Attracting bees, beelining and remote poisoning

Attracting bees, beelining and remote poisoning

  Reliable methods have now been developed to rapidly convert both Asian and European
  honey bees from a nectar source to a synthetic bait, and to locate nests of feral bees. The
  information below was compiled by Barbara Waterhouse and the late David Banks from
  books such as Hunting Wild Bees (Donovan RE (1980), Winchester Press, Tulsa, Oklahoma),
  from published and unpublished information provided by a team from the University of
  California headed by Dr Adrian Wenner, and from personal experience gained using the
  techniques described. Strategies and methodologies developed in response to the 2007
  incursion of Apis cerana in Cairns have been added.

  Conversion to artificial baits
  When bees have a stomach full of nectar or water, they tend to return straight to the nest.
  This ‘beeline’ can be followed, but it is very difficult and time consuming to follow bees
  foraging on natural nectar sources until their honey stomachs are full.

  A solution is to ‘convert’ bees foraging on a natural nectar source to an artificial bait, so that
  they fill up rapidly with a scented nectar and return to their nest immediately. Because the
  scent in the artificial source overpowers the scents of natural nectars, more bees are
  recruited, increasing the number of bees feeding off the artificial bait.

  The main difficulty is to persuade bees to accept the artificial bait. Bees usually ignore a bait
  placed near a nectar source. However, the following two methods for converting Apis
  mellifera and A. cerana, respectively, onto artificial baits have proved to be effective and
  reliable.

  Depending on the method used, required equipment includes an entomological net, bee
  valve, blackout, conversion pad, stand, spray pump, and scented syrup. The scented syrup is
  made by dissolving 1 kg of granulated sugar in 1 L of hot water and adding 20 drops of scent
  after the mixture cools.

  Catching Apis mellifera
  Find foraging bees within flight distance of where the nest is thought to be. Using the
  entomological net, collect from flowering ground flora or shrubs as many bees as possible in
  3–5 minutes. Avoid thorny plants, as the mesh of the net is easily damaged. Sweep the net
  over inflorescences and fold the hoop over the pocket of the net to prevent bees escaping.
  Introduce the bee valve into the net and place it over the bees. Hold the valve in full sunlight
  until the bees enter the ventilated jar (jar uppermost towards the sun). As a general rule, the
  brighter the light, the faster the bees come through the valve; under most circumstances, this
  should only take a few seconds. On very overcast days, shining a torch directly into the
  valve entrance will help. If the funnel has not been sufficiently roughened to allow the bees
  to grip the sides, the bees may take a long time to enter the jar.

  Once the bees are safely in the jar, cover it with the blackout (bees become distressed if left
  for any extended period in full sunlight). Return to the floral source and collect more bees.
  The ideal is to catch up to 20 bees in no more than 5 minutes.

  When the bees are in the jar and 5 minutes have passed, take the bees to the bait station for
  conversion to the artificial bait. It may take a number of attempts to catch the required
  number of bees when foragers are difficult to find.

Foraging bees will sometimes desert one species of plant to forage on another species at
     various times of the day, making collection difficult. Permanent watering points can be a
     useful source of bees when there is a dearth of nectar and pollen, or during periods of hot
     weather.

     Bees from more than one colony may visit a bait station.

     Converting Apis mellifera
     The bait station should be positioned at least 10 m, and preferably more, from the floral
     source on which the bees were captured. If the bait station is nearer than 10 m, bees tend to
     return to the floral source rather than the station.

     Place a sponge pad in a honey jar lid and dampen it by pouring no more than two capfuls of
     scented syrup evenly over the surface. Ensure that the pad is not soaked, or the bees will
     become fouled when they land; it is rare for fouled bees to return to the bait station.

     Place the sugar-soaked pad on top of the bait station platform. Unscrew the ventilated jar
     from the bee valve and quickly place it over the pad. It is not necessary to screw the jar into
     the lid. Then place the blackout over the whole assembly and wait 3 minutes without
     disturbance. At the end of this period, gently remove the blackout. Ideally, several bees will
     be on the pad feeding off the scented syrup, having been attracted down the sides of the jar
     and onto the pad by the light holes at the bottom of the blackout. These are the bees most
     likely to return.

     Remove the ventilated jar and allow the bees to complete their feeding. When feeding is
     completed, they will fly off the pad, making several loops round the bait station. As they get
     their bearings, the loops become wider until they fly off towards the nest.

     Wait to see if any of the bees return to the bait station. As the wait can be extended, even
     when the nest is fairly close, it is best to go back to the natural forage and collect more bees,
     set up another pad and repeat the sequence. The sight of another blackout on the platform of
     the bait station does not seem to distract bees returning to the first pad. Repeat the capture–
     conversion sequence as many times as possible until bees are regularly returning to the
     station, which may be covered in as many pads as will fit on the platform.

     Once bees are regularly returning to the station, the beeline is established.

