Note: Descriptions are shown in the official language in which they were submitted.
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The present invention pertains to a trap for insects,
especially for the extermination of typographer bark beetles.
Drought-weakened spruce forests have provided new and
extensive feeding grounds for the typoyrapher bark beetle~ The
beetle population is large ln the spruce forest districts over
all of southern Norway, and the danger of substantial new attacks
on the old spruce forest in coming years is imminent. It has
therefore been found necessary to work consciously and system-
atically to counteract the typographer bark beetle~
lQ It has been found that these particular beetles emit a
certain odor when a beetle finds a fa~orable feeding ground, for
example, a drought-damaged spruce. It has proved possible to
synthesize this odorr and the substance is marketed under the
trade name "Feromon". This substance is thus very suitable for
use in connection with insect traps.
Insect traps are known, e.g., from Norwegian Patent
No. 85,185, issued March 14, 1955 to Krogsaeter, which consist
of a tubular body having a plurality of openings through which
insects can enter, with a collector chamber for the insects at
; 20 one end and a lid at the other en~, and containing~a bait sub-
stance to attract the insects.
The purpose of the present invention is to improve
the previously known traps of this type.
According to the invention, therefore, traps of the
- general type defined aboYe are chàracterized in that the tube
has radially-projecting protrusions, and that the openings are
provided between the protrusions. A preferred embodiment of the
tube is characterized in that the projections comprise peripheral
ridges, either circular or spiral in shape.
An important feature of the inYention is that the
openings aFe arranged near the upper surface of the projections~
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~ -~nother ~e?tl~re of tht? inl~en~-ion is that the outer sur-
face of` the tube is ro~ h. i~n a(l;:litional advantarre is obtaine`l
if the inner surface o~ the tube is elso rou~h, at least in the
area around every opening.
A further feature of ~'ne~ inven~iorl is that the holes h-Lve
a diameter of between 2 and 3 mm. Preferably, the tubes of the
traps accordin~, to the lnvention ~re hetween l and 3 rneters lonr,
and are dark in color on the outsicle, for e~ample, black.
F,xperiments h-.ve been carrie(l out usinr~ traps of the
type cleflned above, and these traps have demonstrated especially
fr,ood results as comp~red with traps made ln other ways. The trap
was fastened vertically on a pole and was placed in a cleared
area of the forest about 1/2 to 1 meter ahove the ~round. The
odor of the "Feromon"-bait which was placed lnside the tube
attracts the beetles to enter the tube throu~h the holes. Traps
made ln accordance wlth the lnvention captured about 20,~00 beetle,
ln the course of a two-week perlod ln May-June 1978. The reason
that these traps exhlbit such rrood results is connected wlth i-,he
fact that the projectlons, i.e., the rldrres, offer a good landinrr,
slte for the lnsec-ts. It ls then natural for the insects to try
to move inwards toward openings throu~h which they can crawl.
The insects wi]l flnd these openln~s ln the tube wall areas betwee:
-the projectlons. It has also been found to be important that the
holes be placed near the upper surface of the projections. The
insects l~lnd on the projections and crawl lnwards, being attracte~
by the odor Or the substance emanating from the holes. It is thus
lmportant that the holes lie flush with the upper surface of the
projections, such that the insects do not have to crawl upwards
on the vertical tube portion between the projections.
The dark color of the tube results in an elevated terr,-
perature in-s~de the tube; evaporation of -the bait substance
-lncreases wi~,h increasin~ temperature and wlll thus be hirrh pre-
cisely in the perlods of hot weather when the beetles are on the
win~. The provlsion of a rourrhened surface also seems to increase
the number of insects captured. It has also been observed that
when the insects are ~,oin~, to crawl in throu,~,h the opening, they
use their feeiers to examine the conditions inside the hole. If
the inner surface is too smooth, the beetles will withdraw r-~rli
crr~wl out A.~r~-lln. Tnercf`ore, providin~r a rou.~rhened surf~ce insicle
the tllbe, at, l.eas~ rollncl t,he hole openin~s, i5 very desirable.
Experiments have a~lso shown that rel ~,ively long tubes are better
traps than s~orter tubes. '~he c~ ;ch per runnin~J neter w-~s fr~reatest
with tubes of` '-1/2 to 2 meters in len~th,
The invention will be ex~ ined in ~r,reater detail in the
followln~ with reference to the dr~win~r~s, which sho~ one embodi-
ment of the insect trap of the invention,
Fi~rure 1 shows a cross section t;hrough a trap made in
accordance with the invention, with a ~le~ail of the trap also
shown on an enl,~r~ed scale.
Fi~ure 2 is a cletail dra~in,~r of the lower portion of the
trap.
The trap consists of a tubular body 1 with radially-
projecting ribs 2. In the tube wall between the ribs, a lar~re
number of openin~s 3 are cut into the tube. At the upper end of
the tube 1 there is a lid 4. A bait substance 5 to attraGt the
insects is suspended inside the tube f`rom the lid ~.
The tube ] terminat,es at the bot-tom in a funnel 6 which
~ 20 in turn is connected to a collector bot-tle 7 for the trapped
: insects. ~'hen in use in the forest, the trap is attached to a
vertical pole 3.
The bottom of the tube 1 can be provided with a thread
: for en~agement ~ith a fixed, internally-threaded collar 9 at the
upper, wide-mou.thed openin~, of the funnel. 6. If the radial pro--
: jections 2 have the form of spiral-shaped rid~res, these can be
used for enga~ement, with the thread in the collar ~. The upper
free edge of the f'unnel 6 is formecl as an upwardLy ancl inwardly
slopin~ lip 13. Provided above the lip at the ]ower end of the
30 tube 1 ~re drr~ina~e openin~s 11. Draina~,e oPeninf~,s 12 are ~lso
provi.ded r~t ~ e lower portion o.f the collar 9. The purpose o.r'
theSeC)pellingS i9 to catch water, resulting perhaps from conden-
sation inside the tube, and to drain it o:~f such that i-t does
not run down into the conta.lner 7; the openin~s thus prevent the
contain(?r frorn ~eco~ing filled wl-th water, which ~ould irnpair the
functionin~ of'the trap.
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A f`ixed col]ar 14 is also provided at the n~rro~ end 13
of ~he funnel 6j ~he collar 14 havin~ internal threads which
engage with external threads on the neck 15 of the container 7.
The outer, pointed end 1~ of the funnel 6 penetr~tes a distance
inside the container 7 and thus functions in the same way,as the
funnel-shaped entrance in a fish trap or lobster pot.
It has been shown that when the insects enter the tube
throu~h the openin~s, they lose thei,r footinfr and fall down
inside the tube. ~ecause the beet]es require a certain len~th
of time to open their wln~s, they fall all the way down into the
; cont~iner 7. They are then un~hle to fly up a~ain because their
flyin,~ capabilities are relati-vely poor. In addition, the narrow
mouth 16 of the funnel provides an additional safe,Lruard a,~ainst
the insect's bein~r able to leave the container even iI',it does
try to fly.
,~ The invention should not be construed as bein~ limited
to the embocliment illustrated in the drawings and described above,
~, but can be altered and modified and still remain within the scope
outlined in the appurtenant patent cl~-iims. For example, the
water drop collector (the lip 10) might be placed hi~her up or
lower down, for example, at the lower end of the funnel, above
' the co~lar 14.
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