December 2001, Issue No. 188 A monthly report on environmental and pesticide related issues To see this report in Portable Document Format (PDF), please click on the button. Should you not have Adobe Acrobat Reader (required to read PDF files), this free program is available for download at http://www.adobe.com/prodindex/acrobat/readstep.html Open Forum: In an attempt to promote free and open discussion of issues, The Agrichemical and Environmental News encourages letters and articles with differing views. To discuss submission of an article, please contact Dr. Allan Felsot at (509) 372-7365 or afelsot@tricity.wsu.edu; Dr. Catherine Daniels at (509) 372-7495 or cdaniels@tricity.wsu.edu; Dr. Doug Walsh at (509) 786-2226 or dwalsh@tricity.wsu.edu; or Dr. Vincent Hebert at (509) 372-7393 or vhebert@tricity.wsu.edu. The newsletter is available in a hard copy version for a $15 yearly subscription fee. Please contact newsletter editor Sally O'Neal Coates at (509) 372-7378 or scoates@tricity.wsu.edu for details. In This Issue Pesticide Illness Data 1995-1999, Part 2 AENews Goes 100% Electronic Pesticide Safety and Beneficial Arthropods Strobilurin Fungicides: Tools for Fruit Disease Management Bug of the Month: Damsel Bug Upcoming Conferences Pesticide Applicator Training PNN Update Return to Agrichemical and Environmental News Index Return to PICOL (Pesticide Information Center On-Line) Home Page Pesticide Illness Data 1995-1999, Part 2 Jane C. Lee and Bill Mason, Washington State Department of Health For more than a decade the Washington State Department of Health (DOH) has investigated suspected pesticide-related illnesses. Health care providers are required to report incidents of illness associated with pesticide exposure. From January 1, 1995 through December 31, 1999, DOH investigated 1,818 incidents of pesticide illness, involving 2,246 individuals (Table 1). An incident is a pesticide illness involving one or more individual cases. TABLE 1 Annual Number of Pesticide Incidents Investigated by DOH Year Number of Investigations (incidents) Number of Persons Affected (cases) Number of Definite, Probable and Possible cases 1995 396 500 213 1996 398 500 233 1997 363 439 212 1998 390 475 213 * Limited to cases with illness classified by DOH as definite, probable, and possible due to pesticide exposure.   DOH classifies the relationship of symptoms to exposure with the following categories: Definite cases require a high degree of correlation between a pesticide exposure and resulting symptoms (clinical and/or environmental evidence). Probable cases are similar to definite cases, but lack conclusive objective evidence. Possible cases are those in which an exposure was present but ambiguity exists between exposure and reported symptoms. Symptoms may be non-specific and other possible etiologies may be present. Unlikely cases are those in which symptoms are not believed to be due to the reported exposure, but pesticide exposure cannot be ruled out. Unrelated cases are either those in which no pesticide exposure occurred (e.g., product was a fertilizer) or in where the health effects were determined to be caused by another agent. Asymptomatic cases are those in which exposure occurred but no symptoms resulted. Unknown cases are those for which insufficient information was available. Of the 2,246 cases, 1,011 (45%) were classified as definite, probable, or possible, based on the relationship between the symptoms and the pesticide exposure (Table 2). This article summarizes cases investigated by DOH that occurred in agriculture. The July 2001 Agrichemical and Environmental News (Issue No. 183) summarized non-agricultural cases. TABLE 2 Agricultural and Non-Agricultural Definite, Probable, and Possible Cases Year Agricultural Non-Agricultural Total* 1995 90 123 213 1996 97 136 233 1997 93 119 212 1998 102 111 213 1999 68 72 140 Total 450 561 1,011 * Limited to cases with illness classified by DOH as definite, probable, or possible due to pesticide exposure.   