Various Novel Insecticides Are Less Toxic to Humans, More Specific to Key Pests

REVIEW ARTICLE t Various novel insecticides are less toxic to humans, more specific to key pests

Elizabeth E. Grafton-Cardwell Larry D. Godfrey William E. Chaney Walter J. Bentley t

A number of novel insecticides have recently been registered for insect control in agriculture. A major advan- tage of these new products is that they act on insect biological processes that humans do not experience, such as molting. Many also have greater selectivity to target specific species, so they are less likely to harm natural enemies when compared with the While often effective at controlling specific pests, less-toxic new insecticides can also have unintended impacts. When pyriproxyfen was broader spectrum organophosphate, sprayed to control red scale in citrus, it also caused gross abnormalities in carbamate, neonicotinoid and pyre- vedalia beetle pupae, left (normal) and right (abnormal). Vedalia beetles, inset (adult stage), are predators needed to control cottony cushion scale; throid insecticides. Such novel insec- as a result, secondary outbreaks of the scale occurred. ticides currently in use include four targeting lepidopteran pests, three targeting sucking insects, one specific selectivity and so are less likely to the novel insecticides have fairly short to dipteran leafminers and one insect harm natural enemies than the broad- residual activity or affect only immature spectrum organophosphate (OP), car- stages of insects, so the treatment timing growth regulator that controls a wide bamate, neonicotinoid and pyrethroid is less flexible compared with broad- range of insects. One negative aspect insecticides. As such, they are less likely spectrum insecticides. Finally, the cost of these insecticides is that because to cause outbreaks of secondary pests of the new insecticides is usually signifi- of their narrower range of activity — that are well controlled by natural en- cantly higher than the older products. controlling only a limited number of emies, and may be used as “clean-up” It is fortuitous that in recent years pests — growers may need to apply sprays to manage outbreaks of pests insecticides from different chemical additional pesticides for secondary caused by broad-spectrum insecticides. classes have been registered to control pest groups that have poor biological The registration of these insecticides has lepidopteran (primarily moths) and ho- helped to greatly reduce OP and carba- mopteran (primarily scales and white- control, increasing the total number mate insecticide use in California. This flies) pests, because many insects in of treatments per acre and total pest- has had an especially significant impact these groups have developed resistance control costs. in cotton, citrus and stone fruits, where to the older pesticides. The simultane- OP and carbamate use has been reduced ous registration of insecticides with number of novel insecticides with by as much as 70% since the late 1990s. unique modes of action allows growers unique modes of action were reg- The new insecticides also have some to alternate the insecticides used, reduc- isteredA during the late 1990s and early disadvantages. Because of their nar- ing the rate at which resistance devel- 2000s for insect control in agriculture. rower range of activity, each insecticide ops. Insecticide resistance in key pests These new insecticides have several generally controls only one pest group will continue to be a major impetus for advantages over older classes of insec- within a crop. The grower may need adopting novel insecticides. ticides. First, most of the products in to apply additional insecticides for Insecticides for Lepidoptera this group act on insect processes that secondary pests that have inadequate humans do not experience, such as natural control, increasing the total Four insecticides that have activ- molting. Low mammalian toxicity al- number of treatments per acre and total ity primarily affecting lepidopteran lows for short re-entry and preharvest pest-control costs. In addition, many of pests — indoxacarb (Avaunt, Steward), intervals, allowing the insecticides to Insecticide resistance in key pests will continue to be easily incorporated into pest control programs. Many also have greater be a major impetus for adopting novel insecticides.

