Southern armyworm
Spodoptera eridania (southern armyworm) is a moth that is known to be a pest. They are one of the most important defoliators in the tropical and subtropical regions of the western hemisphere that feed heavily on plants while they are young, often resulting in skeleton leaves on their food plants. They are also heavy feeders on tomato in Florida. There is a lot of development in producing pesticides against the S. eridania, specifically a neem-based pesticide that can result in smaller and prolonged development. The wingspan is 33–38 mm. Adults are on wing year-round. The larvae feed on various weeds but prefer Amaranthus species and Phytolacca americana.
The S. eridania is found in North America (the southern US states as far west as Kansas and New Mexico), through the Caribbean and Central America into South America (through Brazil to Argentina). It has been introduced Nigeria and Cameroon.
The number of generations is estimated at four each year in Florida. In northern Florida, moths can be found throughout the year, withstanding several days of freezing weather. S. eridania larvae are found in northern Florida only in the summer months, which is consistent with most other insects. One generation is about 30 to 40 days.
Larvae are defoliators and feed gregariously while young, often skeletonizing leaves. As they mature they become solitary, and also bore readily into fruit, often damaging tomatoes in Florida. It can result in significant yield losses if uncontrolled. When stressed by a lack of food they will eat the apical portions of branches, bore into stem tissue, and attack tubers near the surface of the soil.