Separating Agricultural Cases From 1995 through 1999, DOH received reports of 1,163 cases of suspected pesticide-related illness occurring in the agricultural environment (992 occupational and 171 non-occupational). These occurred among individuals where the application was intended for an agricultural commodity. This includes fruit, field crops, greenhouse, nursery, bulb farms, shellfish, and forest operations. DOH classified 450 of these as definite (98), probable (109), or possible (243). The cases included 353 males and 97 females. Sixty-one percent of the illnesses were male workers aged 18 to 49 (Table 3). Most received medical care for their illness: 204 (45%) at emergency rooms, 54 at physicians’ offices, and 110 at walk-in clinics. Two were hospitalized and 80 did not seek medical care. TABLE 3 Occupational and Non-Occupational Agricultural Cases* by Age and Sex Age Occupational Non-Occupational Total Female Male Female Male 0-5 0 0 1 4 5 6-11 0 0 2 6 8 12-17 0 1 1 2 4 18-29 27 132 3 1 163 30-49 33 146 13 12 204 50+ 7 30 10 19 66 Total 67 309 30 44 450 * Limited to cases with illness classified by DOH as definite, probable, and possible due to pesticide exposure.         DOH received 211 reports of agricultural pesticide-related illnesses from the Department of Labor and Industries, 120 from Washington Poison Center, 70 from Washington State Department of Agriculture, and 49 from other sources. Geographic Distribution The 450 cases occurred in 28 of the 39 counties of Washington, with the majority (88%) occurring in eastern Washington (Table 4). The counties with the most cases were Yakima (132), Grant (62), Chelan (34), Franklin (34), and Okanogan (30). TABLE 4 Occupational and Non-Occupational Agricultural Cases* by Location   Occupational Non-Occupational Total East 334 60 394 West 42 14 56 Total 376 74 450 * Limited to those classified definite, probable, or possible due to pesticide exposure. Severity of Cases Sixty-seven percent of the cases had mild medical outcomes (Table 5). These frequently involved eye irritation, headache, shortness of breath, coughing, and/or nausea. One hundred thirty-three experienced moderate symptoms; 14 were severe. All 14 cases classified as severe were occupational: six were orchard workers, six were field workers, one was an ornamental tree applicator, and one was an irrigation technician. Seven resulted from drift exposure; five from inadequate personal protection during application, mixing, or loading; one from residue exposure while thinning; and one from walking into a field during an application. TABLE 5 Classification by Severity   Mild Moderate Severe Total 1995 32 54 4 90 1996 68 28 1 97 1997 73 18 2 93 1998 71 25 6 102 1999 59 8 1 68 Total 303 133 14 450 Type of Activity The largest number of illnesses (174) was related to pesticide application, mixing, and loading. Exposure to pesticide drift was the second (151) greatest cause of illness and was responsible for the majority (76%) of the non-occupational agricultural cases. The pesticide residues category (18%) represents the third largest source of exposure. TABLE 6 Occupational and Non-Occupational Agricultural Cases* by Type of Pesticide Exposure Activity Occupational Non- Occupational Total Applicator/ Mixer/Loader 173 1 174 Drift 95 56 151 Residues 74 7 81 Cleaning/ Fixing 10 0 10 Fumigation Field 4 1 5 Accident 14 3 17 Other 6 6 12 Total 376 74 450 *Limited to cases with illness classified by DOH as definite, probable, or possible due to pesticide exposure.   Symptoms Reported Table 7 shows the symptoms reported by category. The most frequently reported (55%) occupational health complaint was eye irritation; it was reported by 64 percent of the applicator, mixer, and loader cases. Eye irritation was also reported in 45 percent of the occupational drift cases. Eighty percent of the cases involving cleaning or fixing reported eye irritation. TABLE 7 Symptoms* by Activity, Occupational (O) and Non-Occupational (N) Agricultural Cases    Eye Systemic Skin Respiratory Other O N O N O N O N O N Applicator/ Mixer/Loader 110 1 74 0 77 1 39 0 34 0 Drift 43 33 78 41 25 9 44 29 8 7 Residue 33 0 34 4 38 3 27 2 10 4 Cleaning/Fixing 8 0 3 0 2 0 1 0 0 0 Other/Unknown 11 4 7 5 2 6 6 0 1 3 Total 205 38 196 50 144 19 117 31 53 14 * Individuals frequently report more than one symptom. Systemic effects were the second most frequently reported category of illness. Fifty-two percent of the occupational cases and 68 percent of the non-occupational cases reported systemic effects, which can include headache, nausea, and/or dizziness. Systemic effects were also present in 82 percent of the occupational and 73 percent of the non-occupational drift cases. Of the cases