http://CaliforniaAgriculture.ucop.edu • JANUARY-MARCH 2005 29 tebufenozide (Confirm), methoxyfeno- to each other, as well as spinosad and emphasizes the need for the rotation of zide (Intrepid) and emamectin benzoate Bt, helping to reduce the rate that insec- indoxacarb with emamectin benzoate, (Denim, Proclaim) — are registered for ticide resistance develops. the dibenzoylhydrazine insect growth a number of crops in California. The Indoxacarb. Indoxacarb is an oxadia- regulators (IGRs) and other insecticides greatest uses of these insecticides are zine insecticide that blocks the sodium to maintain the efficacy of all groups of in cotton, cole crops, lettuce, nuts, and channels in insect nerve cells, causing insecticides. stone and pome fruits (table 1). lepidopteran larvae to stop feeding Tebufenozide. Tebufenozide is a In stone fruit, the use of these insec- within 4 hours, become paralyzed and dibenzoylhydrazine stomach poison ticides — in combination with Bacillus die within 2 to 5 days (McCann et al. that acts as an IGR specifically for Lepi- thuringiensis (Bt) products, spinosad 2001). It is more effective as a stomach doptera. It mimics a molting hormone and mating disruption during the poison than as a contact poison. Indoxa- and blocks the completion of the nor- growing season — has greatly reduced carb is fairly selective, having activity mal molting process (Retnakaran et al. the need for dormant sprays of OP, car- primarily against lepidopteran larvae 2001). The insect stops feeding within a bamate and pyrethroid insecticides for and certain species of sucking insects few hours and undergoes a premature peach twig borer (Anarsia lineatella). This such as Lygus bugs. However, the activ- lethal molt within 3 to 7 days, becom- has benefited the stone fruit industry by ity of indoxacarb against the sucking ing trapped within the shedding head reducing pesticide residues in surface wa- insects is weaker than for Lepidoptera capsule. Tebufenozide must be ingested ter, by preserving natural enemies needed because of its slower bioactivation, to take effect and is thus slow-acting, for other pests such as San Jose scale lower sensitivity and a less favorable with a residual activity of 14 to 21 days. (Diaspidiotus perniciosus), and by reducing method of oral uptake in the sucking in- Application timing is critical, because secondary outbreaks of spider mite pests sects. Indoxacarb allows most predators it is more active on early larval stages caused by broad-spectrum-insecticide dis- and immature wasp parasites to survive (Waldstein and Reissig 2001). It is non- ruption of their natural enemies. (Hewa-Kapuge et al. 2003; Studebaker toxic to honeybees and is selective, not The Central Coast Vegetable Inte- and Kring 2003). However, the wet resi- affecting most natural enemies (Dhad- grated Pest Management Program for dues of indoxacarb are toxic to bees and ialla et al. 1998). pest management in lettuce provides adult wasp parasites. The crops for which tebufenozide is another example of the significant Indoxacarb controls important currently registered include cole crops, role that these narrow-spectrum in- pests in alfalfa, apples, cole crops, cot- cotton, grapes, lettuce, tomatoes and secticides play in Lepidoptera control. ton, lettuce and pears. Populations of some nuts, pome and stone fruits. Low Lettuce is highly susceptible to pest obliquebanded leafroller (Choristoneura levels of resistance to tebufenozide damage at the seedling stage and rosaceana) in Michigan (Ahmad et al. have been found in codling moth (Cydia during head formation. Many of the 2002) have exhibited resistance to in- pomonella), beet armyworm and oblique- seedling pests — such as crickets, flea doxacarb in regions where it has not banded leafroller populations that were beetles, aphids and whiteflies — are been used, suggesting cross-resistance not exposed to this insecticide (Moulton controlled with broad-spectrum OP, to older groups of insecticides. This et al. 2002; Ahmad et al. 2002), suggest- carbamate, pyrethroid or neonicotinoid insecticides. These insecticides reduce or eliminate the natural enemies that attack the lepidopteran pests, some- Clark Kelly Jack times causing outbreaks; selective insecticides help to bring the Lepidoptera back under control without creating additional problems. In addition, there are a number of lepidopteran pests that attack both head and leaf lettuce, including cabbage looper (Trichoplusia ni), beet armyworm (Spodoptera exigua), corn earworm (He- licoverpa zea) and tobacco budworm (Heliothis virescens). Lepidopteran pests can destroy seedlings, bore holes and leave frass or insect body contaminants throughout the growth cycle of the lettuce, necessitating multiple treatments. Because lettuce is highly susceptible to insect damage at the seedling stage, many Indoxacarb and tebufenozide provide growers spray broad-spectrum insecticides. Some newer, more selective insecticides unique, selective chemistries for these can bring lepidopteran pests under control without hurting their natural enemies and pests and act as rotational alternatives causing secondary pest outbreaks.

