1920] Chapman: Coleoptera including Strepsiptera 177 



pupal cells, in which they will remain as larvae until the following 

 spring, even though the temperature rises during September 

 and there is ample time for them to transform and emerge as 

 adult beetles. However, there would not be time for the eggs 

 to be deposited and hatched and for the larvae of the next 

 generation to penetrate the bark of the tree before winter. 



Among some of the Staphylinidae which are reported as- 

 being symbiotic with ants, the larval life is said to be only 

 fourteen days. On the other hand there are cases reported in 

 which certain of the Cerambycidae have been known to live 

 as larvae for years in dry wood. 



If a statement were to be made with regard to the usual 

 length of the egg stage of the Coleoptera as a whole, it would 

 probably be to the effect that the egg stage is normally ten days 

 in length. The Staphylinidae already referred to as being 

 symbiotic with ants, have an egg stage which is said to be of 

 only two days duration. Still others of this same family have 

 no egg stage at all. Several species of the Chrysomelid^ and 

 the Strepsiptera are also viviparous. 



The adult life is no more constant throughout the group 

 than the other stages are. The adult life of many beetles- 

 coincides roughly with the growing season, although some of the 

 Carabidae have been observed to live for more than a year> 

 Adults of the genus Tribolium have been kept for more than a 

 year at room temperature and oviposition continued throughout 

 this period. The males of some of the Strepsiptera are reported 

 as living but fifteen or twenty minutes of extremely active 

 life, while the females, in the absence of the egg stage, must 

 live a more prolonged life in order that the young may develop 

 within them. 



The larvae molt their skins in a more or less periodic way. 

 Five or six instars may be considered as common, but among 

 some of the Buprestidae and others the number of molts may be 

 increased when the larval life is prolonged as a result of unfavor- 

 able environmental conditions. One of the Tenebrionidae has 

 already been referred to as having had its life prolonged to three 

 times the normal period during which time it has molted twice 

 the normal number of times. 



To turn to the consideration of the significance of these 

 facts in relation to the environment it is necessary to avoid 

 being lost in a vast amount of detailed information. In this. 



