Seasonal Abundance of Galling Insects (Hymenoptera) on Caryocar brasiliense (Malpighiales: Caryocaraceae) Trees in the Cerrado

摘要

Caryocar brasiliense Camb. (Malpighiales: Caryocaraceae) trees have a wide distribution in the Cerrado, a tropical Brazilian savanna, with high diversity and endemism. This plant is protected by federal laws and is untouched in deforested areas of the Cerrado. This situation increases the damage to leaves from galling insects (Hymenoptera). We studied populations of galling insects and their natural enemies on C. brasiliense trees for 3 successive yr during each season in the Cerrado. A globoid gall-inducing Eurytoma sp. (Hymenoptera: Eurytomidae) and its parasitoid Sycophila sp. (Hymenoptera: Eurytomidae) adults and predator Zelus armillatus (Lepeletier and Serville) (Hemiptera: Reduviidae) on the leaves were most abundant in the winter. The numbers of vein galls correlated negatively with the numbers of discoid and spherical galls, and the numbers of spherical galls correlated negatively with the numbers of discoid galls on C. brasiliense leaflets. Increased percentages of defoliation were correlated with reductions in the percentages of leaflets with total galls and leaflet area with total galls. Increased numbers of Sycophila sp. and decreased numbers of Ablerus magistretti Blanchard (Hymenoptera: Aphelinidae) were correlated with reduction in the numbers of Eurytoma sp. Numbers ofQuadrastichus sp. (Hymenoptera: Eulophidae) and A. magistretti correlated negatively with the numbers of Sycophila sp. Increased numbers of Z. armillatus were correlated with reduction in the numbers of Eurytoma sp. and its galls and parasitoids. We concluded that this differential temporal distribution of galling insects and their natural enemies was influenced by plant phenology and time of colonization on C. brasiliense leaves. View this article in BioOne