Neonicotinoids and the Rice
Plant Hopper Outbreak in Asia
Koa Tasaka
Former Prof. of Chemistry atInternational Christian University,Tokyo, JapanIUCN Symposium in Tokyo

Rice Plant Hopper which threatened the "GreenRevolution" by Dr. Kazushige Sogawa, Oct.25,
2010; Last Chapter
In the Spring of 2008, I went to IRRI where I first
visited 40 years ago. Half a century has
passed since the IMP started, and during thepast 20 years, FAO has been successful instopping the resurgence of BPH through theIPM program. The use of organic phosphatepesticides has decreased drastically. In thepaddy field of IRRI, there was no more
powerful BPH which once gave me so strong
impression!

「緑の革命を脅かしたイネウンカ」
寒川一成著、２０１０年１０月２５日
星雲社より発刊（終章より）２００８年春、４０数年前の青春時代に初めて訪れたフィリピンの国際稲研究所にやってきた。IPMが登場して半世紀が過ぎ、熱帯アジアでFAOのIPM普及事業が発足してから約２０年が経っている。FAO主導のIPM普及事業によって、１９８０年代後半から１９９０年代にはトビイロウンカのリサージェンスを引き起こしていた有機リン系殺虫剤の使用が目に見えて低減し、トビイロウンカの連鎖的大発生が収まった。

Outbreak of BPH in Indonesia andIPM by FAO expert in 1986-1991
Japan Times, May 12,1992

The Rice Planthopper(RPH) Problem isHappening Again!
However, in recent years, the problem of BPH
which seemed to be terminated already, iscoming up again in the paddy fields of various
places in tropical Asia.
Neonicotinoid insecticides were introduced
under the IPM program, but gave serious
impacts on the eco-system of paddy field. They
have nicotine-like structure, penetrate into therice plants and effective at low concentration forlong termネオニコチノイドに耐性を持つトビイロウンカの出現
ところが、一旦は終息したかに見えたトビイロウンカ問
題が、熱帯アジア各地の水田で再燃し始めている。
IPMとの協調を謳って登場したネオニコチノイド系殺虫剤が、水田生態系に深刻な影響を与えている。天然の殺虫成分であるニコチンに類似した化学構造と、イネ体内に浸透し低濃度で長期間殺虫毒性を持続するネオニコチノイド系殺虫剤は、環境にやさしく、天敵生物への影響が少ないとされてきた。更に農民に対しても安全で省力的、かつ経済的とされてきた。
ところが、その負の影響は、まずネオニコチノイドに耐性を持つトビイロウンカの出現となって現れた。
（文献；Matsumura M., et al.,Pest Management
Sci., 64;1115-1121, 2008)

The Chemical Structure ofNeonicotinoids

Neonicotinoids
The Neonicotinoids which chemicallyresemble nicotine, a natural insecticide,
and keeps insecticidal property for a longperiod by penetrating into the rice plants
was believed to be eco-friendly, and not somuch adverse effects on predators or onhuman health. However, the negative
effects have appeared as BPH resistant toNeonicotinoids.

BPH has developed resistance power
against Neonicotinoids. The negative impact of neonicotinoid
appeared in the form of BPH with theresistant power to the pesticide.** Matsumura M., et al., Species-specificinsecticide resistance to imidacloprid andfipronil in the rice planthoppers
Nilaparvata lugens and Sogatella frucifera
in East and South-east Asia. Pest
Management Sci., 64; 1115-1121, 2008.

In the Case of Thailand
In Thailand where Imidacroprid has beencontinuously used to control BPH, theeffectiveness against BPH graduallydicreased from 2003-2005, and as a resultof random use of insecticides such asAbamectin, Cybamethrin orChlorpyriphos, extensive outbreak of BPH
has been happening since 2008!
Ref; K. Sogawa, Green Revolution
threatened by Rice Plant Hoppers, 2010

タイの事例
トビイロウンカの防除にイミダクロプリドを連用してきたタイでは、２００３～２００５年頃から、トビイロウンカに対する防除効果が減退し始めた。効かなくなったイミダクロプリドに代わり、大量に出回ったアバメクチン、サイバメスリン、クロルピリフォスなどの殺虫剤が乱用され、２００８年からトビイロウンカの大規模なリサージェンスが起こっている。

