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Circadian rhythms in Megachile rotundata (Fabricius) and Nomia melanderi Cockerell

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Title Circadian rhythms in Megachile rotundata (Fabricius) and Nomia melanderi Cockerell
Names Tweedy, David Graham (creator)
Stephen, W. P. (advisor)
Date Issued 1966-10-10 (iso8601)
Note Graduation date: 1967
Abstract The purpose of the study was to determine an emergence
rhythm, its period, and the developmental stages susceptible to
emergence synchronization in the leafcutter bee Megachile rotundata
(Fabricius). An attempt was made to determine if an oxygen consumption
rhythm was present in the pupal and adult stages of the
alkali bee Nomia melanderi Cockerell.
A circadian emergence rhythm with a 22 to 24 hour cycle was
determined in Megachile rotundata. Temperature was found to be
an effective emergence synchronizer. A temperature shock of 11 C°
for 12 hours was sufficient to synchronize the emergence of M.
rotundata cultures for at least six days. A temperature perturbation
as low as six hours synchronized emergence in a culture of M.
rotundata but a perturbation of one hour did not saturate the culture
and thus a distinct emergence rhythm failed to develop.
Light intensity up to 14 ft-c. was found to have no effect on the rhythm of emergence.
The phase of the emergence rhythm in M. rotundata is directly
related to the time at which a culture is removed from the cold following
a temperature shock rather than to the time it is placed in the
cold. Cultures subjected to cold periods of 24, 12, and 6 hours displayed
close phase relationship to each other when they were removed
from the cold at the same time.
M. rotundata appears to be susceptible to emergence synchronization
by temperature in the black-thorax and black-abdomen
stages of the pupa and in the adult. It is impossible to draw definite
conclusions from this study as to which stage is susceptible to emergence
synchronization because of the high mortality rate in the insects
used.
Various stages of pupal development were studied in an attempt
to discover an oxygen consumption rhythm in the alkali bee, Nomia
melanderi, but no rhythm was detected.
Genre Thesis/Dissertation
Topic Biological rhythms
Identifier http://hdl.handle.net/1957/47211

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