adminKnow Your Wildlife
Edible Insects Series 8
Ibhombo (Ndebele), mhashu/hwiza (Shona)
Introduction
ATTITUDE, according to the Oxford Dictionary, is a settled way of thinking or feeling or a position of the body indicating a particular mental state, in all that one decided to do and accept as practice, their attitude plays a major role.
It is attitude also that makes one see a swarm of locusts as pests to be destroyed and another see the same as an abundant food supply to be harvested and consumed. You will find that attitude makes the difference between those who will or will not dress in a certain way or eat certain foods. Here is another ingredient for locust stir fry. Our edible insect of the month is The Migratory Locust (English, Locusta migratoria, ibhombo (Ndebele), hwiza/mhashu (Shona).
DESCRIPTION/MORPHOLOGY
Again these, just like all other insects have three distinct body segments (head, thorax and abdomen), six legs and two pairs of wings on both sexes. Their body length varies from 35-50 millimetres for males and 45-55 millimetres for females, females generally have longer body size. Perhaps as a distinct feature, their mandibles (chewing mouthparts) are blue. Their upper wings are long and shiny 43,5-50mm in males and 49-61mm in females. They have long back legs and males have longer legs than females by about two millimetres. This will help you identify them, in case you come across one.
The immature, non-gregarious stages of these locusts are called hoppers.
The Migratory locust Locusta migratoria is among a number of species collectively known as locusts. These are in the Family called Acrididae under the order Orthoptera which has grasshoppers locusts and katydids. This type of locusts sometimes form huge migratory swarms that are known to destroy vegetation, destroy is an understatement here, they devastate crops and vegetation wherever these swarms settle to feed. The locusts appear in two forms (i.e they are polymorphic) which differ in structure and biology. There is the solitary phase which has a sparse populations and in this phase the nymphs follows the colour of the habitat for camouflage, a plain colour. This I will explain again further on.
ECOLOGY
Migratory locusts are normally found occupying grass cover near the ground and their main habitat areas are near rivers, lakes and sea banks where they target reeds and sedges. They hold a lot of economic significance as the adults can damage various vegetable crops, rice, cotton, plantations, and various cash crops such as wheat, barley, oats, maize, sorghum, millet, legumes, soya among others. Locusta migratoria migratoides is among Zimbabwe’s most watched and controlled migratory pests by the Plant Protection Research Institute. It falls in the same league with the notorious quelea bird. Its natural enemies include starlings especially the Rose coloured starling and the common starling. The species is also known to have the widest distribution due to its wide range of habitats. They are even known to have some plaguing routine, for example twice in 10 years or something like that.
BIOLOGY
Migratory locusts are univoltine, and from last issue we defined this to mean that in a year they breed only once, but in the tropical zones they sometimes have five generations in a season where conditions are favorable. They are very successful breeders as each female lays its eggs in big bunches called pods that can contain up to 140 eggs, normally an average of 60 to 80 eggs per pod. Each female lays one to three of these pods in light sandy soils where they are incubated from early August-September period to early May-June period where hatching happens. Nymphs (young ones resembling the adult in how they look) come out of these pods as the non-gregarious hoppers, plain coloured and resembling either the colour of the soil or surrounding vegetation for camouflage.
These nymphs grow through five stages of growth (five instars) before they become adults. As they grow, they will be collecting into swarms which are the gregarious phase, which is problematic for the farming community. I do not recall a direct encounter with these swarms but I have heard some older generations who said they couldn’t remember their birth year but they were born in the year of the locust (akazvarwa mugore rehwiza) so that’s how I know from indigenous knowledge that in the Zimbabwean context, the swarming and destruction of crops has happened before. I would appreciate
feedback from authorities on this subject.
COMMENTS
This species has not been human friendly because of its economic impact especially when in the gregarious stage. Swarms are known to move swiftly and travel up to 130 kilometres per day or more, literally chewing on any green thing they come across. A huge swarm can have 60 million individual locusts on average covering several hundreds of square kilometres at a time with each adult eating a few grams equivalent to its own weight of fresh food per day.
I’d say a swarm of locusts would be an easy source of protein for humans if a harvesting method could be devised and this if done when they haven’t yet approached fields of crops could work as a control measure of the damage they cause BUT, this can only change if the attitude towards their use for consumption changes.
Locusta migratoria is not only important here in Zimbabwe but globally. In the African context, it is recorded that around 1920-1942 there a serious widespread plague hence the constant monitoring that is still done on this species.
This article is written as part of a survey on use of insects as food in Zimbabwe.
For feedback and questions on insects in general and if you’d like to volunteer information on any of these topics: Migratory locusts as food, which areas there is still a practice of eating them and other insects as food, harvesting and preparation, recipes and when they appear please do not hesitate to contact: The Museum Entomologist at the
Natural History Museum of Zimbabwe on: sms or WhatsApp on +263772933071 or post on our Face book page:
<https://www.facebook.com/LetsTalkEntomology?ref=hl>
Online Reporter