Thailand(continued)
The Hopperburn which has started in therainy season of 2009 in three Provinces ofCentral Thailand has spread over 18
Provinces. Moreover, the virus accompany
BPH is also widely spreading .Thai
Government allocated special budget for
insecticide, and started campaign tocontrol BPH by insecticide. But,this policy
lead to more outbreak of BPH

タイの事例（続き）
２００９年雨期に、タイ中央平原の３省から始まったホッパーバーンが、またたく間に１８省に蔓延し、さらにトビイロウンカが媒介するウィルス病が流行し始めている。タイ政府は殺虫剤調達のために特別予算を計上し、殺虫剤によるトビイロウンカの防除を促すキャンペーンを展開した。しかし、国際稲研究所でIPMの研究と普及に長年携わってきたヘオン氏は、このような措置が、火にガソリンを注ぐような結果になるのではないかと警告を発している。

"Hopper Burn" by BPH and the Virus（January 25,２０１０ in Suphan Buri, Thailand）

So many small hoppers were seen on
the stems of rice plant

Imidacroprid, Neonicotinoid Insecticide,sold in a pesticide shop in Suphan Buri,Thailand(on the right), 2010

In 2009, Whitebacked Planthopper Outbreakhappened in Yunnan Province for the first time,
so Prof. Rongping organized an Seminar inNov. in Yunnan.

The Case of China
In 2005, BPH outbreak has happenedsuddenly after the decrease of the caseover the long period since 1999.
It happened when Imidacroprid(Chinese
name; Peetsuolin), the typicalneonicotinoid insecticide became
ineffective against BPH. Almost all the rice
plants of the experimental paddy field ofChinese Rice Research Institute havedied.( Ref. Sogawa, Green Revolution
threatened by Rice Planthopper, 2010)

China Case(continued)
About 40% of all the paddy fields in Sekko
Province was damaged, and rice harvest
was none in the 14,000ha among theaffected area.
Since then, there has been continuous
outbreak of BPH in China.

Neonicotinoid 「虫司令」Made in China(Chong Si Ling;active ingredient; Imidacloprid),
sold in the market in Cambodia(July 2011)中国の事例中国水稲研究所で過ごした最終年の２００５年に、１９９９年以来減少していたトビイロウンカが突然大発生した。代表的なネオニコチノイド系殺虫剤であるイミダクロプリド（中国名；ピーツォンリン）が効かなくなった途端に大発生した。
研究所の過半の試験田がほぼ前面枯死した。
浙江省だけでも、４０％の水田が重大な被害を受け、その内１４０００haが収穫皆無になった。
以来、トビイロウンカの多発が続いている。

Vietnamese Government Officials, NGOs
and Farmers also joined the Seminar

The serious outbreak of WBPH in theMekong Delta region in Vietnam
where the Chinese hybrid rice
varieties were intensively introduced,
may retard all the effort andachievement of IPM to reduce the useof pesticides in the past 20 years!
Also, the overuse of pesticides will
destroy the mechanism of biologicalcontrol by paddy ecosystem!

