Information for pest management professionals and pesticide applicators

Green Bulletinl l Vol. 1 No. 2 July 2010

Efficacy of Argentine Ant Treatments

uring the last several summers, UC Riverside ant control of the methods D entomologists John Klotz, Michael Rust, and Les tested here. Almost as Greenberg have tested several insecticide materials and good control was obtained methods to see which treatments most effectively control with 0.03% thiamethoxam Argentine ants around homes. liquid ant bait in KM AntPro bait dispensers. Ant numbers and effectiveness of treatments were (See the article on these estimated by the ants’ consumption of sucrose water put bait dispensers in the June out in vials over 24 hours. Previous studies have shown issue of UC IPM Green that 1 milliliter of consumption corresponds to about 3,300 Bulletin). This treatment, ant visits to the sucrose water. The vials are weighed before which almost eliminates and after to determine ant consumption. Control vials that runoff of pesticide product, did not allow ants to enter corrected for evaporation. would be the best from a water-quality point of view. One week, 2 weeks, 4 weeks, and 8 weeks after treatment, However, thiamexthoxam the vials were placed for 24 hours both around the house Figure 1. Applying a fan spray 1 foot up bait is not currently foundation and in the yard. Unless otherwise noted all and 1 foot out from a house foundation. registered for this use. treatments were sprays applied with a fan nozzle, which treats 1 foot up and 1 foot away from the house foundation (Fig. 1). Two treatments using fipronil alone applied at 0.06% were tested. These were a standard fan application treatment using Treatments, Efficacy and Water Quality Issues 3 gallons of fipronil and a 1-gallon application of fipronil Reduction of ants around the house foundation and in the using a pin stream spray applied as a narrow band 2 inches yard after 8 weeks for each treatment is shown in Figure 2 up and 2 inches out from the house foundation. Although the below. All treatments achieved acceptable control of ants near pin stream used one-third as much fipronil as the fan spray, the home. A combination treatment consisting of 3 gallons of this treatment was almost as effective in controlling ants. fipronil spray plus bifenthrin granules (2.3 pounds per 1,000 Furthermore, with this treatment there was very little runoff square feet) scattered under bushes and trees gave the best of the fipronil into the street, as shown by analyzing the irrigation runoff. Therefore, we have shown that pest control Figure 2. Percent Reduction in Ant Visits after 8 Weeks operators can reduce their use of fipronil to 1 gallon if it is carefully applied in a narrow band to the house foundation. Bifenthrin fan spray —Les Greenberg, Specialist, Department of Entomology, Fipronil fan spray + UC Riverside, [email protected] bifenthrin granules

Fipronil fan spray WHAT’S INSIDE ...