where individuals were exposed to pesticide residues, 51 percent reported skin irritation, 47 percent reported systemic effects, 41 percent reported eye irritation, and 36 percent reported respiratory effects. Applicator, Mixer, and Loader Cases From 1995 to1999, DOH received 320 reports of suspected agricultural pesticide-related illness involving applicators, mixers, and loaders. Of that number, 174 (54%) were considered definite, probable, or possible cases. Ninety-nine percent (173) occurred on the job: 122 from ground applications, 26 from miscellaneous uses, and 25 through mixing or loading. Sixty percent (103) of these cases occurred in the tree fruit industry, 46 occurred in field crops, and 24 were associated with other agricultural commodity groups. Seventy-one of the applicator/mixer/loader cases in fruit were considered mild, 30 were considered moderate, and two were considered severe. In field crops, 34 were mild, 10 were moderate, and two were severe (both of the severe cases were mixers/loaders). (See Tables 8 and 9.) The following examples of cases illustrate the variety of ways that exposure occurred, resulting in illness to pesticide applicators, mixers, and loaders: Pesticide drifted under shirt collar onto neck during application. Not wearing Personal Protective Equipment (PPE) when spraying. Applicator wearing PPE finished spraying, took off PPE, then had an asthma attack after smelling the pesticide. Poor condition of safety goggles. Wore PPE but removed goggles and rubbed eyes. Splash in eye while spraying. Used work shirt to wipe sweat from head causing skin irritation. Unlicensed farmworker applicator not wearing PPE developed conjunctivitis. Severe skin burn to foot after applying and not wearing rubber boots. Applicator wore respirator but no goggles after applying in a grain bin. Developed severe eye irritation. TABLE 8 Fruit Production Cases* by Severity and Activity    Severity of Occupational Cases Severity of Non-Occupational Cases Total Mild Moderate Severe Mild Moderate Severe Applicator/ Mixer/Loader 71 29 2 1 1 0 104 Drift 23 22 3 28 4 0 80 Residue 37 15 1 2 1 0 56 Accident 4 2 0 3 0 0 9 Other 6 6 0 1 1 0 14 Total 141 74 6 35 7 0 263 *Limited to cases with illness classified by DOH as definite, probable, or possible due to pesticide exposure. TABLE 9 Field Crop Cases* by Severity and Activity    Severity of Occupational Cases Severity of Non-Occupational Cases Total Mild Moderate Severe Mild Moderate Severe Drift 13 23 4 13 1 0 54 Applicator/ Mixer/Loader 34 10 2 0 0 0 46 Residue 3 2 0 0 0 0 5 Accident 2 1 0 0 0 0 3 Total 52 36 6 13 1 0 108 *Limited to cases with illness classified by DOH as definite, probable, or possible due to pesticide exposure. Drift Cases From 1995 to 1999, 151 definite, probable, or possible cases of agricultural pesticide illness were due to exposure to pesticide drift. Of these, 95 were occupational: 49 in fruit production, 40 in field crops, four in nursery and greenhouses, and two in livestock. Of 56 non-occupational drift cases, 32 resulted from applications to fruit, 14 to row crops, seven to berries, and three to forests. The 95 occupational drift cases were classified as definite (14), probable (25), or possible (56). The severity of symptoms reported was 39 mild (41%), 49 moderate (52%), and 7 severe (7%). This compares to 63% mild, 33% moderate, and 4% severe for all occupational agricultural cases. Descriptions of the seven severe drift cases follow: Three farmworkers (tying apple trees) became ill after an aerial application to a neighboring potato field drifted. Two of seven apple orchard thinners experienced drift from an application to another section of the orchard. The two workers received medical treatment. An irrigation technician became ill from an aerial application that drifted. He was treated for organophosphate poisoning. Two field workers inadvertently walked into a field during an application. They were not wearing PPE and became ill; one was classified as severe. Residue Cases From 1995 to 1999, 81 agricultural cases resulted from exposure to pesticide residues; 74 were work-related. These occurred in the production of fruit (56), field crops (5), and vegetables (4); in nursery or greenhouse situations (11); and under other circumstances (5). Exposure to pesticide residues was the most reported cause of pesticide