1801. 191 



I always fouiid it so), and possibly the case-making habit may have 

 been acquired in this group as a protection against the bites of the 

 ants. Microdon, a genus of SyrphidcB, of which I found a new species,* 

 in the pupal state, in a nest of Formica Integra, at West Cliff, has a 

 stronger pupal covering than most of its family ; and the Sisteridcd, 

 some of which live with ants, are very well protected by their curious 

 structure. By being able to live in ants' nests, and protected from 

 the ants themselves, no doubt these insects obtain a much greater 

 immunity from attack by birds, lizards, and other enemies, and are 

 thus benefitted. Many such enemies would not venture to attack a 

 nest of ants ; and those who might do so, would very easily overlook 

 these CoJeoptera or Diptcra in the multitude of hurrying ants. 



3, Fairfax Eoad, Bedford Park, 



Cbiswick, W. : April 2lst, 1891. 



NOTE ON THE LIFE-HISTORY OF ADELA RUFIMITRELLA. 

 BY T. A. CHAPMAN, M D , F.E.S. 



In the " Natural History of the Tineina," Stainton says, " the egg is laid in or 

 on tl)e pods of Cardamine pratensis, and Sis. alliaria, and the young larvce, no doubt, 

 feed on the contents of the pods, wlien they quit the pods they descend to the 

 ground and construct flat bivalve cases." This is, no doubt, a remarkable instance 

 of how near a man of great insight may come to a knowledge of some interesting or 

 unusual fact, and yet just miss it ; since it appears to be certain that he had no idea 

 of the possession by the moth of a piercing apparatus by which the moth does lay 

 her eggs in the pod, and yet, wise after the event, we wonder how he could suppose 

 the eggs to be laid in the pod, without some such apparatus. Last year I found the 

 eggs in the pods, and traced the larva thence to its appearance on the ground in a 

 case. This year I have succeeded in seeing the moth in the wild state laying her 

 eggs. The interest (to me) in this case, as in that of L. ruhiella, being chiefly in 

 connection with the habit of the moth as a " spear-tail." I hope Dr. Wood will 

 give us some details of the anatomy of the " spear " or knife in this as in the other 

 species he has investigated. 



This spring I found A. rtiftmitrella abundant among Cardamine pratensis (I 

 never see it on <S. alliaria), in a conveniently near meadow, and on May 29th and 

 30tli saw the moths in cop., and observed several ? s ovipositing. The moth when 

 80 engaged, walks from one pod to another, on reaching the pedicel of the new pod 

 she walks slowly up it, trailing the abdominal extremity, fringed in all these species 

 with tactile hairs, along its surface as she proceeds, now and then halting a moment 

 as though about to oviposit in the pedicel. It is not, however, till she roaches a 

 point about one-tenth of an inch up the pod that she actually does so. She then 

 adopts an attitude, with the head towards the upper end of the pod, raised as high 



* Not yet described : the type specimen, with pupa-case, is now in the I3ritish Miuseum. 



