Search Results (3)

The fall armyworm (FAW), Spodoptera frugiperda, is a major polyphagous pest that mainly feeds on maize and other cash crops. Understanding S. frugiperda’s behavior on different host plants facilitates the development of effective integrated pest management (IPM) plans. Therefore, this study investigated the oviposition preferences of S. frugiperda females among different host plants using no-choice, two-choice, and multiple-choice bioassays. In no-choice bioassays, para grass, Urochloa mutica (Forssk.) (Poales: Poaceae); maize, Zea mays (L.) (Poales: Poaceae); and napier grass, Pennisetum purpureum (Schumach) (Poales: Poaceae) were identified as highly attractive, while sweet sorghum, Sorghum dochna (Forssk.) (Poales: Poaceae); sunhemp, Crotalaria juncea (L.) (Fabales:Fabacea); Egyptian clover, Trifolium alexandrinum (L.) (Fabales:Fabacea); desmodium, Desmodium uncinatum (Jacq.) (Fabales:Fabacea); natal grass, melinis repens (Zizka) (Poales: Poaceae); molasses grass, Melinis minutiflora (P.Beauv.) (Poales: Poaceae); and mung bean, Vigna radiata (R. wilczek) (Fabales: Fabaceae) exhibited reduced oviposition effects. Two-choice bioassays revealed different levels of attractiveness and repellency among different plant combinations. In multiple-choice bioassays, mimicking an intercropping scenario, differences in the number of eggs and egg mass were observed for M:S:D:W (maize, sunhemp, desmodium, and cage wall), S:D:M:W (sunhemp, desmodium, maize, and cage wall), and D:M:S:W (desmodium, maize, sunhemp, and cage wall). This study provides insights into the egg-laying preferences of S. frugiperda females among different host plants, valuable for the management of S. frugiperda. This encourages further research and further identification of novel repellent and attractant host plants, which will ultimately contribute to the development of sustainable and environmentally friendly crop production practices and techniques. Full article

Grasslands are one of the most threatened terrestrial biomes leading to a loss of grassland biodiversity, including birds. Here, we studied the wintering grassland bird diversity and community structure in two private livestock ranches in the Chihuahuan Desert, Mexico. We explored how bird communities are related to vegetation structure, including shrub cover and invasive exotic natal grass (Melinis repens), two drivers of grassland bird habitat degradation. We used Hill’s numbers to estimate taxonomic species richness and diversity and related these metrics to vegetation covariables using linear models. We employed nonmetric dimensional scaling (NMDS) to explore the importance of vegetation covariates in structuring bird communities. We found that bird species diversity was significantly and negatively related to bare ground cover at a plot level. At the ranch level, shrub cover, grass height and natal grass were important in structuring avian communities, negatively affecting the presence and abundance of grassland specialist bird species. Our results indicated that shrub encroachment and invasive exotic natal grass cover may alter grassland bird communities and should, therefore, be considered in grassland bird conservation management. Full article

After being discovered in Taiwan for the first time in June 2019, the polyphagous invasive fall armyworm (FAW), Spodoptera frugiperda (Lepidoptera: Noctuidae), has since spread throughout the entire nation. In Taiwan, this insect has a significant impact on the quality and output of wheat, corn, sorghum, and millet. It may further infest more crops in Taiwan due to its diverse range of hosts and alternate hosts. Maize and other staple crops have already been the subject of several study. The biology of FAW has not yet been studied in relation to the alternative hosts, particularly those commonly found in Taiwanese farmlands. Therefore, this study proposed to investigate the effects of napier grass (Pennisetum purpureum), natal grass (Melinis repens), and sunn hemp (Crotalaria juncea) on the development, reproduction, survivorship, and population growth of FAW under laboratory conditions. According to the results, the developmental duration was considerably the shortest when FAW was reared on sunn hemp while the longest on natal grass. Furthermore, female adults reared on napier grass had a longer adult pre-oviposition period, total pre-oviposition period, oviposition period, longevity, highest fecundity, and highest net reproductive rate (R_o: 465.12). Among the tested three alternative host plants evaluated, sunn hemp had the highest intrinsic rate of increase (r: 0.1993), finite rate of increase (λ: 1.2206), and shortest mean generation time (T: 29.98). Therefore, this study suggests that all hosts plants can contribute to the development and outbreak of this pest in the absence of its primary host; however, sunn hemp was a relatively more suitable host plant for this insect. The possibilities for the FAW’s growth and development vary depending on the host plant. Thereby, all potential host plants in the area should be extensively examined while developing an IPM program against FAW. Full article