poisoning on the job (394 reports), but only 19 percent of these illnesses were definitely, probably, or possibly related to the exposure. The majority of these cases affected farmworkers who became ill after picking, thinning, or pruning in orchards. The illnesses may have been due to exposure to pesticide residues on foliage, irritation from foliage or branches, heat, exhaustion, a pre-existing condition, or an infection. Pesticide residue may be present hours to days after an application, and can be in the air, soil, dust, or on vegetation. The following are examples of illnesses reported from exposure to pesticide residues (these examples include all reported cases, not just definite, probable, or possible ones): Farmworker developed eye irritation and headache after working in a hop yard. He saw a doctor eight days later. Spray records showed that a fungicide was applied five days before contact. Farmworker thinning pear trees developed a rash and itching. Farmworker thinning apple trees developed shortness of breath and wheezing. He saw a doctor two days later. Spray records showed last application was four days before symptoms. Farmworker covering apples with paper bags developed hives all over body. Nursery worker mowed lawn 24 hours after herbicide application. The re-entry interval (REI) was 48 hours. A farmworker drove through an apple orchard within the REI. An apple thinner became ill. Spray records showed that a pesticide application was made 48 hours earlier. He saw a doctor eight days after symptoms began. Farmworker on a tractor reported symptoms possibly related to exposure from entering a hop field spayed two hours earlier with a miticide. He was not wearing PPE, the REI had not expired, and he did not see the warning signs. The severity of symptoms for the occupational cases with exposure to pesticide residues was predominately mild (72%), with some moderate cases (27%) and one severe case. The severe case resulted from exposure to pesticide residue while thinning trees. DOH classified the case as possible. The seven non-occupational cases were considered mild (6) and moderate (1). Crops Involved The 450 agricultural definite, probable, or possible cases resulted from pesticide applications to fruit (263), field crops (108), nursery/greenhouses (29), berries (10), vegetables (8), livestock (6), forest (6), fire/flood/disaster (5), tree farms (2), and unknown (13). Cases Resulting from Applications to Fruit The greatest number (263) of pesticide illnesses in agriculture occurred in the production of tree fruit; 221 occurred on the job and 42 were not work-related. Pesticide applications (primarily ground applications), mixing, and loading were involved in 104 cases, 80 were attributed to drift, 56 to field residues, and 23 to other causes. Table 8 (above) lists the severity of the cases resulting from applications to fruit. The majority of cases occurred in the production of apples. Other tree fruits included pears, cherries, and apricots. Most cases were classified as mild (141 or 64%) or moderate (75 or 34%). Six were severe. Of the six severe cases, three related to drift, two to ground applications, and one to residues. Cases Resulting from Applications to Field Crops One hundred and eight cases were due to application of pesticide to field crops; 94 were on the job. (Field crops refer to wheat, barley, potatoes, beans, hops, hay, lentils, sugar beets, etc.) Drift was most frequently associated with pesticide illness (54 cases), followed by applicator/mixer/loader (46), residues (5), and accidents (3). Most (94%) cases involved mild (52) or moderate (36) symptoms, with six reporting symptoms of greater severity. All fourteen non-occupational cases related to field crops resulted from drift and most (13) had mild symptoms (Table 9, above). Cases Occurring in Nurseries or Greenhouses From 1995 to 1999, 25 occupational incidents occurred in nurseries or greenhouses, involving 29 cases; 16 were male and 13 were female. The majority (80%) occurred in western Washington, with five each in Skagit and Snohomish counties. Eleven cases occurring in greenhouses and nurseries were due to exposure to residues, seven were due to applications, four to drift, three to mixing or loading, two to cleaning or fixing equipment, and two to other causes. The majority of cases reported mild symptoms (79%); 17 percent reported moderate symptoms and one case was severe. The most frequently reported complaint was eye irritation. Similar to other agricultural cases, the routes of exposure were eye (9), inhalation (7), dermal (1), and ingestion (1). The remaining cases were a combination of exposure routes. Conclusions From 1995 through 1999, the Washington State Department of Health investigated 1,163 cases of pesticide illness in the agricultural environment. 