the AGRI lenial rice ……………………………………….… W88RDFW88RDF5 RICE BUG 101 COMMON NAME SCIENTIFIC NAME Leptocorisa oratorius atangya (Tagalog); dangaw (Ilocano) WHAT IT DOES IT DO? Rice bugs damage rice by sucking out the contents of developing grains at milky stage from pre-flowering spikelets to soft dough stage, therefore causing unfilled or empty grains and discoloration. Immature and adult rice bugs both feed on rice grains. Insect attack results in discolored or shriveled grains; o ff smell of raw and cooked rice. Bugs feed on succulent shoots and leaves. Nymphs cause more damage than adults. Bendoy, C. (2011). Describing Head Shape Variation Between Sexes and Among Two Colormorphs Of The Rice Bug, Leptocorisa oratorius Fabricius, Journal of Nature Studies 10 (2): 44-52 SMALL OR SHRIVELED GRAINS SYMPTOMS OF INFESTATION? DEFORMED OR SPOTTY GRAINS EMPTY GRAINS AND ERECT PANICLES WHERE IT OCCURS? Rice bugs are found in all rice environments. They are more common in rainfed and upland rice and prefer the flowering to milky stages of the rice crop. The insect also becomes active when the monsoonal rains begin. The population of the rice bug increases at the end of the rainy season. ITS LIFE CYCLE? PhilRice (2010). Rice Bug Handout Series. Photo from https://www.pinoyrice.com/wpcontent/uploads/rice-bug.pdf The insect has a paurometabolous life cycle (egg-nymph-adult). Eggs are laid 10-20 in 2-3 rows; yellowish at first, later reddish-brown. They hatch producing green nymphs in 5-8 days that looks similar to the adults, but wingless. Adult longevity is 30-50 days. Mating starts 7-14 days after becoming adult. The life cycle takes about 1 month. HOW TO IDENTIFY THEM? WHY IS IT IMPORTANT? Both the adults and nymphs feed on grains at the milking stage. They can be serious pests of rice and sometimes reduce yield by as much as 30%. They are sucking mouthpart bugs with a slender brownyellowish color and long antennae and legs. Nymphs resemble adults except for presence of wings. It also has its own distinct pungent smell. CULTURAL OPTIONS Eliminate grassy weeds from rice fields, leaves, and surround ing areas by either cutting/burning to reduce habitats for egg‐laying. Avoid staggered planting of fields in the area to break contin uous food source. Smoking the field by burning straw windward, and passing baskets or bags on the inside with sticky material are promisi ng in repelling or capturing them. Netting and handpicking bugs reduce their numbers. Awned varieties are resistant. Varieties with panicles enclosed in the leaf sheath for longer time offer mechanical resistance to feeding. HOW TO CONTROL IT? BIOLOGICAL OPTIONS Small wasps & long-horned grasshoppers TO KILL EGGS ..................... Fungus infect NYMPHS & ADULTS ..................... Spiders, crickets & lady beetles FEED ON ADULTS & NYMPHS BY STIPHEN M. REGALARIO ] AGRI 41 Y21L
