Diel Behavioral Activity Patterns in Adult Solitarious Desert Locust, Schistocerca gregaria (Forskål)

The responses of adult solitarious desert locust to odors from a host plant were evaluated in a two-choice wind tunnel. Solitarious desert locusts collected from the field (Red Sea Coast) were more attracted to volatiles from potted Heliotropium ovalifolium in scotophase than in photophase. The attraction towards the host plant odors rather than to clean air, in both photophase and scotophase, concurs with previous observations on oviposition preferences near these plants. Diel behavioral activity patterns of adult solitarious desert locusts Schistocerca gregaria (Forskal) that were collected from the field in Port Sudan were investigated by monitoring, scanning, resting, taking off, and walking/running in a wind tunnel. Solitarious locusts that had been propagated in the laboratory for 20 generations were also observed for comparison. In both groups of locusts, insects were significantly more active after sunset and this activity attained peak level at 1-2 hours after dusk. Of the two groups, solitarious locusts collected from the field were significantly more active. In the scotophase, the former traversed distances that were about seven times those covered by laboratory-reared locusts. Overall, the results show that the repertoire of behavioral activities of solitarious locusts is maintained in laboratory-reared insects, albeit at a lower level. The implications of these observations in the behavioral ecology of the desert locust are discussed.

[1]  P. Haskell,et al.  Laboratory observations on factors affecting the movements of hoppers of the desert locust , 1962 .

[2]  Boris Uvarov,et al.  Anatomy, physiology, development phase polymorphism introduction to taxonomy , 1966 .

[3]  Rao Rao.  Some Results of Studies on the Desert Locust (Schistocerca gregaria, Forsk.) in India , 1942, Bulletin of Entomological Research.

[4]  W. W. Page,et al.  A Study of Population Changes in the Grasshopper, Zonocerus variegatus, in Southern Nigeria , 1979 .

[5]  Y. R. Rao.  The Desert Locust In India , 1960 .

[6]  G. Woldewahid,et al.  Habitats and spatial pattern of solitarious desert locusts (Schistocerca gregaria Forsk.) on the coastal plain of Sudan , 2003 .

[7]  B. P. Uvarov,et al.  A revision of the genus Locusta, L. (= Pachytylus, Fieb.), with a new theory as to the periodicity and migrations of locusts , 1921 .

[8]  D. Hunter.  Adult development in the Australian plague locust, Chortoicetes terminifera (Walker) (Orthoptera: Acrididae) , 1982 .

[9]  Flight in Desert Locusts in Relation to Humidity , 1953 .

[10]  A. Hassanali,et al.  Insights for the Management of Different Locust Species from New Findings on the Chemical Ecology of the Desert Locust , 1999 .

[11]  Ahmed Hassanali,et al.  Desert locust gregarization: a conceptual kinetic model , 2005 .

[12]  R. Peveling,et al.  New Strategies in Locust Control , 1997, Birkhäuser Basel.

[13]  JEREMY ROFFEY,et al.  Environmental and Behavioural Processes in a Desert Locust Outbreak , 1968, Nature.

[14]  Boris Uvarov,et al.  Grasshoppers and Locusts: A Handbook of General Acridology. Vol. 1. Anatomy, Physiology, Phase Polymorphism, Introduction to Taxonomy. , 1967 .

[15]  David K. Weaver,et al.  Grasshoppers and locusts , 2007 .

[16]  D. Wright,et al.  Lipid accumulation and migratory flight in the Australian plague locust, Chortoicetes terminifera (Walker) (Orthoptera: Acrididae) , 1981 .

[17]  G. K. Wallace.  Visual Scanning in the Desert Locust Schistocerca Gregaria Forskål , 1959 .

[18]  E. Bernays,et al.  THE CHEMICAL BASIS OF RESISTANCE OF SORGHUM BICOLOR TO ATTACK BY LOCUSTA MIGRATORIA , 1978 .

[19]  D. R. Reynolds,et al.  Vertical-looking radar as a means to improve forecasting and control of desert locusts , 1997 .

[20]  Z. Waloff.  Field studies on solitary and transiens desert locusts in the Red Sea area. , 1963 .

[21]  M. Roonwal.  Variation and structure of the eyes in the desert locust, Schistocerca gregaria (Forskål) , 1947, Proceedings of the Royal Society of London. Series B - Biological Sciences.

[22]  J. Kennedy,et al.  THE BEHAVIOUR OF THE DESERT LOCUST (SCHISTOCERCA GREGARIA (FORSK.)) (ORTHOPT.) IN AN OUTBREAK CENTRE , 2009 .

[23]  J. Roffey.  Observations on night flight in the desert locust (Schistocerca gregaria Forskål). , 1963 .

[24]  M. M. Rai,et al.  Changing Oviposition Preferences of the Desert Locust, Schistocerca gregaria, Suggest a Strong Species Predisposition for Gregarization , 2000, Journal of Chemical Ecology.

[25]  G. Varley,et al.  Grasshoppers and Locusts , 1967 .