The fall armyworm, Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae), is a sporadic but serious pest of various warm-season turfgrass species in the mid-southern and southeastern United States (Braman et al., 2000; Reinert and Engelke, 2010). In Georgia, the turfgrass industry is worth US$7.8 billion (Kane and Wolfe, 2012). This pest affects various sectors of the turfgrass industry. From July to late November, landscape maintenance companies and homeowners often must apply insecticides to protect residential and public lawns in urban and suburban areas. S. frugiperda also threatens golf courses and sod farms, where insecticides are intensively used to maintain vast stretches of turfgrass. Currently, sod producers and golf course superintendents use pyrethroid insecticides, such as bifenthrin, for fall armyworm control on the turfgrass starting in July (Buss and Dale, 2017; Waltz and McCullough, 2017).
The early larval stages of S. frugiperda usually go undetected because they remain hidden within the turfgrass canopy during the daytime until the larvae reach the fourth or fifth instar. The young larvae feed on the grass blades, whereas the late instar larvae consume both the stems and grass blades. Severely affected turfgrass appears brown because most of the grass blades are consumed. Compared with young instars, late instar larvae are more tolerant of insecticides (Hardke et al., 2011; Mink and Luttrell, 1989).
S. frugiperda is a polyphagous pest that is known to damage more than 50 plant species, including corn, sorghum, cotton, rice, and bermudagrass (Luginbill, 1928). Multiple overlapping generations of S. frugiperda occur within 1 year and infest several host species. Resistance to older insecticide formulations, such as carbamates, pyrethroids, and organophosphates, has been reported for corn (Carvalho et al., 2013; Diez-Rodríguez and Omoto, 2001; Nascimento et al., 2016; Young, 1979). Because most of the insecticides used in row crops, such as corn, are also used in the turfgrass industry to control S. frugiperda, insecticide resistance by S. frugiperda in turfgrass is a real threat. This suggests that there is a need to develop alternate management options for S. frugiperda control in turfgrass.
Turfgrass breeding programs have always emphasized the improvement of aesthetic characteristics and tolerance to abiotic factors, such as drought and foot traffic (Baxter and Schwartz, 2018; Patton et al., 2017). Because insecticide resistance and nontarget effects of insecticide applications pose serious concerns to the turfgrass industry, alternative control options, such as the development of S. frugiperda-resistant genotypes, have been recently emphasized by turfgrass breeding programs (Reinert and Engelke, 2010). In pastures, S. frugiperda is a major pest of bermudagrass, and severe infestation critically affects grass quality and yield (Croughan and Quisenberry, 1989). Bermudagrass genotypes used for pastures can grow densely and up to 60 cm tall. Previously, S. frugiperda-resistant ‘Tifton 292’ and ‘Tifton 296’ bermudagrass cultivars were developed for pasture production (Leuck et al., 1968), and antibiosis was identified as an underlying resistance mechanism (Lynch et al., 1983). In turfgrass, the zoysiagrass cultivars Cavalier, Emerald, DALZ8501, DALZ8508, Royal, Palisades, Belair, and Zeon were found to exhibit high levels of resistance to neonates of S. frugiperda (Anderson et al., 2007; Braman et al., 2000; Reinert and Engelke, 2010). There are no known S. frugiperda-resistant bermudagrass cultivars available to the turfgrass industry. Therefore, the objectives of the current study were to test 14 promising experimental bermudagrass genotypes for resistance against S. frugiperda and to compare their performance to that of the emerging standard bermudagrass ‘TifTuf’. These experimental genotypes are considered “elite” because of their superior turfgrass quality, drought tolerance, shade persistence, rapid growth, and resistance to foot traffic during multiple years of field testing.
