General Information

Potato tuber moth
Scientific name: Phthorimaea operculella
Lepidoptera:Gelechiidae

Synonyms: PTM, Potato tuberworm, Potato moth, Tobacco leafminer, Tobacco split worm, Stem end grub,

Host plants

Potato is the favored host but also attack on other solanaceous crops

Distribution

Africa, some parts of Asia, Europe, South America, and USA

Damage

The larva mines into the potato leaves causing brown blisters and feeds further into leaf stalks or stems causing death to the upper parts of the plant. It continues feeding into the developing potato tubers. It often enters through the eyes, leaving frass around the eye. It may feed near the tuber surface causing a long irregular gallery across it or tunnel deeply into the tuber leaving a trail of excrement along its path.

Description

The eggs are broadly oval, smooth, iridescent, and yellowish in color. These are laid singly or in batches on the leaves of the host plant or near the eye buds of exposed tubers.

The larva has a grayish-white or pale-greenish gray body with a dark-brown head. It is about 1.5 cm long, when fully mature. The larval stage lasts 13-33 days.

The pupa is yellowish or reddish-brown in color. Pupation normally takes place in the soil but also on plant debris around potato plants. The pupal period lasts for about 6-29 days.

The adult has a narrow silver-gray body and grayish-brown wings patterned with small, dark specks. Its body length is about 1 cm and its wingspan is about 1.2 cm. The moth is active mainly at night and is attracted to light, but can be seen flying sporadically among the potato crops during the day. They live for up to 10 days. The moth breeds continuously where conditions permit. The complete lifecycle ranges from 17-125 days.