41. Bark beetles can form a Ophiostomatales fungi.42. Specialist predatory beetles find bark beetles ( their prey ) using the pheromones the bark beetles produce. 43. The area is vulnerable because drought and an infestation of bark beetles have left millions of dead trees. 44. A number of trees also fell after being weakened by fire and a previous infestation of bark beetles . 45. Continuous problems with bark beetle and storms were the negative side effects of mining in the Harz Mountains. 46. The fungus is carried from tree to tree by a bark beetle , and soon spread across the country. 47. Bark Beetle Links Page : http : / / www . watertalk . org / wawa / beetle/48. The blaze has consumed pine trees ravaged by years of drought and an infestation of tree-killing bark beetles . 49. After the budworms weaken the stands . . . the bark beetles move in and finish the job. 50. He also studied other pests, like bark beetles and the mechanisms that parasites use to find their hosts.