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Mechanisms of orientation in the leaf-cutter bee Megachile rotundata (Fabricius)

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Title Mechanisms of orientation in the leaf-cutter bee Megachile rotundata (Fabricius)
Names Osgood, Charles Edgar (creator)
Stephen, William P. (advisor)
Date Issued 1968-03-28 (iso8601)
Note Graduation date: 1968
Abstract The leaf- cutter bee Megachile rotundata (Fabricius) is an important
alfalfa pollinator in western North America.
This study was designed to provide information on methods of
orientation used by M. rotundata in order to make recommendations
regarding the parameters within which adult nesting populations may
be relocated.
Preliminary studies suggest that this bee species may possess
a sun compass although they depend predominantly on landmarks for
orientation.
Color discrimination experiments with bees conditioned to various
colors (i.e., red, orange, yellow, green, blue and purple)
showed that they could distinguish all colors except red from 22
shades of gray, black and white, Tests with yellow indicate that it
was a much stronger stimulus for homing bees than other colors
I)
.
tested. Bees appeared to be unable to distinguish red from black
and therefore are thought to be color blind to red.
Figure studies indicated that bees could discriminate between
a variety of configurations including squares, circles, triangles,
crosses, stars, I's and Y's. In these studies,bees were conditioned
to a cross - shaped figure and tested for their ability to discriminate
between it and triangles, squares and circles, all of three -inch maximum
diameters. The data indicate that bees are quite able to make
the distinction.
Adult relocation studies indicated that population losses were
high (50 per cent or more) when bees were moved from nesting sites
possessing many landmarks (e. g., buildings, rows of trees) into
alfalfa fields with few prominant landmarks; from field situations
providing an abundance of foraging blossoms into fields with little
bloom; and when strong winds prevailed.
Conditions favoring minimum relocation population losses
were moving bees with their original shelters into areas similar in
landmark composition to original nesting sites; moving them in progressive
steps of 20 -100 yards when relocating populations over
short distances; color conditioning bees to shelters painted various
colors before short distance moves; moving bees into areas with
sufficient bloom to maintain themselves; and conducting moves when
strong winds did not exist. General orientation was discussed with respect to flight range,
landmark importance, nest entrance location and orientation inside
the nest.
With the advent of commercial nesting boards containing hundreds
of similar nesting tunnels, bees experience major orientation
difficulties. Recommendations are outlined in this study regarding
methods to ameliorate proximate orientation problems using combinations
of figures and colors applied to the surface of nesting
boards.
Genre Thesis/Dissertation
Topic Bees
Identifier http://hdl.handle.net/1957/46873

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