Anderson, W.F., Snook, M.E. & Johnson, A.W. 2007 Flavonoids of zoysiagrass (Zoysia spp.) cultivars varying in fall armyworm (Spodoptera frugiperda) resistance J. Agr. Food Chem. 55 1853 1861
Braman, S.K., Duncan, R.R. & Engelke, M.C. 2000 Evaluation of turfgrass selections for resistance to fall armyworms (Lepidoptera: Noctuidae) HortScience 35 1268 1270
Braman, S.K., Duncan, R.R., Engelke, M.C., Hanna, W.W., Hignight, K. & Rush, D. 2002 Grass species and endophyte effects on survival and development of fall armyworm (Lepidoptera: Noctuidae) J. Econ. Entomol. 95 487 492
Buss, E.A. & Dale, A.G. 2017 Insect Pest Management on Turfgrass. UF/IFAS Ext. Bul. ENY-300/IG001
Croughan, S.S. & Quisenberry, S.S. 1989 Enhancement of fall armyworm (Lepidoptera: Noctuidae) resistance in bermudagrass through cell culture J. Econ. Entomol. 82 236 238
Carvalho, R.A., Omoto, C., Field, L.M., Williamson, M.S. & Bass, C. 2013 Investigating the molecular mechanisms of organophosphate and pyrethroid resistance in the fall armyworm Spodoptera frugiperda PLoS One 8 4
Diez-Rodríguez, G.I. & Omoto, C. 2001 Inheritance of lambda-cyhalothrin resistance in Spodoptera frugiperda (JE Smith) (Lepidoptera: Noctuidae) Neotrop. Entomol. 30 311 316
Hardke, J., Temple, J., Leonard, B. & Jackson, R. 2011 Laboratory toxicity and field efficacy of selected insecticides against fall armyworm (Lepidoptera: Noctuidae) Fla. Entomol. 94 272 278
Kane, S. & Wolfe, K. 2012 Economic contributions of turfgrass production, ornamental horticulture, and landscape services, and Related Industry in the Georgia economy, 2010. The University of Georgia, Center for Agribusiness and Economic Development, Center Report: CR-12-05. 26 Jan. 2020. <https://athenaeum.libs.uga.edu/bitstream/handle/10724/33891/CAEDTurfgrassandRelated2012_FINAL.pdf?sequence=1>
Leuck, D.B., Taliaferro, C.M., Burton, G.W., Burton, R.L. & Bowman, M.C. 1968 Resistance in bermudagrass to the fall armyworm J. Econ. Entomol. 61 1321 1322
Luginbill, P. 1928 The fall armyworm. U.S. Dept. Agr. Tech. Bul. 34.
Lynch, R.E., Monson, W.G., Wiseman, B.R. & Burton, G.W. 1983 Bermudagrass resistance to the fall armyworm (Lepidoptera:Noctuidae) Environ. Entomol. 12 1837 1840
Mink, J.S. & Luttrell, R.G. 1989 Mortality of fall armyworm, Spodoptera frugiperda (Lepidoptera: Noctuidae) eggs, larvae and adults exposed to several insecticides on cotton J. Entomol. Sci. 24 563 571
Nascimento, A.R.B.D., Farias, J.R., Bernardi, D., Horikoshi, R.J. & Omoto, C. 2016 Genetic basis of Spodoptera frugiperda (Lepidoptera: Noctuidae) resistance to the chitin synthesis inhibitor lufenuron Pest Manag. Sci. 72 810 815
Patton, A.J., Schwartz, B.M. & Kenworthy, K.E. 2017 Zoysiagrass (Zoysia spp.) history, utilization, and improvement in the United States: A review Crop Sci. 57 37 72
Reinert, J.A. & Engelke, M.C. 2010 Resistance in zoysiagrass (Zoysia spp.) to the fall armyworm (Spodoptera frugiperda) (Lepidoptera:Noctuidae) Fla. Entomol. 93 254 259
SAS Institute 2012 Version 9.3, SAS Institute Inc., Cary, NC
Waltz, C. & McCullough, P.E. 2017 Turfgrass Pest Control Recommendations for Professionals. UGA Ext. Bul. 984