450 cases were classified as definite, probable, or possible. 84% of cases were occupational. 97% of individuals reported mild or moderate symptoms. (The most frequently reported health complaints were eye irritation and systemic effects.) Most incidents resulted from exposure during applications, pesticide drift, or exposure to residues. Locations of Incidents 263 cases occurred in the production of tree fruit. 108 cases occurred in the production of field crops. 29 cases occurred in nursery/greenhouse environments. Risk Factors Identified Lack of eye protection. Removing personal protective equipment (PPE) too soon. Inadequate PPE. Prevention Messages Be certain that people are not present during applications. Use pesticides as directed on the label. The annual average number of cases investigated over the last five years is 360. Of this number, two hundred individuals annually experience some measure of pesticide-related illness. Though this number is relatively small compared to the number of uneventful pesticide applications made statewide, efforts should continue to provide intervention measures to the public and pesticide user community. Jane C. Lee and Bill Mason are with the Washington State Department of Health, http://www.doh.wa.gov. The Pesticide Incident Reporting and Tracking (PIRT) review panel created by the state legislature coordinates pesticide-related investigations. For more information, please contact PIRT coordinator Jane C. Lee at (425) 453-1340 or jane.lee@doh.wa.gov. Return to Table of Contents for the December 2001 issue Return to Agrichemical and Environmental News Index Return to PICOL (Pesticide Information Center On-Line) Home Page After 30 Years in Print, Next Month AENews Goes 100% Electronic Beginning January 2002, Agrichemical and Environmental News will be available in electronic format only, on the Internet at URL http://aenews.wsu.edu. If you have been receiving a paper copy of this newsletter, you will now need to log onto the Internet to read it. This decision represents good news and bad news both for the production staff at Washington State University’s Pesticide Information Center and for you, the reader. From the staff’s perspective, the bad news is that resources are simply not available to continue printing the paper version of the newsletter. The good news is that the readership of our electronic version has increased dramatically, with electronic “subscriptions” (more on those in a moment) doubling each of the past two years. From your perspective as a reader, the good news is that the electronic edition is free. The bad news is, well, we are all going to miss the paper version. Agrichemical and Environmental News’ electronic format will evolve in the months ahead. Initially, we will be eliminating the PDF (portable document format) version and publishing an HTML (hypertext markup language) version only. Current readers of the electronic version will notice very few other changes, except that we will no doubt take greater advantage of the Internet’s ability to offer color photographs and other visual enhancements. However, AENews has always been, and will continue to be, a content-driven publication. We will continue to emphasize original, accurate information and analyses over graphic style. Some of our electronic version readers like to receive an e-mail notification when each month’s new issue goes on-line. We call this our “electronic subscription,” and it has become a very popular (free) service. If you would like to take advantage of this monthly reminder, please send an e-mail to majordomo@tricity.wsu.edu, with body of message reading "subscribe aenews_dist". Make sure nothing (not even a signature line) follows the subscribe message. To unsubscribe, simply do the same thing with the message unsubscribe aenews_dist. (These directions are also written at the top of the AENews home