Fipronil pin spray Insecticides in Runoff | Page 2

Thiamethoxam in Just Released | Page 4 bait stations

0% 20% 40% 60% 80% 100% Ask the Expert | Page 4 Ants in the yard Ants near the home Page 2 | July 2010 from CaliforniaHomes Insecticides inRunoffWater family homes. At each site, grab ranging from 150to 500single- sizes ofthe neighborhoods these and four inOrange County, with neighborhoods inSacramento samplingThe sites included four Sample sites runoffin the water. ofoccurrence dominant insecticides we an take assessment initial on the InSouthern California. article, this neighborhoods inNorthern and runoff water drainingfrom large constituents were analyzed in (i.e., pathogens) and chemical goal, range awide of biological residential homes. To achieve this “health”the of runoff waterfrom generate adiagnostic snapshot of goals of projectprimary this was to (SWRCB).Board One of the Statethe Water Resources Control funding support from Fed Cal and Oki and Darren Haver, with and statewide project by led Loren kindisthis probably multiyear the The most comprehensive study of New California study strategies. as developing mitigation practical sources of contamination as well to focus their understanding the however, researchers have shifted to invertebrates. More recently, and potential the acute toxicity sediments and water columns such as pyrethroids, inurban presencethe of insecticides, studies generally demonstrated waterways Earlier by insecticides. increase incontamination of urban M consistently shown an during have decade this onitoring studies neighborhood inOrange County. Figure 1.Total pyrethroid concentrations (ppt or ng/L) inrunoff waterfrom a Sampling inmid-2006 started from homes these was collected. assuring that only runoff the water stormthe drain outfall points, samples were directly taken at neighborhood inOrange County. Figure 2.Relative makeup instorm of insecticides runoffsamples from a Whole water samples (including weekly, biweekly, or monthly basis. of 2008.Sampling on a occurred and continued through end the ... continued on Page 3 Page 3 | July 2010 ; ; and — Jay Gan, — Jay —Loren Oki, —Loren [email protected] Extension Center, [email protected] Water Quality Advisor, Quality Water Environmental Sciences, Environmental [email protected] UC Cooperative Extension UC Cooperative of Plant Sciences, UC Davis, Plant of Professor of Soil Science of and Professor UC Riverside, UC Riverside, —Darren Haver, Water Resources/ Water Haver, —Darren Orange and Riverside counties and and counties Riverside and Orange Director, South Coast Research and and Coast Research South Director, Landscape Horticulture Department Department Horticulture Landscape UC Cooperative Extension Specialist, Extension Specialist, UC Cooperative UC Cooperative Extension Specialist, Extension Specialist, UC Cooperative scarce, the few available studies studies the available few scarce, these metabolites that show even higher possess or similar the activities than biological and Fipronil compound. parent more much are metabolites its pyrethroids than soluble water a tendency for have therefore and move might and in water transport toxicity The distance. long over its and fipronil for thresholds to be established must metabolites assessment. risk better for allow found in runoff from the southern the southern in runoff from found and cyfluthrin addition, In sites. permethrin frequently also were a snapshot 3 is Figure detected. this pattern. demonstrating finding A significant and fipronil of finding The special of is metabolites its increasingly is Fipronil significance. applicators professional used by and termite in California for the environment, In control. ant to readily converted is fipronil fipronil i.e., metabolites, three fipronil and sulfide, fipronil sulfone, desulfinyl. still are values toxicity While In In The The In In Pyrethroids Fipronil and its metabolites metabolites its and Fipronil Higher levels in storm runoff. runoff. storm in levels Higher Most found insecticides. found Most High levels of fipronil and and fipronil of levels High n (and fipronil and bifenthrin general, always almost were metabolites) its combined levels were 200 to 440 200 to were levels combined to toxicity potential implying ppt, crustaceans. shrimplike n insecticides high of levels general, than runoff in storm present were is 2 Figure runoff. in irrigation the composition of example an runoff insecticidesof in storm the Orange of one from samples sites. County of parts per trillion (ppt) (ng/L) parts (ng/L) perof trillion (ppt) implying range—concentrations sensitive the most to toxicity acute 1 serves species. Figure invertebrate the Orange for example an as sites. County n California Southern in metabolites runoff. all from in samples appeared always median The sites. County Orange Southern California runoff. California Southern in pyrethroids of levels total were County Orange runoff from in the severaltypically hundreds Fipronil Organophosphates were regularly found found regularly were In general, higher general, In Southern vs. Northern vs. Northern Southern Both pyrethroid and fipronil fipronil and pyrethroid Both High levels of pyrethroids in in pyrethroids of levels High n were often severalfold, depending depending severalfold, often were sites, the specific compounds, on time. sampling and Orange County sites than at the at than sites County Orange differences The sites. Sacramento California. fipronil and pyrethroids of levels the at found consistently were at both Northern and Southern Southern and both Northern at Californiasites. n n insecticides Based on preliminary data assessment, assessment, data Based preliminary on or observations the following becan made: conclusions watersheds. watersheds. insecticides dominant The unprecedentedly large data sets on sets on data large unprecedentedly urban in pesticide contamination concentrations. A total of 69 to 69 to of A total concentrations. analyzed were per site 98 samples yielding years, two than more over ... continued from Page 2 Page from ... continued extracted were solids) suspended total obtain to analyzed and Figure 3. Frequency of detection in runoff from a neighborhood in Orange County. neighborhood Orange in a runoff in detection from of Frequency 3. Figure Ask the Expert! Just Released! C has recently released several updated I understand that currently the main U IPM Pest Notes publications of interest to Q problem with pyrethroid insecticides landscape or structural pest managers or their is that they kill tiny crustaceans when customers. View them at www.ipm.ucdavis.edu/ contaminated runoff gets in creeks PMG/menu.homegarden.html. They include: and streams. Why is this a problem? n Bordeaux Mixture; Even though many people rarely see these tiny, aquatic invertebrates, they are very important in the n Crabgrass; Redhumped Integrated Pest M CateRpillaR A anagement for Home Gardeners a nd Landscape Professionals food chain, or pyramid, that supports fish, birds, and The redhu mped caterpillar, concinna, is found throughoutSchizura much of California. Although the cl coastal regions usu imate of the LIFE CYCLE n development of destructially doesn’t favor In autumn, caterpillars drop to th tions, it can b ve popula e a serious problem in -the ground and s e Creeping Woodsorrel and warm Centra pin silken cocoons. They other wildlife (Fig. 1). In fact, pyrethroids are also l Valley. This pest most remain inside the cocoons duri commonly attacks liquidambar (sweet ter and transform into pupae in ngs win- gum), walnut, and plum trees, but you pring. also can find them on almond, apple, Moths begin emerging from pupae in apricot, birch, c herry, cottonwood, pear, April and May. They mate, and each prune, redbud, willow, and others, Figure 1. Redhumped caterpillar egg female can lay more than 200 eggs. especially where insecticid cluster. The eggs hatch into tin very toxic to fish, so the presence of pyrethroids at es applied Bermuda Buttercup; to control other pests h y caterpillars that feed, grow, a ave killed their nd then drop to the natural enemies. ground to pupate. There are often as many as four or five generations per IDENTIFICATION year. Redhumped ca The redhumped cat be more abundant a terpillars seem to stages of development—egg,erpillar has larva four fter a warm winter. levels that kill the smaller organisms gives us warning (caterpillar), p upa, and adult (moth). DAMAGE Adults lay eggs, which are near Upon hatching, caterpillars feed in spherical and pearly whit ly groups on lower leaf surfa colored, in groups of 25 toe 100 to creamon the n etonize the leaves (Fig. 5). Asces th and skel undersides of younger leaves (Fi - Figure 2. Redhumped caterpillar l become larger, they tend to dispe larvae g. 1). Fleas; arva. and consume the entire leaf, leavingerse that even more serious environmental problems Caterpillars (Fig. 2) are 1 to 1 only the tough, woody veins. When long when fully 1 /2 inches grown and have a base infestation is light, larvae eat leaves on color of yellow. Longitudinal only a few branches, but occasi dish brown, or sometimes bl white, red - heavy infestation develops that onallydefoli a mark the body. The h ack stripes ead is usually or ates entire tree - ange or brick red, as i - s. segment, which is distinctlys the fourth humped body will occur if we don’t change our pest management Most severe defoliation occurs during and has two prominent, black tubercles (spines). Each body se the summer. Even if completely defo n less distinctive black tugment also has liated, trees that are otherwise healthy- bercles. Caterpil usually recover. When defoliation oc- lars rest with their hind end - elevated. Figure 3. Redhumped caterpillar curs on walnuts, the nuts are subject Nematodes; pupa. to sunburn. practices. The pupa (Fig. 3) is reddish brown, a little more than 1 /2 inch long, and enclosed in a silken cocoon in the organic debris soil or in the layer of covering the soil. Adult moths (Fig. 4) have a wingspan of 1 3 to 1 /8 inches. The forewings are reddish to grayish brown and often are darkest along the hind margin. The hind wings n are off white to light gray or brown. Redhumped Caterpillar; Figure 4. Redhumped caterpillar moth. Figure 5. Redh umped caterpillar feeding on walnut showing a EST skeletonized leaf. PUniversity of California OTES Statewide Integrated N Pest Management Pr Publication 7474 Agriculture and Natural Resources Tertiary ogram n consumers Sycamore Scale; June 2010 feed on fish

