Peter Neuenschwander: How Africa can control invasive pests

P Neuenschwander
P Neuenschwander
The “father of biocontrol”, Peter Neuenschwander, joined IITA’s biocontrol project against the cassava mealybug in 1983. The project was later expanded to include biological control and integrated pest management of mango mealybug, spiraling whitefly, and floating water weeds. He retired in 2003. Last year, the International Organization for Biological Control recognized his life-long contributions to biological control by giving him Honorary Membership. In this interview with Godwin Atser, he bares his mind on the contribution of biocontrol and strategies on how Africa can check invasive pests.

Please explain the concept of biocontrol.
Biological control is a technique whereby we use natural enemies to combat pests. The pests can be insects, mites, pathogens, or even plants. Most times we apply biocontrol against invading pests. The beauty is that once something works, it spreads on its own and it carries on its business without difficulties.

Please give an overview of your work on biocontrol in Africa.
The cassava mealybug was actually one of the things that brought me to Africa. The mealybug was introduced in Africa in the 1970s. Eventually parasitoids were found in South America and transported here. With national partners, we made about 150 releases in most sub-Saharan African countries. From there we went on to other projects such as the mango mealybug, and water hyacinth control.

How can biocontrol check the spread of invasive pests in Africa?
Biocontrol is good; it slows the pests but it would have been best not to have introduced those exotic organisms in the first place. So, we need to strengthen and train the quarantine people.

We also need to tighten quarantine services in all African countries, not just on land borders but also the seaports and the airports so such invasions which cost so much can be reduced.

What has been the impact of biocontrol?
For the cassava mealybug alone, the project resulted in money directly going to the farmers with the entire cassava improvement project in Africa.

What are the challenges you faced in the biocontrol projects?
Our main challenge is the uptake or adoption by the countries. Countries are autonomous in their decisions to import or not to import.

So, we have to convince some 30 quarantine authorities that they should give us quarantine permits, that they should help us, and that they should allow the insect to come in, and so on.

The challenges also include unsatisfied expectations from colleagues from different disciplines who expect us to extinguish the pest. We don’t really extinguish anything.

What is the perception of people towards biocontrol?
The public in most cases is more afraid of biocontrol (insects) than the invasion itself. This is because they don’t understand how it works.

Does biocontrol break down?
In technical terms, yes, it can break down—when biocontrol is working and you forget about it and suddenly start spraying the field with pesticides. That is, you kill the natural enemies and the pest.

What is the future of biocontrol?
The demand for biocontrol is already there and there will always be invasive pests. We also have to maintain the human capital in biocontrol. Unfortunately, the capacity in biocontrol worldwide is declining, not only in IITA.

Your colleague referred to you as the father of biocontrol. Can you comment on this.
I am the last surviving biocontrol specialist at IITA. That was what was written about me when I retired 6 years ago. I am still helping out.

What were the most exciting moments in your work on biocontrol?
The excitement was going out in the field and also the fact that I had a “privileged” job. It also includes getting recognition. In the scientific world, the cassava mealybug project was seen as a success.

You have been retired for several years now. What’s next?
I have a request to go to Asia, because after 20–30 years, the cassava mealy bug turned up in Asia, and it is spreading. They want us to introduce biocontrol to curtail the spread.