     It has been found that bees will not always ‘work’ bait stations. Experience has shown that
     bees can be collected in jars and released at various intervals to follow the beeline (Lee Allan,
     Senior Apiculturalist, Agriculture Western Australia, pers comm).

     Converting Apis cerana
     The conversion of A. cerana to an artificial bait requires a very different technique because
     foraging A. cerana workers become very distressed when captured, even to the extent of
     killing one another inside the jar, and are very reluctant to return to the artificial bait.

     A method that has proved very successful with A. cerana involves placing scented syrup in
     an atomiser and spraying a group of inflorescences on which the bees are foraging 1. It is
     important not to spray all the available flowers, because the sudden change in scent may
     stop the bees foraging. If bees are foraging on a shrub, for example, spray up to a quarter of
     all flowers. While moving from flower to flower, bees will come into contact with the syrup,

1An alternative method is to spray the foraging A cerana with scented sugar syrup, or to spray near the flowers
and place the feeding station among the flowers.

and some will become converted to the new scent. Once this occurs, with bees regularly
returning to the same group of flowers, a bait pad can be placed near the sprayed area.

Conversion to the pad may be assisted by placing sprayed flowers onto the surface of the
sponge. Once bees are regularly visiting the pad, conversion can be further aided by
spraying the original forage with water to dilute the scent, so that the pad becomes more
attractive in comparison. When full conversion to the pad is achieved, it can be placed on a
stand, which is then moved incrementally away from the original forage. Once established,
bait stations for A. cerana are used in much the same way as those for A. mellifera. In recent
experiments with A. cerana, conversion time has varied from one hour to a couple of days.
This conversion technique also works equally well for A. mellifera, but takes much longer
than the capture method mentioned above.

The ‘traditional’ feeding stations using tin baking dishes and kitchen sponges were used
initially in Cairns in 2007 but were later replaced with plastic Flowmatic automatic waterers
bought from pet food stores. Two-litre soft-drink bottles fitted into the top as a reservoir
lasted a day or two, depending on the number of bees. The bowl was filled with clean, coarse
sand that allowed bees to walk across the surface without the risk of falling into the liquid
and drowning, as sometimes happens with the sponge system.

It is important to replace the syrup and wash the containers regularly because the syrup will
ferment. Discard and replace fermented syrup. Keeping the liquid from overheating in the
hot sun is also important as the bees will refuse to eat if it is too hot. Avoid the use of
insecticides, repellents and other chemicals near the feeder.

Ensure that the bees visiting the flowers are nectar gatherers, as conversion to the artificial
nectar is much less likely using pollen gatherers. Note that pollen-collecting bees will
frequently visit nectar sources to ‘top-up’ — these bees should not be used. Determine if any
inflorescences are being visited more frequently than others; these are the ones to spray.

A. cerana are harder to coerce onto a feeding station if too many inflorescences or too much
of the bush is sprayed. Care should be taken not to spray too much foliage. In the tropics,
predatory green tree ants move in rapidly, and feed upon both the syrup and A. cerana.
When this happens, A. cerana will avoid the sprayed inflorescences altogether. It may be
necessary to trim the surrounding foliage and apply ‘Tanglefoot’ to the stem to reduce the
risk of attack by the ants. A ring of Tanglefoot may also need to be applied to the pole of the
bait station.

Other strategies to locate bees
Two strategies that were developed during the Cairns 2007 incursion to cope with problems
of locating foraging bees were the ‘mega garden’ and the ‘scorched earth’ option.

The mega garden
The mega garden concept was created in an effort to concentrate the bees on a manageable
floral source. The idea was to maintain a mobile garden of potted ‘mad hatter’ plants (or
flowering plants that the bees had been seen working) that could be easily relocated
throughout the survey area. The pot plants were complemented by ‘sticky frames’ and sugar
syrup trays, and the plants were sprayed regularly with syrup using aerosol bottles. The
complete mega garden was fitted on to a portable table and moved about in the tray of a
utility. As it attracted bees, they could be refocused from the plants onto the syrup trays. The
mega garden was shifted several times around the survey area until foraging A. cerana found
it.

The scorched earth option
The scorched earth option was planned for the eventuality that none of the strategies being
used produced populations of foraging A. cerana that could be ‘converted’ to sugar syrup to
begin the process of beelining. The strategy of the scorched earth option was to take control
of all bee food supplies in the target area, thereby forcing the bees to the mega garden.

The components of the scorched earth option were:
•   survey, GPS and map every urban tree and garden that would attract bees in the
    immediate Portsmith survey;
•   consult widely with property owners, government authorities and environmental
    agencies about the proposal;
•   outline the plan in detail in the media and by using door-to-door consultations and
    information brochures; and
•   obtain permission from property owners to treat their trees and gardens as per the
    following steps
    –    remove the flowers of all palm trees by severing them with pruning saws
    –    cover garden beds, where possible, with insect-proof netting
    –    spray with herbicide any gardens and other flowers that could not be treated by the
         steps above.

