- Author: Ben Faber
This odd pattern that has shown up on polyethylene irrigation tubing was sent in by an observant Santa Paula grower. The fruit trees were covered with aphids and there was sooty mold growing on the honey dew dripping onto the tubing. Such a beautiful pattern, but what causes it?
Turns out Mark Hoddle, Biocontrol Specialist at UC Riverside had an answer - snails. Brown garden snails are active with this warm, wet weather and they are enjoying feeding on the sweet taste of honey dew.
The bottom side of the snail has a mouth composed of raduli which are sharp teeth which scrape along the surface of the tubing, leaving marks.
All images from Los Angeles Natural History Museum - https://nhm.org/stories/microscopic-look-snail-jaws
- Author: Cheryl A. Wilen
The Italian white snail aka white garden snail (WGS)(Theba pisana) has been in San Diego County for about 100 years. However, it has rarely caused significant damage to crops or gardens. Historically, it climbs up on weeds like mustards or fence posts in the day and during hot periods of the year and does not really move too far from abandoned fields or other relatively undisturbed areas.
In 20 years in my job here, I got a total of 1 call about it. However, about 6 weeks ago I went to a site in Escondido that bordered a weedy fallow field. That area had not been reported to have the WGS but they were clearly established there. The problem was that the snails had traveled to the adjacent property and were on almost all of the citrus and peach trees and groundcover. The avocado grove across the street was also impacted. WGS were on the tree trunks and leaves and this worried me more since they are not really a crop of choice for the more common brown snail. I thin drove down the street and observed small numbers of snails on walls and posts up to about 1/2 mile away. They are clearly expanding.
About 4 weeks later, I was at another small farm in Carlsbad and they asked me to the take a look at a snail problem. I expected it to be the brown snail and was shocked to it was also the WGS on their fruit trees. Even worse, that farm is next to cut flower growers who may be impacted not only from direct damage but restricted shipping since WGS is a B-rated pest.
B-rated pest (CDFA Pest Ratings): An organism of known economic importance subject to: eradication, containment, control or other holding action at the discretion of the individual county agricultural commissioner.
or
An organism of known economic importance subject to state endorsed holding action and eradication only when found in a nursery.
I am in the process of writing an advisory for ornamental plant growers. I am also doing some limited tests to see what can be done to reduce its impact. However, I wanted to get this out ASAP so people can be on the lookout. If you see it drop me a line here of by email (cawilen@ucanr.edu). I am very concerned that this snail will have a bigger impact on production and landscapes than the brown snail.
Description: White or light tan, about the side of a dime or nickel when full grown (sorry - I only had a quarter when I took the photo). May or may not have brown markings on the outside. Inside shell color of opening is light colored (milk snail looks similar but has a dark inside shell).
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![DSC02273 DSC02273](/blogs/blogcore/blogfiles/44978.jpg)
![DSC02269 DSC02269](/blogs/blogcore/blogfiles/44980.jpg)
By Brent McGhie, Butte Coounty Master Gardener, April 21, 2017.
To control snails, slugs and other pests, the University of California recommends that homeowners follow the Integrated Pest Management (IPM) process. IPM is a strategy that focuses on long-term prevention of pests by utilizing cultural, biological, mechanical and physical controls. With IPM, pesticides (chemical control) are used only as a last resort, and when pesticides are used, they are applied in ways that minimize harm to nontarget organisms, humans, pets, and the environment.
Cultural controls involve manipulating the environment to make an area less hospitable for a pest. In the case of snails and slugs, a good first step is to eliminate places they can hide during the day. Such hiding places include boards, stones, debris, weedy areas around tree trunks, leafy branches close to the ground and dense ground covers. If hiding places can't be eliminated, vegetable gardens and susceptible plants should be located as far from them as possible. Switching from sprinklers or flood irrigation to drip irrigation will also make the habitat less desirable for snails and slugs by reducing the humidity and moist surfaces they prefer.
Mechanical or physical controls kill a pest directly or block a pest from an area experiencing damage. In the case of snails and slugs, handpicking is an effective mechanical control if it is done on a regular basis. They can be searched out after dark with a flashlight and then either crushed in place or picked up with rubber gloves. Once they have been picked up, they can be placed in a bag and thrown away in the trash, or placed in a bucket of soapy water and disposed of in a compost pile after they are dead. Alternatively, if you are lucky enough to know someone with pet turtles, you can give your snails and slugs to them (as long as they are healthy) -- most turtle owners are happy to receive these pests, which add protein to the turtle diet. Those with backyard chickens may be similarly appreciative, as chickens, too, eat snails.
Another method of mechanical control is trapping. Traps don't have to be elaborate. Boards, flower pots and even melon rinds scattered throughout the garden will attract snails and slugs and then it is just a matter of scraping off the accumulated pests and destroying them every day or so, using the methods described above. Do not use salt to kill slugs and snails because is harmful to the soil. Another type of trap consists of a can or jar buried in the ground and baited with beer or a sugar-water yeast mixture. Because the liquid in these traps must be replenished every few days, and will only attract slugs and snails from an area within a few feet, they are not considered to be particularly effective.
