446 



The Genus Chermes. 



[SEPT., 



larch needles suck the needles. As the cold season approaches, the 

 larvae leave the needles, and fix themselves in crevices of the bark 

 of the larch by the proboscis, and so fixed pass the winter. In the 

 next spring — just like their grandmothers, the foundresses— they feed, 

 and after three moults become adult, and lay round them their eggs. 

 The eggs are bright green. From these eggs are hatched larvae which 

 develop into the adults of Generation 4. 



Generation 4 : The Sexuparce. — This is the generation preparatory 

 to the Sexual Generation. The naked larvae feed on the young shoots 

 and needles, the needles becoming kneed in consequence. The young 

 and adults of Generation 4 are pale yellowish-green. The adults 

 are all females, and are winged. They resemble their grandmothers 

 of Generation 2, only they are smaller and lay a less number of eggs. 

 They fly to the Spruce and lay on the leaves a small number (the 



Chermes arietis Kalt. (after Nitsche) : a, winged female ; b, separated wing. 



(Highly magnified.) 



number is given in the literature on the subject as ten) of greenish- 

 yellow eggs, in May or June. From these eggs are hatched larvae 

 which will develop into the adults of Generation 5. 



Generation 5 : The Sexual Generation of Males and Females. — 

 The larvae feed on the needles of the Spruce, under, it may be, the 

 wings or dead body of the mother, and after three moults become 

 sexual individuals — males and females. Both are wingless. They are 

 extremely minute, the females measuring in length 0*5 mm. to o'6 mm. , 

 and the males less. The proboscis is short, and the antennae in both 

 sexes are four-jointed (the antennae are three-jointed in the larvae). 

 Pairing takes place, after which the fertilised female, in high summer, 

 creeps into some crevice in the bark at the base of the shoot, and there 

 lays one large egg. From this egg in autumn there hatches the larva 

 which passes the winter at the base of a bud, and develops in the 

 next spring into the adult foundress of Generation 1. 



Graphically this life history may be represented as on p. 445. 