Competing Apis mellifera
With patience and care, even pollen-seeking bees can often be converted to sugar syrup. The
process is to bring the syrup as close as possible to the bees so that it is difficult for them to
avoid sampling it while they are seeking pollen. A syrup tray is inserted into the most active
feeding part of an inflorescence where bees can hardly avoid landing on the tray. The effect
is enhanced by placing or shaking fresh flowers from the inflorescence on to the feeding
surface and by spraying syrup on to some of the most-visited flowers. A percentage of
feeding bees will sample the syrup and then encourage other workers from the colony to
visit the tray.

The conversion process will attract any honey bees, including A. mellifera, which are
obviously not required on the feeding trays. Once a syrup feeding station started to attract
bees in the Cairns incursion, it was typically A. cerana that moved in first and dominated the
site on the first day. Only later did A. mellifera foragers locate the feed and begin to compete
with the A. cerana. By sheer weight of numbers, the local bees would then displace the
A. cerana, outnumbering them by about 10:1.

The problems of beelining were considerably increased for inspectors trying to monitor a
situation in which A. mellifera bees flew from a feeding station in two or three different
directions and A. cerana bees left the same station in another one or two directions.

Some strategies to deal with the problem of competing A. mellifera bees are as follows:
•   Where there are only one or two known managed hives, these can be covered by an
    insect-proof ‘Mozzie Shelter’ for periods of time. Stress and heat can become a problem
    for the hive, and shade should be provided.
•   Sentinel hives can be relocated outside the surveillance area (but not outside the
    restricted area).
•   All A. mellifera feral colonies and swarms located should be destroyed.

•   The owner of multiple hives can be encouraged to remove their hives (but not outside
    the RA).
•   Where a feeding tray carries a feeding population of pure A. mellifera, they can be
    removed by covering the complete tray with a net, jarring the net to set the insects in
    flight, or securing all the insects in the net and killing them by crushing.
•   Individual A. mellifera on a feeding tray can be killed by crushing with the fingers. This
    technique is particularly effective if commenced as soon as the feeding station is set up
    so that the first A. mellifera scouts to visit the tray are killed. When these bees do not
    return, it sends a message to the colony not to send more foragers to that food source.

Other bee pests
For other species, such as the African bee (A. mellifera scutellata), both techniques should be
attempted, starting with the spray method. In experiments with A. cerana in the Torres Strait
islands, large numbers of the stingless native bee (Trigona spp.) have converted onto artificial
nectar at some of the bait stations. On occasions, they have been present in such large
numbers that their tendency to alight upon and ‘bully’ A. cerana has apparently deterred
A. cerana from making return visits. Flower wasps sometimes locate the bait stations and also
become regular visitors, apparently bothering A. mellifera.

Scenting
Occasionally, it is very difficult to collect foraging bees because there are no melliferous
plants in flower, or bees are foraging in tree canopies and cannot be reached with a net.

One way to attract passing bees is to heat wax cappings in a pan over a camping stove. As
bees approach to investigate, they can be caught in the net and introduced into the bee valve
in the normal way. Ensure that the stove is placed away from obstructions to make it easier
to use the net. If cappings are not available, a mixture of water, honey and wax works just as
well. Although this method works reliably with A. mellifera, attempts to attract A. cerana in
the Torres Strait using A. mellifera honey and wax have been unsuccessful. The use of
A. cerana honey and wax has not been attempted.

Beelining
The objective of beelining is to find a nest by following bees travelling between the nest and
a bait station. The technique uses the principle that bees generally take the direct route home
and fly at a relatively constant speed of about 7 m per second, or 25 km per hour.

The equipment required is: bait station, bait pads, scented syrup, correction fluid (white,
blue, yellow, green), entomological scissors, stopwatch, calculator, note pad, a straight ruler
or stick, compass (or a GPS unit that can be used as a compass) and binoculars. It is best to
have at least two observers with good eyesight.

When and where to set up a bait station
When setting up the bait station, several factors should be kept in mind. If it is not possible
to avoid windy days, bait stations should be set up in sheltered areas; otherwise, bees have
great difficulty finding them. In high winds, bees tend to fly closer to the ground, making
them more difficult to see. The initial direction bees take on windy days can also be more
erratic than on calm ones. If bees are mass converted on a windy day, their tendency to fly
upwind along a scent plume can be observed.

The temperature must be high enough for bees to remain active. Because scent volatilises
more readily at higher temperatures, bees find it easier to locate bait stations on warm days.
Mass conversion, which is explained below, is also easier to achieve on warm days.

The angle of light is also important, and beelining is difficult when the sun is overhead.
Beelining tends to be more successful in the early morning or late evening when the angle of
the sun is low and light reflected off wings makes bees easier to see. Beelining on overcast
days is also easier on the eyes than squinting into the sun on a sunny day.

