An improved oviposition cage for moths of the European corn borer

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Material Information

Title:
An improved oviposition cage for moths of the European corn borer
Physical Description:
Book
Creator:
Vance, Arlo McGrillis, 1899-
Painter, Henry R
United States -- Bureau of Entomology and Plant Quarantine
Publisher:
U.S. Department of Agriculture, Bureau of Entomology and Plant Quarantine (Washington, D.C )
Publication Date:

Record Information

Rights Management:
All applicable rights reserved by the source institution and holding location.
Resource Identifier:
aleph - 030360199
oclc - 782951963
System ID:
AA00023145:00001

Full Text


February 1946


United States Department of Agriculture
Agricultural Research Administration
Bureau of Entomology and Plant quarantine

AN IMPROVED OVIPOSITION CAGE FCR MOTHS OF TH EROPEAN CORN BORER

By A. No Vance and H. R. Painter
Division of Cereal and Forage Insect Investigations

The oviposition cage herein described (fig. 1) was developed in
connection with quantity production of egg masses of ,the European corn
borer aus nubilalis (Hbn.)), for the manual infestation of corn
being tested for resistance to this insect* The cage is simple in con-
struction, light in weight, easy to handle, and readily cleansed. The
sheets of wax paper on which the egg masses are deposited can be quickly
removed from the top of the cage and replaced with fresh paper, and
drinking water'for the moths can be provided by spraying moisture onto
the netting around the-cage. The general pr Inciple of the cage struc-
ture and its utility were devised by QuestelUi and used successfully by
him for some time in the production of corn borer egg masses for insecti-
cide tests*
The present cage is 22 inches long, 11 inches wide, and 11 inches
high. The top and sides are constructed of 14-mesh galvanized hardware
cloth, and the bottom of 14-mesh galvanized wire screen. It is prefer-
able to purchase these materials in 2- or 3-foot widths to avoid wastage.

Several methods of constructing the cage have been tried. The most
satisfactory has been to cut a strip of hardware cloth 22 by 33 inches
and bend it crosswise in two places 11 inches apart to provide the top
and two sides of the cage. Two pieces of the hardware cloth, each 11
inches square, are then cut for the ends and secured to the edges of the
sides and top of the cage by small loops of twisted wire spaced an inch
or two apart. The botton is constructed separatelyof a wooden frame 11
by 22 inches made of 5/9- by 3/S-inch material across which is tacked a
piece of 14-mesh wire screen. The bottom is then inserted screen side
up into the open portion of the hardware-cloth framework and fastened in
place with double-pointed tacks. An opening approximately 3 inches
square is cut near the center of one end of the cage, over which a wire-
screen hlap is fitted. The flap is made of a square piece of the hardware



I/ Questel, D. D., Smith, L. U., and Vivian, D L. Laboratory and
field tests of toxicity of some organicvcompounds to the European corn
borer. U.S. Bur. Ent. and Plant Quar, ,-557, 17 pp. 1941. C(rocessed.2


ZT-227








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cloth slightly larger than the opening and is covered on the inner side
with 14-mesh wire screen held in place by folding it back over the edges
of the flap. tt is hinged at the top, just above the opening, with two
small loops of wire and held flat against the cage by a bent paper clip
inserted through its lower edge and into the wire of the cage. This end
opening provides for the insertion of a metal funnel through which the
moths may be introduced.

A piece of white mosquito netting, preferably of the reinforced
type, is cut 67 inches long and 11 inches wide. This is placed around
the sides and ends of the cage and, sewed onto the wire with heavy thread
along all edges. A square is then cut out of the netting to accommodate
the screened flap at the one end of the cage, and the edges of the netting
around the opening are sewed to the wire of the cage. It is essential
that the netting be well fitted to the cage at all pointS, as moths may
escape through the meshes of the hardware cloth at any exposed places.

Two sheets of wax paper, each 6 by 24 inches, are laid lengthwise on
the hardware-cloth top of the cage, the sheets overlapping slightly along
their longitudinal inner edges and so adjusted that no open space occurs
along their outer edges. The paper is held in place and in conformity
with the wire top by laying over it a piece of ozite rug pad l by 24
inches. The moths deposit their egg masses through the meshes of the
hardware cloth onto the under surface of the paper.

Cages so prepared and stocked with moths can be stacked on top of
one another. Twice each day, in the morning and late evening, the rug
pad is removed from the top of a cage, the two sheets of wax paper with
the adhering egg masses are exchanged for two fresh pieces, and the pad is
replaced. During this process a few moths occasionally escape through the
meshes of the hardware-cloth top of the cage. However, the activity of
the moths which enables them to escape may be largely prevented by spray-
ing the netting around the cage with water just before exchanging the wax
papers. In fact, spraying of the cages in this manner at least twice a
day is advisable.

The number of moths that can be confined efficiently in a cage of
this type is variable. In 1944 on an average 18.8 egg masses per female
moth were obtained from 11 cages when 100 females and an equal number of
males were confined per cage, and an average of 12 masses per female from
7 cages, each of which confined 200 females and 150 to 200 males. A max__-
mum of 25.5 egg masses per female moth were procured from 1 of the cages
containing 100 moths of each sex. Too much crowding of the moths decreases
the production of eggs per moth. The oviposition cages are usually held in
a room-size incubator at a controlled temperature of 800 F., and in an
atmosphere of 80 to 90 percent relative humidity. After a cage has been
used, the dead moths are shaken or brushed out through the end opening or
removed with an electrical vacuum apparatus. The cage is sterilize& by
dipping in a vat of dilute formaldehyde.






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?ig re 1.-Improved oviposition cage for moths of
the Swuopean corn borer. The cage on the left
illustrates the general construction of hardware
cloth, with screened bottom attached. In the
foreground a screened bottom is shown separately.
The cage on the right is complete with netting,
wax papers, and piece of rug pad. The pad and
one sheet of paper are rolled back to show method
of exposing the paper to the moths. The flap
covering the end opening appears on both cages.





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