page.) This mailing list is not used for any other purpose, the messages are screened, and no other user will be able to see your e-mail address or contact you. Should you have any comments on the electronic version of AENews, please contact Managing Editor Catherine Daniels at (509) 372-7495 or cdaniels@tricity.wsu.edu or Editor Sally O’Neal Coates at (509) 372-7378 or scoates@tricity.wsu.edu. Return to Table of Contents for the December 2001 issue Return to Agrichemical and Environmental News Index Return to PICOL (Pesticide Information Center On-Line) Home Page Pesticide Safety and Beneficial Arthropods Dr. David G. James, Entomologist, WSU In the February 2001 issue of Agrichemical and Environmental News, Jennifer Coyle and I presented the first results from a new entomological and pesticide research program being conducted at Washington State University’s Irrigated Agriculture Research and Extension Center (IAREC) in Prosser (2). This program, funded by the Washington Hop Commission, the Washington Association of Wine Grape Growers and the Washington State Commission on Pesticide Registration, aims to identify pesticides (insecticides, miticides, fungicides) that are safe to common beneficial insects in Washington’s vineyards and hop yards. Identification of safe pesticides is essential to the development of integrated pest management (IPM) programs, which are currently being researched in both crops. This article presents our latest findings on the safety of various pesticides to five species of beneficial insects and mites. Both laboratory data and field monitoring data will be presented. I will also discuss results from the study that have immediate, practical significance to hop and grape growers. Methodology We based our decisions as to the relative safety of various pesticides on a sensitive laboratory bioassay technique (described in detail in the February article). The five species on which our study focuses include three predatory mites (Galendromus occidentalis, Neoseiulus fallacis, Amblyseius andersoni) and two predatory lady beetles (Stethorus picipes, Harmonia axyridis). G. occidentalis, N. fallacis, A. andersoni and S. picipes are important predators of spider mites in Washington hops and grapes, while H. axyridis is a predator of aphids. From April through September 2001, effects of the new miticides bifenazate (Acramite) and fenpyroximate (Fujimite) and the insecticides pymetrozine (Fulfill) and imidacloprid (Provado) on populations of predatory mites and the overall complex of beneficial arthropods were evaluated in three commercial hop yards. Populations of spider mites, predatory mites, hop aphids, and total beneficial arthropods were sampled weekly. For mites and aphids, we collected thirty leaves at random from each yard on each visit, then examined the leaves under a stereomicroscope and recorded the numbers of mites and aphids. For the total beneficial arthropod count, we randomly selected nine bines each week (three bines in each of three locations) and shook them vigorously to dislodge arthropods onto a collecting tray, from which they were aspirated and placed in alcohol for identification and counting in the laboratory. Groups and families of beneficial arthropods recorded include mature and immature stages of lady beetles (Coccinellidae), lacewings (Neuroptera), predatory bugs (Nabidae, Miridae, Pentatomidae, Anthocoridae), predatory thrips (Thripidae), parasitic wasps (Hymenoptera), whirligig predatory mites (Anystidae) and spiders. All of these arthropods are known to feed on herbivorous insects and mites and thus may play a role in suppressing pest outbreaks (e.g., mites, aphids, caterpillars) in hop yards. Cooperating growers provided us with records of spray applications at the end of the season. Results Safety ratings of pesticides (at full field rates) to the beneficial arthropods tested to date are shown in Table 1 at the end of this article. Most miticides were harmful to the beneficial arthropod species with only hexythiazox (Savey), propargite (Omite), and bifenazate (Acramite) having moderate or low toxicities. Similarly, most insecticides were harmful except for pymetrozine (Fulfill) and, to a lesser extent, pirimicarb (Pirimor). The synthetic fungicides, myclobutanil (Rally), trifloxystrobin (Flint), and quinoxyfen (Quintec) were non-toxic but the sulfur