(Spodoptera cosmioides) is one of the main insect pests in tropical South American regions. It is a polyphagous species, which attacks soybean, aubergine, pepper and cotton, amongst others.
Appearance and life cycle of Spodoptera cosmioides
The eggs are a light greenish colour, grouped irregularly. They are laid in two or three layers and covered by scales and hairs to protect them. The caterpillars are polyphagous and irrigated crops allow the pest to survive longer. In cotton plants, they start to occur at the emergence of flower buds, and during blossoming. They initially feed mainly on the leaves. Later they become solitary and feed on buds, fruits, pods and grains, leading to the establishment of pathogenic micro-organisms in the plants. The ideal temperature for their development varies from 22 to 30°C. At the start of development, the caterpillars are brown with a black head and display three longitudinal orange lines. During their development, they become a darker brown colour. A darker tone is noted between the third pair of thoracic legs and the first pair of false abdominal legs. The glabrous pupae are found in the soil, inside a basic pupal chamber. They are brown, and measure around 15 to 30 mm in length and are 4 to 5 mm wide. Adults have a wingspan of approximately 40 mm. Females are brown with a white pattern on the forewings, while the hindwings are white. The males have yellow forewings with dark patterns. The insects’ wing patterns can be used to distinguish male and female.