Editing Migratory locust (section)

==Polyphenism==
The migratory locust is [[Polyphenism|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:

{{block indent|1=Solitaire = solitary phase → {{lang|la|transiens congregans}} (intermediate form) → gregarious phase → {{lang|la|transiens 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&nbsp;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.<ref name="Hou2020">{{cite journal |last1= Hou|first1= Li|last2= Wang|first2= Xuesong|last3= Yang|first3= Pengcheng|last4= Li|first4= Beibei|last5= Lin|first5= Zhe|last6= Kang|first6= Le|last7= Wang|first7= Xianhui|title= DNA methyltransferase 3 participates in behavioral phase change in the migratory locust|journal= Insect Biochemistry and Molecular Biology|date= 2020|volume= 121|pages= 103374|doi= 10.1016/j.ibmb.2020.103374|pmid= 32283278|s2cid= 215758648|url= https://www.sciencedirect.com/science/article/pii/S0965174820300631|url-access= subscription}}</ref> Transcriptionally, ''Dnmt3'' is linked with phase-core transcriptional factor, [[hormone receptor]] HR3.<ref name="Hou2020" />