DAÑOS Y DIVERSIDAD DE INSECTOS DESCORTEZADORES DE CONÍFERAS DEL NORESTE DE MÉXICO

Abstract

By the middle of 1999, in the forests of northeastern Mexico, coniferous bark beetles were detected over a territory near 12,000 hectares of coniferous forest in Coahuila State and 13,000 in Nuevo Leon State, out of which 418.5 and 799 hectares réspectively, were strongly affected and distributed in large spots which favored its quick dissemination. Such situation allowed the populations of these insects to grow quickly and infest thousands of trees.in a few weeks. Because of the lack of knowledge of the causal agents, it became necessary to carry out this work with the purpose of identifying the insect species that attack the forests aforementioned. To fulfill this work, collections of attacking insects were taken to the laboratory for their identification. This work was done in the Campo Experimental Saltillo, where genitalia and karyotype techniques were used. The following results were found: the damage to Pseudotsugae flahaultii is caused by Oendroctonus pseudotsugae. Abies vejarii is attacked by Scolytus spp. in top of the tree and Pseudohylesinus variegatus in the lower part of the stem; Oendroctonus adjunctus damage upon Pinus rudis, and Ph/oesinus spp. on Cupressus arizonica. lt was also found that young trees of the Abies, Pseudotsugae and all pine species are attacked by the Pityophthorus spp. At the same time, Pinus teocote and Pinus pseudostrobus are damaged by Oendroctonus mexicanus and Pinus arizonica by Oendroctonus brevicornis.