MR. NEWPORT ON THE TEMPERATURE OF INSECTS. 
287 
Meloe proscarabceus and M. violaceus, Linn. 
These insects (the Oil Beetles), like their congeners the Blister Beetles (Lyttce), 
have a temperature corresponding to their natural habits. The temperature of a 
number of Lyttce vesicatorice was found by Juch to be several degrees above that of 
the atmosphere. This, to a certain extent, is the case with the Meloes, which love to 
bask in the heat of the sun, and respire a large quantity of atmospheric air. On the 
1st of May I examined the temperature of a female Meloe proscarabceus soon after it 
was captured, and found its temperature amounted to very nearly 3° above that of the 
atmosphere when the insect was a little excited ; but half an hour afterwards, when 
the insect had become more calm, it had subsided to 1°*5. I have in general found 
that the temperature of a single Meloe varies from one to two degrees above that of 
the atmosphere when not excited, and it seldom sinks down to the temperature of 
the atmosphere, because during the season in which the perfect Meloe is found it is 
almost always active. But when the newly developed Meloe first leaves its nidus in 
the earth in the beginning of March or end of February, I have seldom been able to 
detect more than one, or at most two tenths of a degree, in those of one species 
which I have had opportunities of examining, Meloe cicatricosus ; and the same is 
the case with the nymph of the same species found in the month of August. 
Gryllus viridissimus, Linn. 
All the Grylli or locust tribes have comparatively a high temperature, and exist 
but a short time when the atmosphere around them becomes vitiated. This accords 
with their usual habits. We find them in the most sunny places, basking in the 
hottest rays, or chirping among the bushes at some distance from the ground. Hence 
we should conclude, a priori, that they have a high temperature. In a female spe- 
cimen of G. viridissimus, captured on the 14th of July, when confined for a short 
time, atmosphere 73°'7 5 the temperature of the air of the phial had risen to 74°'7> and 
that of the insect at rest to 75 0, 4, but when excited 75°’8, a difference of 2°T. When 
the insect had been confined in a phial about an hour it respired at the rate of 37 irre- 
gular and forcible contractions per minute. It was then becoming affected by the 
carbonic acid in the phial, the atmosphere of which had been raised to 74°‘9, while 
the insect was perfectly at rest. In a subsequent experiment the temperature of the 
insect was 76°, that of the atmosphere continuing at 7 3° - 7. When the observations 
were repeated at 7 o’clock on the morning of the 15th, atmosphere 63 0- 3, the tempe- 
rature of the phial was soon raised to 67°’4, while that of the insect not excited was 68°, 
a difference of 4 0- 7. At 11 a.m., atmosphere 71°‘6, insect 73°'6, phial 7 % 0 ' 7 , and on 
the morning of the 16th at 7, the insect having fasted for thirty-six hours, atmo- 
sphere 69°*1, phial 70°, insect 70°'5, but when excited 70 o, 8, thus proving that a great 
diminution of its power of generating heat had taken place during its abstinence. 