compounds varied from harmless to very harmful, depending on the beneficial species tested. Bifenazate and pymetrozine had minimal impact on the abundance of predatory mites or the overall community of beneficial arthropods in the monitored hop yards (Figures 1-3). In contrast, fenpyroximate had an adverse impact on populations of beneficials (Figures 2-3). Imidacloprid (at one quarter of the recommended rate) appeared to reduce the overall community of beneficial arthropods (Figure 2). However, predatory mite (mainly G. occidentalis) numbers increased substantially following the use of this insecticide (Figure 4). FIGURE 1 Effect of bifenazate (Acramite) on the beneficial arthropod community in Hop Yard 1 during 2001. FIGURE 2 Effect of selected pesticides on beneficial arthropod communities in Hop Yards 2 and 3 during 2001. FIGURE 3 Effect of selected pesticides on predatory mite populations in Hop Yard 2 during 2001 FIGURE 4 Effect of selected pesticides on predatory mite populations in Hop Yard 2 during 2001. Implications Eighteen months after its inception, this project has resulted in the creation of a significant and rapidly expanding database on the toxicity of commonly used and new pesticides on some important beneficial arthropods resident, or potentially resident, in Washington hop yards and vineyards. The three predatory mite and two lady beetle species are also important in other agroecosystems in Washington, extending the relevance of this project to other industries. I believe the safety tables are a good guide to the compatibility of specific miticides, insecticides, and fungicides to biological control and IPM. Certainly the field data thus far obtained for bifenazate, fenpyroximate, pymetrozine, and imidacloprid support the conclusions provided by laboratory bioassays. Fenpyroximate, bifenazate, and pymetrozine were available to hop growers under a Section 18 for the first time in 2001. They are likely to become the basis for mite and aphid management in hop yards for the next few years. These compounds were chosen for use in hops due to their efficacy against target pests and their relative compatibility with biological control agents, using information gained from the WSU project. Bifenazate is an effective miticide and also appears to be relatively safe to beneficial arthropods. It is labeled for use at 0.75 to 1.5 lbs/A (pounds per acre). In laboratory tests, the highest labeled rate of this compound (1.5 lbs/A) did not kill 100% of the predatory mite and lady beetles species tested; around 50% mortality was usual. At the lower rates of 0.75 and 1.0 lb/A, mortalities were usually below 33% for most species. This contrasts with the industry standard miticide, abamectin, which, when used at full rate in laboratory tests, consistently resulted in 100% mortality. Furthermore, field evidence in 2001 indicated bifenazate at the lower rates had very little effect on G. occidentalis or the beneficial arthropod community in general. Bifenazate, therefore, appears to be a very useful IPM tool for mite (and aphid) management in hops. For the first time, hop growers have an effective miticide that kills motile stages, but does not destroy the beneficial arthropod complex. Consequently, biological control using endemic natural enemies can be considered an additional control tactic when this miticide is used. The appropriate timing for use of bifenazate in a hop IPM program is likely to be mid-season (July) if natural enemies appear to be struggling to control mites. A well-timed application should reduce mite numbers, while allowing the natural beneficial arthropods to take over control during August. Bifenazate will soon be registered for use in wine grapes where it will provide the same opportunities for improvements in IPM. In laboratory tests and field studies, fenpyroximate (Fujimite), the second new miticide, appears to be far more harmful to beneficial arthropods than bifenazate. All rates of fenpyroximate gave 100% or near 100% mortality to all the beneficial species tested in the laboratory. This severe effect on beneficials appeared to be confirmed by the sampling data from Hop Yard 2. The use of fenpyroximate in hop IPM is best reserved for rescue treatments when biological control is not working and bifenazate cannot be used (bifenazate use is currently restricted to one application