288 



FOREST ENTOMOLOGY. 



About the middle of September many insects will be found deposit- 

 ing eggs on the leaves, as seen in fig. 271. In some cases an insect is 

 found on almost every leaf. The head of the insect points towards 

 the base of the leaf, and she generally places herself fairly near the 

 base of the leaf. After depositing the eggs the female dies, but the 

 dead body is so placed that it forms a protection for the eggs. It 



Fig. 271.— Winged forms of Chermes abietis on spruce leaves (enlarged). Found in autumn. 

 This stage should be carefully studied, as it is considered the sexupum stage, which again 

 produces the sexual stage. 



should be noted, however, that the eggs are not thrust outside the 

 body, as Ch. laricis, but on the contrary the ovisac is slightly ex- 

 tended and placed bodily on the leaf prior to the death of the 

 creature. 



These insects just referred to are, according to alternating genera- 

 tions, the return generation from the intermediate conifer. 



