How to rear grasshoppers

Saturday May 11 2019

Prof Nyeko explains how grasshoppers hatch

Prof Nyeko explains how grasshoppers hatch eggs. Photo by Lominda Afedraru 

By Lominda Afedraru

They have become a valuable source of income to farmers in central and West Nile regions especially in Masaka, Arua, Masindi and Hoima districts.

The edible Ruspolia Differens Tettigoniidae locally known as nsenene is an important source of food in East Africa but seasonality of its population dynamics and host plant use are not fully understood by consuming communities.

Experts say the insect is consumed by communities in Africa, Asia, South America and Australia but in Uganda it is a delicacy although its natural habitat is seasonal the reason scientists are studying its biological habit to enable farmers breed the insects throughout the year.

This has been a collaborative research an initiative by scientists from Makerere University Department of Biodiversity and Tourism, College of Agricultural and Environmental Sciences and the University of Eastern Finland.

The scientists for the last five years have been rearing the insects under confined laboratory condition where they are fed on artificial mixture of feed as well as confined habitat at various places in central Uganda including National Crop Resources Research Institute (NaCRRI) Namulonge, Makerere University Agricultural Research Institute Kabanyolo (MUARIK) and Makenke village near Kabanyolo.

Prof Phillip Nyeko, the co-principal investigator of the research at Makerere University Department of Biodiversity and Tourism, College of Agricultural and Environmental Sciences while giving the background of the existence of the insect, explained that scientists have been conducting research about the biological behaviour of nsenene during earlier days, dating back to 1930s to 1970s but no sufficient information was available.


He explained that in Uganda people have different beliefs about the origin of the insect, some tribes say it is God given and therefore they fall from the sky, others think once the insects swarm in large numbers it is a blessings for women to give birth and others think it strengthens marriages while to some communities it is a prestige, especially for tribes who take it as a delicacy.

His team embarked on the first scientific research between 2000-2014, which was conducted to establish if the insect is a pest that can destroy crops, its egg development and caustic physiology, traditional methods of harvesting, processing for commercialisation and food and feed product development.

Prof Nyeko and team managed to add value by crushing the dried insect into powder and made snacks such as biscuits, bread, and cake out of it. He says some students pursuing courses in food science have taken on the initiative as a business entrepreneur. However in 2015 the real biological research study about the insect started involving PhD students from Ugandan Universities and those from the University of Eastern Finland.

Seeds of Gold caught up with Dr Geoffrey Malinga from Gulu University who carried out studies about which artificial feed meal the insects can be fed on and below are excerpts.

Feeding nsenene
Dr Malinga explains that due to pressure on the wild nsenene by consuming communities, it is advisable to engage farmers to breed the insects.

From experiments conducted by him at the lab, the insects can feed on mixture of wheat bran, sorghum seed, germinated finger millet, milled rice seed. The ratios should be measured equally and the amount can be measured according to the number of insects reared.

What happened is that he reared the insects in glass jars and hatched the eggs on the appropriate grass species, ranging from guinea grass, Congo signal grass, Thatcher grass, Rhodes, Tussock guinea grass and elephant grass though the insects tend to lay eggs more on the guinea grass, species.

It is advisable for farmers intending to rare the insect to have a range of mixture of the food mentioned above because the more the diversified mixture the better for the growth of the insect and increased weight and the survival rate will be high.

The survival is also determined by the host plants especially for the mature ones, Rhodes grass and Elephant grass is preferred while for the young ones Guinea grass is appropriate.

From the experience where the scientists mixed two ratio of food the female insect ended up producing 75 eggs and if eight different types of meals are mixed, the female insect may end up laying up to 150 eggs or more.

The normal temperatures ranging from 27 degrees Celsius to 30 degrees Celsius is appropriate. The meal is mixed in liquid form and placed on spongy materials for the insects to suck and the same applies to providing them with water.

About grasshoppers
Preliminary results have shown that both grasshoppers and crickets have high protein content of more than 60g/100g dry weight basis.
The high protein content can be utilised to solve the Protein-Energy-Malnutrition (PEM), a condition that is evident in children suffering from kwashiorkor and marasmus.

Apart from protein, grasshoppers are rich sources of fats, especially the polyunsaturated fatty acids which have many health benefits, and minerals such as iron and zinc.

From the study carried out by Dr Levtovaara Vilma from Finland for possibilities of scientists manipulating the diet for it to produce Oleic fatty acid, she fed the insects in saturated coconut protein meal, pea protein meal, milk, corn starch and rice flour. She got the Linoleic acid (LA) which include omega-6 and Olinoleic Omega3 are essential fatty acids for humans, who must obtain it through their diet.
In her experiment it is possible for scientists to incorporate these fatty acids in the nsenene for humans to get it direct by consuming the insects. The fatty acid content increases according to the amount of protein feed mixture with that of fatty omega 6, and Omega 3 acids which can be obtained from fish fat.