PLATE XXVIII. 



Trochilium sphegiforme. 



1, larva after last moult ; 1 a, section of alder branch 

 showing burrow of the larva. 



See p. 49 and 127. 



Trochilium scolleforme. 



2, larva after last moult ; 2 a, 2 6, pieces of birch- 

 bark burrowed by the larva. 



See p. 127. 



/ 



Trochilium tipuliforme. 



3, larva after last moult ; 3 a 9 3 b, stems of currant- 

 bushes burrowed by the larva. 



See pp. 49, 50 and 128. 



