Factors facilitating the continued presence of Colotis evagore (Klug, 1829) in southern Spain

Colotis evagore (Klug) is a multivoltine pierid butterfly that has repeatedly invaded the Iberian Peninsula from Africa over the last four decades. In 1983 at invaded Spain, reproducing successfully there on its foodplant, Capparis spinosa L. During the cold season this plant is not available in most areas of Spain, and the butterfly must find alternative foodplants to maintain its populations in this newly colonized territory. Our data show that C. evagore is unable to survive on alternative cruciferous hosts, and incapable of entering diapause to avoid inhospitable times of the year and the absence of host plants. The relative growth rate of larvae depends on temperature; the threshold temperature for development is 12⚬C, and the estimated physiological time for larval development is 162.5⚬d. Our observations show that C. evagore has survived continually in certain coastal sites in southern Spain since 1983. Microenvironmental conditions in these sites are particularly favourable for the foodplant. Hence, the plant is available throughout the year, allowing the caterpillars to complete successfully their life-cycle.