Rachid Hanna is an entomologist by training with a diverse academic background (BSc in Horticulture, MSc in Plant Protection and Pest Management, PhD in Entomology). He joined IITA-BÃ©nin in 1998 to lead the cassava green mite (CGM) biological control program. In BÃ©nin, he initiated several other programs on biocontrol and IPM of other crop pests. He recently relocated to IITA-Cameroon and has been entrusted in helping to rebuild the research program with a new focus.
What were the differences in research priorities when you first started working for IITA and now?
When I joined IITA, there were several ongoing or recently concluded and highly successful biocontrol programs. We now need to give more attention to developing biological control options for insect vectors of the causal agents of serious crop diseases. There is still considerable appreciation within IITA and among our partners for the potential for biological control to solve many pest problems in agriculture, with numerous invasive pests lurking outside African borders. We need to maintain the capacity to provide a rapid response to these alien species. Biological control is often the only viable and sustainable solution.
IITA went through a period when scientists were pulled more toward the development side as core funding declined. It seems we now have a good balance in the R4D continuum. At present there is increased emphasis on biotechnologyâ€”molecular biology in particularâ€”but natural resources management has suffered. IITA has also put greater emphasis on the commercialization of agricultural products as a means of reducing farmersâ€™ risks and increasing farm income. It has also given increasing attention to food safety and human health.
What are your current projects?
We have spent a lot of time and resources figuring out how CGM biocontrol works through predators and acaropathogens, and determining its socioeconomic impact. I have also been involved in classical biological control of the coconut mite, which is present in the Americas, Africa, and the Indian subcontinent.
IITA and icipe have been collaborating for the last 3 years on a BMZ-funded project to develop IPM for several mango pests. At the core of this project is biological control of the invasive fruit fly, Bactrocera invadens, or Sri Lanka fly that is now present in at least 34 countries in Africa where it has caused huge losses in fruit production. With icipe we have explored natural enemies of this pest in Sri Lanka, its putative origin, and imported from Hawaii, tested, and initiated field releases of Fopius arisanus, a parasitoid known to be an excellent biocontrol agent of several fruit fly species closely related to the Sri Lanka fly. We have already released nearly 95,000 individuals of F. arisanus in BÃ©nin and Togo, with encouraging recovery rates.
More recently, I began research on the banana aphid, also an exotic pest in SSA, and the only known vector of banana bunchy top virus that causes a very serious disease of banana and plantain. This disease is presently found in 12 countries in Africa and continues to move to others. IITA, in collaboration with partners, has initiated efforts to develop integrated options to control the banana aphid with emphasis on biological control.
For some years, I have been developing with several partners IPM for the African root and tuber scale, a pest of cassava in Central Africa. This pest is indigenous to Central Africa where it has evolved on native hosts in association with an indigenous ant on which it depends for its survival and dispersal. We figured out how to deal with the scale using â€˜less scale-suitableâ€™ varieties, cultural practices that reduce the frequency of hosts that serve as a reservoir for the scale, and ecofriendly baits to kill the ants. To complicate matters even further, we recently discoveredâ€”using molecular biology toolsâ€”that the scale is a complex of species and not one species as has been suggested based on morphology. This work is part of a larger IFAD-supported project to develop integrated management approaches to high-profile cassava pests and diseases in SSA. Swiss funding is supporting a PhD student to elucidate the ecological factors that promote ant abundance and the nature of ant/scale interactions.
What is unique about biocontrol research?
We seek to develop sustainable solutions to major pest problems that limit agricultural productivity. Nearly all this research has unique scientific aspects. Biological control is not really new. It is a useful approach, but the process of discovery of natural enemies, understanding how they work, and promoting their abundance and persistence has many innovative and unique aspects.
What are your challenges at work? What are the rewards?
There are many challenges. One is farmersâ€™ acceptance of the technologies. Farmers like simple solutions to their problems. With biological control, the natural enemies work on their own, mostly without the farmersâ€™ intervention. In contrast, the success of a crop-variety pest control approach will largely depend on the farmersâ€™ acceptance of the varieties.
The breadth of our geographic coverage is also challenging and at times daunting. There is considerable restriction now on the exchange of biological materials and it is becoming increasingly difficult to export, import, and test natural enemies.
The rewards are equally many. Chief among these is the satisfaction of getting farmers to adopt a new practice and so achieving a noticeable impact in our work. The satisfaction of discovering a new natural enemy and figuring out how it goes about its business of consuming and suppressing its prey is immense.
Discovering and describing a new species is equally satisfying. So are seeing students successfully complete their training and becoming full-fledged members of the scientific community, and farmersâ€™ glowing and wide eyes when they see through a hand-held magnifying lens the little mites that cause the damage to their crop, or the equally small predator that kills those pests and protects their crop.
We also get rewards through the recognition we receive from our employer and peers.
What is the impact of your work on African farmers, producers, and consumers?
The return on investment from biocontrol can be very high and the results are permanent. Except on rare occasions, farmers need not intervene at all.
All the work we are doing on biological control is important for agriculture. Take for example the work on cassava mealybug and CGM biocontrol. These pests devastated cassava production across the cassava belt in SSA. Their control has resulted in preventing billions of dollars worth of losses to African agriculture and translates to more food security and income. The cassava mealybug has already invaded Thailand, and its farmers stand to reap the benefits from our work. The same is true for the other pests for which we trying to develop sustainable solutions. This underscores the fact that biocontrol benefits can be obtained independent of the location where it was developed.
We are now trying to do the same with disseminating control measures for the African root and tuber scale in the Congo basin, coconut mite in BÃ©nin, Tanzania, and Sri Lanka, the highly destructive Sri Lanka fly, and the banana aphid. Each of these achievements will have considerable positive impact on the productivity of targeted crops, in turn enhancing food security and peopleâ€™s livelihoods.
Who are your collaborators?
We have an excellent network of collaborators both in Africa and abroad, and a cadre of superb students and support staff. My main collaborators on strategic research have been IITA scientists and those from universities and government institutions in Europe, United States, Brazil, and Kenya. In Africa, I have worked closely with icipe and more than 14 NARSâ€”government and universityâ€”partners in adaptive research and technology transfer. While not all collaborations were equally successful, the best were those when all partners had ownership, trusted one another, had common interests, and were fully engaged.
Any insights for colleagues or partners?
Keep an open mind. Strive to be a scientist in search of new knowledge that can be translated to ways of improving peopleâ€™s livelihoods. For crop protection specialists, give biological control a chance. It is permanent, the safest, and most ecologicallyâ€”and in most cases most economicallyâ€”sound means of pest control.
Start thinking of the next project (or phase) or research topic as soon as you start one. Think big and act with humility.
To our partners: IITA is with you. Letâ€™s keep working together for we can achieve a great deal more together than alone.
How could IITA be more effective?
IITA is a very effective R4D organization; this is largely due to an appropriate balance between strategic research and development activities at present. However, we may be presently too spread out. Expansion often happens at the expense of existing posts. Some posts that have been very effective in R4D should be strengthened. Plant health and crop improvement research have led to huge impact; letâ€™s continue to give them priority and support.
Biodiversity should be everyoneâ€™s business. We are well placed to work on biodiversity and conservation while enhancing crop productivity and livelihoods. We need to recruit topnotch scientists and keep them. We should promote a healthy work environment. We should also reestablish and restore the student training program to its previous prominence; the large majority of our NARS collaborators were trained through this program. Many are now older or retired. IITA has recently increased investment in specialized training of its entire staff. This is a good move.