specimens: 981
Subfamilies: 8
Genera: 44
Species/Subspecies: 305
Valid Species/Subspecies: 266
Endemic: 26
Introduced: 23
Show All Specimens
https://www.antweb.org/about.do
AND WAIT, THERE"S MORE - ALEX WILD'S SITE HAS EVEN MORE WONDERFUL IMAGES AND HISTORIES OF ANTS
https://www.alexanderwild.com/Ants
Plus a menagerie of other Insect images - https://www.alexanderwild.com/Insects/Portfolio/
Check it out
And if you want to get down with the Argentine Ant. Don't forget the Workshop next week
Argentine Ant Workshop and Registration
David Haviland says the best Ant Costume wins free admission. Actually it's free to all who register for the meetings.
/span>- Author: Ben Faber
UCCE & UCR Argentine Ant & Citrus Pest Management Field Day
Get Down with Argentine Ants
November 1 – Redlands, CA
November 2 – Saticoy, CA
Mornings: 8-12
Overview of Biocontrol Methods for ACP in Southern California, Mark Hoddle, Entomology and Extension Specialist at UC Riverside, Director of Applied Biological Control Research,
Overview of ACP/HLB Area-wide Spray Programs in Southern California, Sandra Zwaal, Citrus Pest & Disease Prevention Program, ACP/HLB Grower Liaison San Diego, Riverside, San Bernardino, and Ventura Counties,
Then out to the field to see:
Argentine Ants in Citrus at designated stations in small groups
- Discussions and demonstrations of use of hydrogel beads for Argentine ant control and we would cover aspects of ant biology/ecology/behavior/other control options at this station, Ivan Milosavljevic, UC Riverside
- Discussion and demonstration of monitoring programs for Argentine ants with a focus on using infra-red sensors, visual sampling, sugar-water saturated cotton wool balls, and liquid monitoring vials, Mark Hoddle & Michael Lewis, UC Riverside
- Enhancing natural enemies in citrus orchards with the use of cover crops. This station will cover possible species that could be used, aspects of flowering plants that make them good candidates for use in conservation biological control, the types of generalist natural enemies that will respond to these floral resources, and benefits and drawbacks of using cover crops. Nicola Irvin, UC
- The potential for hydrogels across regions, ant species, crops, and active ingredients. Discussion about major ant groups, resources to identify ants, a little about ant biology in the context of making hydrogels work, and then give an update on the results of trials funded by DPR to evaluate hydrogels against different ant species in different crops across California using five different active ingredients. This station will include the Ant ID mini station. David Haviland, UC Cooperative Extension, Kern County
REGISTRATION Acknowledgment Reply will include agenda and directions for the different sites
Contact: Ben Faber, bafaber@ucanr.edu, 805-645-1462
November 1 Location: Carriage House Prospect Park, 1399 Prospect Dr, Redlands CA 92373
November 2 Location: 2641 SP Milling Rd, Saticoy, CA, follow the signs to Rancho Santa Clara del Norte, which is at the end of the road. Watch at turn to SP Milling Rd for traffic on Hwy 118/Los Angeles Ave.
/span>- Author: Ben Faber
Dr. Hoddle presented about how to monitor and manage Argentine ant in citrus orchards with liquid baiting systems and discussed why ant management has such strong benefits for the suppression of sap-sucking pests by natural enemies. This information is critical for PCAs and growers to better understand why managing Argentine ant is important. (Presentation slides in the PDF format)
From: https://www2.ipm.ucanr.edu/agriculture/citrus/Ants/
There are numerous species of ants present in citrus orchards, however, the most common are the Argentine ant (southern and coastal California), the native gray ant (San Joaquin Valley) and the southern fire ant (statewide). The red imported fire ant has been found in Southern California, but is not yet established in citrus orchards. It is important to identify the primary ant species in the orchard, because management tactics depend on which ant species is present.
The Argentine ant, is a small, uniformly deep brown ant. Worker ants travel in characteristic trails on trees, the ground, or irrigation lines and build their nests underground. Ant populations peak in mid-summer through early fall.
The southern fire ant is light reddish brown with a black abdomen. These ants build nests of loose mounds or craters near bases of trees, do not aggregate in colonies as large as those of the Argentine ant, and will sting and bite.
Native gray ants are gray and considerably larger than the other two species. They nest in topsoil or under rocks and debris and move in irregular patterns. In contrast to Argentine and fire ants, the native gray ant is solitary and its importance in disrupting biological control is often underestimated.
Red imported fire ant is new to California and can make large, dome-shaped mounds. They feed on almost any plant or animal material.
Damage
Most ant species feed on honeydew excreted by various soft scales, mealybugs, cottony cushion scales, whiteflies, psyllids, and aphids. As part of this relationship, they protect these pest insects from their natural enemies, thus interrupting biological control. They also protect some non honeydew-producing pests, such as California red scales.
Argentine and native gray ants are the most common ant species that aggressively protect pest insects. In addition, Argentine ants and fire ants can plug up irrigation sprinklers. Fire ants directly damage citrus by chewing twigs and tender bark of newly planted trees; they also sting people working in the orchard and may cause allergic reactions.
No effective natural enemies of ants are known.
Cultural Control
Skirt prune trees, i.e., remove branches within 12 to 30 inches of the ground, and apply sticky material to the trunk to prevent access to the trees by ants. Use polybutenes, as oil-based materials may cause phytotoxicity and should not be used.
The application of sticky polybutene materials directly to the trunk of citrus trees can cause bark cracking, especially if multiple applications are applied to the same area of the trunk, the area is exposed to sunlight (topworked trees), or both. The sticky material can be applied on top of a tree wrap or a base layer of latex paint. Young trees, which have a very thin cambium layer, are most susceptible to damage.
Sticky material should last from 1 to 4 months and will also prevent the access by Fuller rose beetles. If the sticky material contains tribasic copper sulfate, it will also control brown garden snails. The persistence of sticky material can be increased by applying it higher above the ground to reduce dust and dirt contamination and to decrease irrigation wash-off.
Baits
Argentine ant adults are liquid-feeding only and have physical digestive "blocks" in the mouth and gut to prevent them from swallowing and digesting solid food particles. They may bring back solid food to the colony to feed the brood (but solid-food digestion not been confirmed in Argentine ant brood), or harvest the bodily fluids inside of insect prey/moisture in food items. Dry insects or food items are of little use to them, even though they may pick these things up. Feeding studies have shown ants feed several times faster on liquids than gels and gels than solids. This faster feeding resulted in much higher toxicity with liquid. Gel was intermediate, and solids provided the lowest control.
Put out bait in the shade to increase feeding and overall kill. You do not need to obscure it. The soil temperature and moisture are going to be more moderate in the shade, particularly under the canopy. This is the environment the ants will prefer to feed in. There will be less evaporative loss in the shade, as well. Sometimes when the toxins become too concentrated they are less attractive to the ants. The other issue is that many toxins (like borax products) may photodegrade at a faster rate in direct sunlight.