Giant water bug

Insects to feed the planet

Insect-eating, or entomophagy, has been commonplace in many parts of the world since prehistoric times. However, this practice is no longer in favour in the West, as it is deemed disgusting or primitive. This perception is likely to change in view of demographic growth, limits on farmland available for meat production, and climate change. Insects are rich in proteins and good fats hence, according to the FAO, insect breeding is a solution of the future. What’s more, insect breeding emits fewer greenhouse gases than livestock breeding.

Hemiptera, an order that includes water bugs, cochineals and cicadas, accounts for 10% of the world’s insect consumption. The most commonly eaten insects in the world are beetles (31%), caterpillars (18%), bees, wasps and ants (14%), and grasshoppers, locusts and crickets (13%). To a lesser extent, termites account for 3% of world insect consumption, along with dragonflies (3%) and flies (2%).

© Shutterstock / kwanchai.c - Grilled giant water bug

The life of a voracious little predator

A member of the Corixidae family, the giant water bug, or Lethocerus Americanus, is a large aquatic insect measuring between 5.5 and 6.5 cm. It is found in America as well as South-East Asia. It has a brownish, flattened, hydrodynamic body and legs fringed with hairs that help it swim quickly and efficiently. Its abdomen ends in a respiratory tube. Its head features compound eyes (comprising a set of light-sensitive receptors) and a short, pointed beak called a rostrum.

Giant water bugs reproduce in summer, in mid-flight. The female then lays her pale brown eggs (up to 150 eggs) in aquatic vegetation, where a larva will be born. This develops into a nymph shedding its skin five times before reaching its adult form. The beginnings of wings appear at the penultimate sloughing. In the winter, this insect stays buried in the mud at the bottom of lakes and ponds. The giant water bug feeds on aquatic insects, tadpoles, frogs, snails, salamanders, fish larva and small fish which are often larger in size than itself. To hunt, it swims vigorously towards its prey before catching it with its legs and injecting its saliva, using its pointed rostrum to liquefy the prey’s flesh. The giant water bug then sucks in its pre-digested food.

A product exported to Europe

The giant water bug, which the Aztecs would coat with corn before eating, is a major food resource in Mexico. However, pollution and the drying up of wetlands now threaten harvesting. Owing to their granular appearance, giant water bugs’ eggs, known as water amaranth, are also very popular and their taste is said to be similar to caviar. In France, giant water bugs are sold in sachets in shops specialising in the sale of edible insects. They are sold cooked, without wings or legs. Rich in proteins, calcium and iron, giant water bugs are eaten as an appetiser or in a salad.