A behavioural analysis of phase change in the desert locust

@article{Simpson1999ABA,
  title={A behavioural analysis of phase change in the desert locust},
  author={Stephen James Simpson and Alan R. McCaffery and Bernd F. H{\"a}gele},
  journal={Biological Reviews},
  year={1999},
  volume={74}
}
A programme of research into phase change in the desert locust, Schistocerca gregaria, is described. The ability to change phase between solitarious and gregarious forms in response to population density is a key feature of locusts and is central to their occasional yet catastrophic impact on humans. Phase polymorphism is an extreme form of phenotypic plasticity. The most labile phase characteristic is behaviour. It is argued that a fully integrated study of behavioural phase change provides a… 
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References

SHOWING 1-10 OF 76 REFERENCES
Analysis of phase-related changes in behaviour of desert locust nymphs
An assay is developed in which the behavioural responses of an individual locust to a group of conspecifics are used to derive an index representing the ‘behavioural phase status’ of that insect. The
The influence of environmental microstructure on the behavioural phase state and distribution of the desert locust Schistocerca gregaria
TLDR
It is shown that the fine‐scale distribution of food plants, perches and favourable microclimatic sites influences the spatial distribution of locusts, both in the laboratory and under semi‐field conditions.
The time‐course of behavioural phase change in nymphs of the desert locust, Schistocerca gregaria
TLDR
Results indicate that, while behavioural gregarization is maximal within a few hours of crowding, solitarization is a two‐stage process, changing rapidly at first, then more slowly as a function of the period of previous crowding.
Spatial scales of desert locust gregarization.
TLDR
Computer simulations and a laboratory experiment are presented that show how differences in resource distributions, conspicuous only at small spatial scales, can have significant effects on phase change at the population level; local spatial concentration of resource induces gregarization.
Primer pheromones and polymorphism in the desert locust
Solitarization in the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae)
TLDR
It had been previously considered that S. gregaria nymphs lose very little of their gregarious tendency once it is acquired; this is now shown not to be the case.
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