Sweet potato vine borer
Scientific name: Omphisa anastomosalis
Synonym: Sweet potato stem borer
Sweet potato and Ipomea weeds
Southeast Asia and Hawaii
Feeding damage on the vine causes wilting and poor growth. The feeding that occurs on the plant's crown often results in plant death. The accumulation of fecal matter on the soil surface and holes on the vines are signs of larval feeding.
Egg is ovate with a flat base and greenish in color. It is about 0.5 mm in diameter. It is laid singly either on the upper or lower surface of the leaf lamina and on the leaf petiole. An egg hatches in about 7 days.
nLarva is light-purple and/or yellowish-white in color. Its head is brown and has brown spots that form prominent stripes along its sides. A fully-grown larva can measure up to 2.5-3.0 cm long. It undergoes 6 larval instars that usually vary from 21-90 days, depending upon the climatic condition.
A pupa is light-brown in color and is about 1.6 cm long. It pupates on the vine where the larva has been feeding, but also on the soil near the roots.
The adult is white in color and has a brownish-yellow pattern on its wings. It has dark-brown forewings and lightly-pigmented hind wings. The female has a broader abdomen than the male, with the latter having clasper-like structures on the last abdominal segment which is not found on the former. Both are immediately fertile upon emergence. A female lives for about 10 days.