per season). Pymetrozine is an aphicide combining good efficacy with great safety to beneficial arthropods. In laboratory tests, the full rate had low toxicity to all the beneficial species tested. This selectivity to beneficials was further demonstrated by observations in Hop Yard 2 where neither G. occidentalis or the general beneficial arthropod community were adversely affected. Pymetrozine is intended to be an alternative to imidacloprid for aphid control on hops. Imidacloprid is generally harmful to beneficial arthropods even at reduced rates (see below). In addition, evidence is accumulating to suggest it is a stimulant to spider mite oviposition (3). The low impact of pymetrozine on beneficial arthropods makes it an important component of IPM in hops. As reported in the February 2001 issue of Agrichemical and Environmental News, imidacloprid at the full field rate is harmful to predatory mites and lady beetles (2). For experimental purposes, we observed the effects of imidacloprid applied at one-quarter rate in Hop Yard 3. This rate appeared to have a detrimental impact on the overall beneficial arthropod community, but not on the predatory mite G. occidentalis. This latter predator showed a spectacular increase in population size after exposure to imidacloprid. Besides being implicated in stimulating oviposition in spider mites (3), imidacloprid is known to increase egg laying in at least one species of predatory mite (1). Thus, it is possible that a reduced rate of imidacloprid, instead of killing G. occidentalis, increases oviposition and population development. Obviously, further research is required. Using rates below the labeled rate is not recommended, and could in fact lead to resistance development. In hops and grapes, use of the systemic formulation of imidacloprid is encouraged, because of its likely reduced impact on beneficials compared to the foliar-applied formulation (Provado). The toxicity of lime and/or wettable sulfur to predatory mites is of particular significance to grape growers, many of whom routinely use these materials for powdery mildew control. Adverse impacts of sulfur on predatory mite populations have also been seen in field studies in vineyards, particularly when sulfur is the only material used for disease control, and multiple applications are made. Early-season sulfur and broad-spectrum insecticide (e.g., carbaryl, chlorpyrifos, methomyl) applications, all of which are toxic to the beneficial arthropods we have examined so far, are probably one of the major reasons why secondary pests like spider mites are a problem in Washington vineyards. Hopefully, this project in due course will identify vineyard pesticides that are more compatible with IPM/biological control, improving the prospects for reduced chemical inputs in the way that bifenazate and pymetrozine have done for hops. Dr. David James is with WSU’s IAREC facility in Prosser. He can be reached at (509) 786-9280 or djames@tricity.wsu.edu. Acknowledgments I wish to thank Jennifer Coyle, Tanya Price, Larry Wright, Joe Perez, and Maria Mireles for their invaluable technical assistance in this project. David James   REFERENCES 1. James, D.G. 1997. Imidacloprid increases egg production in Amblyseius victoriensis (Acari: Phytoseiidae). Experimental and Applied Acarology 21: 75-82. (GO BACK) 2. James, D.G. and J. Coyle. 2001. Which pesticides are safe to beneficial insects and mites? Agrichemical and Environmental News 178: 12-14. (GO BACK) 3. James, D.G. and T.S. Price. 2001. Pesticides as “fertility drugs” for mites. Agrichemical and Environmental News 183: 27-28. (GO BACK) TABLE 1 Safety ratings of selected pesticides against selected beneficial arthropods in Washington hop yards. Ratings derived from direct toxicity laboratory bioassays. Type of Pesticide  Galendromus occidentalis Neoseiulus fallacis Amblyseius andersoni Stethorus picipes Harmonia axyridis MITICIDE Abamectin H H H H H Cyhexatin H H ------ ------ ------- Propargite S S MH H S Hexythiazox S S S S S Fenpyroximate H H H H H Bifenazate MH MH H MH MH Milbemectin H H H H MH Biomite H H H H S Dicofol ------- ------- ------ ------- S Fenbutatin Oxide MH S S ------- S Acaritouch MH S S ------ ------- INSECTICIDE Imidacloprid H H MH H H Pirimicarb H S ------ H S Chlorpyrifos H H H MH H Bifenthrin H H H H H Thiamethoxam ------- ------- -------</