The time of day when bees are converted to an artificial bait is not particularly important. If
conversion occurs late in the evening, once bees have made a few return trips they will
return early next morning. Experiments with A. cerana have demonstrated that once they are
familiar with scented nectar, they can be found seeking it at first light.

The location of bait stations is often determined by the local terrain and, in some
circumstances, the beeliner may not have much choice. However, where possible, stations
should be established in open areas, fully exposed to the sun and preferably without too
much vegetation as a backdrop (against which flying bees are difficult to see).

Beelining can be very frustrating at first. It requires persistence and a lot of patience.

Taking the bearing
Once bees are returning regularly to the bait station, the first task is to determine the
approximate direction from which they are coming and in which they are leaving. It is
usually easier for a single beeliner to face away from the sun and observe bees departing
from the pad. If working in a team, it is usual to space the members equidistant round the
station and about 3 metres from it.

At newly established bait stations, bees will generally fly in an ascending spiral after they lift
off the pad. As the bee gets higher, the circuits get wider until the spiral is broken off and the
bee heads for the nest. This change in direction is frequently very sudden and is often
accompanied by a rapid increase in speed, which can be difficult to follow with the human
eye. Also, as the bee gets its bearings, the initial flight path towards the nest may be a little
erratic. However, after a few weaves, the flight path settles down to a fairly constant bearing.
Take this bearing on a magnetic compass and enter it into a notebook for future reference.
This should be repeated a number of times before deciding to move on, particularly as the
bees on the bait pad could come from several nests. In areas heavily populated by bees, it is
not unusual to establish several beelines from the one bait station.

There are three basic systems of finding the location of a nest — the single station, leapfrog
and triangulation methods. The single station system is more suitable for the beeliner who
has to carry all their equipment with them. It involves trapping some bees on the bait station
by placing the ventilated jar over the cap and screwing it on. The secured bees are then
placed in the blackout to keep them cool. The bait station is then dismantled and re-
established some distance along the bearing the bees have taken towards the nest. The exact
positioning of the next bait station depends on the terrain, but a distance of a few hundred
metres is ideal. Choose an open area, sheltered from the wind as before. Set up the station,
release the bees, and wait for some to return to the new site before establishing the new
bearing.

The leapfrog method is a modification of the single station system but uses two stations
instead of one. Once the first station is established and a bearing has been determined, a
second forward station is set up along the beeline. However, the first station is not then

dismantled but remains as a reference point in case the forward station fails. Occasionally, if
bees have been retained in the ventilated jar for an extended period, they will not return to
the new location of the forward station. In these circumstances, it is an easy matter to return
to the first station, trap another group of bees, and quickly return to the new location to
release them. Alternatively, if the forward station has been established on the far side of the
nest (ie the nest is between the first and second stations), released bees will fail to return. The
advantage of the leapfrog method is that if this occurs it is not difficult to return to the first
station, trap more bees and then set up the forward station a shorter distance from the first
than before.

The triangulation method is a little more complicated, but is particularly useful when
attempting to find nests in thickly wooded areas. It involves establishing a series of bait
stations round the outside of the wooded area and taking bearings from each. The bearings
are then drawn on a map and the intersect searched for nest sites. If a hand-held GPS
receiver is available, it will usually have a facility that enables the location of the nest to be
estimated using the bearings taken from each bait station. The beeliner would then only have
to walk to the calculated intersect position and start searching.

When looking for nests in dense vegetation bordering water, bait stations can be set up on
boats anchored a little distance offshore. Provided the procedure is carried out smoothly and
quietly — the noise of an anchor chain rattling on the hull of an aluminium dinghy appears
to agitate trapped bees — offshore stations can be very effective, as bees are strongly
contrasted against the sky and there are no obstructions to flight, making determination of
an accurate bearing fairly simple. The procedure can be assisted if the bait station is raised
on a pole or mast so that the beeliner can lie underneath and make observations. This
technique works well with A. mellifera but has not been attempted with A. cerana. In view of
the difficulty of finding nests in shoreline mangroves in the northern Torres Strait islands, it
may be worthwhile experimenting with this method.

Where there are not many bees, it may be necessary to move the bees to a different site to get
another beeline. Once a feeding station is working, establishing a second one, at a new site,
can be achieved by either:
•   attracting bees to a new site; or
•   taking bees with you to the new site.

Attracting bees to a new site
This requires the same processes at a second site as were used to attract the bees to the first
site (feeding station, mega garden, etc). This can be a frustrating process that may take a day
or two but is usually successful. In Cairns in 2007, individually marked bees would
sometimes be found at new feeding stations 300–400 m away, within hours of the feeder
being moved there from the initial sites. The longer the distance, the more time it is likely to
take for the bees to discover the new site.
Taking bees with you to the new site
Once A. cerana are converted to sugar syrup, they can be carried about, with care, from site
to site. The main precautions are to:
•   maintain the food supply to ensure their interest;
•   avoid frightening the bees eg with sudden movements, etc;
•   not cover the feeding trays (eg with a lid);

•   avoid moving the bees too far in any ‘stage’ — this depends on conditions, but 10 m is
    usually safe; relocation over longer distances will work if the movement is along the
    beeline, as bees returning from the colony will fly over the new site and locate it quickly;
    and
•   leave the bees at any one site long enough for them to become familiar with it — this
    assumes sufficient time for foragers to make a number of round trips from colony to
    feeder and return.

