Under timber trespass are included the following acts: the cutting, killing, girdling, or otherwise damaging trees; the cutting of timber under sale contract or permit before it is marked by a Forest officer; the removal of timber before it is scaled, measured, or counted by a Forest officer; and the fraudulent stamping of any timber belonging to the United States with the regulation marking tools or similar device. Under grazing trespass are included such acts as: grazing stock on National Forest lands without permit; grazing stock on areas which are designated as closed to grazing; driving stock across a National Forest without permit; and refusal to remove stock upon instructions from an authorized Forest officer when an injury is being done to the National Forests by reason of the improper handling of the stock. The use of National Forest land without a permit for any purpose for which special use permits are required constitutes occupancy trespass. But traveling, temporary camping, hunting, surveying, or prospecting may be carried on without permit, and camp wood and forage for stock used in connection with such activities may be taken free of charge. The unauthorized appropriation, damage, or destruction of property belonging to the United States, which is used in the administration of the National Forests, also constitutes trespass. Innocent trespass is usually settled amicably between the trespasser and the Supervisor. If the violation of the timber, grazing, or land regulations was due to a misunderstanding and was not of a willful character, a permit is issued and the trespasser pays for the timber or special use, as under regulation. Fire and property trespass cases seldom can be construed as innocent, hence in most cases such offenses result in litigation. _Forest Insects._ Protection against forest insects is carried out in coöperation with the Bureau of Entomology of the Department of Agriculture. An essential part of good forest protection is the work of locating and reporting evidences of insect depredations. There are scores of insects which are constantly working in the forests, either injuring or killing live trees or attacking the wood of trees after they have been killed. Weevils kill young shoots on trees and destroy tree seeds; bark beetles and timber beetles infest the bark, girdle the tree and destroy the wood; and various borers and timber worms attack seasoned and unseasoned forest products and destroy the wood in the forest after it has been cut down and sawed into lumber. The greatest annual loss by insects is caused not so much by conspicuous local outbreaks as in the sustained annual loss of scattered merchantable trees. Local infestations often kill a large percentage of trees on an area, but these outbreaks are easily seen; the scattered infestations that kill a tree or two here and there over large forest areas are not so noticeable, but, taken all together, add up to a startling total.