ENTOMOLOGY. 163 



On the northern border of the infested district the adults appear 

 nearly two weeks later than those along the southern border. As 

 between the lowest and the highest altitudes there seems to be a dif- 

 ference of appearance of about four weeks, which corresponds with the 

 difference in average summer temperature to be found between the 

 localities. Between the northern and southern boundaries of the region 

 this difference is 3.5°, between the lower and higher altitude 10°. Each 

 degree of difference in the mean summer temperature appears to make 

 about three and one-half days of difference in the time of the first 

 general appearance of the cicada. Whether this seeming rule will also 

 apply to other broods remains to be determined. The character of the 

 weather at the time of emergence is important. If it be cold the insects 

 become chilled, crawl slowly, and become an easy prey to birds, poultry, 

 and other predatory enemies. 



The author notes rinding an isolated specimen in May, 1895, which, 

 although appearing two years earlier than the normal time, he feels 

 certain belongs to Brood XV. None were seen or heard during the 

 spring of the next year, but during the fall of 1890 several specimens 

 were heard. This appears to be the second record of an occurrence of 

 this cicada in the fall of the year. 



At Morgantown, West Virginia, the first cicadas Avere heard May 27 

 and 30. Copulation commenced about June 9, oviposition about the 

 13th. The leaves and wounded twigs began to wilt four days later. 

 The insects began disappearing the last w r eek of June and none were 

 heard after July 1. Eggs on twigs began hatching August 20 and all 

 the young during the following week seemed to have emerged. 



The eight broods and nine swarms occurring in the State are XVII 

 (1S98), XX (1900), XXI (1901), XXII (1902), V (1905), VIII (190G), XI 

 (1910), and XV (1914). It will be noted that they occur in periods of 

 2, 1, 1, 3, 1, 4, and 4 years. The author gives brief notes, historical 

 and otherwise, on each of these broods and swarms, and then notes 

 the sections of the State where several broods overlap. Of the eight 

 broods in point of numbers XXI, XXII, V, VIII, and XV are most to 

 be feared, the last being the largest swarm. 



Among natural enemies mentioned, aside from numerous predatory 

 and parasitic insects not definitely named and a contagious disease 

 often of an epidemic nature, are English sparrows, hogs, poultry, and 

 squirrels. 



Some common injurious insects of western Nevada, E. H. Hill- 

 man (Nevada iSta. Bui. 36, pp. TX-\-39). — A popular descriptive list of 

 39 insects, including a brief key for their identification. The habits of 

 each are brought out and in most cases the most practical remedies. 

 Some of the more important points are the probable occurrence of two 

 distinct broods of Euvanessa antiopa in Xevada, the first about dune, 

 the second in August or September. It has fed only on the elm and 

 willow, Vanessa cardui does not feed on hollyhock in that region. 



