These photographs & captions are from a hand-colored photo album called “Barkbeetle Enemies of California Forests”.
The album was produced by the USDA Bureau of Entomology and Plant Quarantine in cooperation with the State Emergency Relief Administration – Project 3F-2-302 – and the Emergency Educational Program in Berkeley, California. February, 1935.
The photographs were taken by variousUSDA Bureau employees between 1919-1934 and hand coloured exquisitely.
1. Drawing of adult beetle enlarged about 8 times.
2. Full grown larvae in outer bark of ponderosa pine, where they complete feeding and development.
3. Pitch tube on outer surface of bark, where the adult beetle bored into the live tree. Resins pour into the wound when sap layer is reached, and the beetle works these to the surface to keep the entrance open. Adult beetle at right of entrance hole.
4. Egg galleries on the inner surface of bark. At frequent points along the course of winding galleries, eggs are deposited; from these tiny larvae mine for a short distance in inner bark (shown as fine lines extending away from egg galleries). The larvae then turn into outer bark to complete feeding. Blackened areas are caused by fungus stain.
5. Infested ponderosa pine with bark removed to show scoring of egg galleries on surface of sapwood.
Photos by Burke, Keen, and Patterson.
“The drought-related stress to trees on million of acres of ponderosa pine forests in the inland West caused dramatic levels of tree mortality that could not be ignored by politicians. Miller, Keen, and Patterson also played a clever propaganda game to procure appropriations to increase the research efforts on the western pine beetle. During the depression, government agencies provided some level of support for artists, cartographers, and draftsmen as a “make work” program. These artisans were eagerly employed by Miller at bargain prices to produce hand-colored photo albums showing the extent of the tree mortality caused by bark beetles, what was being done, and what was needed in the form of research programs to curb this wasteful tree loss. Miller got the message across by supplying these albums to trade associations, chambers of commerce, politicians, and universities.”
From: Wickman, Boyd E. 2005. Harry E. Burke and John M. Miller, pioneers in Western forest entomology. Gen. Tech. Rep. PNW-GTR-638. Portland, OR: USDA, Forest Service, Pacific Northwest Research Station. p. 126.
The crew of an average sized control camp consists of the foreman and assistant, mess (cooks and flunky), spotting crew, treating crews, and truck driver. Mess tent and bunk tents are shown in the background. Van Brewer Wells Camp.
Photo by: J.E. Patterson, October 1920
Infested sugar pines in the Yosemite National Park were treated by burning method while winter snow was still on the ground.
Photo by: Anderson (National Park Service). 1933.
Tree on right is in first stages of attack with upper crown fading and sorrel; tree on left with red foliage is completely killed and has been abandoned to the beetles.
Photo by: J.M. Miller, September 1932.
Flying about 1,200 feet above this open forest of mature ponderosa pine, the observer photographed a new and active infestation of the western pine beetle. The large group and scattered outlying trees resulted from one attack early in the season. More than twice as many trees were killed on this area during the year. Old snags on the ground show where old infestations thinned this stand.
Photo. by: F.P. Keen. 1927
Photo by: J.M. Miller. September 1934.
The second operation in treating an infested tree is to peel off the infested bark and pile it along the sides of the felled tree.
Limbs are also trimmed and piled.
A. First phase (fading). Soon after attack the foliage changes from normal green to a yellowish green.
B. Second phase (sorrel). As the beetle broods develop the fading phase changes to light yellowish red.
C. Third phase (red). By the time the broods have completed development the foliage enters the final red stage which is retained until the dead needles fall. Beetles have usually abandoned trees in this color phase.
During the summer season, broods can be destroyed by spreading infested bark in the sun. When air temperatures are above 85 F., bark so exposed will heat up to 120 F., which is sufficient to kill the insects.
Photo by: J.M. Miller. No recorded date.
Photo by J.M. Miller, 6 August 1924.
The spotter was first directed to the tree by off color condition of foliage. Holes made by woodpecker when feeding on insects in bark also indicate that tree is infested. Work of barkbeetles is uncovered by removing section of bark. To mark the tree for the control crew, it is blazed on sapwood, numbered, measured, mapped and records made on form.
The pile of limbs and brush at the top is already fired and the men are starting other fires along the peeled log. The cleared trench in the foreground is the fire line which prevents the control fires from spreading to the surrounding forest.
Note: Probably Al Wagner pictured. Photo by: K.A. Salman. May 1930
These insects resemble Dendroctonus but usually occur only sporadically in infested areas. Their common habit is to kill only the tops of the larger trees which survive unless followed by Dendroctonus.
Photo by: K.A. Salman, 1933.
Other species of insects are at times associated with Dendroctonus in kiling trees. The pine flatheaded borer (Melanophila spp.) usually attacks first in the upper part of the crown. The lower part of the tree survives until later attack by Dendroctonus or Flatheads follows.
Photo by: K.A. Salman, 1932.
These trees first weakened by a needle miner, were later killed by the barkbeetle.
The green trees in the background are mountain hemlock and red fir, both immune to the insects.
Photo by: J.E. Patterson. 1923.
Photo by: J.E. Patterson. Date not recorded.
All infested bark is completely burned but the log is only charred by the fire and may still be utilized.
Photo by: J.E. Patterson. November 1934.
1. Adult beetle enlarged about 8 times.
2. Egg galleries, larval mines, and brood in inner bark of sugar pine.
A – larva; B – pupa.
3. Infested ponderosa pine with bark removed to show work of sapwood.
4. Infested lodgepole pine showing pitchtubes on outer bark.
Photos by: Patterson, Keen, Miller.
The spotter has blazed 21 trees recently attacked by barkbeetles in a heavy center of infestation.
Photo by: J.M. Miller, 1924.
It is the function of the Bureau of Entomology and Plant Quarantine to study all phases of forest insect problems in order to develop methods of control. Here screen cages have been built around the bases of two living trees and bark from infested trees enclosed with them. Beetles emerging in the cages from this bark are confined and forced to attack the green trees. This attracts beetles flying in the vicinity and the entire trees are soon infested. In this way information applying to rate of death of trees and development of broods as well as concentration of natural enemies is secured.
Photo by: J.M. Miller, 1927.
Guided by the map and records of the spotter, a control crew has reached an infested tree. The next step is to cut it down so that it can be peeled.
Photo by: J.E. Patterson. No date recorded.
Western Pine Beetle Infestation in Blue Canyon – Sierra National Forest
From a lookout point, the spotter counts fading, sorrel, and red trees and notes their location.
Photo by: K.A. Salman, J.M. Miller, and J.E. Patterson. Date not recorded.
When the burning method is not feasible the broods of this beetle, which develop between the bark and wood, may be destroyed by exposing them to the weather. It is necessary to remove the bark from all sides of the log when using this method.
Photo by: Anderson (National Park Service). 1933.
View of an area of ponderosa pine where an epidemic infestation of the western pine beetle is decimating the stand. The faded and sorrel trees have only recently been attacked one and two years previously and have been abandoned by the beetles.
Photo by: J.M. Miller. Date not recorded.
Red and sorrel trees are ponderosa pines killed by barkbeetle epidemic during 1930-1932. Loss of these trees will reduce forest cover on recreational areas such as the above.
Photo by: J.M. Miller. No date recorded.