Behind IITA’s Extensive Insect Museum

177
George Georgen, head of IITA’s insect museum in Cotonou, Benin

Most likely, you have heard or read about all kinds of musea (museums) but certainly not an insect museum. Generally, a museum, according to Encyclopedia Britannica, is an institution dedicated to preserving and interpreting the primary tangible evidence of humankind and the environment. 

‘’In its preserving of this primary evidence, the museum differs markedly from the library, with which it has often been compared, for the items housed in a museum are mainly unique and constitute the raw material of study and research. In many cases, they are removed in time, place, and circumstance from their original context, and they communicate directly to the viewer in a way not possible through other media. 

‘’Museums have been founded for a variety of purposes: to serve as recreational facilities, scholarly venues, or educational resources; to contribute to the quality of life of the areas where they are situated; to attract tourism to a region; to promote civic pride or nationalistic endeavour, or even to transmit overtly ideological concepts’’, the encyclopedia says. 

But, George Goergen, a German entomologist/bio-control specialist is heading the International Institute of Tropical Agriculture’s (IITA) insect museum in Cotonou, Benin. It is promoted as the most extensive insect collection in West Africa with over 366,000 insect species. The museum houses both pests and beautiful insects and offers free insect identification services.

According to Goergen, the IITA’s insect museum exists to offer a free identification service for any insect that is of concern to agriculture or health, pointing out, ‘’over time, we have developed a reputation that we offer this service, and in return, we are often the first to be informed of new pests in West Africa. This was the case with the fall armyworm. Once our partners proved that they were confronted with a new pest, they sent us samples for identification.” 

The CGIAR -IITA insect collection emerged from the first bio-control success in Africa, which was targeted at the cassava mealybug. Scientists studied the cassava mealybug food web as well as its most efficient and effective natural enemy. 

Some of the insects in the museum

CGIAR is, however, a global research partnership for a food secure future dedicated to reducing poverty, enhancing food and nutrition security, and improving natural resources.

In reviewing the mealybug’s natural enemies, the researchers were confronted with the lack of a facility to identify samples locally. “All samples were sent abroad for identification, which was characterised by long delays in both dispatch and response”, IITA says. 

It is against that background and the regional need for an arthropod diagnostic service that the Institute decided to open its identification centre. What started as a small insect collection at IITA’s headquarters in Ibadan, Oyo State in Western Nigeria was later moved to Cotonou in Benin at the Institute’s bio-control centre. 

From 1,000 specimens in Ibadan, the insect collection now boasts of 366,000 specimens and more than 6,000 identified species, making it the best insect collection in West Africa with both pests and beneficial insects.

This growth has come mostly from material kept from past projects, as Goergen explains: “In the past when a project would end, the identified materials would be discarded, which was a pity because they were valuable references. The insects are now preserved permanently so that future projects could benefit from them.” 

Permanent preservation is possible because of the suitable conditions in the museum, such as controlled access. One cannot have direct access to the collection; they must pass through two doors which limits unnecessary movement. 

The room is also permanently air-conditioned with back-up generators in case of an electricity outage. The windows are not only small to avoid exposure to sunlight, but they are also never opened. George explains the rationale, “Insects decay mostly from fungi, attack from fellow insects and exposure to sunlight. If these conditions are minimised, then permanent preservation is possible.”

There are so many insects of the same species, i.e., several kinds of houseflies, butterflies, bees, or beetles, and there is a reason for this. “We collect everything we can get from different regions. It may seem like a waste to the untrained mind, but nothing is never in vain, as Goergen explains. “When the opportunity availed itself, we collected aquatic beetles, and everyone wondered whether we had gone bonkers. 

Then, 10 years later, it was discovered that aquatic beetles are involved in the transmission of the Buruli ulcer, a locally emerging infectious skin disease. Suddenly, everyone was interested in what type of aquatic insects we have in West Africa, and thankfully we had preserved some of them.” 

That is why, when Goergen or anyone on his team, find themselves in a new environment, they collect a sample that is representative of the region’s insects—you never know when you will need them! “The idea is to store them and come back anytime by looking into the cabinets – i.e. the museum – because the past helps us to master current problems”. 

Also, one cannot know if a species is new to the continent or not without any reference. In the case of the Fall Armyworm, Goergensays they would never have known that it was alien to Africa if they had not collected other moths to which it was compared.

So, there it is—the collection is essential to identifying and studying new invasive and beneficial insects as well as finding an effective bio-control measure, i.e., natural enemies that can suppress an insect pest. Over the years, IITA has used natural enemies (beneficial insects) to control pests such as the cassava mealybug. Bio-control of cassava mealybug delivered the highest return on investment in the history of the CGIAR. 

