Fall Armyworm Moth

• The adults are extraordinary migrants: they can cover hundreds of kilometres in a single night on high-altitude winds, which explains the speed of their spread around the world.
• It does not survive cold winters, so in North America it recolonises the continent each year from Florida and Texas.
• Its caterpillars are cannibalistic when they compete inside the same whorl, which naturally limits how many complete their development on each plant.
• It was first detected outside the Americas in Nigeria and Ghana in early 2016, and within a year it had colonised 47 African countries; today it is in more than seventy.
• It flies some 100 km a night, which would let it completely infest a country the size of Senegal in under a week.
• It feeds on more than 350 plant species, above all maize, sorghum and sugar cane.
• The damage attributed to it in Africa alone is estimated at 9.4 billion dollars.
• Newly hatched caterpillars burrow inside the plant, where contact insecticides cannot reach them; and the species develops resistance very quickly.

Skeleton type

Invertebrate - chitin exoskeleton (insect)

Habitat and environment

Maize, sorghum, rice and pasture crops in warm regions

Birth weight

First-instar larva of about 0.003 g

Size at birth

Dome-shaped egg about 0.4 mm across; first-instar larva of 4.63 mm

Sexual maturity

Copulation takes place a few hours after emergence, mainly between 20:00 and 23:00; pre-oviposition period of 2-3 days

Gestation / incubation

The eggs hatch in 2-3 days, with a hatching rate of 80-87 %

Litter / clutch size

An average of 469 +/- 22 eggs per female and an observed maximum of 1,184; other studies record averages of 1,015 and maxima of 1,485 depending on temperature and host plant

Sources consulted: Wikipedia (es): Spodoptera frugiperda · Psyche (Marri et al. 2023) · PubMed 36153756 (fecundidad y longevidad a temperatura constante) · Psyche: A Journal of Entomology (Marri et al. 2023) · Iowa State University Extension, ficha Fall armyworm