Prostephanus truncatus

Definition

A species of wood-boring beetle in the family Bostrichidae, commonly called the larger grain borer (LGB) to distinguish it from the smaller Rhyzopertha dominica (lesser grain borer). Native to the Neotropics but introduced to Africa in the early 1970s, it is a primary pest of stored maize and dried cassava, capable of completing its life cycle in approximately 27 days under optimal conditions (32°C, 80% relative humidity). Adults bore into intact kernels and woody tissues, causing substantial post-harvest losses in West and East Africa.

Etymology

Example

In West African grain stores, Prostephanus truncatus often co-occurs with Sitophilus zeamais, with the former preferentially attacking intact maize cobs while the latter exploits damaged kernels.

Synonyms

• Larger grain borer
• LGB

Related Terms

• Rhyzopertha dominica
• Bostrichidae
• stored-product entomology
• post-harvest pest
• Grain borer
• Sitophilus zeamais

Usage Notes

The common name 'larger grain borer' is strictly relative to Rhyzopertha dominica; at 6 mm, P. truncatus is still a small beetle. In invasion biology and agricultural extension literature, 'LGB' is frequently used without expansion. The species is distinguished from other Bostrichidae by its association with stored grain rather than structural timber, though adults retain wood-boring capabilities. Quarantine and biological control programs (notably using the predator Teretriosoma nigrescens) often refer to this species by its scientific name to avoid ambiguity.