A Benefit: Cost ratio of 149:1, meaning every $1 invested in cassava mealybug bio-control gave a return of $149. Other noteworthy bio-control successes include controlling the water hyacinth on Lake Victoria, the world’s largest freshwater body, using weevils… The water fern in Congo Brazzaville was also entirely controlled by introducing a specific weevil.

However, in 2015 Ylva Hillbur, IITA’s former Deputy Director General (DDG) Research for Development was in talks with a Swedish team of researchers at the Swedish University of Agricultural Sciences who were interested in studying the African armyworm. 

Hillbur requested for samples of the moth from Goergen, the entomologist who heads IITA’s insect Biodiversity Centre in Cotonou. “I kept an open eye so that if ever we saw the moths, we’d send some to the DDG”, he says.

IITA said it knew it would only be a matter of time since the African armyworm is a seasonal insect, which only appears in the first rains after a very long dry spell. It was also aware that it never stays long in the same place, usually a week or two, and it leaves behind only one generation in any given place before moving to the next location.

While the team in Cotonou was on the lookout, the farm manager at IITA-Ibadan, was going on about his daily work of inspecting maize fields and spraying any pests. This was in March 2016. After the usual spraying, the farm manager noticed that this particular insect was not dying. 

The more they sprayed, the more the insects multiplied, and they fed audaciously. This strange insect that didn’t respond to pesticides alarmed the farm manager, so he alerted Lava Kumar, IITA’s virologist. Kumar informed an entomologist—Abou Togola based at IITA’s Kano Station in Northern Nigeria. Togola went to Ibadan and immediately recognised that this moth was different from other native African species. This is when samples were sent to IITA’s bio-control centre in Cotonou for Goergen to identify.

Georgen was excited to receive the samples thinking it must the African armyworm that the DDG had asked for. However, when the specimen arrived, he was surprised. “It was different from what I knew! Surely, it was a species belonging to Spodoptera but there are over 30 species of Spodoptera although Africa had eight species by then”, he says. 

“We first received caterpillars (larvae) and the adults (moths) came later. Based on the genitalia, we identified the moths as the fall armyworm—at this point excitement reached fever pitch. New information is always exciting. We knew it to be an important pest that required us to move fast. However, you can only publish such information when you are 200% sure. If one is wrong, one can ruin their own and the institute’s reputation.” 

In ensuring that he was 200% sure, Goergen asked Kumar, the virologist, to DNA barcode the samples and they matched the barcodes of genomic databases in the US. By early June 2016, they were absolutely certain that it was indeed the worm. 

The scientists notified the Nigerian Agricultural Quarantine Service (NAQS) about the new pest, and with their consent, made this information public by publishing it in a journal in October 2016. It took 16 months from when the paper was published to the first major outbreak on the continent.

“The first outbreaks were seasonal and contained. However, we knew that this would be a long-lasting problem—when the fall armyworm gets a foothold on the continent, there is nothing you can do to stop it because it’s a migratory insect, which can fly over 50 km per night. That explains how such a tiny insect can colonize an entire continent in a short time.”

While the Food and Agriculture Organisation (FAO) decided to take an active role in coordinating partners’ activities and plans to provide sustainable solutions to the fall armyworm challenge, a series of awareness workshops organised by IITA, CIMMYT, and USAID were conducted in various western, eastern, and southern African countries. 

It soon became clear that there is no single solution to control the new pest, which called for an Integrated Pest Management approach. At IITA, efforts currently include biological control using natural enemies and developing bio-pesticides, advocacy and awareness-raising, the development of an App for early detection of FAW by farmers as well as breeding for resistance in support of efforts led by CIMMYT.

In 2018, the outcry from farmers was less vibrant than the two preceding years, so one can wonder why? “FAW is still with us but is less pervasive as initially, conditions for outbreaks were particularly conducive. Today moth populations are still important, but farmers no longer panic when their maize is damaged and have learned from past seasons how to minimise damage.” 

However, both Kumar and Goergen agree on one thing, “the fall armyworm is bound to stay and become a lasting threat in the newly invaded regions. We need to use an integrated pest management strategy. Pesticide application is one of them, but it is not sustainable. Not all farmers can afford pesticides since they are expensive and if used excessively, they induce pesticide resistance, destroy the environment, kill beneficial insects, and make our food unsafe since overuse leads to pesticide residue in food. Pesticides should be used only when necessary, we should look at environmentally compatible options like bio-control—the use of natural enemies”, Goergen advises.

LEAVE A REPLY

Please enter your comment!
Please enter your name here