Bulletin of Entomological Research (1980) 70, 621-633

W.W. Page (1980)
Occurrence of the grasshopper pest Zonocerus variegatus (L.) (Orthoptera: Pyrgomorphidae) in south-western Nigeria in relation to the wet and dry seasons
Bulletin of Entomological Research 70 (4), 621-633
Abstract: An investigation into the seasonal abundance of Zonocerus variegatus around Ibadan, Nigeria, showed that hatching occurs between October and March and peak abundance is in late November. Adults occur almost throughout the year. Oviposition takes place between March and October with a peak in April. Eggs laid in March and April hatch in October and November after a diapause, while those laid from June onwards do not enter diapause and hatch at the same time. Parasitism by Blaesoxipha filipjevi (Diptera, Sarcophagidae) during March and April results in a rapid decline in adult numbers which may be followed by a secondary peak when larvae, which are rarely parasitised, reach adult stage. The fungus Entomophthora grylli plays an important role in controlling the abundance of larvae and adults. It is concluded that there is one generation of Z. variegatus a year, with a peak in population coinciding with the dry season November-March). The species may have originated in the semi-arid zones of the north.
(The abstract is excluded from the Creative Commons licence and has been copied from Acridological Abstracts with permission by NRI, Univ. of Greenwich at Medway.)
Link to article at publishers website

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology

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Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Zonocerus variegatus		Nigeria