414 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 4 



marked on the lower leaves as the season advances. May 25 the nymphs were 

 about three fourths grown. The first adults were observed June 3. 



Miastor. Recent collecting has resulted in finding the larvae in the decaying bark 

 of maple, chestnut, oak, birch, beech and hickory, rearings confirming the identity 

 in all cases except one. In addition, a species of Oligarces has been obtained from 

 decaying elm bark. The vitality of Miastor larva; is amazing. Some have lived and 

 propagated for nearly six months in a small piece of decaying wood lightly clamped 

 to a microscopic slide, while individual larva? were kept in sealed water cells for about 

 four weeks. The latter were subjected to daily examinations with a microscope, 

 and in spite of the adverse conditions, the vital processes continued and the embryos 

 developed though slowly. We were fortunate, in the case of two larvse, to witness 

 the development of the egg in the ovary, its separation by fi.ssion and the growth of 

 the embryo to an individual ready to escape from the mother larva. The develop- 

 ment of the embryo is at the expense of the mother, pulsations continuing in the 

 latter so long as a fragment of the dorsal vessel remains. In one specimen observed, 

 the dorsal vessel was ruptured in the vicinity of the sixth body segment, and the 

 free anterior portion continued violent pulsations and irregular wrigglings till the 

 next day, at which time the movements were much slower and the following day 

 had disappeared entirely. An indefinite number of pedogenetic generations succeed 

 each other. The appearance of the two sexes is presaged by the larvae developing 

 distinct breastbones, soon followed by a change to the prepupa. This stage has a 

 duration of two to three days and is characterized by a marked swelling and trans- 

 parent condition of the anterior body segments of the larva, the portion occupied 

 by the pupal head and thoracic region. The duration of the pupal stage is from three 

 to six days, numerous adults appearing within a few days and emerging from their 

 habitat in the late morning hours, approximately from 9 a. m. to noon. Miastor 

 larvae are actively preyed upon by the pinkish larvae of Lestodiplosis and also the 

 larger predaceous maggots of Lonchcea polita Loew and a species of Medeterus. It 

 not infrequently happens in nature that an abundance of the larvae of these two 

 latter is about the only available evidence of the earlier occurrence of Miastor larvae, 

 though exploration of the bark beyond where these predaceous enemies occur, fre- 

 quenth' results in finding colonies of Miastor. 



E. P. Felt 



A CoRRECTipx. In my paper, "Further Notes on the Aphididae Collected in the 

 Vicinity of Stanford University," Journal of Economic Entomology, August, 

 1910, p. 372, I described an aphid of the genus Pemphigus on the California butter- 

 cup {Ranunculus californicus) giving it the name of Pemphigus ranunculi sp. nov. 

 According to the new rules in Zoological nomenclature this specific name does not 

 hold good since Kaltenbach described an European species under the same name 

 (Monog. Pflz. 1843), although the latter has been lately regarded as a synonym for 

 Pemphigus affinis. Accordingly I propose the name of Pemphigus californicus 

 Davidson. Mr. E. O. Essig has lately sent me examples of this insect labeled "on 

 Ranunculus californicus Benth., Xordhoff, Cal." 



W. M. Davidson 