30 CALIFORNIA AGRICULTURE, VOLUME 59, NUMBER 1 Omnivorous leafroller moth Peach twig borer larva attacking almond ing that there may be cross-resistance to older classes of compounds, including Clark Kelly Jack Photos: OPs. There is also likely to be cross- resistance between tebufenozide and methoxyfenozide, because they have the same mode of action. These insecticides will need to be used infrequently, alter- nated with other insecticide chemistries, and coupled with alternative methods of control, such as mating disruption, to delay resistance in key pests. Methoxyfenozide. Methoxyfenozide is a dibenzoylhydrazine IGR, similar TABLE 1. Novel insecticides primarily targeting Lepidoptera* to tebufenozide in its mode of action, Indoxacarb its ability to induce a lethal molt and Crop Pests controlled its specificity for Lepidoptera (Carlson Alfalfa Egyptian alfalfa weevil (Hypera brunneipennis), various Lepidoptera et al. 2001). Methoxyfenozide was only Apple, pear Codling moth (Cydia pomonella) recently (2003) registered in California Cole Various cutworms, cabbage looper (Trichoplusia ni), and its use is likely to increase due to its diamondback moth (Plutella xylostella) better binding with lepidopteran recep- Cotton Cabbage looper, beet armyworm (Spodoptera exigua), tors and longer residuality compared western yellow-striped armyworm (Spodoptera praefica); with tebufenozide. Methoxyfenozide (Lygus hesperus) suppression of Lygus bug has a much lower ability to bind with Lettuce Corn earworm (Helicoverpa zea), tobacco budworm (Heliothis virescens), receptors in nonlepidopteran species, beet armyworm, various loopers making it a highly selective insecticide Stone fruit† Codling moth, oriental fruit moth (Grapholita molesta) and useful in a number of crops. Low levels of resistance to methoxyfenozide Tebufenozide in codling moth, beet armyworm and Crop Pests controlled obliquebanded leafroller have been Cole Cabbage looper, diamondback moth found, necessitating prevention precau- Cotton Alfalfa looper (Autographa californica), cabbage looper, tions similar to those for tebufenozide. saltmarsh caterpillar (Estigmene acrea), western yellow-striped armyworm Emamectin benzoate. Emamectin Grape Various leafrollers, skeletonizer (Harrisina brillians) benzoate is a second-generation aver- Lettuce Various loopers, beet armyworm mectin analog with exceptional activ- Stone fruit Codling moth, peach twig borer (Anarsia lineatella), oriental fruit moth, ity against lepidopterans, acting by omnivorous leafroller (Platynota stultana), decreasing the excitability of neurons. obliquebanded leafroller (Choristoneura rosaceana) Shortly after contact or feeding expo- Tomato Beet armyworm sure, the insect larvae stop feeding, be- Walnut, pistachio, Codling moth, obliquebanded leafroller, green fruitworms pear, apple (Orthosia hibisci, Amphipyra pyramidoides) come irreversibly paralyzed and die in 3 to 4 days. Emamectin benzoate toxicity is broader spectrum than methoxy- Methoxyfenozide Crop Pests controlled fenozide, tebufenozide or indoxacarb, Artichoke Artichoke plume moth (Platyptilia carduidactyla) which is a benefit in that it kills a wide variety of lepidopterans (Argentine et Cotton Beet armyworm, western yellow-striped armyworm; suppression of Heliothis species al. 2002). However, its broad-spectrum Grape Omnivorous leafroller, grape leaffolder (Desmia funeralis), activity also makes fresh residues toxic orange tortrix (Argyrotaenia citrana) to natural enemies (Studebaker and Nuts, stone fruit Navel orangeworm (Amyelois transitella), peach twig borer, oriental fruit moth, various leafrollers Kring 2003). Natural enemy survival improves after about 5 days due to Pome fruit Various leafrollers; codling moth suppression in conjunction with mating disruption Vegetables, cole Various armyworms, cabbage looper; suppression of diamondback moth rapid photodegradation. The toxic activity lasts longer for the pest because the photodegradate moves through plant Emamectin benzoate Crop Pests controlled tissue (translaminar activity) and is toxic to the plant-feeding pest. Cole Cabbage looper, tobacco budworm, beet armyworm, various loopers Lettuce Corn earworm, tobacco budworm, beet armyworm, various loopers Emamectin benzoate is used primarily against pests in cole crops and let- * Current uses in California. tuce. (It is registered for cotton in other † Likely to be registered within a few years.

