Control of the Beet Armyworm and Pepper Weevil on Pepper1
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Proc. Fla. State Hort. Soc. 95:349-351. 1982. CONTROL OF THE BEET ARMYWORM AND PEPPER WEEVIL ON PEPPER1 D. J. Schuster Newer insecticides have been evaluated for control of IFAS, University of Florida, the pepper weevil on pepper. Genung and Ozaki (3) found Agricultural Research & Education Center, carbaryl (Sevin®), acephate, chlordimeform (Fundal®), 5007-60th Stree East, methomyl, toxaphene, leptophos (Phosvel®) and endosulfan Bradenton, FL 33508 (Thiodan®) to be effective in reducing the number of adult weevils observed on foliage of treated plants. Rolston (5), P. H. Everett however, demonstrated in laboratory experiments that 4-5 IFAS, University of Florida, day old residues of acephate, chlordimeform and endosulfan Agricultural Research Center, did not induce more than ca. 15% adult mortality while Rt.I,Box2G, residues of methomyl and toxaphene induced no more than Immokalee, FL 33934 65% mortality. Rolston did demonstrate that residues of Additional index words. Spodoptera exigua (Hubner), carbofuran 4F (Furadan®), carbaryl, EPN + methyl Anthonomus eugenii Cano, Capsicum annuum L. parathion, thiodicarb (Larvin®) and permethrin (Pounce®) all resulted in over 90% mortality of adult weevils in the Abstract. Four field experiments were conducted to eval laboratory. The laboratory results with endosulfan and uate insecticides for control of insects on bell pepper carbaryl were substantiated in a field test. (Capsicum annuum L). Significant reductions in the numbers The purpose of the present investigations was to com of fruit damaged by beet armyworm larvae (Spodoptera pare various insecticides for control of the beet armyworm exigua (Hubner)) were observed with fenvalerate (Pydrin®), and pepper weevil on bell pepper grown in the field. permethrin (Ambush®, Pounce®), methomyl (Lannate®), acephate (Orthene®), cryolite (Kryocide®), chlorpyrifos Materials and Methods (Lorsban®), and encapsulated methyl parathion (Penncap M®). Control of the pepper weevil as measured by internal One experiment was conducted in the winter 1978-79 fruit damage was significant with fenvalerate, chlorpyrifos, season at the Agricultural Research $c Education Center and cryolite. (AREC) in Bradenton and 3 experiments were conducted in the spring seasons of 1980-82 at the Agricultural Research Bell pepper is a major vegetable crop of Florida amount Center (ARC) at Immokalee. Pepper cv. 'Early Cal Wonder' ing to a value of $55 million produced on 18,000 acres in was used in all experiments except in the spring 1980 when 1979 (1). This accounted for approximately 1/3 of the total 'Keystone Resistant Giant' was used. Transplants were set U.S. production and nearly 50% of the production during 12 inches (30.5 cm) apart in single rows in the middle or the period of November to June. The beet armyworm, black polyethylene-covered beds of either Myakka fine sand Spodoptera exigua (Hubner), and pepper weevil, Anthon (AREC) or Immokalee fine sand (ARC). Beds were either omus eugenii Cano, are important insect pests of peppers 2.5 ft (0.8 m) wide by 8 inches (20 cm) high (AREC) or 3 ft in Florida. Beet armyworm larvae may feed on foliage, par (0.9 m) wide by 6 inches (15.2 cm) high (ARC). Plots con ticularly in early instars. However, the most important sisted of either 10 (AREC) or 15 (ARC) plants and treat damage is inflicted when larvae bore into the fruit to feed, ments were replicated 4 times in randomized complete rendering them unharvestable. Pepper weevil females blocks. Plots were harvested 1-7 times. In addition, in the usually oviposit directly in the fruit and both males and spring 1980 and 1982 experiments, all fruit that had drop females may feed directly on the fruit. However, the result ped from the plants and were trapped in 2 inch (5 cm) ing feeding and oviposition scars are not readily discernible high barriers as well as all fruit larger than 0.5 inch (1.3 and would rarely reduce the marketable grade of affected cm) in diameter remaining on the plants at the last harvest fruit. The most destructive injury occurs when larvae hatch also were collected. All fruit were examined for damage by and migrate to the seed mass where they feed on the core beet armyworm larvae and external feeding/oviposition and developing seeds. If fruit are small when infested, they scars and internal feeding damage by the pepper weevil. may drop from the plant before maturing. Older fruit may The numbers of beet armyworm larvae and larvae, pupae support the complete development of concealed larvae and, and adults of the pepper weevil inside the fruit were if no secondary rot or adult emergence holes are evident, counted. Percentage data were transformed