AC303,630 A new novel insecticide-acaricide for control of resistant arthropod pests

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1 AC33,3 A new novel insecticide-acaricide for control of resistant arthropod pests S. C. Lee 1, C. Sujin, P. J. Huang 3, X. M. Zhang and G. T. Ooi 5 1 Cyanamid International, Singapore Cyanamid (Thailand) Ltd., Bangkok, Thailand 3 Cyanamid Taiwan Corporation, Taipei, Taiwan Cyanamid (China) Co.Ltd., Shanghai, People s Republic of China 5 Tiram Crop Protection Sdn. Bhd., Kuala Lumpur, Malaysia Abstract AC33,3 (chlorfenapyr), a member of a new class of compound known as the pyrroles, is a broad spectrum insecticide/acaricide on many economically importance crops. AC33,3 is highly active by ingestion, posesses contact activity and provides moderate residual activity on plants. Extensive field study in many Asian countries has shown AC33,3 to be highly effective on many economically important arthropods which have shown resistance to conventional classes of insecticides. Examples of pests that are effectively controlled by AC33,3 include Spodoptera exigua, Plutella xylostella, Heliothis virescens, Thrips palmi and Tetranychus spp. AC33,3 can be a promising and cost effective candidate for use in resistance management programmes in high value crops. This paper describes the bioactivity of AC33,3 on insect pests found on economically important crops in selected Asian countries. Key words: Chlorfenapyr, pyrolles, insect pests, resistance management Introduction AC33,3 (Trademark: Rampage, Secure, CHU-JIN) is a new broad spectrum insecticide-acaricide, belonging to the pyrroles chemical group discovered and developed by American Cyanamid Company. Miller et al. (199), reported that AC33,3 provided commercially acceptable control of 35 insect and mite pests important in crop production. Merriam et al. (199), also characterized the insecticidal activities of AC33,3 against Heliothis virescens and Plutella xylostella. This paper describes the field performance of AC33,3 for the control of certain insect, thrip and mite species which are known to exhibit resistance to various insecticides and acaricides. Materials and Methods The study on organophosphates, pyrethroid, carbamate and IGR-resistance of diamondback moth and beet armyworm has been well documented by research workers and scientists in Thailand (Dept. of Agriculture, 199), the People's Republic of China (PRC), (Guangdong Prov PPI, 1993) and Taiwan (AVRDC, 195), using the bioassay technique. Results presented in this paper were obtained from in-house and cooperative field trials in various Asian countries on conventional class insecticide-resistant diamondback moth, beet armyworm, thrips and - spotted mites. Emulsifiable concentrate (EC) and the suspension concentrate (SC) formulations of AC33,3 (1 g ai/li EC or SC) were used in the trials. Foliar applications were made at rates ranging from 5 to 3 g ai/hectare, comparing with local standard treatments (chlorflurazuron and abamectin) applied at recommended rates and with untreated check plots.three to four replicates were used in randomised complete block design. Insect population indices and damage ratings were determined by standard evaluation procedures which varied by insect species. Yield performance was assessed based on marketable yield quality and damage rating. Results Plutella xylostella (DBM) In trials conducted in Thailand, Taiwan and the PRC on Chinese kale, common head cabbage and cauliflower, both the emulsifiable concentrate (1% EC) and the suspension concentrate (1% SC) at rates from 5 to g ai/ha provided near complete control of 1 and 3 instar DBM larvae, and was superior to the standards abamectin and chlorfluazuron (Figures 1,, 3 and ). All treatments were applied 7 times at 5 to 1-day intervals. The g ai/ha rates were consistently comparable or superior to abamectin or chlorfluazuron. Spodoptera exigua (Beet armyworm) Figures 5,, and 7 demonstrate the excellent performance of AC33,3 on beet armyworm on Chinese kale and common head cabbage. All doses of AC33,3 tested were superior to abamectin (1 g ai/ha). The degree of residual control was directly correlated with AC33,3 application rates. The 1 15 g dose range appears optimum to provide effective control of this pest which has shown to be increasingly difficult to manage. At harvest, all AC33,3 treatments were providing sufficient DBM and beet armyworm control 19 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests

2 Mean larvae count/ plants 1 1 Figure 1. AC 33,3 SC/EC efficacy Thailand diamondback moth, Chinese kale, Mean larvae count/ plants Chlo 1 g/ha g/ha 1 g/ha 1 g/ha 7 sprays at 5 7 day interval Mean of nine trials Mean larvae count/1 plants Chlo 1 g/ha g/ha 1 g/ha 1 g/ha Figure. AC 33,3 SC/EC efficacy Thailand diamondback moth, Chinese cabbage, 199 Mean larvae count/ plants Chlo 1 g/ha g/ha 1 g/ha 1 g/ha Bt-carbofuran-Mevin 3 g/ha 1 g/ha sprays at 7 day interval Figure 3. AC 33,3 SC/EC efficacy Taiwan diamondback moth, Cauliflower, Mean larvae count/ plants sprays at 5 7 day interval Mean of nine trials Chlo 1 g/ha g/ha 1 g/ha 1 g/ha Figure 5. AC 33,3 SC/EC efficacy Thailand beet armyworm, Chinese Kale, sprays at 7 day interval Figure. AC 33,3 SC/EC efficacy Taiwan diamondback moth, Common cabbage, Mean larvae count/1 plants 7. Chlo 1 g/ha g/ha 1 g/ha 1 g/ha Figure. AC 33,3 SC/EC efficacy Thailand beet armyworm, Chinese Cabbage, Chemical control 191

