Medhat: CO 2 exposure affects certain brian cells to turn on and release
hormone that acts on the corpora allata (glands behind the brain) to
release JH. The production system then is turned on.
In the case of regulation of egg laying through queen's life that is
different.
other of CO2
A TEMPERATURE-INDUCED SWITCH FROM DIFFUSIVE TO
CONVECTTVE VENTILATION IN THE HONEYBEE
http://jeb.biologists.org/cgi/reprint/154/1/509.pdf
Summary
It is known that many insects emit CO2 in widely spaced 'bursts' or
discontinuous
ventilation events, usually characterized by active abdominal ventilation.
We
describe the discontinuous CO2 emission characteristics of the honeybee
(Apis
mellifera ligustica Spinola), and utilize its 'chill coma' temperature
threshold
(12°C) to effect transitions from continuous, diffusive to discontinuous,
convective
ventilation regimes. Increasing temperature abruptly switched the dynamics
of ventilation from diffusive and continuous (^11 °C) to convective and
discontinuous
(>12°C). The ventilation cycle frequency was 7.84mHz and CO2 output
per ventilation event (burst phase) was 1.56/A: neither variable was
temperaturedependent
in the range 12-15 °C. The rate of CO2 emission did not change
significantly in the range 7-15 °C, possibly owing to increased membrane
leakiness
at lower temperatures. At 15°C, honeybee metabolic rate (2.69 W kg"1, mean
mass 0.094 g) is similar to that of other similarly sized insects capable of
significant
endothermy.
Introduction
*A**CTIVATION OF **N**OSEMA APIS SPORES BY CARBON DIOXIDE*
*Krystyna Czekońska*
Department of Pomology and Apiculture, Agricultural University, of Krakow,
Poland; E-mail of the
corresponding Author: kczekon©ogr.ar.krakow.pl
Carbon dioxide (CO2) can be used to disinfect honeycombs against the most
harmful pest of the honeycombs, the greater wax moth (Galleria mellonella
L.).
However, it is not known, how this gas affects Nosema apis which are one of
the most
common parasites on the honeybee. The aim of this study was to examine if
treatment of
N. apis spores with CO2 effects their ability to infect honeybee workers.
An inoculating solution was prepared and divided into 4 doses. Three doses
were
exposed to the effect of CO2 (100% concentration), for 30, 35 and 40 hours.
The fourth
dose was used as a control, without exposure to CO2. Each of the four doses
was used to
individually inoculate 120 workers from each group. The fifth group was
formed of
workers that were not inoculated with spores of N. apis. The cages with the
bee workers
were kept in an incubator, under 30ºC. The course of invasion by parasites
was tested
every third day, by counting the number of N. apis spores in the digestive
tracts of living
workers.
The significant differences in the rate of infection were observed from the
9th day
after inoculation. Between groups there were significant differences in the
survival rates
of workers. Treatment of the N. apis spores with CO2 resulted in a faster
proliferation of
the parasite and higher mortality among the workers.
http://www.ncbi.nlm.nih.gov/pubmed/19551367
Heat and carbon dioxide generated by honeybees jointly act to kill hornets.
Sugahara M<http://www.ncbi.nlm.nih.gov/pubmed?term=%22Sugahara%20M%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract>,
Sakamoto F<http://www.ncbi.nlm.nih.gov/pubmed?term=%22Sakamoto%20F%22%5BAuthor%5D&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVAbstract>
.
Department of Bioscience and Biotechnology, Faculty of Bioenvironmental
Science, Kyoto Gakuen University, 1-1 Nanjo-Ohtani, Sogabe-cho, Kameoka,
Kyoto 621-8555, Japan.
We have found that giant hornets (Vespa mandarinia japonica) are killed in
less than 10 min when they are trapped in a bee ball created by the Japanese
honeybees Apis cerana japonica, but their death cannot be solely accounted
for by the elevated temperature in the bee ball. In controlled experiments,
hornets can survive for 10 min at the temperature up to 47 degrees C,
whereas the temperature inside the bee balls does not rise higher than 45.9
degrees C. We have found here that the CO2 concentration inside the bee ball
also reaches a maximum (3.6 +/- 0.2%) in the initial 0-5 min phase after bee
ball formation. The lethal temperature of the hornet (45-46 degrees C) under
conditions of CO2 concentration (3.7 +/- 0.44%) produced using human
expiratory air is almost the same as that in the bee ball. The lethal
temperature of the honeybee is 50-51 degrees C under the same air
conditions. We concluded that CO2 produced inside the bee ball by honeybees
is a major factor together with the temperature involved in defense against
giant hornets.
--
Juanse Barros J.
APIZUR S.A.
Carrera 695
Gorbea - CHILE
+56-45-271693
08-3613310
http://apiaraucania.blogspot.com/
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