1920] Chapman: Coleoptera including Strepsiptera 179 



The more complicated life cycles have the most extreme 

 changes of form connected with them, such as have been referred 

 to in connection with the form changes of the larvae. The 

 Meloidae are the best examples of this specialization, including 

 such examples as Epicauta, the larva of which is at first cam- 

 podiform and free living, but after it has located the egg pod of 

 one of the Orthoptera, it enters into an arcuate larva with 

 greatly reduced thoracic legs. Thus we have in a single life 

 cycle a combination of the free living and restricted habits 

 of life and they are accompanied by the typical larval forms 

 which are to be correlated with them. 



The impress of climate on the life cycle of the beetle is 

 unmistakable. However, the effect of temperature upon the 

 length of the various stages has already been referred to in 

 connection with the length of life cycle and will not be discussed 

 further. 



Food is a factor which, like climatiq conditions, may alter 

 the length of the cycle as a whole or certain stages of it. This 

 factor has been greatly neglected and a better understanding 

 of it will undoubtedly be a great , aid in bringing order out of 

 the confusing detail which is to be met with in studying the 

 biology of the Coleoptera. 



The herbivorous beetles which are dependent upon growing 

 plant tissue for their food may be said to have the factors of 

 food and climatic conditions more or less merged into one. 

 Conditions which favor the growth of plants favor the food 

 supply, and thus control the growth and development of the 

 beetles. 



Beetles which live within their nutrient medium may be in 

 the leaves of plants, in the fruiting bodies, or they may be in 

 the supporting structures such as wood. These forms lend 

 themselves to experimentation, for it is possible to correlate 

 their rate of growth with the nutrient value of the material in 

 which they live. The wood boring forms are notoriously long 

 lived and the leafminers are usually short lived. Here with 

 conditions of temperature and humidity constant it is possible 

 to prolong or shorten the life cycle by controlling the nutrient 

 value of the food. 



The relatively simple condition just cited merges into a more 

 complicated condition met with in the forms which are termed 

 scavengers. While these forms appear to be subsisting upon 



