Modified grasshoppers are on the menu

Research from the University of Eastern Finland has shown that it is possible to modify the fatty acid composition of edible grasshoppers by adding essential fatty acids in their feed. While over 2000 insect species are known to be consumed by humans, the study focused on the long-horned grasshopper Ruspolia differens, an economically and nutritionally important insect species that is common and widespread in Africa.

Researchers view edible insects as a potential solution to global food security problems, as their production requires less space and water, and produces lower greenhouse emissions, than meat. However, effective mass rearing methods for different species are needed to make edible insects a viable solution for global food insecurity, as what works for one species may not work for another.

Researchers have explored what kind of egg-laying media would be suitable for mass rearing of Ruspolia differens, focusing on how the insects are utilised for food security in rural areas like Uganda, Africa. The insects often supplement people’s diets and are consumed as snacks.

Fried Ruspolia differens seasoned with salt and onion. Image credit: Vilma Lehtovaara.

While many wild insects are collected by harvesting populations during swarming seasons, Ruspolia differens only swarm twice a year, with unpredictable yields. Overexploitation is also a cause for concern as harvesting has increased, causing diminishing grasslands due to changes in land use.

A study published by the University of Eastern Finland suggests that mass rearing could preserve wild populations, analysing how these species live in the world and whether those conditions could be mimicked in a lab. Researchers also analysed what the grasshoppers ate in the wild, and tested whether they’d accept other foods. Through this, it was discovered that adding essential fatty acids in the diets of Ruspolia differens could modify their fatty acid composition, making them healthier for human consumption.

“This is a phenomenon that hasn’t been studied in insects so much. We know that some species essentially ‘are what they eat’ and that their diet has an impact on their fatty acid composition. However, we didn’t know how dramatically their fatty acid composition could be modified, or how much alpha-linoleic acid (an omega 3 fatty acid) they could take in,” said Vilma Lehtovaara, a researcher from the University of Eastern Finland.

In some Ruspolia differens, up to 60% of their weight comprises fat, while wild insects typically contain only 10–30% fat, with the fatty acid profile of lab-reared insects differing from that of wild insects. Researchers modified the fatty acid composition of Ruspolia differens by making modifications to their feed at the end of their life span, proving that it is possible to use feed boosted with fatty acids to feed grasshoppers, making their fatty acid composition more suited to human consumption.

Top image credit: Vilma Lehtovaara.