Crunchy coneheads: edible insects

Coneheads (Conocephalinae) are not particularly common in the UK – there are three species in southern England – but head south, and they start to get much more abundant. In many tropical and sub-tropical areas, they become extremely abundant and can be a severe pest, damaging a wide range of cultivated plants. Indeed, some Ruspolia coneheads, discussed here, can form huge aggregations, and like plagues of locusts, they can travel long distances (mostly at night it seems) before descending to feed on some poor farmer’s crops. In many parts of Africa however, people have taken advantage of their abundance and harvest them as a source of food.

Ruspolia species all look very similar. According to one scientist, ‘many Ruspolia spp. have no apparent diagnostic features, and thus their taxonomy largely requires molecular evidence’ (Matojo & Hosea, 2013). Which is not much use to a field biologist! There are over forty Ruspolia species listed on Wikipedia, but there must be many more which are unknown or undescribed.. Apparently, they all have a yellow ‘jaw’ base, which can be seen in the following photograph I took in Spain (below).

I think it is the mandibles, and maybe some other mouthparts (labrum?) which are yellow. This magnificent photograph (below) of a round-tipped cone-head from North America, also shows nice yellow (and reddish-brown) mouthparts.

I am used to seeing one species, the Large conehead (Ruspolia nitidula) in Galicia, Spain, where it is quite common in late summer, crawling through the grass (in which it is superbly camouflaged) (top and below). This species does not gather together, it is exclusively solitary. It is an Asian, European and Mediterranean species; in Africa it only occurs in North Africa.

However, it has been widely confused in the literature (Matojo, 2017) with another (congeneric) closely related, Ruspolia species, R. differens, which occurs over most of tropical Africa. The two species do not, I think overlap. Ruspolia differens is a Sub-Saharan species called the Longhorn Grasshopper, although this is a misnomer, taxonomically speaking. Another, more accurate name, is the African edible bush‐cricket. It has a unique swarming phase, a colour polymorphism (there are brown forms) and the sexes differ: for example, the male has much longer antennae (below).

The East African longhorn grasshopper (R. differens) is widely harvested and consumed as a traditional snack in Zambia and regions around Lake Victoria crescent including Tanzania, Uganda, Kenya and Democratic Republic of Congo (Mmari et al., 2017). It is called  senene in Swahili, but has many similar local names: senesene in Kenya, nsenene in Uganda and nshokonono in Zambia. There are other Ruspolia coneheads in these areas and reportedly, it can easily be confused with related species including Ruspolia lineosa, R. nitidula and R. dubia, also referred to as senene. Not sure which ones taste best!

Although mostly eaten as a snack, the nutritional value of these insects is high, and they are rich in essential amino acids, as well as essential fatty acids, vitamins and minerals (Lehtovaara et al., 2018). In fact, they are almost all protein and fat! They must be good for you. In Uganda, the average retail price in 2016 was five thousand Uganda shillings (~US$ 2.80) per kilogram. I wonder how much a small portion, like the one shown below, would cost?

There are many advantages to eating insects (entomophagy) in addition to the nutritional benefits. They are much cheaper to produce than the vertebrates (cattle, sheep, pigs, chickens etc) we usually consume, because they are much more efficient in converting their food (feed) into protein. They are also better for the planet, because they take up much less room and produce less CO2 than say, pigs or cattle. We in the West are going to have to overcome some of our taboos about eating insects if we want to save the planet! Luckily, for people like me however, they can be made to taste exactly like meat!

Apparently, senene is becoming increasingly popular in parts of Africa (Mmari et al., 2017), and also provides a livelihood for collectors, traders and retailers. In some parts of Africa, swarms of these insects are seasonal and arrive around Christmas time! This quotation from a Ugandan blogger shows how popular it is:

All over the country, across streets in towns and villages, the word on every one’s lips (young and old) is ‘ensenene’. This green flying ‘manna’ is the leading cause of ecstasy. Men, women and children stay up late in the night to trap the seasonal grasshopper.

Another, charming article – in pidgin English – also shows are they are caught and prepared. N.B. Pidgin is a widely-spoken language in West Africa.

Read more about African cone-heads, also called conehead katydids, by the entomologist and acclaimed wildlife photographer, Piotr Naskrecki, here and here. He even has one named after him! (Ünal, 2005)

References

Lehtovaara, V. J., Roininen, H., & Valtonen, A. (2018). Optimal temperature for rearing the edible Ruspolia differens (Orthoptera: Tettigoniidae). Journal of economic entomology, 111(6), 2652-2659.

Matojo, N. D. (2017). A Review Work on How to Differentiate the Longhorn Grasshoppers Ruspolia differens and Ruspolia nitidula (Orthoptera: Tettigoniidae). Journal of Applied Life Sciences International, 1-4.

Matojo, N. D., & Hosea, K. M. (2013). Phylogenetic relationship of the longhorn grasshopper Ruspolia differens Serville (Orthoptera: Tettigoniidae) from Northwest Tanzania based on 18S ribosomal nuclear sequences. Journal of Insects, 2013.

Mmari, M. W., Kinyuru, J. N., Laswai, H. S., & Okoth, J. K. (2017). Traditions, beliefs and indigenous technologies in connection with the edible longhorn grasshopper Ruspolia differens (Serville 1838) in Tanzania. Journal of ethnobiology and ethnomedicine, 13(1), 60.

Ssepuuya, G., Aringo, R. O., Mukisa, I. M., & Nakimbugwe, D. (2016). Effect of processing, packaging and storage-temperature based hurdles on the shelf stability of sautéed ready-to-eat Ruspolia nitidula. Journal of Insects as Food and Feed, 2(4), 245-253.

Ünal, M. (2005). A new genus and species of Conocephalinae (Orthoptera: Tettigoniidae) from the Northern Province of Zambia, E. Africa. Transactions of the American Entomological Society, 449-455.