3 Larvae/15 plants/plot 7 days after nd application 5 3 Series g a.i./ha 3 15 g 3 3 g Bifenthrin g Check Figure 7. AC33,3 1SC/maize beet armyworm, Taiwan-Mean of two trials % Distribution Yield Quality 1 No. damage g/ha Moderate Severe 1 g/ha Chlo 1 g/ha 1 g/ha Figure. AC33, 3 SC/EC efficacy Thailand yield performance, Chinese kale, Mean leaf/head damage rating..5 sprays at 7 day interval 9 = Severe Damage = No Damage Standard TM Aba 1g/ha g/ha 3 g/ha 1 g/ha. 3. Figure 9. AC 33,3 SC/EC efficacy Taiwan yield performance, cauliflower, Mean marketable yield (kg/5 plants) Figure 1. AC 33,3 SC/EC Efficacy Thailand yield performance Chinese cabbage, Chlo 1g/ha Aba 1g/ha g/ha 1 g/ha 1 g/ha to allow for a high percent distribution of yield (Chinese kale) in the grade of No Damage, ranging from % (75 g ai/ha) to >5% ( g ai/ha), (Figures and 9). Avermectin provided only % yield with No Damage which was significantly less than that proivided by any AC33,3 treatment. Yield quality ratings in the chlorflurazuron (1 g ai/ha) and the untreated plot were significantly low with close to % and % Severe feeding damaged leaves. (Figures 1 and 11) All rates of AC33,3 were clearly enhancing superior yield, be it on Chinese kale, common head cabbage or cauliflower. 19 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests

4 Mean yield (kg/ plants) No damage Grade A Slight damage Grade B Severe damage Grade C 1 g/ha 3 g/ha Bt-Carbofuran-Mevin sprays at 7 day interval x-1x-1x Figure 11. AC 33,3 SC/EC efficacy Taiwan yield performance, common cabbage, Mites nos/15 leaves 7 days after 1st and nd application, respectively DA 1T 7 DA T 5 AC33,3 5 gai/ha 3,75 g 3,1 g 3, g Bifenthrin g Check Figure 1. AC33, 3 1SC/water melon redmites, Taiwan, 1993 Thrips nos/1 leaves 7& 1 days after 1st and nd application, respectively DAT 1 DAT AC33,3 75 g ai/ha 3,15 g 3,3 g Deltamethrin Carbosulfan 3 5 g Figure 13. AC33,3 1EC/egg plant/thrips palmi, Taiwan 1993 Tetranychus urticae (-spotted red spider mite) In trials conducted in Taiwan in 1993, AC33,3 1%EC at rates from 5 g ai/ha, using a 7-day interval spray regime had provided excellent fast knock-down of the mite population. Figure 1 shows the rapid reduction in number of the mites in all AC33,3 treated plots versus standards and the untreated check 7 days after the 1st and nd application. Bifenthrin at 5 g ai/ha failed to provide adequate control in watermelon. Thrips Species In egg-plant trials in Taiwan, AC33,3 at 75 to 3 g ai/ha provided excellent control of the pest in terms of thrip population reduction following applications at weekly spray interval. Figure 13 shows the reduction in numbers of Thrips palmi larvae in AC33,3 treated plots. The two standards deltamethrin and carbosulfan gave only marginal reduction of the thrips population. In Japan, AC33,3 1SC at 15 g ai/ha provided excellent initial (%) and residual control (97 and 9% at 7 and 1DAT, respectively) of a high population T. palmi on eggplant. Figure 1 shows the Chemical control 193

5 Number larvae/leaf Pre-treatment 3 DAT 7 DAT 1 DAT 1 g sulprofos/ha 15 g AC 33,3/ha Figure 1. AC 33,3 1 SC efficacy Japan Thrips palmi, eggplant, 1991 reduction in number of T. palmi larvae in the AC33,3 treated plots. Sulprofos 5EC at 1 g ai/ha reduced the number of T. palmi larvae/leaf to 7.7 at 3 DAT, but failed to provided sufficient residual control(only 33 to 39% control). Conclusion Results from extensive field trials in the Far East have shown AC33,3 at the tested dosages to be effective for control of many economically important arthropod species which have been reported to be resistant to various classes of insecticides and acaricides, some of which were mentioned in this paper under Materials and Methods. These results suggest that AC33,3 can be an effective, useful alternative and integral part of resistance management programmes. References T.L. Merriam, R. Farlow, J. Beam, S.C. Lee and T.W. Homan (199). Efficacy of AC33,3 Insecticide Acaricide for control of resistant arthropod pests. In: Proceeding XIX International Congress of Entomology, Beijing 199, China. Miller, T.P., M.F. Treacy, I.E. Gard, J.B. Lovell, D.P. Wright, Jr., R.W. Addor and V.M. Kamki (199). AC33,3 Summary of 19-9 field trial results. In: Proceedings Brighton Crop Protection Conference Pests and Diseases. British Crop Protection Council, Brighton, Sussex, England 3. Asian Vegetable Research and Development Center (195). Diamondback Moth Management. Proc. of First International Workshop, Tainan, Taiwan. March 195. Department of Agriculture (199). Report Meeting of the Joint Research Project. Insect Toxicological on Resistance to Insecticides in Diamondback Moth. Thailand. 19 Proceedings: The Management of Diamondback Moth and Other Crucifer Pests