Making it easier
There are aids to assist beelining during the middle of the day. Probably the main reasons
that flying bees are difficult to see at that time are the lack of contrast between the bees and
the backdrop against which they are viewed, and the speed at which they fly (25 km per
hour). The aim is therefore to increase the contrast between a flying bee and the background,
or slow the bee down to make it easier to follow with the eyes.

Efforts to make bees brighter against a dark background, such as by covering them with
glitter, have largely proved unsuccessful. If the natural dark colouration of the bee can be
contrasted against the sky, however, it becomes easier to see. This is achieved by lying on the
ground towards the bait station and about 2 m from it. The single beeliner will have to do
this from several positions around the station until the direction of the beeline is established,
but a team of three or more people, evenly spaced, will make the task much quicker.

A reliable method of slowing bees down and making them easier for the human eye to
follow is to reduce the effectiveness of the wings by cutting a small segment from each
wingtip with fine, curved scissors. Crop the wings while the bees are feeding at the bait
station. Make the cut halfway between the tip and the wing-fold, but no closer to the thorax
than the wing-fold or the bee will be unable to fly. Bees with cropped wings can be identified
in flight by their increased wing-beat frequency (sounding like mosquitoes) and an unusual
angle of flight in which the abdomen hangs down. They return to bait stations for several
days in succession and appear not to be unduly disadvantaged by the procedure, other than
being rather slow and cumbersome in flight.

Estimating the distance
Mark four or five bees on the thorax (or abdomen) with correction fluids of different colours
(white, blue, yellow and green) while they are feeding. Commercial acrylic artists’ paint and
fine artists’ brushes also work. Avoid painting legs, eyes and wings. Paint only four or five
bees for a session as too many painted bees become a distraction. Allow the bees to make
two or three round trips before recording times. (This also results in a more accurate
beeline.) Then use a stopwatch or a wristwatch with a second hand to record the time taken
for a full round trip, comprising take-off from the pad, return to the nest, disgorging to other
workers, flight back to the bait station, fill-up with syrup and second take-off. Timing
requires a team of at least two people, preferably three. One uses the stopwatch and records
the time at which a particular bee leaves the feeding station. The timekeeper records the time
when the same bee returns to the feeding station. The difference between these readings is
the cycle time for that bee. Other team members call the relevant events for the timekeeper to
record (eg by announcing ‘red abdomen leaving...now’ or ‘white back just returned’). At
least 10 visits by each of three or four bees should be recorded per session. For A. cerana,
water-based correction fluids (not always available) have been found to be preferable to
solvent-based markers. The bees tend to ‘buzz-up’ angrily as soon as the cap is removed on
solvent-based markers, making it difficult to mark any bees at all. This is probably
exacerbated by warm temperatures, which increase the volatility of the solvent.

As the time taken to fill up will be influenced by the amount of syrup absorbed into the
sponge pad, it is important to ensure that adequate syrup is available. Avoid pouring too
much onto the pad, as bees that become fouled by syrup spend a lot of time cleaning
themselves before lifting off from the pad and this can significantly increase the time for a
round trip.

Avoid timing the first round trip made by returning bees, as this can be protracted, possibly
because of ‘dancing’ on arrival at the nest or because of the time taken to find the bait station
again. More accurate estimates of distance to the nest can be made if bees are marked and
then left for a while until the round trip becomes routine. Once the marked bees have settled
down to regular return trips, the distance to the nest can then be calculated by the following
formula, developed by Adrian Wenner and colleagues at the University of California:
   distance = (time × 150) – 500
where distance is the distance in metres from the bait station to the nest, and time is the
shortest time in minutes.

The formula provides an approximate distance to the nest site. A series of 12 observations
should be taken to determine the distance.

Note: Times will vary if bees from more than one colony visit the bait station.

Locating the nest
If the light conditions are good (for example, in the late afternoon), and using binoculars, it is
possible to follow an individual bee straight to the nest. More often, bees will be seen
heading for a particular group of trees or buildings. A. mellifera appears to prefer live trees to
dead trees, and nesting sites of a suitable volume are more likely to be found in large trees
than small ones. When the beeliner is confident that the nest is nearby, rather than setting up
another bait station it is often more efficient to use binoculars to start scouring the largest
trees or most suitable buildings in the area (beelining from bait stations positioned very close
to the nest can be difficult).

A. mellifera appears to favour, in order of preference, trees, buildings and rock crevices as
nest sites. The order of preference for A. cerana is not so well established, although this
species seems to find buildings almost as attractive as trees.

