LIFE HISTORY OF COMMON CUTWORM, Spodoptera Litura Fabricius (NOCTUIDAE: LEPIDOPTERA) IN BENGUET

ABSTRACT

Common cutworm, Spodoptera litura Fabricius underwent the holometabolous
type of development. The insect’s development duration is:
egg (5.0 + 0.00 days), larva (23.9 + 0.71 days), pupa (17.80 + 2.33 days),
adult female (12.10 + 2.65 days) and male (7.45 + 1.31 days). The egg is
round and dirty white. The body of the newly emerged larva is cylindrical;
head size is wider than the body while the abdomen tapers towards the caudal
region. But during the 2nd instar until pupation, the body turns wider
than the head. The true legs and pro-legs are distinct. The newly emerged
larva is whitish, then turns yellow green an hour after with a pattern of red,
yellow, and green lines from the head to the anal region. As the larva grew
bigger, the body turns brown with 3 thin yellow lines down the back. The
newly emerged larva singled out the leaf veins during feeding while the big
larva includes them. Bigger larva is an excellent feeder and active at night.
The larva hides in the soil at day time and ceaseless when about to molt.
The body length and width of the smallest and full grown larva, respectively
are: 2.16 + 0.14 mm and 0.32 + 0.02 mm; 46.91 + 2.25 mm and 6.87 +
0.16 mm.

Pupation was in the soil. The pupa is elongated oval and shiny red.
The body length and width measures 22.29 + 0.71 mm and 7.51 + 0.36 mm,
respectively. The adult female and male are hairy. The female is pale brown
while the male is darker. The female is bigger with a stout abdomen while
the male is narrower and tapering towards the tip. Courting the female
lasted for 10 to 20 minutes while mating was 2-3 hours between 2:00AM to
5:00AM. The eggs are laid in mass of 2-3 layers on the lower surface of the
leaves near the petiole. Egg mass of 8.7 are laid within 12 days egg laying
as the shortest and 14 days as the longest. There are 874.9 individual eggs
in one egg mass.

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