General Information
common name: Rice gall midge
Scientific name:
Orseolia oryzae
Diptera:Cecidomyiidae
Synonym: Asian rice gall midge
Host plants
Rice and corn
Distribution
Bangladesh, Bhutan, Cambodia, China, India, Indonesia, Lao PDR, Myanmar, Nepal, New Guinea, Pakistan, Sri Lanka, Thailand, and Vietnam.
Damage
The infested rice plant has a hollow cavity or a tubular
gall at the base of a
tiller which does not bear
panicle. Its feeding damage also causes elongation of leaf sheaths called 'Onion leaf or Silvershoot'. The gall is a silvery-white hollow tube which has a size of 1 cm wide and 10-30 cm long.
Description
Eggs are elongate and tubular. The newly laid eggs vary from white to pink, red, and yellow colors. The eggs turn like shining-ambers before hatching. They are laid either singly or in groups of 3-4 at either on the base of the plant, the
ligule, the leaf blade, or on the leaf sheath. The egg development lasts for 3-4 days.
The larva is maggot-like, about 1 mm long, and is grayish-white in color. It situates itself at the growing point of the apical or side buds of a node in order to feed. One larva occupies a single tiller. The larval feeding damage causes the formation of a tubular gall at the base of the tiller and inhibits growth of the leaves and the panicle. The gall enlarges at the base of the tiller as a result of the larva's continuous feeding. There are 3-4 larval stages, which last for 15-20 days.
The pupa is light-pink with abdominal spines and it turns red before emergence. It is 2-2.5 mm long and 0.6-0.8 mm wide. Pupation is 2-8 days. Both the larval and the pupal developments are completed inside the gall.
The adult looks similar to a mosquito. The female midge has a bright
red abdomen while the male has a yellow-brown body. The male is generally smaller than the female. It has a wing expanse of 3.0-3.5 mm. Both adults have bead-like antennae with more than 10 segments. The adults are nocturnal. They are easily collected using light traps. They mate soon after emergence. A female midge mates only once. It can lay as many as 100-200 eggs in its lifespan of 4 days. The male midge lives only 12 to 18 hours.