arcsine may be harvested and enter the marketplace. Subsequent discovery of infested fruit could jeopardize the marketability V(%) 0^1) prior to statistical analysis but are presented in of the entire lot. the original scale. While newer insecticides have been evaluated for control Sprays were applied weekly to run-off with either a 2.5 of the beet armyworm on other crops, they have not been gal (9.5 liter) hand-held stainless steel sprayer with a single evaluated on pepper. Janes (4) found that the pyrethroids adjustable cone nozzle at 40 psi (2.8 kg/cm) or a Soalo® decamethrin (FMC 45498), permethrin (Ambush®) and motorized mist blower which was operated at 20-25 mph air fenvalerate (Pydrin®) were highly effective in reducing flow (1300-1400 RPM). The amount of spray applied in sweet corn whorl damage inflicted by larvae of both the creased as plants grew and ranged from ca. 95-125 gal/acre beet armyworm and fall armyworm, 5. frugiperda (J. E. (889-1169 liters/ha). Smith). DuRant (2) showed that profenofos (Curacron®), fenvalerate, sulprofos (Bolstar®), acephate (Orthene®) and Results and Discussion methomyl (Lannate®) reduced the number of beet army- Few or no pepper weevils were present in the winter worm larvae on cotton. 1978-79 or spring 1981 experiments whereas few or no beet armyworm larvae were present in the spring 1980 and 1982 iFlorida Agricultural Experiment Stations Journal Series No. 4268. experiments. Consequently, only data for the respective Mention of a proprietary product does not imply its endorsement by the author or by the University of Florida. pests in these experiments are presented. Proc. Fla. State Hort. Soc. 95: 1982. 349 Plants sprayed with iienvalerate, permethrin (botii Table 3. Control of the pepper weevil on bell pepper at ARC-lm- formulations), methomyl, and acephate produced fewer mokalee, spring 1980z. fruit damaged by beet armyworm larvae than plants sprayed only with water in the winter 1978-79 experiment (Table 1). Damaged fruit (%)y However, significant reductions in numbers of larvae rela Pepper tive to the water check were found only in fruit from plants Insecticide and Lb. a.i./ External weevils/ sprayed with fenvalerate or methomyl. In the spring 1981 formulation 100 gal only Internal plant experiment, all insecticides evaluated, with the exception of oxamyl (Vydate®), resulted in fewer damaged fruit and Cryolite 96WP 8.0 21.2 ex 11.2 a 0.1a larvae than in the water check (Table 2). No treatment re Fenvalerate 2.4EC 0.1 5.0 a 35.5 be 3.5 abc Methamidophos 4EC 1.0 13.0 abc 39.3 bed 3.5 abc sulted in significantly increased yields of undamaged fruit Toxaphene 8EC 2.0 9.4 abc 44.8 bed 4.5 abc compared to the check. However, significantly fewer un Permethrin 3.2EC 0.1 6.3 a 57.0 bede 4.4 abc damaged fruit were harvested from plants sprayed with Chlorpyrifos 4EC 0.5 19.3 be 34.4 b 2.1 ab chlorpyrifos (Lorsban®) and cryolite (Kryocide®), thus in Methamidophos 4EC 0.5 10.9 abc 48.4 bed 4.6 abc Acephate 75SP 1.0 9.6 abc 53.6 bede 7.7 c dicating a possible phytotoxic effect. Permethrin 3.2EC 0.05 4.3 a 62.2 cde 6.7 be Acephate 75SP 0.5 9.7 ab 65.0 de 6.7 be Table 1. Control of the beet armyworm on bell pepper at AREC- Check (water) - 4.9 a 77.7 e 8.2 c Bradenton, winter 1978-79z. ^Seedlings were transplanted March 6, sprayed March 25, April 1, 9, 17, No. fruit/10 plants 24, 30, May 7, 13, 19, 27, and June 3, and harvested May 21, 27, June 3 No. and 10. Insecticide and Lb. a.i./ Un- larvae/ yPercentage date were transformed arcsine V% x .01 prior to analysis formulation 100 gal damaged Damaged 10 plants but are presented in the original scale. xMean separation within columns by Duncan's multiple range test, 5% level. Fenvalerate 2.4EC 0.1 163.5 N.S. 12.7 ay 0.7 a Permethrin 3.2EC 0.1 155.5 16.5 ab 2.0 ab sprayed with cryolite or chlorpyrifos also had significantly Methomyl 90SP 0.45 153.7 20.0 ab 0.7 a more external damage (feeding and oviposition scars) only. Permethrin 2EC 0.1 149.7 18.0 ab 2.2 ab Methamidophos 4EC 1.0 134.7 25.0 be 5.7 b This might indicate either that adult weevils continued to Endosulfan 2EC 0.5 122.2 48.2 d 6.2 b feed but oviposited less in treated pepper fruit or that eggs Carbaryl80WP 1.0 118.7 26.0 be 4.2 ab deposited in treated fruit failed to hatch. Although the ex Phosmet50WP 1.0 117.7 32.5 c 5.5 ab tent of internal fruit damage was greater in the spring 1982 Acephate 75SP 1.0 114.2 19.0 ab 5.0 ab Check (water) - 110.0 34.0 c 6.0 b experiment, fewer fruit from plants sprayed with cypermeth- rin (Ammo®), fenvalerate, chlorpyrifos, permethrin or cryo lite were damaged internally than fruit from plants sprayed ^Seedlings were transplanted September 7, sprayed November 3, 10, 17, 24, December 1, 8, 15, 22, January 5, 12, 19, 26 and February 2, and with water (Table 4).