Herpetogramma bipunctalis, commonly known as the southern beet webworm moth or two-spotted herpetogramma, is a species of moth in the family Crambidae. It is found from New England to Florida, west to Texas and north to Illinois. In the south, the range extends through Central America and the Caribbean to South America.
Morphology of Southern Beet Webworm Moth
Eggs are circular to oblong in shape. They are laid in transparent clusters on the underside of leaves. Eggs appear colorless when freshly laid but turn pale brown before hatching.
H. bipunctalis has 5 larval instars. They can reach up to 3âÂÂ4 cm when matured. First instar has a pale green and slender type of body with aàdark head. Fifth instar appears to have a deeper green color on the body with a dark head. This stage is mostly seen in large groups.
Pupal stage is found concealed within the leaf folds or on the soil debris. It is dark brown and obtect. Obtect pupa have appendages like legs and wings glued to the body wall. The pupa of H. bipunctalis has seven spiral crochets.
Adults are moths having a wingspan of 23-24mm. Their fore-wings and hind-wings look similar to each other with a creamy brown color. Wavy and discoidal spots are present on the wings. The abdomen of Brinjal Leaf Webber has 2 dark dorsal spots.
Life Cycle/Biology
The incubation period of egg lasted 4âÂÂ5 days. The development period of I<sub>1</sub>, I<sub>2</sub> and I<sub>3</sub> of larvae was 2âÂÂ3 days. I<sub>4</sub> developed over a period of 2âÂÂ4 days and I<sub>5</sub> ranged 3âÂÂ7 days. Initial instars affected leaves, later made exit holes in stem to reach soil for pupation. Pupal stage lasted 7âÂÂ12 days and adults were produced. The study showed development of H. bipunctalis from egg to adult ranges from 23âÂÂ39 days. It showed evidences of holometabolous type of metamorphosis.