Visit regarding cassava pests and diseases

"CIAT wants to send a small delegation to collect more information on the pest and disease issues affecting cassava in SE Asia, especially in Viet Nam and Thailand. The main people in the team are Dr. Tony Bellotti, who has been the entomologist at CIAT for decades, and Dr. Elizabeth Alvarez, who is the CIAT pathologist. Throughout their visit they will be accompanied by Dr. Tin Maung Aye, who runs our main cassava project in SE Asia. In addition, I will join parts of the visist and we hope that Kaith and Tiago may be able to join some parts of the visit"

Rod Lefroy (D.Phil)
Regional Research Leader, CIAT in Asia
PO Box 783, Vientiane, Lao PDR
phone: +856-21-770090 mobile: +856-20-5509-863
email: r.lefroy@cgiar.org http://www.ciat.cgiar.org/asia





























"... Dr Tony (Entomologist) and Dr Elizabeth (Pathologist) from CIAT and I will visit to Vietnam in the middle of November, from 15 to 22 Nov in Vietnam. As you know that there is a cassava disease problem in Vietnam and it seems to spread out very quickly in many parts of cassava growing areas in Vietnam. The main reason to visit Vietnam is that to get a better idea of the pest and disease problem on cassava in Vietnam. I believe that the coming trip will help us to fight against the pest and disease in the region. I am now organizing their trip to Vietnam to visit cassava planning provinces especially the serious disease affected areas in the provinces."

Dr. Tin Maung Aye,
(Who runs CIAT main cassava project in SE Asia)
CIAT, c/o FCRI, Dept. of Agriculture
Chatuchak, Bangkok 10900, Thailand
Office telephone: +66-02579-7551
Office telephone and fax: +66-02940-5541
Email: t.aye@cgiar.org
ciat-bangkok@cgiar.org

Keith Fahrney
(CIAT-Asia)
Email: k.fahrney@cgiar.org,

Tiago Wandschneider
(CIAT-Vietnam)
Email: t.wandschneider@cgiar.org



POTENTIAL MEALBUG PROBLEM IN CASSAVA

From: Reinhardt Howeler CIAT-BANGKOK
To: "Jarungsit Limsila" , "Wang Wenquang" , "Wani Hadi Utomo" , "Marjuki" , "Sholihin" , "yudi widodo" , "Wargiono" , "Augustinus Omar Rahmanadi" , "Jonathan Schofield" , "Rod Lefroy" , "Tin Maung Aye" , "Keith Fahrney" , "Lao Thao" , "Thiphavong Boupha" , "Hongthong Phimmasan" , "Viengsavanh Phimphachanvongsod" , "Phoumi Inthapanya" , "Phanthasin Khanthavong"

, "Rob Kelly" , "Silinthone Sacklokham" , "Engku Ismail Engku Ahmad" , "Narul Nahar Esa" , "Tan Swee Lian" , "Algerico Mariscal" , "Dioscoro Bolatete Jr." , "Tran Ngoc Ngoan" , "Nguyen Vu Thai" , "Nguyen Thi Hoa Ly" , "Hoang Kim" , "Phuong Nguyen" , "Nguyen Huu Hy" , "Pham Thi Nhan" , "Nam Ho Dai" , "Khanh Ton That Minh" , "Tiago Wandschneider"

Date: Tuesday, 17 February, 2009, 11:32 AM

Dear friends and colleagues:

You may be aware that two insects have been causing serious damage to cassava in Thailand during this past year. One is the spiraling white fly (Aleurodicus disperses), which has long existed in many countries in Asia, on many different crops, but seldom did serious damage to cassava. Last year the infestation was quite severe. Even so, this insect affects mostly the lower leaves and thus has less impact on yield. Spraying insecticides may be counterproductive as it may kill the biological control agents.

The second insect is more worrisome. In many parts of Asia we have had a minor problem in cassava with the striped-mealy bug, Ferrisia virgata, which caused only minor damage. However, late last year and especially during the current dry season in Thailand, there is a serious mealy bug infestation in various parts of the country. Dr. Bellotti, the CIAT cassava entomologist, who visited Thailand in October, suspected that the increased damage was done by one or more new species of mealy bugs, possibly Phenococcus manihoti and/or Phenococcus herrinni, which have also caused serious damage in Africa and Latin America, but have not previously been observed in Asia (including India). Thai entomologists agree that this is probably a new and more dangerous species, and they are trying to identify the exact species and possible biological control agents. Since CIAT/IITA collaboration during the 1980s was very successful in bringing a similar new infestation of P. herrinni in Africa under control, we may consider a similar effort in Asia with the possible introduction of effective biological control agents from Latin America into Asia. But before this is done, we first need to identify the exact species causing the damage and to get some indication of the seriousness of the problem and the extent of its spread. Thus, with this Email, I would like to request everyone to report to the CIAT-Bangkok office any serious or unusual infestations of both the whitefly and mealy bugs (or other insect or disease problems) on cassava in your area.

In addition, since mealy bugs are easily transported on planting material, it is very dangerous to take any stakes or vegetative planting material across borders, especially from Thailand, but even more so from Africa, Latin America or India (where cassava mosaic disease is a serious problem). Since these new insect pests have the potential to devastate the cassava industry in all of Asia, your help and collaboration is essential to bring this problem under control.

With best regards,

Reinhardt

Reinhardt Howeler
Senior Expert
CIAT, c/o FCRI, Dept. of Agriculture
Chatuchak, Bangkok 10900, Thailand
Email: r.howeler@cgiar.org

For Vietnam:
Nguyen Van Bo nvbo@hn.vnn.vn, vaas@hn.vnn.vn,
Ngo Vinh Vien ngovinhvien-bvtv@hn.vnn.vn,
Le Dinh Don ledinhdon@hcmuaf.edu.vn
Hoang Kim hoangkim_vietnam@yahoo.com, hoangkim@hcmuaf.edu.vn