20 



Journal of Entomologx an<l Zoolojry 



bluish green, with median ridge and the margins of the body 

 brown. The median ridge was quite prominent in the larva. The 

 coarse reticulum on the body has a pattern somewhat like that 

 figured for M. tristis, as can be seen from the figure. The length 

 was 11 mm. 



The puparium shorten.s to about 9 mm. The reticulum is much 

 more distinct than in the larva and two prothoracic tubercles push 

 out (in the specimen described one of the tubercles did not push 

 through the body wall). The reticulation is arranged in a more or 

 less symmetrical design and when examined under a high magni- 

 fication is seen to be made u]5 of two types of processes; those on 

 the dorsal ridge and along the sides just above the fringe are of a 

 shape which might be likened to an inverted wine glass and the 

 other processes are (luite short and composed almost entirely of the 

 white stalked portion (see figs. 6 and 7). The base in both cases is 

 dark brown and the apical portion white. From above the boJv 

 appears to be covered with white di.scs arranged in a reticulated 

 pattern, the center of each disc with a depression and a minuU' 

 cavity which appears to penetrate almost or quite through the 

 body wall. These minute structures may function as pores. The 

 anterior margin of the ventral fringe of the body is deeply notched 

 in the middle as shown in figure 4. The structure of the marginal 

 fringe is shown enlarged in figure 8. The fly emerges from the 

 puparium by bi-eaking off the cover in three rather symmetrical 

 pieces, illustrated in figure 2. 



The specimen described was taken the last of March and soon 

 commenced to pupate, the puparium being fully colored by April 8. 

 The adult emerged just a month later. 



Wheeler notes that the most typical and frequent hosts of t' 

 Microdon larvae are ants of the genus Fonn'uct but Wasmann has 

 recorded a speci<"< "•'""•" '-<../'.///, iH \!.-.il,iir;,<, ■,,• -.^ a host. 



%^ 



2 •* 8 



Fijr. 1- F'uparium of Microdon piprii Knab; 2, anterior portion of puparium, 

 showing symmetrical breaking; 3. posterior respiratory tubercle; 

 4, mari;inal frinpe of puparium, showing split in anterior region ; 

 b, reticulations of two kinds, those with a short, and those with a 

 high base; 6, and 7, portions of the reticulations more highly mag- 

 nified; 8, marginal fringe, greatly magnified. 



