Phase characters of the desert locust

Since the desert locust gregarises and dissociates very readily in response to population density and as crop damage is done by gregarious phase, it is essential to be aware of difference between phases and to watch the signs of phase transformation.

Characteristics	Solitary	Gregarious
Behaviour	Do not form groups.	Form persistent and cohesive groups- Bands and Swarms
	Roost, bask, feed and move as individuals.	Roost, bask, feed and move together.
	Hoppers move little, adults fly as individuals at night.	Very mobile- fly as swarms by day. Concerted movement by hoppers in a band marching.
Colour	Hoppers uniformly green in early instars but may be brown in last two instars.	Hoppers heavy black pattern on yellow or orange background.
	Adults pale grayish brown, buffer peach coloured. Males change to pale yellow on sexual maturation. Females show no colour changes on maturation at very low densities.	Adults rosy pink on fledging, darken in with age to grayish or brownish red then to yellow on sexual maturation (brighter in males).
Number of moults	5 or 6 (occasionally 4 or 7)	5
Pronotum	Convex; its hind angle pointed.	Concave, its hind angle rounded.
Antenna	27-30 jointed	26- jointed
Femoral spines	Both strong and weak present.	Only weak present.
Eye-stripes	6 or 7	6
Morphometrics	F/C Male 3.75 and over Females 3.85 and over	3.15 and under 3.15 and under
	E/F Males 2.025 and under Females 2.075 and under	2.225 and over 2.272 and over
	C = Width of head,  E = length of forewing F = length of hind femur.