INFESTATION RATE OF ARGAN FRUIT (ARGANIA-SPINOSA) BY THE MEDITERRANEAN FRUIT-FLY (CERATITIS-CAPITATA) IN RELATION TO PHENOLOGY AND MATURATION OF THE FRUIT

Argan (Argania spinosa (Sapotaceae)) forest covers about 700,000 ha in the Souss region (Morocco). The medfly Ceratitis capitata Wiedemann ( Diptera: Tephritidae) is known to develop in argans. In this study, we examine variations in medfly infestation rates according to argan phe nology from 1987 to 1990. Argan phenology varies greatly among trees, total fruit drop spreading from late March to mid-July; moreover, an e xceptional fructification may occur in Autumn in some trees. From Febr uary to about May, the infestation rate is low except in fruit produce d during autumnal fructification. In June and July, the rate increases greatly reaching 100% in some trees. Ripe and ripening argans are the most heavily infested; only 10% of immature fruits on the average are attacked by the medfly. Fallen argans are more heavily infested than fruit still on the tree. Productivity per argan averaged from one to t hree adult medflies. Our results demonstrate that argan forest in the Souss acts as an enormous reservoir of medflies for the nearby citrus orchards.