Biology and natural enemies of the citrus weevil Compsus n. sp. (Coleoptera: Curculionidae)

Abstract

Compsus n. sp. was recorded for the first time in 1939 associated with citrus crops in Colombia. Since 1995 populations of this insect have increased causing economic losses on citrus crops in Quindio and Tolima. To contribute to the knowledge of this species a study was conducted in citrus plantations in Montenegro, Quindío (1250 m.a.s.l., 21.9ºC, 78% R. H., 2026 mm) and Armero - Guayabal, Tolima (350 m.a.s.l., 28.5ºC, 62% R. H., 1400 mm). The life cycle, behavior, natural enemies, and population fluctuation through time, were studied at these sites. Compsus n. sp., completed its life cycle from 132 to 219 days. Adult females oviposit irregular egg masses on the aerial part of the trees; neonates larvae fall to the soil and bury into the ground were first instars feed on small adventitious roots of the tree. Later on bigger larvae start feeding on more developed roots. At the end of its developmental stage, they build a pupa! camera in the ground and the pupation period takes about one to two months. Then adult emerges and the life cycle goes on twenty-five natural enemies were recorded, which confirms that this weevil has a good number of organisms regulating its populations.