CHERMESIDiE IN RELATION TO BRITISH FORESTRY. I41 



lays about ten yellow eggs under the protection of copious 

 " wool." Many of these eggs do not hatch. 



(5) Sexnaks. — According to Marchal, only females hatch 

 from these &ggs. Many die during development, while those 

 reaching the adult stage are unable to carry on the cycle owing 

 to the absence of the males. 



The following is a diagram showing the life-cycle of Pineus 

 pini, Indigenous race, according to Marchal. The main points 

 have been confirmed for this country by my researches : — 



Fig. I. — Diagram of the Life-Cycle of Pineus pini (Indigenous race), 

 according to Marchal. 



{B) The Oriental Race oi Pineus pini. 



I have not found this race even where Picea orientalis was 

 present. The descriptions are according to Bornerand Marchal. 



(i) Fundatrix Generation. — The Fundatrix hatches out on 

 the Picea orientalis in the second half of July. It anchors itself 

 at the base of a needle (not bud) on the shoot of the current 

 year. This larva secretes coarse, single strands of " wool," 

 and thus passes the winter. These larv^ wake up in March, 

 feed, moult three times, and become adult during the second 

 half of April. Each female lays numerous orange-coloured 

 eggs under copious "wool." As the Fundatrix is situated at 

 some distance from the extremity of the twig, its feeding has 

 little effect on the needles of the opening bud. 



(2) Gallicola Generation. — The larvae crowd amongst the 

 needles of the opening buds of the Picea orientalis. Their 

 feeding produces a long, loose gall. These larvae moult four 

 times within the gall, the nymphs generally moulting before 

 issuing from the gall. The gall turns purplish and opens 

 towards the end of June. The winged Gallicolae migrate from 

 the Picea orientalis to the needles of Scots pine, and there lay 

 20-40 yellowish-brown eggs under some " wool." These eggs 

 hatch in two to three weeks. 