Secondary n consumers Voles (Meadow Mice); feed on the primary n consumers Windscorpions; and

Tiny insects or n crustaceans are Wood-boring Beetles in Homes. the primary consumers

Algae and other plants

Figure 1. The aquatic food pyramid in balance (left) and disturbed (right).

How can I tell if the insecticides Q I am using are pyrethroids? None of the pesticides I am using says “pyrethroid” on the label.

“Pyrethroids” is the name given to a group of A insecticides that mimic the action of the botanical insecticide pyrethrin, which is derived from chrysanthemum daisies but is more persistent in University of California Supported by the University of the environment. To determine if the pesticide is Statewide IPM Program California Statewide IPM Program One Shields Avenue and the California Department of a pyrethroid, look at the active ingredient listed Davis, CA 95616-8621 Pesticide Regulation through the in small type on the pesticide label. Common Urban Pesticide Runoff Mitigation Phone: (530) 752-8350 and Outreach Project. pyrethroid active ingredients often, but not always, The contents of this document E-mail: [email protected] do not necessarily reflect the views end in “-thrin” such as bifenthrin, cypermethrin, and policies of UC IPM or CDPR permethrin, cyfluthrin, and deltamethrin. Pyrethroid Online: www.ipm.ucdavis.edu nor does mention of trade names or commercial products constitute insecticides are sold under many brand names, so it endorsement or recommendations is important to find the active ingredient. for use.

If my clients ask for information on health or environmental impacts of The University of California prohibits discrimination against or Q harassment of any person on the basis of race, color, national origin, the pesticides I am applying, is there a religion, sex, physical or mental disability, medical condition (cancer good resource that I can send them to? related or genetic characteristics), ancestry, marital status, age, sexual orientation, citizenship, or status as a covered veteran (special disabled veteran, Vietnam-era veteran, or any other veteran who served on active Yes, the National Pesticide Information Center is a duty during a war or in a campaign or expedition for which a campaign badge has been authorized). good place to start. They have lots of information University policy is intended to be consistent with the provisions of A applicable state and federal laws. on their Web page, http://npic.orst.edu. They even Inquiries regarding the university’s nondiscrimination policies can have a toll-free phone number, 1-800-858-7378. be directed to the Affirmative Action/Staff Personnel Services Director, University of California, Agriculture and Natural Resources, 300 Lakeside

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