New Pest Response Guidelines - Phytosanitary Resources

Noctuidae: Spodopotera
Chapter 2. Pest Information
Life cycle
In some areas, pupae appear to be more tolerant of cold conditions than
larvae.
Spodoptera litura
Female moths of S. litura lay eggs at night, leaving batches of up to 300 eggs
on the undersurface of host leaves. Sometimes, females lay eggs on other flat
surfaces such as the walls of houses (Bishara 1934).
Newly hatched larvae are very susceptible to dry heat, usually staying on
lower leaf surfaces during the day and feeding at night. In their last two
instars, they feed only at night and seek shelter during the day under the
lowest leaves or in the soil at the base of the host. Males can fly up to 3.1
miles per night when temperatures exceed 68 °F. Males mate once each night
and avoid previously-mated females (Brown and Dewhurst 1975).
Members of the genus Spodoptera undergo complete metamorphosis and pass
through the following stages:
• Egg
• Larva (caterpillar)
• Pupa
• Adult (moth)
Spodoptera over-winter as adults or pupae in plant debris. In spring, adults
emerge at dusk in search of mates.
Spodoptera littoralis
The life cycle of S. littoralis requires from 19 to 144 days. Host plant species
may influence the length of time necessary for development.
Incubation of eggs requires from 2 days (in warm weather) to 26 days (in cold
weather). Larvae develop through five or six instars. Larval development
requires from 12 days (during hot summer months) to 85 days (in winter).
Pupation takes place in cells 1 to 2 inches below the soil surface and varies
from 5 days (in summer) to 31 days (in winter).
Newly emerged moths are active from dusk to dawn. Females begin calling
within 1 hour of dusk. Females mate once or twice at most, while males may
mate up to six times. Females live for periods of 2 days (in summer) to 22
days (in winter). Females live longer than males (Miller 1977).
Spodoptera litura
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