http://CaliforniaAgriculture.ucop.edu • JANUARY-MARCH 2005 31 states, but not California.) Emamectin ate have shown only slight levels of re- pyriproxyfen is not fully compatible benzoate provides a rotational insecti- sistance (Waldstein and Reissig 2001). with natural enemies because it is high- cide for the control of caterpillars and so ly toxic to predatory coccinellid beetles, Treatments for sucking insects helps to reduce the development of re- halting both egg hatch and pupation sistance. Populations of obliquebanded Three insecticides — pyriproxyfen (Grafton-Cardwell and Gu 2003). The leafroller tested with emamectin benzo- (Esteem, Knack, Seize), buprofezin heavy use of pyriproxyfen in citrus for (Applaud, Courier) and pyme- California red scale control created a Silverleaf whitefly nymphs and pupae trozine (Fulfill) — have activity cottony cushion scale (Icerya purchasi) primarily affecting sucking in- problem due to the loss of vedalia beetle sect pests such as whiteflies and (Rodolia cardinalis). It may also be re- armored scales, many of which sponsible for pest resurgences in other Photos: Jack Kelly Clark Kelly Jack Photos: have developed resistance to OP, crops due to its effect on coccinellid carbamate or pyrethroid insecti- predators of armored scales, mealybugs cides. The greatest uses of these and mites. insecticides for whitefly control Second, pyriproxyfen has a narrower are in cotton and tomatoes, for range of activity compared with the car- California red scale (Aonidiella au- bamate and OP insecticides. Pyriproxy- rantii) in citrus, and for San Jose fen has no effect on the secondary pests scale in nuts, and stone and pome forktailed bush katydid (Scudderia fur- fruits (table 2). Their cost is often cata) or citricola scale (Coccus pseudom- significantly higher than OPs, agnoliarum), which lack natural enemies, carbamates and pyrethroids. and so these insects have become pri- Pyriproxyfen. Pyriproxyfen mary pests that must be controlled with is a pyridine compound that acts additional insecticide treatments. In as a juvenile hormone mimic past years, katydids and citricola scale IGR, inhibiting egg production were easily controlled by the OP treat- San Jose scale and the metamorphosis of im- ments applied for California red scale. mature stages into adults (Ishaa- Currently, pyriproxyfen is used in

TABLE 2. Novel insecticides targeting sucking insects* ya et al. 1994). It is most effective California to control pests in apples, in late-stage larvae or nymphs citrus, cotton, nuts, pears, and stone Foliar-applied pyriproxyfen and early pupal stages when and pome fruits. In bait form, it is effec- Crop Pests controlled juvenile hormone is normally tive against the protein-feeding native Apple Apple leafminer (Phyllonorycter species) low. It is active primarily against southern fire ant (Solenopsis xyloni). Citrus California red scale (Aonidiella aurantii) sucking insects such as scales, An extensive resistance-management Cotton Silverleaf whitefly(Bemisia argentifolii) pear psylla (Cacopsylla [Psylla] program has been developed for cotton pyricola) and whiteflies. It is also that limits the number of applications of Pear Pear psylla (Cacopsylla [Psylla] pyricola) effective against fire ants and pyriproxyfen to one per growing season Stone fruit, pome fruit, nuts San Jose scale (Diaspidotus perniciosus) apple leafminers (Phyllonorycter to reduce the rate of resistance devel- species). Because of its persis- opment. Caution should be exercised Buprofezin tence and efficacy, pyriproxyfen by growers as to the frequency of ap- Crop Pests controlled has been extremely effective in plication, because resistance has begun Almond San Jose scale, apple leafhopper reducing California red scale to develop in whitefly populations in Citrus California red scale and San Jose scale populations other areas of the world, even when the that developed resistance to OP