Copper flashing or copper foil can be used as a physical barrier for slugs and snails. It is believed that copper is an effective barrier because it reacts with the slime of these pests, causing a disruption in their nervous system that is similar to an electric shock. These barriers should be at least four inches wide with the bottom buried in the soil to prevent slugs from crawling under them. Dry ashes or other abrasives such as diatomaceous earth can also be used as barriers for slugs and snails. Such abrasives should be piled about one inch high and 3 inches wide to be effective. However, these materials lose their deterrent value if they become damp, making them not very useful in most garden situations. Another drawback of wood ashes is that they are quite alkaline and can have a detrimental effect on soil pH.
Biological control involves using natural enemies to control pest populations. Snails and slugs have many natural enemies, but these beneficials are rarely effective enough to provide satisfactory control in the garden. Domestic fowl such as chickens, ducks, or geese can be effective snail predators, but will also eat seedlings and should be employed with this in mind.
Slug and snail baits can be applied as a last resort, but are most effective if used in conjunction with the IPM methods described above. There are other effective baits, but baits containing iron phosphate are the only ones that are safe for children, domestic animals, birds, fish and other wildlife. Iron phosphate baits are sold under many trade names including Sluggo and Escar-Go. The bait should be placed in moist areas that snails or slugs are likely to frequent. Timing is also important. If the weather is very hot, dry, or cold, baiting will have a limited effectiveness because slugs and snails are least active during these times. Take advantage of snail and slug habits by irrigating before baiting and scattering the bait in the late afternoon or evening.
For more information, consult:
http://ipm.ucanr.edu/PMG/PESTNOTES/pn7427.html
http://www2.ipm.ucanr.edu/WhatIsIPM/
http://ipm.ucanr.edu/PMG/H/I-SM-HASP-AD.017.html
- Author: Cheryl A. Wilen
[From the May 2013 issue of the UC IPM Green Bulletin newsletter]
For the last 30 years, the primary mollusk (snail and slug)
You can find this active ingredient in new formulations of Corry's Slug & Snail Killer as well as Dr. T's Slug & Snail Killer, Slugexx, Iron Fist Slug & Snail Bait, Amdro Snail Block Slug & Snail Killer, and Ferroxx. Ferroxx is marketed
Although all these active ingredients are effective against snails (Figure 1) and slugs (Figure 2), there are important differences. Metaldehyde works very quickly, and you will see foaming and dead snails by the morning if applied at night. However, metaldehyde can poison and even kill dogs and other mammals that might feed on it.
Iron phosphate is much safer but also much slower acting. Snails may stop feeding on plants after consuming iron phosphate baits but can take up to seven days to die. On the plus side, iron phosphate may be more effective than metaldehyde during periods of high humidity or if there are rainy conditions.
Also note that recommended application rates for ferric sodium EDTA may be considerably lower than iron phosphate (Table 2). Formulated iron phosphate and ferric sodium EDTA molluscicides look very similar, so it is important to check the label to be certain the product is applied at the appropriate rates. To be most effective, products containing the active ingredients metaldehyde, ferric sodium EDTA, or iron phosphate should be broadcast or spread, not piled, near areas where the mollusks are causing damage (Figure 3).
Applicators and maintenance workers should also be reminded to remove plant debris and other snail and slug hiding places and to avoid overwatering, which increases mollusk activity.
For more information about snail and slug management, see Pest Notes: Snails and Slugs. Briefer versions of this information, called Quick Tips, are also available on the UC IPM Web site both in English and Spanish.
This article was originally published in the May 2013 issue of the UC IPM Green Bulletin. See this and other articles at http://www.ipm.ucdavis.edu/greenbulletin/index.html.
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- Author: Jeannette E. Warnert
Some people believe eating low on the food chain is one way to help preserve the environment. And, in fact, livestock production consumes much more land and other resources per calorie than the production of plant foods.
A story on the website Bohemiam.com suggests it also makes sense to eat insects for improved dietary sustainability. Insects and other arthropods constitute an edible resource of tremendous biomass, the article said. Ants alone reportedly make up about a third of all terrestrial animal biomass.
Iowa State University's entomology department provides recipes for "rootworm beetle dip," which includes a cup of dried and roasted beetles. The site also has recipes for "banana worm bread," chocolate chip cookies with dried crickets crumbled into the dough and "mealworm fried rice," calling for equal parts rice and larvae.
Writer Alistar Bland got information for his story about the consumption of snails from a UC Davis website. Mainly known as a garden pest, snails were introduced into California from France in the 1850s as a food source. Snails may be sautéed in butter and garlic and served in the shell.
An eight-page UC publication is available for $1.50 from the UC Agriculture and Natural Resources catalog with instructions for raising and preparing snails for food.
![Common garden snails can be a sustainable food source. Common garden snails can be a sustainable food source.](/blogs/blogcore/blogfiles/5528.jpg)