Mexican rice borer

Mexican rice borer moths are light tan with delta-shaped wings. Adult moths lay spherical, cream-colored eggs in groups of five to 100. Young larvae feed on the tissue inside the leaf sheath and bore into the rice stem after about one week of feeding. Larvae are whitish in color with a light-colored head capsule and two pair of dark purple stripes running the length of the body. Pupation takes place inside the rice stem after mature larvae have constructed an emergence window covered by one or two layers of plant tissue. Emergence holes are smaller than those made by the sugarcane borer.
Damage: Injury to rice results from stem borer larvae feeding on plant tissue as they tunnel inside the stem. Injury is often first noticed when the youngest partially unfurled leaf of the plant begins to wither and die, resulting in a condition called deadheart. Later in the growing season, these rice stems are weakened and may lodge before harvest. Stem feeding that occurs during panicle development causes partial or complete sterility and results in the whitehead condition. The white, empty panicles are light in weight and stand upright.