Climate Control for BSF Greenhouses

Global population growth, increasing demand for animal products and scarcity of conventional feed ingredients drive the search for sustainable alternative protein sources for animal feed. On the African continent, where most of the population growth is expected to occur, economic growth and changing dietary patterns will lead to a 70% increase in the demand for livestock products by 2050. In East Africa, the expected growth of demand for animal protein is expected to be 4% per annum in the upcoming years.

Currently, mainstream protein sources in animal feed are soybean meal and fishmeal. However, the use of soybean meal in animal feed competes with its use as food and the availability of fishmeal is decreasing because of overexploitation of our seas. As the costs of these feed ingredients are expected to increase, prices for animal feed products will be driven up. With feed cost already representing 60-70% of the total costs of livestock production, the search for more sustainable and less costly alternatives has led to a growing interest in insects as protein source in animal feed. Amongst these insects is the Black Soldier Fly (BSF). BSFs contain high levels of protein and fat, and are rich in micronutrients, vitamins and essential amino acids; hence, they are considered an excellent replacement in pig, poultry and fish feed. Their production has a small ecological footprint and contributes to a circular economy by recycling of organic waste.

Climate control is a crucial factor in BSF farming as the insects are sensitive to external factors such as temperature and humidity. It is challenging to pinpoint the exact optimal conditions for BSF rearing as studies have shown that what is considered optimal is context dependent as, for example, sources of waste can predicate the range of ideal temperatures. Even though determining exact generic optimal conditions is therefore challenging, it is commonly believed that larvae are most active with temperatures ranging between 25-35 degrees Celsius. Consensus on the optimal humidity levels for BSF is also lacking. Personally, it has been observed that for flies to emerge properly, become active and mate and produce quality eggs, temperatures between 27-37 degrees Celsius with humidity levels of >35% are required. Additionally, flies need a sufficient amount of daylight and undisturbed environment as mating naturally occurs in direct sunlight. In the hatchery, the ideal temperature range is similar to that of the larvarium (25-35 degrees Celsius) as long as the substrate remains moist.

In general, Kenya has a favorable climate for BSF farming. However, climatic conditions differ across Kenya and throughout the year. In Eldoret where F&S’s pilot farm is located for example, we observe how during the rainy season and at night temperatures drop too low, while in dry seasons it becomes too hot and dry for BSF to develop properly. Therefore, without adequate climate control tools production levels fluctuate heavily depending on the weather. Smaller scale BSF businesses are impacted mostly due to a lack of knowledge on, and access to, affordable climate control measures that can mitigate outside climatic factors. As a result, smaller scale BSF businesses face significant challenges optimizing their production and creating a reliable supply for their off-takers which directly impacts their success as a business at large.