The development and termination of the 1968 plague of the desert locust, Schistocerca gregaria (Forskål) (Orthoptera, Acrididae)

1976 ◽  
Vol 66 (3) ◽  
pp. 511-552 ◽  
Author(s):  
L. V. Bennett
Keyword(s):  
Population Dynamics ◽  
Schistocerca Gregaria ◽  
Control Measures ◽  
Desert Locust ◽  
Large Area ◽  
Mature Adults ◽  
Westerly Winds ◽  
Threshold Rainfall ◽  
Gregarious Locusts ◽  
Parent Generation

AbstractThe population dynamics of the desert locust, Schistocerca gregaria* (Forsk.), in Africa, the Middle East and Asia from 1966 to 1969 have been analysed to determine the causes of the beginning and the abrupt end of the plague of 1968. Evidence indicates that in 1966 there were no persistent sequences of breeding by gregarious populations, but in 1967 and early 1968 there were four sequences of breeding by initially solitary behaving locusts, each resulting in a substantial increase in numbers and density. These events led to a plague that ended by mid-1969.The threshold rainfall requirement for successful breeding, defined as an increase in numbers from mature adults of the parent generation to filial fledglings, has been related to the rainfall required for the germination of ephemerals and their growth to sizes that can provide food and shelter for hoppers throughout their development. It is suggested that the minimum quantity of rainfall required initially over a large area is 25 mm. This requirement is usually met in the summer breeding areas. Rainfall in the winter-spring breeding areas is more variable, and falls exceeding the threshold are most commonly associated with deep troughs in the mid- and upper-tropospheric westerly winds in winter and spring. A season in which many such troughs occur may be essential for plague development. It is also suggested that the timing of successive periods of rainfall allowing successful breeding is critical in determining the occurrence of upsurges.Control against non-gregarious infestations failed to contain the upsurge, but later control measures against hopper bands and swarms contributed to the plague decline. The most economical strategy for plague prevention might be one of upsurge elimination, that is to say control in selected areas against gregarious locusts only. The implications of adopting such a strategy are discussed.

scholarly journals The 2019–2020 upsurge of the desert locust and its impact in Pakistan

2021 ◽  
Vol 30 (2) ◽  
pp. 145-154
Author(s):  
Riffat Sultana ◽  
Santosh Kumar ◽  
Ahmed Ali Samejo ◽  
Samiallah Soomro ◽  
Michel Lecoq
Keyword(s):  
Middle East ◽  
East Africa ◽  
Schistocerca Gregaria ◽  
Control Measures ◽  
Desert Locust ◽  
The Future ◽  
Local Impact ◽  
Locust Control ◽  
Insight Into

The recent upsurge of the desert locust Schistocerca gregaria (Forskål, 1775) has had an impact on East Africa and the Middle East as far as India. It has affected and slowed down many aspects of the Pakistani economy. Swarms of locusts have infested many areas and caused immense damage to all types of crops. Both farmers and economists are concerned and are trying to get the most up-to-date information on the best strategy to manage this pest. This paper is an attempt to (i) provide insight into the dynamics of this upsurge internationally as well as in the various regions of Pakistan, (ii) briefly assess its local impact and locust control measures, and (iii) clarify the role of the various stakeholders in the management, both nationally and internationally, suggesting various improvements for the future.

STRATEGIES FOR THE USE OF ENTOMOPATHOGENS IN THE CONTROL OF THE DESERT LOCUST AND OTHER ACRIDOID PESTS

1997 ◽  
Vol 129 (S171) ◽  
pp. 5-25 ◽  
Author(s):  
C. Prior ◽  
D.A. Streett
Keyword(s):  
United States ◽  
Large Scale ◽  
Schistocerca Gregaria ◽  
The United States ◽  
Environmental Damage ◽  
Desert Locust ◽  
Large Area ◽  
Breeding Grounds ◽  
Fast Acting ◽  
Oedaleus Senegalensis

AbstractLarge-scale applications of non-persistent but broad-spectrum chemical insecticides in Africa during the 1980s for control of acridoid pests, particularly the desert locust (Schistocerca gregaria Forskål) and Sahelian pest grasshoppers, raised concern about environmental damage and human safety. Similar concerns have been expressed in Australia, the United States, and Canada and have led to a search for alternative strategies. To lessen dependence on chemicals, an integrated pest management (IPM) approach for grasshopper control has been encouraged in the United States with emphasis on biological control as an important component and this is also desirable elsewhere, but additional biocontrol components are needed. Current strategies for most pest acridoids rely on short-term destruction of outbreak populations. Nymphs are the preferred target wherever possible and inundative augmentation of entomopathogenic deuteromycete fungi formulated as biopesticides could replace chemical spraying in some cases, especially where the major threat is to crops remote from the pest breeding areas. Entomopathogens are slower acting than chemicals and thus best suited for use where the pest is not immediately threatening to crops. Schistocerca gregaria and Oedaleus senegalensis Krauss pose particularly difficult problems because of the very large area and inaccessibility of their potential breeding grounds, their very sudden upsurges, and their great mobility as adult swarms. Fast-acting chemicals are likely to be needed when rapid intervention is required to control these pests, but an IPM strategy could incorporate biopesticide application in the early stages of upsurges and also be used for swarm control in some cases. However, improved prediction and monitoring are needed to facilitate the use of biopesticides and other IPM techniques against these pests.

A gregarizing factor present in the egg pod foam of the desert locust Schistocerca gregaria.

1998 ◽  
Vol 201 (3) ◽  
pp. 347-363 ◽  
Author(s):  
A R McCaffery ◽  
S J Simpson ◽  
M S Islam ◽  
P Roessingh
Keyword(s):  
Phase State ◽  
Schistocerca Gregaria ◽  
Desert Locust ◽  
Early Separation ◽  
Active Factor ◽  
Gregarious Locusts ◽  
Series Of Experiments ◽  
Potent Factor

The behavioural phase state and coloration of hatchling Schistocerca gregaria were examined in a series of experiments to determine the means by which phase characteristics are passed between generations. Both crowding of solitary-reared females at the time of oviposition and high egg pod densities promoted behavioural gregarization, although the former appeared to be a rather more potent factor. In contrast, egg pod density alone appeared to promote the development of hatchlings with dark patterns characteristic of the gregarious phase. The phase characteristics of hatchlings were unaffected when sand previously used for oviposition was used to collect further egg pods. Early separation of presumptive gregarious eggs from egg pods laid by crowd-reared females led to solitarization of the hatchlings, indicating that a factor, either in or around the eggs, removed by early separation promoted gregarization. Both the eggs and foam plugs of egg pods from crowd-reared, gregarious females appeared to be a source of this gregarizing factor. In contrast, there was no evidence for a solitarization factor in egg pods from solitary-reared S. gregaria. Saline extracts of egg pod foam plugs produced an active factor which promoted gregarization both in eggs from solitary-reared females and in eggs from gregarious females which were separated and washed to removed the factor. Solitary eggs were influenced by the gregarizing factor in foam plug extracts for up to 1 day after oviposition. Saline extracts of foam plug retained their activity for up to 1 day. Initial studies on the properties of this factor were made. We conclude that the foam plugs of egg pods from crowd-reared, gregarious locusts contain a small (<3 kDa), hydrophilic gregarizing factor which is produced at the time of oviposition and which predisposes hatchlings to attain characteristics of the gregarious phase.

Sign in / Sign up

Export Citation Format

Share Document