Published online by Cambridge University Press: 10 July 2009
The genus Schistocerca is one of very great economic importance, since it includes the Desert locust of the Old World, Schistocerca gregaria (Forsk.) and the South American locust, S. paranensis (Burm.). It was therefore considered of value to study the life history of one of the solitary species living in Trinidad, and the present investigations were made during 1942 at the Imperial College of Tropical Agriculture at St. Augustine.
The climate of Trinidad is humid tropical. The annual rainfall over nineteen years at St. Augustine averaged 68·4 inches, but in the north-east of the Island the rainfall is over 100 inches per annum, falling to below 60 inches on the West coast. The rainy season usually begins about June, with a break in August or September, and lasts till the end of the year or the early part of January. November may be taken as one of the wettest months with a rainfall of about 11·5 inches (at St. Augustine), while more than half an inch is not usual for April. The humidity in November averages about 85 per cent. in the morning and 77 per cent. in the afternoon, but it is still high in April, being 75 per cent. and 64 per cent. for morning and afternoon respectively. The night humidities are even higher. The temperature remains practically constant throughout the year, averaging about 84°F. (29°C.) during the day, and 74°F. (23·3°C.) at night. The temperature may reach 95°F. (35°C.) during the day in the dry season, but it seldom falls as low as 65°F. (18·3°C.) at night.