MORPHOLOGICAL CHARACTERISTICS of Sesamia grisescens
Egg (Eggs hatch in 8-9 days)
Colour: White to cream Shape: Barrel-shaped with longitudinal striations. Size: Between 0.90-1.1mm long and 0.42-0.69mm wide. Laying Habit: laid in masses of about 120. Each female can lay 2-3 masses. 62% egg masses are laid in sheath numbers 6 and 7, while 94% in numbers 5 and 8. Larvae: Seven (7) larval instars in total Identification within Sesamia spp. is difficult. Newly hatched: Approximately 25mm long with a dull pink to cream head capsule and brown cuticle. Final instars: Up to 48mm long with deep brown head capsule. Thoracic shield: light brown with smooth, pink to violet cuticle on the dorsal surface and creamy white underneath. With two rows of lateral tubercles on each side of the abdomen. (Young & Kuniata 1992) |
Pupae
Length: Between 4-7mm. Colour: Initially light tan becoming brown with age and blackish at adult emergence. Adult Moths have no comprehensive description. Shape & Size: Stout bodies up to 20mm in length. Forewings: Dark brown in colour with darker longitudinal streak with a small orbicular spot. Hindwings: Dirty whitish-grey without colour patterns. Head, Thorax & Abdomen:Dull gray; palpi externally darker. Wing expanse: 39mm (male); 47(female) (Young & Kuniata 1992) |