22 PROCEEDINGS OF THE NATIONAL MUSEUM. vol.60. 



ing of the larvae ; they are yellow green in color and so much swollen 

 as to protrude from the slit. The puncture itself becomes more dis- 

 tinct, as a brownish scar, with age. 



METEOROLOGICAL NOTES. 



All life has its optimum conditions for growth and also its maxi- 

 mum and minimum requirements and limits for existence of each 

 of the various factors that go to make up those conditions. The ex- 

 treme heat and humidity of a part of the summer of 1918 gave an 

 excellent opportunity for observing the effect of high temperatures on 

 this species. The following account is from notes made by S. A. 

 Rohwer. 



After a maximum temperature of 105.5° and a minimum of 76° 

 with the humidity varying from 32° to 83° and including a period of 

 between 10 to 12 hours when the humidity was 80° or more,^° but few 

 larvae were found in the rose garden, and these " sicklooking " and 

 not feeding. Three days before a large number of young and par- 

 tially developed larvae were observed on these plants. Further, 

 there was no mature feeding work done at this date, proving that 

 the larvae had not completed development. The variation of temper- 

 ature and humidity between the position occupied by the larvae 

 and that of the hygrothermograph was considerable, the latter record- 

 ing air temperature as 92° and humidity as 54° while a sling psy- 

 chrometer at the former location read 99.5° temperature and 73° hu- 

 midity. Later records of the same day showed 104° temperature and 

 40° humidity by the hygrothermograph and 106° temperature and 

 43° humidity by the sling psychrometer with all larvae gone. 



This hot spell was of slightly over a week in duration and the 

 summary of the temperature for the first six days as recorded by the 

 hygrothermograph is as follows: 



.6.25 hours above 100' 

 12.5 hours above 95" 

 26.5 hours above 90° 

 80.5 hours below 80" 



53.0 hours below 75" 

 9.75 hours below 70" 

 hours below 68' 



Following this period of excessive temperature and high humidity, 

 Cladius larvae were rare and remained scarce throughout the rest of 

 the year, whereas earlier in the season they had been quite abundant. 



PHENOLOGICAL NOTES. 



The seasonal phenomena of development for plants are often of 

 much importance in indicating the appearance of or the approach of 

 a particular stage of an insect. In the bristly rose slug, however, the 



1" Records from a hygrothermograph located a few feet from the rose garden and about 

 4 feet above the ground. The long period of high humidity was recorded the day before 

 these observations. 