number of applications per season was Cotton Silverleaf whitefly insecticides. It is safer for hy- limited to one (Horowitz et al. 2002). Grape Mealybugs (Pseudococcus species and Buprofezin. Planococcus ficus), leafhoppers menopterous parasites than OP Buprofezin is a thia- (Erthroneura elegantula and E. variabilis) insecticides, greatly increasing diazine IGR that disrupts molting by Stone fruit† San Jose scale parasite numbers and so improv- preventing chitin development (Uchida ing the control of both target et al. 1985). It is active primarily Pymetrozine and nontarget pests within crop against sucking insects such as scales, Crop Pests controlled systems. Pyriproxyfen is toxic whiteflies, mealybugs and leafhoppers, Cole, lettuce, Various aphids, various whiteflies to crustaceans, limiting its use although it also has activity against celery, tomato around bodies of water. beetles. Buprofezin is slow-acting Cotton Cotton aphid (Aphis gossypii) but persists a long time. It has poor Citrus provides an example * Current uses in California. of two potential problems as- ovicidal activity, but treated adults † Likely to be registered within a few years. sociated with the use of IGR of some pest species may lay sterile insecticides in agriculture. First, eggs. It has little or no effect on lepi-

32 CALIFORNIA AGRICULTURE, VOLUME 59, NUMBER 1 dopteran (moths), dipteran (flies) or hymenopteran (wasp) insects. Bupro- fezin is toxic to crustaceans, limiting its Clark Kelly Jack Photos: use around bodies of water. In citrus, buprofezin is not as effective as pyriproxyfen in controlling California red scale because it requires Liriomyza leafminer adult Tunnels produced by leafminer larvae the majority of the scale population to TABLE 3. Current uses of cyromazine in California be in an immature stage (Grout and

Richards 1991). Buprofezin is less toxic Crop Pests controlled than OPs and carbamates to a number Cole, lettuce, pepper, spinach, Dipteran leafminers (Liriomyza species) of natural enemies, especially wasp celery, tomato, cucurbit parasites, allowing their numbers to greatly increase. However, similar to pyriproxyfen, it is highly toxic to coccinellid beetles, preventing larval molt- Pymetrozine is active against impor- tance to the older groups of insecticides ing (Grafton-Cardwell and Gu 2003). tant pests in cole crops, lettuce, celery around the world. Because leafminers Buprofezin use has led to outbreaks of and tomatoes. It has been registered for often require multiple insecticide treat- cottony cushion scale in citrus due to California cotton since 2001 to control ments, it will be important to rotate the loss of vedalia beetle. It also may cotton aphid (Aphis gossypii), but has not cyromazine with other insecticide be responsible for pest resurgences in yet been incorporated into management chemistries to combat resistance. other crops due to its effect on coccinel- programs to any extent. Pymetrozine A product with broad activity lid predators. must be applied when populations of Currently, buprofezin is used in cotton aphids are low, but in Califor- Diflubenzuron (Dimilin, Micromite) California to control pests in almonds, nia the treatment threshold for aphid is a benzoylphenylurea chitin-synthesis- citrus, cotton and grapes. Buprofezin populations has traditionally been fairly inhibitor IGR that disrupts molting. It has been an important component of high. When used for whitefly control, is slow-acting, requiring up to 14 days the silverleaf whitefly management pymetrozine causes adults to stop feed- for population reduction, because it is program for cotton, where it has helped ing, but it must be used in combination active against all molting stages. The delay resistance to insecticides. In with other insecticides such as IGRs to symptoms of diflubenzuron poisoning grapes, buprofezin can be rotated with reduce whitefly populations below the in grasshoppers include