米価高騰をもたらしたベトナムでのトビイロウンカの大発生
ベトナム南部のメコンデルタでは、トビイロウン
カは1991年～1992年の大発生の後、少発状態を保っていた。しかし、2006年から再び多発し始め、トビイロウンカが媒介する稲ウィルス病の大流行に悩まされている。2007年、ベトナムはウンカとウィルス病の被害が原因で米の輸出を抑制した結果、周辺の米輸入国で米価が高騰し、大きな社会問題となった。
いわゆる2008年のライスクライシスである。Adverse Effects of
Neonicotinoid Insecticides• Noenicotinoid type insecticides are known to affectthe nerve system of honey bees, and make them
unable to return to their nest. As a result, honeybees are disappearing from the areas where
neonicotinoid insecticides has been used.
• Ｎｏｔ ｏｎｌｙ ｈｏｎｅｙ ｂｅｅｓ， ｂｕｔ ａｌｓｏ ｖａｒｉｏｕｓ ｎａｔｕｒａｌｅｎｅｍｉｅｓ， ｅｓｐｅｃｉａｌｌｙ ｔｈｏｓｅ ｂｅｌｏｎｇｉｎｇ ｔｏ ｂｅｅ ｆａ
ｍｉｌｙ， ｗｉｌｌ ｂｅ ｋｉｌｌｅｄ ｂｙ ｔｈｅ ｕｓｅ ｏｆ ｎｅｏｎｉｃｏｔｉｎｏｉｄ
ｓ． Ｔｈｕｓ， ｎａｔｕｒａｌ ｅｃｏ－ｓｙｓｔｅｍ ｗｈｉｃｈ ｃａｎ ｃｏｎｔｒｏｌ ｔｈｅ ｐｏｐｕｌａｔｉｏｎ ｏｆ ｒｉｃｅ ｐｌａｎｔｈｏｐｐｅｒｓ ｗｉｔｈｉｎ ｃｅ
ｒｔａｉｎ ｌｅｖｅｌ， ｗｉｌｌ ｂｅ ｄｅｓｔｒｏｙｅｄ．
• Ｙｏｕ ｗｉｌｌ ｓｅｅ ｔｈｅ ｅｘａｍｐｌｅ ｏｆ ｓｕｃｈ ｃａｓｅ ｉｎ ｔｈｅｆｉｌｍ, “Hopper Race” ｐｒｏｄｕｃｅｄ ｂｙ ＴＶＥ Ｊａｐａｎ in2013．

水田生態系を破壊する
ネオニコチノイド• 浸透性殺虫剤のネオニコチノイドとフィプロニルは、ミツバチの神経系統を破壊して帰趨能力を奪ったり、殺すことが知られている。
• さらに、ミツバチだけでなく、水田の生態系の一部として、イネウンカの爆発的な増加を抑えている天敵には、これから見ていただく• フィルムに登場するハナモグリコバチのように、イネウンカの卵に自分の卵を産み付けてウンカの数をコントロールする蜂の仲間もおり、ネオニコチノイドの使用は、こうした水田の生態系を破壊する。

Comparison of China, Thailand
and Vietnam with Lao PDR• China, Thailand and Vietnam; Introduced hybrid
varieties or high-yielding variety of rice over 50%, Inmost areas, rice is grown twice or three times a year.
By the heavy use of insecticides, the predators werekilled, while RPH got resistance to insecticides, andquickly multiply with their food available all through theyear, leading to the outbreak of RPH!
• Lao PDR; According to the JICA experts in RISEP,mostof the farmers are growing traditional variety of sticky
rice for domestic consumption, and there is not so muchneed to use insecticide . As a result, the ecologicalbalance of pest(RPH) and the predators are maintained.
There is no outbreak of RPH in Laos!
Ref. "Occurrence and insecticide susceptibility of rice
planthoppers in Northern Lao." Seiji Tamotsu etal ,Kyushu Plant Protection Res., 54:51-55(2008)

In 2010, JICA
Cambodiaassisted theCambodian
Government toProduce a
Booklet tocontrol theBanned
Pesticides.

No Illegal Pesticides in theMarket!
• Methyl parathion which was used to befound in the market with the trade name,"Folidol" have completely disappeared !
• Also, Methamidophos under the tradename, "Monitor" was not found in themarket when I did survey in July, 2011,together with the member of CEDAC,
an NGO promoting organic farming.

Methyl parathion(Folidol), Methamidophos(Monitor),
Phosdrin etc.,were sold in Cambodian Market(2000)

Dinotefran, made in Japan(MitsuiChemicals) Neonicotinoid "OSHIN",
sold in Cambodia(July 2011)

Japanese Scholars to be includedin the Task Force of IUCN
1. Dr. M. Matsumura, Kyushu Agriculture
Research Institute
2. Dr. Kazushige Sogawa
3. Dr. Kazuro Ohno
Associate Professor of Entomology
Dept. of Agricultural and EnvironmentalSciences, Faculty of Agriculture,
University of Miyazaki