If bees transferred to the forward bait station using the leapfrog method persistently fail to
return, the nest is nearby. Bees taken from the established station past the nest site to the
forward station will lift off, get their bearings and then fly in the same direction as before,
but this time away from the nest. Presumably, these bees eventually find their way home,
but they do not return to the forward station. It is for this reason that bearings should not be
taken on the first flight away from a newly established forward station — the bees and the
beeliner may be equally deceived.

If bees released from a forward station persistently fail to revisit, return to the previous
established station, set up another forward station closer to it but in front of any possible
nest sites, and take another bearing. Alternatively, collect some foraging bees at the forward
position, convert them to the syrup and take a new bearing. If the bees fly off on a back-
bearing, the beeliner has leapfrogged past the nest.

Once an approximate location has been determined on the map, the best action is to comb
the area with a line of people, equipped with binoculars to explore likely nest sites. When a
nest is located, it may be possible to confirm that it is the source of some or all bees visiting

the bait station. Using a different colour from that used at the bait station, mark a small
number of bees leaving the nest and see whether these visit the bait station.

Finding nests in thick woodland is difficult because of lack of light, the dark background and
the flight of bees around obstructions, which leads to false bearings. In this situation, the
triangulation system using several stations established round the outside of the wooded area
is probably the most useful.

Poisoning
If the exact location of a nest is known and it is accessible from the ground, the best way to
eliminate it is to block the entrance at night and apply an approved chemical (see
Section 2.3.3). Specialised equipment, such as cherry-pickers, may be needed to reach nests
in tall trees or buildings. In the case of an incursion by diseased bees or pests, the chemical
should rapidly eliminate all stages of the honey bee life cycle (as well as parasitic mites).

Remote poisoning
If the exact location of the nest is not known, or if the nest is not accessible (eg a swarm of
A. cerana established in mangrove swamps), a method is needed to have foraging bees take
poison back to their nest to destroy it. Such a poison should:
•   be palatable to bees when fed in syrup;
•   not be immediately toxic to bees, or foragers will not live long enough to take sufficient
    quantities of it back to the nest;
•   have some persistence, so that it will have time to circulate among bees in the nest;
•   not be so persistent that it is an environmental hazard; and
•   be nontoxic to mammals and birds.

At the time of writing, no poison that fulfils all the above requirements is available. A 1%
solution of Ivermectin, the active ingredient in some preparations used to eliminate internal
and external parasites in animals, has been trialled with varying success. Although it killed
nucleus colonies, it failed to totally eliminate feral colonies when used as a remote poison.

Several insecticides, such as acephate, fipronil (0.02%) or carbaryl, which kill colonies if fed
in syrup, could possibly be used in an emergency. However, they do not meet the preferred
environmental criteria and can be toxic to nontarget species. Bait stations can be established
and only spiked if no non-target species are accessing the station. It is also necessary for the
chosen chemical to be approved for use by the Australian Pesticides and Veterinary Medicines
Authority (APVMA).

Remote poisoning requires a bait station, a baking tray, sponges, several litres of scented
syrup, ivermectin and a 20-mL syringe. Details of poisoning stations are provided in the
following two reports, which can be obtained from Michelle Taylor, HortResearch, Private
Bag 3123, Hamilton, New Zealand (phone 07 858 4861; fax 07 858 4704; email
mtaylor@hortresearch.co.nz):
•   The effectiveness of remote poisoning was assessed in a New Zealand study (MA Taylor
    and RM Goodwin, 2003, unpublished report). Twenty nucleus honey bee colonies were
    established between nine bait stations. Each bait station was filled with poison when at
    least 300 bees were foraging from it. Unsuitable spring weather conditions, coupled
    with inconsistent spraying and bait station assessment, resulted in the trial being

postponed until autumn, but despite these conditions, eight of the 20 nucleus colonies
    were poisoned and four of these were successfully destroyed.
•   The residual action of fipronil was assessed in another New Zealand study (MA Taylor,
    2003, unpublished report). If an area from which honey bees have been eradicated is
    repopulated after 5 weeks, the colonies are likely to die if they ’rob out‘ and consume
    the stored fipronil. This persistent poisoning action increases the likelihood of a honey
    bee eradication attempt being successful because the colonies that are not killed in the
    first round of poisoning may be poisoned by robbing the honey from a previously
    poisoned hive containing fipronil.

In Australia, the effectiveness of fipronil in sugar baits for the elimination of feral honey bees
was demonstrated in an unpublished study by Clark R, Bates T and Manning R in 2006. The
report 'The elimination of feral honey bees (Apis mellifera) using Friponil in sugar baits in
Western Australia' is available from Mr Ron Clark, 4 Eskdale St, Roleystone, WA 6111;
phone 08 9496 3363; email bossladyqueens@yahoo.com.au.