slowed move- the neonicotinoids to control mealybugs economic threshold. ment, uncoordinated jumping, loss of and leafhoppers and so help to man- legs, decreased feeding and malformed Controlling dipteran leafminers age resistance. Because of its selectiv- wings (Weiland et al. 2002). It is used ity favoring hymenopteran parasites, Cyromazine (Trigard) is a triazine against a variety of insects including buprofezin and parasites work together insecticide used as a chitin-synthesis- rice water weevils (Lissorhoptrus ory- to control grape and vine mealybugs. inhibitor IGR, which disrupts the molt- zophilus), beetles, various Lepidoptera, Buprofezin is likely to receive registra- ing of larval and pupal cuticles. It has grasshoppers, Mormon crickets (Ana- tion for San Jose scale in stone fruit in translaminar activity that quickly pen- brus simplex) and katydids. It does not the near future. etrates into leaves. It is active against cause mortality to adults, but does ster- Pymetrozine. Pymetrozine is a pyri- a very narrow range of insect pests, ilize the females of some species. dine azomethine. It is active primarily notably the larval stages of dipteran Because diflubenzuron is primar- against sucking insects such as aphids leafminers. Because of its high level ily active through ingestion, it is less and whiteflies. Its mode of action is not of specificity, cyromazine is much less toxic to a number of natural enemies, fully understood, but differs from other toxic to natural enemies, compared with especially wasp parasites. Similar insecticide groups. It interferes with IGRs such as diflubenzuron, making it to other IGRs, the eggs and imma- feeding behavior, resulting in the com- highly compatible with integrated pest ture stages of predatory beetles, as plete cessation of feeding within hours management (IPM) programs (Schuster well as lacewings, can be sensitive of contact (Harrewijn 1997). Aphids 1994). Cyromazine is nontoxic to crusta- to diflubenzuron (Ables et al. 1977). remain alive for 2 to 4 days before they ceans, bees, fish and birds. However, effects such as reduced egg die of starvation. Pymetrozine has The current uses of cyromazine are hatch can be rapidly reversed when been shown to reduce both direct dam- for Liriomyza leafminers in cole crops, the predators enter an untreated age and virus transmission by aphids lettuce, peppers, spinach, celery, toma- environment (Peleg 1983). Difluben- (Bedford et al. 1998). Because of its toes and cucurbits (table 3). Cyromazine zuron is toxic to crustaceans; however, specificity for sucking insects, it is rela- is important as a new chemistry for populations recover rapidly because it tively nontoxic to most natural enemies controlling dipteran leafminers, as a rapidly dissipates in water. (Sechser et al. 2002). number of species have developed resis- Currently, diflubenzuron is used to

http://CaliforniaAgriculture.ucop.edu • JANUARY-MARCH 2005 33 Devastating Grasshopper.grasshopper

Harrewijn P. 1997. Pymetrozine, a fast-

Jack Kelly Clark Kelly Jack acting and selective inhibitor of aphid feeding. In-situ studies with electronic monitoring control pests in artichokes, citrus, cot- of feeding behavior. Pesticide Sci 49:130–40. ton, rice, nuts and stone fruits (table 4). Hewa-Kapuge S, McDougall S, Hoff- Diflubenzuron is also registered to man AA. 2003. Effects of methoxyfenozide, indoxacarb, and other insecticides on the treat grasslands infested with grass- beneficial egg parasitoid Trichograma nr. hoppers — which often devastate brassicae (Hymenoptera: Trichogrammatidae) nearby crops — providing an impor- under laboratory and field conditions. J Econ Entomol 96:1083–90. tant replacement for OP and carbamate TABLE 4. Current uses of diflubenzuron Horowitz AR, Kontsedalov S, Denholm I, in California insecticides. Resistance to diflubenzuron Ishaaya I. 2002. Dynamics of insecticide resis- in codling moth populations