Desert locust

  • desert locust
Abstract from DBPedia
    The desert locust (Schistocerca gregaria) is a species of locust, a periodically swarming, short-horned grasshopper in the family Acrididae. They are found primarily in the deserts and dry areas of northern and eastern Africa, Arabia, and southwest Asia. During population surge years, they may extend north into parts of western Spain and southern Italy, south into Eastern Africa, and east in northern India. The desert locust shows periodic changes in its body form and can change in response to environmental conditions, over several generations, from a solitary, shorter-winged, highly fecund, non-migratory form to a gregarious, long-winged, and migratory phase in which they may travel long distances into new areas. In some years, they may thus form locust plagues, invading new areas, where they may consume all vegetation including crops, and at other times, they may live unnoticed in small numbers. During plague years, desert locusts can cause widespread damage to crops, as they are highly mobile and feed on large quantities of any kind of green vegetation, including crops, pasture, and fodder. A typical swarm can be made up of 150 million locusts per square kilometre (390,000,000 per square mile) and fly in the direction of the prevailing wind, up to 150 kilometres (93 mi) in one day. Even a very small, 1-square-kilometre (0.39 sq mi) locust swarm can eat the same amount of food in a day as about 35,000 people. As an international transboundary pest that threatens agricultural production and livelihoods in many countries in Africa, the Near East, and southwest Asia, their populations have been routinely monitored through a collaborative effort between countries and the United Nations Food and Agriculture Organization (FAO) Desert Locust Information Service (DLIS), which provides global and national assessments, forecasts, and early warning to affected countries and the international community. The desert locust's migratory nature and capacity for rapid population growth present major challenges for control, particularly in remote semiarid areas, which characterize much of their range. Locusts differ from other grasshoppers in their ability to change from a solitary living form into gregarious, highly mobile, adult swarms and hopper bands, as their numbers and densities increase. They exist in different states known as recessions (with low and intermediate numbers), rising to local outbreaks and regional upsurges with increasingly high densities, to plagues consisting of numerous swarms. They have two to five generations per year. The desert locust risk increases with a one-to-two-year continuum of favourable weather (greater frequency of rains) and habitats that support population increases leading to upsurges and plagues. The desert locust is potentially the most dangerous of the locust pests because of the ability of swarms to fly rapidly across great distances. The major desert locust upsurge in 2004–05 caused significant crop losses in West Africa and diminished food security in the region. The 2019–2021 upsurge caused similar losses in northeast Africa, the Near East, and southwest Asia.

    サバクトビバッタ(砂漠飛蝗、学名:Schistocerca gregaria、英名: Desert locust)は、バッタ科のバッタ。サバクワタリバッタ、サバクバッタ、エジプトツチイナゴとも。サバクトビバッタは大規模な蝗害(こうがい、野生植物や農作物が喰い荒らされる災害)を引き起こす、世界を代表するワタリバッタ(別称: トビバッタ、locust)の1種として知られている。 ワタリバッタとは、バッタの中でも特に何らかの理由で群れを成して相変異(獰猛化する変身モード)を起こし、広域に飛翔する。サバクトビバッタが孤独相 (単体で生息しておとなしいモード) から群生相に相変異すると、黄色に黒色が混じった体色に変化し、体長と比して翅が長くなる。 その名の通り、砂漠および半砂漠地帯に生息しており、地理的にはサハラ砂漠に位置する西アフリカから中東、東南アジアにかけて確認されている。通常時は世界30か国ほど、また大発生時には世界60か国(世界の陸地の20%相当の面積)に渡って生息・飛来すると言われ (2012年時点の情報)、飢餓や貧困の原因の一つになっている。 サバクトビバッタは、『聖書』や『コーラン』にも被害が記載されるほど、古くから恐れられているが、大発生のタイミングは不定期である。国際連合食糧農業機関 (FAO) がサバクトビバッタ対策専門チームを編成しており、被害に苦しむ各国政府や研究機関と連携しながら、発生状況のモニタリングや防除用の殺虫剤の管理・散布トレーニングなどの役割を担っている。しかしながら、相変異を起こすメカニズムなどは完全には把握できていない。また成虫になると1日で100kmを超える飛翔能力を有することから、幼虫のうちの防除が肝要であるが、これが後手に回ると被害が拡大しやすい性質がある。21世紀に入ってからも2003年 - 2005年、および2019年 - 2020年に大発生が確認されている。