See also
Family:Acrididae
The migratory locust (Locusta migratoria) is the most widespread locust species, and the only species in the genus Locusta. It occurs throughout Africa, Asia, Australia and New Zealand. It used to be common in Europe but has now become rare there. Because of the vast geographic area it occupies, which comprises many different ecological zones, numerous subspecies have been described. However, not all experts agree on the validity of some of these subspecies.
Many other species of grasshopper with gregarious and possibly migratory behaviour are referred to as 'locusts' in the vernacular, including the widely distributed desert locust.
At 6.5 Gbp, the migratory locust possesses one of the largest known insect genomes
The migratory locust is polyphenic. It transitions between two main phenotypes in response to population density; the solitary phase and the gregarious phase. As the density of the population increases the locust transforms progressively from the solitary phase towards the gregarious phase with intermediate phases:
Solitaire = solitary phase → transiens congregans (intermediate form) → gregarious phase → transiens[check spelling] dissocians (intermediate form) → solitaire = solitary phase.
Pigmentation and size of the migratory locust vary according to its phase (gregarious or solitary form) and its age. Gregarious nymphs have a yellow to orange covering with black spots; solitary nymphs are green or brown. The gregarious adult is brownish with yellow, the latter colour becoming more intense and extensive on maturation. The solitary adult is brown with varying extent of green colour depending on the colour of the vegetation. Gregarious adults vary in size between 40 and 60 mm according to the sex; they are smaller than the solitary adults.
The phase transition may be mediated by DNA methylation in the brain. Expression of the DNA methyltrasferase gene Dnmt3 is high in the brain of the gregarious form, decreases in gregarious locusts when they are isolated, and increases in solitary locusts when they are crowded. Knock-down reduces phase-related locomotor activity. Transcriptionally, Dnmt3 is linked with phase-core transcriptional factor, hormone receptor HR3
The migratory locust is an edible insect. In Europe, the migratory locust is officially approved for the use in food in Switzerland (since May 20 On 2 July 2021, the European Food Safety Agency published a scientific opinion stating that the consumption of migratory locust in frozen, dried or ground state is safe for humans. On 12 November 2021, the EU member states gave their green light for the EU Commission to authorize the placing on the market of migratory locust as a food. This is one of the final steps in the novel food authorization procedure. As a next step, the Commission will now adopt a legal act
Photos Geri 26/6/2006 by George Konstantinou