Edward R. Speyeh 173 



i. the spruce cycle. 



The winged Sexupora, flying from Larch, lays 5-10 yeHow-brown 

 eggs on the okler needles of Spruce in June, under a considerable covering 

 of wax- wool. 



The male and female Sexuales hatching from these moult four times 

 each, and, having reached the adult wingless stage, the female lays a 

 single fertilized egg during the second half of July. 



A Fundatrix larva hatches from this straw-coloured egg in August, 

 secretes wax-wool and hibernates until the following April. Having 

 moulted three times, the wingless adult Fundatrix lays 50-100 eggs 

 under much wax-wool on a weak bud. 



These eggs are at first yellow, but later become greenish-brown. 



Larvae of the Gallicola migrans hatch from them, and, together with 



their Fundatrix mother, convert the Spruce bud into a "gall." The 



larvae undergo three moults within the gall, which opens from the 



beginning to the middle of July; they emerge as the fourth stage nymph, 



and a final moult gives the winged adult Gallicola migrans, which flies 



to Larch. 



II. THE LARCH CYCLE. 



The Gallicola migrans lays 20-1:0 dark brownish-green eggs on a 

 Larch needle, under a very sparse wax-wool covering. 



Lidividuals emerging from a gall on June 14th, 1913, at Oxford, 

 were transferred to young Larch, where they finished ovipositing on 

 June 19th. The larvae hatched from these eggs on July 1st. 



A cluster of eggs collected from Larch in Hertfordshire on June r2th, 

 1919, hatched from June 20th-23rd. 



The Colonici Generations. 



All larvae hatching from the latter were of the Sistens form, and 

 were active at first, but later settled on the bark of shoots and went 

 into hibernation (Plate VI, Fig. 1). 



In the following spring the larvae started feeding (Fig. 2), and were 

 observed to undergo the first moult on April 9th, 1914 (Fig. 3), the second 

 on April 15th (Fig. 4), and the third and last on April 20th (Fig. 5). 

 The adult Sistens is wingless (Fig. 6) and, according to Mr Steven, lays 

 5-12 eggs a day, until 35-50 is reached, from March till the middle of 

 May, The eggs are at first yellow, then bronze-green, and hatch into 

 two kinds of larvae, (1) Progrediens (Plate VII, Fig. 7) and (2) Sistens, 

 the latter being in the minority, and many of them appearing to die 

 soon after hatching. The survivors appear to hibernate. 



