1914 ENTOMOLOGICAL SOCIETY. Gl 



forming cocoons. Most of the larvje of the genus I'ontania which form galls or 

 abnormal growths on the leaves of Salix and Popalus, leave the galls and trans- 

 form in cocoons in the ground, in rotten wood, or in the pith of plants, differing 

 with the species. Some of the species leave their galls and evidently crawl over 

 the bush and enter the vacant galls of cecidomyiids or of other individuals of the 

 same species, where they transform. Tractically all tlie adults of Pontania pisum 

 that I have seen were bred from cecidomyiid galls collected on Salix. The larva? 

 of Euurct, which form galls on the stems of Salix, transform in cocoons either in the 

 galls or enter the ground. The larvge of the Cladiina3 transformed in the breeding 

 cages in cocoons made of a thin, transparent, homogenous sheet of silk formed 

 between the leaves of the food plant. In nature they probably transform in 

 the ground. 



In most insects with a complete metamorphosis that transform in rotten 

 wood, in cocoons, or in cells in the ground, the body of tlie larva becomes shortened 

 while preparing its place for pupation and almost immediately after its completion, 

 a fewl days at the most, the last larval skin is shed and the pupal condition is 

 assumed. A very different condition is found in the Xyelidse, Pamphiliid?e, and 

 Tenthredinidge. The most of the species are single brooded, that is, the larvae 

 emerge early in June, complete feeding by the end of the month, enter the ground 

 or rotten wood, spin cocoons, and the adults emerge the following April or May. 

 Writers in referring to the transformations of species of these groups frequently 

 state that they pupated at a certain date, referring to the time when the larvae 

 entered the ground or rotten wood. Such a statement is incorrect, for in all 

 the species so far as known, the insect lives as a larva until the following spring, 

 March or April, or even later. The pupal period is, therefore, very short and 

 many of the metamorpliic changes must take place during this quiescent period 

 of the larva. The larvae of the leaf-feeders, if one may judge from breeding cage 

 experiences, have many idiosyncrasies. Just before they are ready to cast their 

 larval skins and become pupa% they may leave their cocoons or earthen cells or 

 their tunnels in rotten wood and force themselves to the surface of the soil, 

 where they will remain as if dead, only wriggling the body when disturbed. Such 

 larvffi may pupate on the surface of the soil and produce adults or they may die. 

 The larvfe are very subject to the attacks of hymenopterous and dipterous para- 

 sites, but in no case observed did any of these larvae produce parasites. 



The pupas are typically hymenopterous in type, the antennae, legs, and wings 

 are enclosed in separate cases, the wings are pad-like in structure. The pupae 

 are ordinarily green in color, becoming darker with age, sometimes with yellow 

 or orange spots. The pupal state lasts about twelve or fifteen days. The adults 

 when they emerge from the pupal skin remain in the place of pupation until 

 the wings are fully expanded and the cuticular parts hardened. They emerge 

 from the cocoon by roug'hly cutting out one end; but in the Lophyrinae and Cimhex 

 and Trichiosoma a neat lid is cut and is left attached to the cocoon. 



With the exception of the Tenthredinidae, all the species are clearly single 

 brooded. While many of these are single brooded, others apparently have 

 more than one brood. Any statement as to the number of broods should 

 be made with care. It is a well known fact of observation that many 

 species of insects, probably a large majorit}^, appear at a stated time, the males 

 frequently a few days before the females, a week or ten days covering the entire 

 period. This is not true in this family, for adults may appear over a period 

 of four to six weeks, so that with some species, full grown larvae and just emerged 



