368 PHILOSOPHICAL TRANSACTIONS. [aNNO 1747. 



way. And what makes this pest the more deplorable, is the long time of their 

 continuance in their eruca, or most mischievous state, which, according to Goe- 

 dartius, is 4 years at least, but MoufFet writes, that in Normandy they are ob- 

 served to be most numerous every 3d year, which is therefore called I'an des 

 hannetons. And it is not improbable, that in the open fields where they are 

 well fed, they may come to their perfect state a year sooner than those did which 

 Goedartius almost starved in glass jars. 



Mr. Arderon says, he has frequently been told by people of credit and obser- 

 vation, that neither the severest frosts of our climate, nor the being immerged 

 in water, will destroy these erucae; some having been exposed for many days to 

 the keenest frosts, and others covered with water for as long a time, which were 

 found to revive, and become as vigorous as ever. 



Crows and hogs devour these erucae greedily; but their numbers are too great 

 to be thus much diminished. The most effectual way, though very laborious, is 

 to beat them off the trees in the day time with long poles, and then sweep them 

 together and burn them. On a farm at Heathal, near 5 miles s. w. from Nor- 

 wich, of 80l. per Annum, belonging to St. Helen's hospital in this city, in the 

 occupation of Mr. James Ebdin, these insects were so numerous last year, that 

 the farmer and his servants affirmed they gathered 80 bushels of them, the 

 erucae of which had so spoiled the produce of his farm, that the court of this 

 city, in compassion of the poor man's misfortune, allowed him 25l. 



In the day time few of the beetles fly about, but conceal themselves under 

 the leaves of oaks, sycamores, limes, &c. where they seem asleep till near sun- 

 set, when they take wing and fly about the hedges, as thick as swarms of bees; 

 at which time they frequently dash themselves against people's faces with great 

 violence, and by so doing occasioned the common proverb, as blind as a beetle. 

 MoufFet tells us, it is recorded, that on Feb. 24, 1574, there fell such a mul- 

 titude of these insects into the river Severn, that they stopped and clogged the 

 wheels of the water-mills; as to which Mr. A. takes notice, that their coming so 

 early in the year was no less extraordinary than their multitudes; for the larger 

 species seldom appear till the month of May; and a smaller sort, which come 

 out in July and August, are seldom seen after the evenings grow cold. 



We are told in the Transactions of the Dublin Society, that the country people 

 in one part of that kingdom suffered so greatly by the devastation made by these 

 insects, that they set fire to a wood some miles in length, which parted two adja- 

 cent counties, to prevent their dispersing themselves any farther that way. 



Mr. Arderon further says that some ingenious persons account for the great increase of these in- 

 sects from the decrease of rooks in this country, which they say greedily devour them in their grub 

 state; and the decrease of rooks is owing to most of the ancient rookeries having been destroyed by 

 the large fall of timber trees made of late years, which has obliged the rooks to remove into other 

 parts of the kingdom. 



