東亞飛蝗

東亞飛蝗（）是飛蝗的一個亞種。
由於本物種跟同種的非洲飛蝗在體型及結構上的差別很大，所以被認為是另一個亞種。本物種發現於中國大陸及東南亞，是當地農業的主要害蟲，對當地作為主食的禾本科經濟作物造成巨大損耗

分佈
東亞飛蝗分佈於東南亞。蝗災曾發生於泰国、馬來西亞、爪哇、苏拉威西岛以及日本南端。

生活史
The adult female Oriental migratory locust deposits a number of egg pods in the ground over the course of a few weeks. The sites selected include soft soils such as volcanic ash, alluvial soils and sand. Each pod contains between fifteen and a hundred eggs and most females lay from two to seven pods during the breeding season. The eggs hatch 10 to 24 days later and the nymphs develop through 5 or 6 instars, taking between 26 and 61 days to fully develop.

Locusts change their behaviour and are attracted to each other when there are large numbers in close proximity. This behaviour starts when the nymphs are quite small and form a band that move together as a cohesive unit. The band of hoppers can travel a distance of up to per day, mostly moving downhill, stopping sporadically to feed and bask in the sun. When the insects are fully developed and have wings, they stay together as a swarm. Solitary adults usually fly by night but gregarious ones fly by day. The new adults mature and become sexually active in three or four weeks. There may be up to five generations per year in the Philippines, but in the cooler parts of China, there may be just one or two.

Outbreaks in China historically occurred about every ten years, usually after dry summers were succeeded by warm winters. The swarms were mostly restricted by the surrounding uplands to the river valleys.

In the Philippines, there were four major plagues in the first half of the twentieth century. They seem to have originated in southern Mindanao around Sarangani Bay. They tended to follow periods of below average rainfall. Since about 1960, the Oriental migratory locust has been less of a problem in the Philippines, probably because cultivation practices have changed and there is less untended grassland where populations can build up undetected.

An outbreak in southern Japan was discovered on an uninhabited island in 1986. A wildfire had restricted the area available to the locusts for feeding and later provided ideal conditions for egg deposition. Hopper bands with a density of 1000 insects per square metre roamed around and swarms of adults occurred over the whole island; the outbreak was brought under control later in the year by spraying.

參考文獻