I3S TRANSACTIONS OF ROYAL SCOTTISH AREORICULTURAL SOCIETY. 



GallicolDe of this species, which differ thus from those of 

 Cn. lapponicus. 



(3) Colo7iici Getieraiion. — The eggs hatch in about three 

 weeks. The dark brown larvae migrate from the needles of the 

 larch to the twigs in the case of older trees, and to the trunk in 

 the case of very young trees. They hibernate without secreting 

 any "wool." These first-stage larvae wake up in March, feed, 

 moult three times and become adult during the first half of May. 

 Each bronze-green female lays 35-50 eggs (Plate II. Fig. 4). 

 The colour of the eggs is bronze-green with a purplish tinge, 

 but the powdery " wool" secreted by the last segments of the 

 female's body gives them a grey appearance. These eggs hatch 

 in about three weeks and give two types of larvae. 



(i.) A very small number of Sistens larvae, which settle on the 

 twig and remain undeveloped until the following 

 spring, 

 (ii.) A large number of Progrediens larvae. These larvae are 

 black and migrate to the needles. They feed there 

 during June and cause the needles to bend fantastically. 

 The third moult results in two types. 



{a) Nymphs of the Sexupara generation. 

 (/;) Wingless forms. 



The latter moult and become adult wingless Progredientes. 

 Each brown female lays 20-30 brown eggs under copious " wool" 

 secreted by the adult. These eggs hatch in two to three weeks, 

 and give a small number of Sistens larvae and a large number of 

 Progrediens larvae. These latter develop on the needles into a 

 second generation, which becomes adult from mid-July onwards. 

 A third generation becomes adult during August. From the 

 eggs laid by the females of this generation, a large number of 

 Sistens larvae hatch and a small number of Progrediens larvae. 

 The former pass the winter together with the Sistens from the 

 Colonici eggs, the Sistens from the Progredientes eggs, and 

 the Sistens from the eggs laid by the Gallicolae migrantes from 

 spruce, while the latter perish. 



(4) Sexupara Generation. — For early development see 

 Colonici (ii. a). The nymphs moult during the second half of 

 June, and the reddish adult Sexuparae migrate to the needles of 

 spruce. There, each lays about ten yellow-brown eggs under 

 cover of the wings and copious "wool." 



