MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
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flight, and moderate its temperature. But the power of radiating from its body into 
the surrounding atmosphere is not confined to the insect in its perfect state only, but 
exists also in the larva, as I have had opportunities of observing in the larvse of the 
Sphinges, Puss Moth, &c. From these observations it is clear that a very large pro- 
portion of the heat evolved by insects in all their states passes off into the surrounding 
medium, and that the amount of heat evolved is in proportion to the degree of excite- 
ment and consequent quantity of respiration. 
III. Temperature of different Tribes of Insects. 
Having found that every insect maintains its own temperature of body, and that 
the amount of this temperature differs in the different states of each insect, it yet re- 
mains to be seen which are the families that generate the greatest amount, and 
what relation that amount in the different families bears to the habits and localities 
of the species. Our previous observations lead us to anticipate the fact that the 
volant insects in their perfect state have the highest temperature, while on pursuing 
the inquiry it is found that those species which have the lowest temperature are con- 
stantly located on the earth. Among the volant insects, those hymenopterous and 
lepidopterous species have the highest temperature which pass nearly the whole of 
their active condition on the wing in the open atmosphere, either busily engaged 
in the face of day despoiling the blossoms of their honied treasures, or flitting wan- 
tonly from flower to flower and breathing the largest amount of atmospheric influence. 
Of these it may be almost superfluous to remark, the Hive Bee and its long train of 
near and distant affinities, and the elegant and sportive Butterflies have the highest. 
Next to these probably are their predatory enemies the Hornets and Wasps, and others 
of the same order ; and lastly, a tribe of insects which have always attracted attention, 
and in general are located on the ground, but sometimes enjoy the volant condition, 
— the Ants, the temperature of whose dwellings has been found to be considerably 
above that of the atmosphere : according to Juch the temperature of an ant-hill was 
17° Reaum. (70 o, 25 Fahr.), while that of the atmosphere was 10° Reaum. (54 0, 5 Fahr.). 
Next below the diurnal insects are the crepuscular, the highest of which are the 
Sphinges and Moths, and almost equal with these are the Melolonthce. But the fol- 
lowing experiments with the different tribes, while they still further illustrate the 
causes of the variability of temperature in insects, will also show the relative amount 
of heat evolved by different species. 
Melolontha vulgaris, Steph. 
May 20, 1835, 7 a.m. — Having captured many individuals of this species of Chaffer 
Beetle on the preceding evening, I now found them perfectly quiet. The temperature 
of the external atmosphere was 60° Fahr., and that of the interior of the box in which 
they had been confined during the night was 61 0, 3, while on carefully introducing the 
bulb of the thermometer among the beetles, without disturbing them, the mercury 
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