Lepidoptera (Insecta) associated with soybean in Argentina, Brazil, Chile and Uruguay

Natural resistance of soybean cultivars to the soybean looper larva Chrysodeixis includens (Lepidoptera: Noctuidae)

“…Chrysodeixis includens is known as a species that only defoliates soybean; however, other larvae species, such as Spodoptera spp., can also feed on pods (Formentini et al, 2015). Santos et al (2010) concluded that even though S. eridania and S. cosmioides can feed on different cotton (Gossypium hirsutum L.) structures, their survival is highly dependent on the type of food.…”

“…In the antixenosis assay, larvae were free or not (free-choice and no-choice tests, respectively) to choose among new leaves, old leaves, and pods, which were obtained from the four soybean cultivars in the R5 growth stage, i.e., at the beginning of seed filling (Fehr & Caviness, 1977). New leaves were collected from the upper third of the plant, which was not fully distended; old leaves were collected from the lower third of the plant, which was distended and not senescent; and pods were collected from the whole plant.…”

“…During the first one, leaves were collected from the middle third of the soybean plant, without distinguishing between new and old ones. The leaves were detached from the four evaluated cultivars after the R2 phenological stage, i.e., full bloom (Fehr & Caviness, 1977). Leaf discs with 2.24 cm in diameter were supplied to neonate larvae (< 24 hours old) individually in 145-mL plastic containers lined with filter paper previously moistened with distilled water.…”

“…In Argentina, Brazil, Chile, and Uruguay, 69 species of the order Lepidoptera have been associated with the soybean crop (Formentini et al, 2015). The majority of the larvae are considered defoliators, such as the velvetbean caterpillar Anticarsia gemmatalis Hübner, 1818, and the soybean looper Chrysodeixis includens Walker, 1858.…”

“…The majority of the larvae are considered defoliators, such as the velvetbean caterpillar Anticarsia gemmatalis Hübner, 1818, and the soybean looper Chrysodeixis includens Walker, 1858. However, some species, including those of the genera Spodoptera, Helicoverpa, and Heliothis, can also damage the pods by feeding on them (Santos et al, 2010;Hoffmann-Campo et al, 2012;Formentini et al, 2015); these injuries to the pods reduce soybean grain yield and quality (Rogers & Brier, 2010;Shankar et al, 2014).…”