Oxya intricata & Locusta migratoria manilensis
Symptoms differ depending on the plant type and the hunger of the grasshopper. Grasshopper and locust feed primarily on leaves damaging the margins or cutting out large portions of the leaf. Grains, seed pods and fruits may also be attacked by the insect. When they are very hungry they might even feed on stems and bark. They also nibble at the shoots, hence severing the reproductive parts.
The characteristic symptoms on leafs and panicles are caused by the nymphs and adults. Aquatic environments are suitable for their development (e.g. rice fields, floodplains, deltas). The grasshoppers range in sizes from 5 mm to 11 cm in length, and they could either be long and slender or short and stout. They can blend easily into their surroundings as they are either green or straw colored. Females lay yellow eggs on the foliage. The adults can develop wings, swarm and migrate.
Biological control agents which occur naturally such as wasps, parasitic flies and worms, ants, birds, frogs, web-spinning spiders should be promoted. Fungal pathogens and entomopathogenic fungus (Metarhizium acridum) could also be used to reduce the population density of larvae. Use home-made poison baits from salt water and rice bran.
Always consider an integrated approach of preventive measures together with biological treatments if available. Use foliar insecticidal sprays to control grasshoppers in fields that show >10% damage. Granules are not effective. Poisonous bait traps can be used to attract the adults. Insecticides that can be sprayed against the pest include chloropyriphos, buprofezin or etofenprox. Other FAO recommended chemicals include bandiocarb 80% WP @ 125 g/ha, chlorpyriphos 50% EC @ 480 ml/ha, deltamethrin 2.8% EC @ 450 ml/ha.