Mass conversion
Before attempting to poison a colony, as many foraging bees as possible must be attracted
from the target nest onto an artificial bait so that many bees can carry the poison back to the
nest. As a general rule, the larger the proportion of field bees converted, the better the chance
of eliminating the nest.

Care must be taken when grasping pieces of equipment, as bees on the undersides of trays
and pads will often sting if crushed. Once addicted to the syrup, the bees remain remarkably
tolerant to handling and will rarely sting, but people not used to handling bees should wear
protective clothing.

Mass conversion usually occurs naturally if a bait station is left in one place, with the time
taken varying from less than an hour to several days. The nutritional status of the target nest
and competition from other sources of nectar appear to influence mass conversion.
Observations suggest that mass conversion of A. mellifera is easier to achieve at the beginning
or end of the season and during periods when there is no honey flow. A. cerana in the Torres
Strait islands have readily converted at the end of the wet season (April–May), but have been
difficult to convert at the peak of the dry season (November).

If mass conversion fails, the concentration of scent in the syrup can be increased (try up to
50 drops per litre). A stronger scent often overcomes the attraction of alternative sources of
nectar, with mass conversion fairly soon after the change in concentration. If this method
fails, the only course of action is to keep a few bees returning to the bait station until
competing flora dies off. This is achieved by placing a pad of syrup on an established bait
station every few days (ideally once a day, but bees will continue to return to a pad of
scented syrup after an interval of up to a week). Good conditions for mass conversion exist
when the pad is covered by a frenzied mass of bees within a few hours of exposure.

When the conditions are right for mass conversion, several bait stations should be
established around the target nest. The stations should be located close to the nest in order to
reduce the time taken for bees to travel between the nest and bait station. However, if the
stations are less than about 100 metres from the nest, bees lifting off from them mill around
and do not immediately fly towards the nest. It has been suggested that bees foraging near
their nest will extend their flight to allow invertase to react with the nectar in their honey
stomachs before their return. It is important to determine the direction of flight from a bait
station to ensure that the right nest is being poisoned, but this can be very difficult if the
station is located too close to the nest.

Once the nest is surrounded by three or four bait stations, the syrup pads are replaced with
baking trays, the bottoms of which have been covered with dampened sponges. A litre of
scented syrup is then poured slowly into the tray so that the sponges float on the surface,
forming a platform from which the bees can feed. The tray is kept topped up with syrup
until the sponges are covered in several layers of bees competing to get at the bait. In order
to ensure that as many field bees as possible are converted onto the artificial bait, it is best to
continue topping up with syrup until no more bees can be attracted. In very hot conditions,
plastic trays may be preferable to metal baking trays because they absorb less heat.

Introducing the poison
Once this point is reached, the level of syrup in the trays is allowed to decline so that, while
there is still sufficient syrup to attract as many bees as possible, the sponges rest on the
bottom of the tray. At this stage, one litre of syrup with poison is poured down the side of
the tray gently and slowly, to avoid fouling the bees — fouled bees spend a long time
cleaning themselves before returning to the nest, and very wet bees cannot fly at all.

After the poison syrup has been added, the number of bees returning to the trays declines. If
enough bees continue to return after the first litre of poisoned syrup has been consumed,
successive doses of 500 mL can be added until no more bees return to the station.

Because returning field bees pass the contents of their honey stomachs to nurse bees in the
nest, more bees in the colony will consume the adulterated syrup. The nurse bees will either
use the syrup to feed uncapped brood or store it in honey cells, so that the only stages of the
bee life cycle unlikely to come into immediate contact with the poison are the eggs and
capped brood and these will be subject to a delayed effect.

Construction notes
The equipment used in beelining and remote poisoning is cheap and easy to construct, as
described in the following sections. With the exception of the net, the parts are readily
obtainable from hardware stores.

Net
Materials
•     1 collapsible hoop
•     1 × 5-mm bolt and wing nut
•     1 net handle
•     Mesh

Tool
5-mm drill bit

Construction
Connect the two halves of the hoop together, and then thread the hoop through the fold of
material supporting the mesh. Push the two ends of the hoop into the sockets at the end of
the handle until the bolt holes line up. Finally, secure the hoop to the handle using the bolt
and wing nut. The holes in the handle and hoop may need to be cleared with a 5-mm drill bit
before the bolt will go through.

Bee valve
Materials
•   1 × 330 mL (500 g) plastic honey jar with lid
•   1 PVC threaded sleeve for 90 mm (inside diameter) stormwater pipe
•   1 PVC end cap to fit the threaded end of the sleeve (screw cap)
•   1 PVC end cap to fit the unthreaded end of the sleeve (glued cap)
•   3 × 5-mm diameter bolts, 12 mm long, with nuts
•   1 plastic funnel — 90-mm (minimum) diameter wide end, 12-mm diameter narrow end
•   Solvent cement for PVC water pipes
•   Silicone sealant

Tools
•   3-mm drill bit
•   20-mm drill bit
•   6-mm drill bit, electric drill
•   Electric sander/sandpaper
•   Tin snips
•   Wire cutters
•   Marking pen

Construction
Place the lid of the jar upside down in the centre of the open end of the plain (unthreaded)
end cap (the part with the wider rim, which is not to be glued into the sleeve). Drill three
equidistant holes 15 mm in from the lid rim through both the lid and the end cap. Before
drilling, ensure that the heads of the bolts will not interfere with the jar when it is screwed
onto the cap/endpiece assembly. Secure the lid to the cap with the nuts and bolts. Make sure
they are tight, as it may be difficult to adjust them later.

