82 NEW YORK STATE MUSEUM 



APPENDIX 



MIASTOR AMERICANA FELT 

 An account of pedogenesis 



The remarkable larvae of Miastor, presumably M. americana 

 Felt, were found Oct. 5, 19 10 under the partially decayed inner bark 

 and in the sapwood of a chestnut rail used to fence a shady road- 

 side in the vicinity of Highland. Additional material was secured 

 October 19th, and from these two lots we have been fortunate in 

 being able to follow through the larval life cycle and to actually 

 witness pedogenesis, now regarded as a modification of partheno- 

 genesis. These minute larvae are very easily handled and studied 

 and should therefore be extremely serviceable to teachers of zoology 

 and biology desiring to give their classes first-hand information 

 respecting this phase of reproduction. Our studies of this form are 

 given below in some detail in the hope that many teachers will find 

 it advantageous to make use of these larvae in their class work. 



Habitat. The moist inner bark of various trees showing 

 incipient decay is the most likely place to find Miastor larvae. Those 

 discussed in these pages were discovered in the fall, working in the 

 partially decayed chestnut bark of a rail fence along a shaded road- 

 side. The larvae were most abundant in the soft, partly decayed 

 bast just beyond the point invaded by various borers in dead wood 

 and the accompanying predaceous Dipterous larvae. An allied, 

 though undetermined, species was taken under similar bark of a 

 chestnut stump in a wood lot. European observers report the occur- 

 rence of these and allied larvae under the bark of a variety of trees, 

 such as beech, birch, poplar, oak, elm, ash and ironwood, and even 

 in sugar beet residue. 



Recognition characters. It is very probable that these larvae 

 have been repeatedly overlooked by collectors, simply because when 

 occurring singly or in small colonies they present no very striking 

 characteristics. Large colonies of this remarkable form are easily 

 recognized by the masses of more or less adherent yellowish or 

 whitish larvae, and especially by the presence here and there of 

 larger, motionless individuals, some of which usually contain young 

 sj^ well developed as to be easily seen with a hand magnifier. A 

 careiui examination with a pocket lens will show, even in the case of 

 isolated larvae, a distinct head and a fuscous ocular spot in the 

 sedgment just behind. The head is flattened, triangular, with a pair 



