ET-182 September 1941
United States Department of Agriculture
Bureau of Entomology and Plant Quarantine
A SATISFACTORY TREE-TRUNK SCREEN CAGE
By F. W. Carlson and M. A. Yothers,
Division of Fruit Insect Investigations
To facilitate the stuCy' of codling moth larvae in cocoons at the base of apple tree trunks, the follo wing described treetrunk cage was devised and built by the writers in 1939 at the Yakima, Wash., laboratory.l/ lor case in putting the cage in place and in removing it frow the tree, it was made in two parts. Two equal frames, 13" x 13" x 102, were made, and four facs of each frame (ends, top, and one sid) are covered with 14-mesh screening (16-mesh screen would bae >r better) (figs. 1 and 2) T'herc the half cages came together the ate;ial was tongue-and-groove to insure a tight joint The two half frames were held together very closely by the use of two 11" hooks and eyes on each side. The tongue-and-groove pieces in the top center were held rigid hy angle braces from underneath, the same as were used in the corners. The top screen was stapled to screen molding, which was than fastened with screws, so that the cp could be removed or partly raised if necessary.
The method used to obtain a close fit around the tree was to place the cage in the position desired, then lay a piecc of cardboard on top of the screen of the cage and cut it out until a perfect fit was secured. This template was then placed on top of the screen to be cut out for the tree trunk, It was found best to make the cut in the screening a little smaller than the pattern to be sure that the cut was not too large, and then enlarge it as necessary.
A piece of --" x -" felt was tacked to the tree just below where the screen touched the trace. The felt matting that .s ordinarily used on automobile (Loor boards is satisfactory aua much less expensive than the felt used for bearings in motors.
1/ Yothers, M. A., and Carlson, F. W. Orchard observations of the Emergence of Codling Moths from Two-Year-Old Larvae. Jour. Econ. Ent. 34 (1): 109-110. 1941.
After the cage was in place, about 3 nails were driven through the screen and felt to prevent the screen from rising. A good coating of adhesive was finally smeared around the tree at the union of screen, felt, and bark.
The cage was set down in the soil from 3 to 4 inches to help keep out rodents.
List of Materials
12 pieces clear pine, 3/4" x 1-3/8" x 13" 34S (surfaced 4 sides)
4 pieces clear pine, 3/4" x 1-3/8" x 10" #4S 4 pieces clear pine, 3/4" x 1-3/8" x 26" 34S 16 pieces clear pine, 3/4" x 1-3/8" x 3" $4S
The following 4 items are ripped from 1" x 4" flooring which is tongued on one edge (T.JE) and grooved on one edge (G.lE) to insure a tight union of the two half-cages.
2 pieces 3/4" x 1-5/8" x 13" T.lE. 33S (surfaced 3 sides)
2 pieces 3/4" x 1-5/8" x 13" G.lE. $3S 2 pieces 3/4" x 1-5/8" x 5" T.IE. 3S 2 pieces 3/4" x 1-5/8" x 5" G.lE. $3S
24 pieces 5/16" x 3/4" x 13" screen molding 6 pieces 5/16" x 3/4" x 26" screen molding 4 pieces 5/16" x 3/4" x 6" screen molding
6 feet of 26", 14-mesh galvanized screen
4 1"' hooks and eyes
28 round head wood screws, 1" #5
4 feet of 3/4" x 3/4" cheap felt Nails, 1-1/8" finish and 5/8" wire brads Adhesive
Approximate cost, $1.85
TyeeiIu-nK Scyeefl CagjeFigure 1.---ree-trunk screen cage showing details of construction.
Fiur 23retuksrencg npsto
about an apple tree trunk.
UNIVERSITY OF FLORIDA 3 1262 09240 9654