occurs in tance in Bemisia tabaci: A case study with the France (Sauphanor et al. 2000), indicat- Crop Pests controlled insect growth regulator pyriproxyfen. Pest ing the need for the careful rotation of Almond, stone fruit Peach twig borer Manage Sci 58:1096–100. Ishaaya I, De Cock A, Degheele D. 1994. this insecticide with insecticides that Artichoke Armyworms, artichoke Pyriproxyfen, a potent suppressor of egg have different modes of action. plume moth hatch and adult formation of the greenhouse Citrus Citrus leafminer whitefly (Homoptera: Aleyrodidae). J Econ Pros and cons (Phyllocnistis citrella), Entomol 87:1185–9. citrus peelminer McCann SF, Annis GD, Shapiro R, et al. Novel insecticide classes play a criti- (Marmara gulosa); 2001. The discovery of indoxacarb: Oxadi- cal role in the IPM of many California being tested for katydid azines as a new class of pyrazoline-type insec- crops. Excellent efficacy, high selectivity (Scudderia furcata) ticides. Pest Manage Sci 57:153–64. Moulton JK, Pepper DA, Jansson RK, Den- and low mammalian toxicity make them Cotton Beet armyworm nehy TJ. 2002. Pro-active management of attractive replacements for OPs and car- Grassland (near crops) Grasshopper, beet armyworm (Lepidoptera: Noctuidae) bamates, and the majority are considered Morman cricket resistance to tebufenozide and methoxyfenozide: Baseline monitoring, risk assessment, Rice Rice water weevil by the U.S. Environmental Protection and isolation of resistance. J Econ Entomol (Lissorhoptrus oryzophilus) Agency to be “reduced risk” insecticides. 95:414–24. However, their high level of selectivity Walnut Codling moth Peleg BA. 1983. Effect of 3 insect growth can increase the need for other insecti- regulators on larval development; fecundity and egg viability of the coccinelid Chilocorus cides if they allow secondary pests that bipustulatus [Col.: Coccinelidae]. 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Pest Manage Sci 58:834–8. populations (Cydia pomonella). Pest Manage the adoption of these chemistries in- Argentine JA, Jansson RK, Halliday WR, Sci 56:74–82. clude human health concerns and pest et al. 2002. Potency, spectrum and residual Schuster DJ. 1994. Life-stage specific toxic- activity of four new insecticides under ity of insecticides to parasitoids of Liriomyza resistance to OPs, carbamates and glasshouse conditions. Florida Entomol trifolii (Burgess)(Diptera: Agromyzidae). Int J pyrethroids. The wide variety of new 85:552–62. Pest Manage 40:191–4. modes of action is extremely helpful for Bedford ID, Kelly A, Banks GK, et al. 1998. Sechser B, Reber B, Bourgeois F. 2002. Py- The effect of pymetrozine, a feeding inhibi- metrozine: Selectivity spectrum to beneficial delaying resistance in key pests such as tor of Homoptera, in preventing transmission arthropods and fitness for integrated pest whiteflies, scales and aphids. As grow- of cauliflower mosaic caulimovirus by the management. J Pesticide Sci 75:72–7. ers and pest control advisors become aphid species Myzus persicae (Sulzer). Ann Studebaker GE, Kring TJ. 2003. Effects of familiar with the unique characteristics Appl Biol 132:453–62. insecticides on Orius insidiosus (Hemiptera: Carlson GR, Shadialla TS, Hunter R, et al. Anthocoridae), measured by field, green- of these insecticides, their adoption is 2001. The chemical and biological properties house and petri dish bioassays. Florida Ento- likely to increase. of methoxyfenozide, a new insecticidal ec- mol 86:179–85. dysteroid agonist. Pest Manage Sci 57:115–9. Uchida M, Asai T, Sugimoto T. 1985 Inhibi- Dhadialla TS, Carlson GR, Le DP. 1998. tion of cuticle deposition and chitin synthesis New insecticides with ecysteroidal and ju- by a new insect growth regulator, bupro- venile hormone activity. Ann Rev Entomol fezin, in Nilaparvata lugens. Stal Agric Biol E.E. 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34 CALIFORNIA AGRICULTURE, VOLUME 59, NUMBER 1