Entomological Society. 151 



Dr. Calvert presented some living larvae of one of the species of 

 Noctuid(e, which he had found exceedingly destructive to his wheat 

 crops in the north of Yorkshire, the larvae ascending the stems and 

 devouring the grain at the end of September. The land upon which 

 the crops attacked were sown was reclaimed moor land, and it was 

 considered that it was owing to the lateness of the ripening of the 

 crop that it was subject to these attacks, earlier crops in more south- 

 ern parts of the country escaping. It was further suggested that it 

 would be desirable to plough up the soil several times to a consider- 

 able depth, whereby the larvse or chrysalides in the winter or spring 

 would become exposed, and would be greedily devoured either by 

 the rooks or by ducks, which might be turned into the fields for that 

 purpose. 



The following memoirs were read. 



Observations on the Migrations of certain Butterflies in British 

 Guiana. By Robert Schomburgk, Esq., Corr. Memb. E.S., &c. 



In this memoir the author notices that several species of Callidryas 

 are often observed in the months of September and October, settling 

 in prodigious numbers on the wet sand banks, and which, when 

 alarmed, presented a brilliant spectacle in the display of the differ- 

 ent shades from deep orange to the palest sulphur colours. The 

 Indians, when they observed a number hovering over a particular 

 spot, said that they were come to celebrate a marriage dance, 

 whilst such as were settled with their long spiral tongues unrolled, 

 and resting on the moist sand bank, were compared to paiwori drink- 

 ers. On the morning of the 10th October 1838, while ascending 

 the river Essequibo, he observed myriads of these butterflies coming 

 from the south-west and flying to the north-east, always crossing 

 the river in that direction, flying over the tops of the forest trees, 

 but descending nearly to the surface of the river when they had to 

 cross it : the distance which the boat had travelled during the day 

 was nine miles, and the butterflies continued an uninterrupted column 

 from 8 o'clock a.m. till half-past 5 p.m., so that their numbers must 

 have been incredible. It was supposed that they came from the 

 extensive savannahs along the Pacaraima mountains, and were flying 

 toward those which extend between the rivers Berbice and Corentyn. 

 The Accawai Indians at the upper river Demerara sometimes collect 

 large numbers of caterpillars, which they use as food : indeed their 

 numbers are so great that whole baskets-full are gathered, after which 

 they are roasted and mixed with the flour prepared from the root of 

 the cassava {Jatropha manihat), and baked into cakes ; the cater- 

 pillars are also sometimes mixed with turtle eggs, which constitutes 

 a great delicacy. The Accawai Indians in Mr. Schomburgk's com- 

 pany asserted that the butterflies there seen deposited their eggs in 

 the plants from which the caterpillars used as food are collected. 



Mr. Gould also stated that he had observed a species of caterpillar 

 in vast profusion in the interior of New South Wales, distinct from 

 the bugong, upon which the natives fed, and which was also de- 

 voured by a species of hawk and the ibis. 



There was also read a memoir by J. O. West wood, F.L.S., con- 



