D E S E R
T L O C U S T B U L L E T I N
Glossary
of terms
The following special terms are
used in the Desert Locust Bulletin when reporting
locusts:
Non-gregarious adults and
hoppers
-
- isolated (few)
-
- very few present and no
mutual reaction occurring;
- 0 - 1 adult per 400 m foot
transect (or less than 25 per ha).
- scattered (some, low
numbers)
-
- enough present for mutual
reaction to be possible but no ground or basking
groups seen;
- 1 - 20 adults per 400 m
foot transect (or 25 - 500 per ha).
- group
-
- forming ground or basking
groups;
- more than 20 adults per 400
m foot transect (or more than 500 per ha).
Adult swarm and hopper band
sizes
- very small
-
- swarm: less than 1
km2
- band: 1 - 25 m2
- small
-
- swarm: 1 - 10
km2
- band: 25 - 2,500
m2
- medium
-
- swarm: 10 - 100
km2
- band: 2,500 m2 - 10
ha
- large
-
- swarm: 100 - 500
km2
- band: 10 - 50
ha
- very large
-
- swarm: 500+ km2
- band: 50+ ha
Rainfall
- light
- 1 - 20 mm
- moderate
- 21 - 50 mm
- heavy
- more than 50 mm
Other reporting terms
- breeding
- the process of reproduction
from copulation to fledging.
- summer rains and
breeding
- July -
September/October
- winter rains and
breeding
- October -
January/February
- spring rains and
breeding
- February -
June/July
- decline
- a period characterised by
breeding failure and/or successful control leading to the
dissociation of swarming populations and the onset of
recessions; can be regional or major.
- outbreak
- a marked increase in locust
numbers due to concentration, multiplication and
gregarisation which, unless checked, can lead to the
formation of hopper bands and swarms.
- plague
- a period of one or more years
of widespread and heavy infestations, the majority of
which occur as bands or swarms. A major plague exists
when two or more regions are affected
simultaneously.
- recession
- period without widespread and
heavy infestations by swarms.
- remission
- period of deep recession
marked by the complete absence of gregarious
populations.
- upsurge
- a period following a recession
marked initially by a very large increase in locust
numbers and contemporaneous outbreaks followed by the
production of two or more successive seasons of
transient-to-gregarious breeding in complimentary
seasonal breeding areas in the same or neighbouring
Desert Locust regions.
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