ECOLOGICAL INTERACTION OF PANTOPHTHALMUS ROSENI (ENDERLEIN) (DIPTERA: PANTOPHTHALMIDAE) AND THE RED OAK QUERCUS GERMANA SACHLTDL. ET CHAM. (FAGACEAE) IN A MEXICAN CLOUD FOREST

Abstract

The interaction of the wood driller (Pantophthalmus roseni) and the red oak (Quercus germana) in the cloud forests of the Biosphere Reserve El Cielo at Gómez Farías, Tamaulipas, Mexico was studied. Forty mature individuals of Quercus germana were selected for comparison (20 healthy trees, 20 with severe damage, i.e. ³ 15 wood perforations caused by P. roseni). Healthy and damaged trees were measured for levels of herbivory, percentage of foliar nitrogen, total phenols concentration and acorn production. Herbivory was significantly greater (P< 0.05) in healthy than in damaged oaks. The healthy group had 1.5 times more leaf herbivory than the damaged group. Foliar nitrogen content in Q. germana (5.3%) showed significant variations in relation to the seasons (rainy season = 5.2% and dry season = 5.1%) and between damage groups, as well as in the interaction of season and group. The damaged trees group had 1.2 and 1.5 times more phenols concentration than the healthy group during the rainy season and dry season, respectively. Acorn production was significant greater (P< 0.05) for the damaged group than the healthy group. The importance of these results in understanding and managing this insect as a forest pest, as well as, the effects of herbivory in the cloud forests are discussed.