ja wa7 1946. ET-226
STATe LA '3,
United Sta&te Department of Agriculture
Agricultural Research Administration
Bureau of Intomology and Plant (uirantine
A IXJZRNA IOW CAG JOR TE PXIK BLL)ORK
By Ivan chiller, V_
Division of Pink Bollworm Control
A hibernation cage that closely approximates outdoor conditions
has long been recognized as essential in the biological studies of
the pink bollworm oora. goesg3iella (Saund.)). The cage pre-
viously used consisted of a 3-foot-square frame made of 1- by S-inch
boards with & removable flat top covered with black satoon cloth. A
5-tnch hemispherical screen fly trap was Installed in the center of
the black cloth for trapping the emerging moths. The frame of the
cage was buried 5 or 6 Inches In the soil, and Infested cotton bolls
ere plac d on the soil surface or buried to the desired depth. The
wah h er temperature and humidity within the cage than outside
stimulated an earlier-than-normal emergence of the moth. Moreover,
the efficiency of the cage In trapping the moths was low.
The cage described herein more closely simulates outside condi.-
tions; its efficiency In capturing pink bollworm moths is high (82
percent), It can easily be cleaned of weeds since the covers are
removable, and it can be stored in a minimum of space Inasmuch as the
covers can be telescoped into each other. Because of these advan-
tages fte cage my prove useful In the study of other Insects.
Meteorological records were taken Inside and outside the cage at
Presidlo, Tez., over an 18-day period, May 6 to 23, 191. The aver-
so mean temperature 3 inches above the soil was 5$,90 7. inside the
cage and 93*53 outside the cage; the respective ximum temperatures
ere 1130 and 112.10, and the minimum temperature was 680 in both
cames. Nouovor, the variation In the soil temperature at the 2-iach
depth was considerably greater; the average man temperature ws
71.20 inside the cage and 71T430 Outside, the maximum temperatures
ere 86o and 99,50, and the minimum temperatures 57.20 and 52.r.
ivaporatilo outside the cage as measured in open metal pans was
1,60 al. as compared with 1,,414 al. inside. As would be expected,
the soil moisture was somewhat higher inside the cage than outside,
the percentages being 30.5 and 26.5.
-AckowVledaments are dW to A. J. Chapemn, L. V. Noble, and
V. L. Lowry, who contributed to the development of this cage.
Materials and Construction
The following materials are required for one cage:
Lubel,(lO pieces of each size): For base, 1 by 9 by 35 1/4
inches (A) and 2 by 2 by 7 1/2 inches (B); for removable cover,
1 by 1 374 by 36 3/ inches (D). 1 by 1 374 by 37 1/8 Inches (C),
1 by 1 3/8 by 34 1/2 inches (). screen molding 37 T/s Inches
long, and screen mold ng 314 172 inches long.
Hardware: S-ounce glass jar, with metal (preferably copper)
cap, 5 inches high, having an opening 1 7/S inches in diameter
(1); 1 cone of 16-mesh screen wire 2 1/2 inches high and 1 7/8
inches in diameter at the base to fit into the mouth of the Jar
(G); 2 pieces of 16-mesh screen wire 314 inches wide out into
rhombic figures with all sides 39 1/4 inches long so that the
angles in two opposite corners are 1200 and in the other two 600
(fig. 2); and 1 metal ring 6 inches in diameter made of 1/2 by
1/5 inch strap with 4 holes 3/16 inch in disaster and at 900
The construction of the cage is shown in figures 1, 2, and 3.
The base (fig. 1) consists of four pieces of lumber (A).?/ nailed
to four corner blocks (B) for added support and strength. This base
is embedded 4 to 6 inches in the ground, and the sides are banked with
The removable cover of the cage consists of a pyramid-shaped
wooden frame covered with 16-mesh screen wire (figs. 1 and 3). The
lower part of the cover is made by nailing the four pieces of lumber
(D) at right angles to the four pieces (C) so that these pieces can
fit tightly over the base of the cage. The four ridge pieces of lumber
(1) which support the screen pyramid are held in position by screws
through the holes in the ring (H).
The screen wire for the cover consists of two rhombic pieces
(fig. 2), which when folded along the center of the 1200 angles and
soldered together, fit over the pyramid frame, leaving a small open-
ing at the apex. The screen is fastened on the wooden frame of the
cover by the use of screen molding.
/Letters refer to the various pieces of lumber and hardware as
shown in figure 1 and in list of materials required for one cage,
The trap consists of an 8-ounce glass jar (7) with a metal screw
top and a small inner screen cone (G) that fits snugly inside the
mouth of the jar.
The screen cone (G) is made by forcing the screen wire over a
wooden form of the proper else. While the screen cone is still on
the form, a small strip of adhesive tape is placed on the wire around
the base of the cone to maintain the shape. The cone is then removed,
and the wire is trimmed along the bottom edge of the tape. A second
piece of tape holds the bottom edge of the screen cone in the mouth
of the jar. An opening is made in the apex of the cone with an ice
pick or similar Instrument, its ase depending on the insects to be
The center of the metal .jar cap Is cut out with about 3/16 inch
of the metal left adjacent to the rim. This metal cap is then
soldered to the top of the screen-wire pyramid so that the screw edge
of the cap is upward.
The glass jar containing the small screen cone is screwed into
the metal cap and is readily removed for counting the insects and for
Figure l.--Oblique cross-sectional drawing of hibernation cage, the letters
referring to the same parts of lumber and hardware as given in the list
of materials. The method of cutting piece E is also shown.
Flpze2.-M v ra~o]Loo mfda LoE ete f h/10
ane ad8ldrd ofrntep~stdcrt fte ~orsin/ae
Figure 3.-- Hibernation cages containing cotton bolls infested
with pink bollworms.
UNIVERSITY OF FLORIDA
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