Drill a 20-mm hole through the centre of the lid/end cap assembly, without damaging the
ends of the three retaining bolts. Glue the end of the assembly with the narrower diameter
into the sleeve, so that the jar lid is on the outside of the sleeve.

Cut the large end of the plastic funnel down to a diameter of 90 mm with tin snips or wire
cutters, so that it makes a snug fit with the inside of the sleeve. One way to do this is to place
the sleeve over the funnel, run the marking pen around the junction of the two parts, cut the
funnel just inside the line, and trim off the rough edges with an electric sander or sandpaper.
Smear a little silicone sealant around the 20-mm hole in the assembly at one end of the sleeve
and also round the inside of the open end. Push the funnel into the sleeve as far as it will go,
so that the tip protrudes approximately 20 mm through the jar lid.

While the sealant is setting, drill 15–20 ventilation holes in the plastic jar with the 3-mm drill
bit. Use the 6-mm drill bit to thoroughly roughen the inside of the funnel, including the tip,
so that bees can grip the surface and escape quickly through the valve. Finally, screw the jar
onto the lid/endpiece assembly and screw the threaded cap onto the other end of the sleeve.
Place the valve in the sun for a while to allow the smell of the sealant to disperse before use.

Blackout
Materials
•   1 × 200-mm length of 100-mm (inside diameter) PVC sewage pipe
•   1 PVC plain end cap for 100-mm diameter sewage pipe
•   Solvent cement for PVC pipe

Tools
•   3-mm drill bit
•   Electric drill
•   Rule

Construction
Glue the cap onto one end of the pipe. Drill four 3-mm holes equidistant around the open
end of the pipe. Start the holes 10 mm from the open end and, drilling from the outside,
angle them inwards and towards the closed end. When the blackout is placed over the
ventilated honey jar and cap, bees in the jar will be attracted downwards towards the light,
which emerges at the same level as the rim of the cap, and will come into contact with the
dampened sponge.

Conversion pad
Materials
•   Lid from a 330-mL (500 g) honey jar
•   Flat cellulose sponge (approx 9 mm thick) in blue, yellow or green (household sponge,
    normally sold in packs of six)

Tools
Scissors or shears

Construction
Soak the sponge in water to remove the chemicals in which it is packaged. Rinse several
times and squeeze out any residual water. Place the jar lid on top of the sponge and cut the
sponge around the circumference of the lid. Trim to ensure a good fit inside the lid.

Mass conversion tray
Materials
•   1 aluminium or plastic baking tray, approximately 250–300-mm square, with a rim of
    25 mm, able to hold at least 1 L of fluid.
•   4 large domestic (kitchen) sponges — approximately 100 mm × 140 mm square

Construction
Cut the sponges to cover the bottom of the tray. Soak the sponges in water, rinse several
times, squeeze out any residual water, and place them in the bottom of the baking tray.

Bait station
Materials
•   1 × 100-mm length of 40 mm × 40 mm plain pine block

•   1 × 240 mm × 240 mm × 20 mm plain pine planking (the dimensions are not critical)
•   4 × 38-mm, 6-gauge wood screws
•   1 × 25-mm thick × 1.5-m long dowel or broomstick

Tools
•   25-mm drill bit
•   2-mm drill bit
•   4-mm drill bit
•   Countersink
•   Electric drill

Construction
Drill a 25-mm diameter hole throughout most of the length of the 100-mm long pine block.
Place the undrilled end in the centre of the 240-mm pine planking and mark round it with a
pencil. Drill four 2-mm holes in the planking, 10 mm inside each corner of the outline. Place
the block over the outline again and hold it there while the drill bit is pushed through the
four holes in the planking from the reverse side and into the block. These are the pilot holes
for the four screws. Enlarge the holes in the planking using a 4-mm drill bit, and finish them
with the countersink. Place four screws through the planking and into the block, and tighten
them until the block is firmly attached to the planking to form a platform. Some PVA glue
introduced between the two helps to form a strong bond.

Sharpen one end of the dowelling/broom handle so that it can be hammered more easily
into the ground. When erected, the platform can be slid over the end of the dowel to make
the bait station.

Note: As volatile solvents are used in the construction of the bee valve and blackout, it is
advisable to leave them out in the sun for several days (if time permits) to remove any last
traces of odour.