It is well known that bees play a crucial role in securing food for
humans, due to their outstanding pollination activities on plant
crops. But the bee population is shrinking and researchers are on a
quest to get to the bottom of this problem. A combination of
various factors like agricultural chemicals, loss of habitat, and
diseases are pushing scientists to kick—start the race and
find a solution in a laboratory.
Enter researchers from the University of Würzburg who came up
with an innovative idea to rear honey bee larvae within a
four—wall room; this would help them determine why the bee is
dying. Existing laboratory rearing methods are lacklustre as they
involve ‘grafting’, where the small first instar bee larvae (around
1 millimetre long) are collected using brushes, feathers or
needles. As the pressure mounts to gather the information,
mechanical stress grows, triggering mortality among the tiny
larvae.
‘To sustain the vital ecosystem service of pollination, new
methodical developments are needed for research on the underlying
factors of globally observed bee losses,’ say the authors of the
study. ‘In particular, robust laboratory methods for assessing
adverse effects on honey bee brood are required. In addition, from
a statistical point of view, the shared origin of test individuals
must be considered when analysing ecotoxicological data.’
The researchers adopted a non—grafting method to collect honey
bee larvae; this ensured no direct manipulation of the larvae. The
team allowed the honey bee queens to lay eggs directly into an
artificial plastic honeycomb about the size of a cigar box to
ensure the larvae’s safety. Professional honey bee queen breeders
use the plastic honeycomb, and the researchers realised that these
honeycombs facilitate their rearing of the larvae and guarantee
positive results.
‘The artificial comb has a hexagonal pattern with 110 holes the
size of wax cells,’ explains Harmen Hendriksma, lead author of the
study. ‘The queen lays her eggs directly into these small plastic
cells. Because the back of each cell has a small plastic cup, we
can collect the larvae without handling them.’
Dr Hendriksma decided to use the plastic honeycomb in the
laboratory following a stint with a Dutch company that produced
honey for medical purposes.
‘Like many people I am a bit lazy and wanted to find a quicker,
easier way of rearing honey bees in the laboratory,’ he says. ‘When
I tried using the plastic honeycomb system I found it was just
perfect.’
By using the plastic honeycomb, the team ensured the survival of
97% of the larvae and they successfully collected over 1 000 larvae
in 90 minutes.
This latest technique could also give the quality of bee research a
boost, particularly because the results generated in various
laboratories will be more directly comparable. The research
findings also indicate that applying statistical approaches used in
other areas of ecological science can give bee researchers the edge
they need to get more positive analyses.
‘Bee research is like an arms race, where researchers try and keep
up with monitoring emerging new risks to bees,’ Dr Hendriksma says.
‘Because so many factors — such as environmental pollution,
new agricultural pesticides, bee diseases, changing habitats and
bees’ genes — may be playing a part in the loss of our bees,
we need better ways of analysing our results.’
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