PSYCHE. 



NOTES OX THE RELATIONS OF TWO CECIDOMYIAXS TO 



FUNGI. 



BY WILLIAM TREI.KASE. MADISON', WlSf. 



For i^ome veins, while collecting the 

 commoner iiredineae or rust fungi, mv 

 attention has been attracted bv certain 

 small orange-red insects, that are verv 

 treqnent in and aliout some of the sori. 

 Thev are most often noticed in the aeci- 

 ilia or ciuster-CLips and in those sori 

 \\ hich contain nredo-spores. At times 

 thev are so alnindant that it is almost 

 impossible to collect a specimen of the 

 commoner nredo or aecidia! forms with- 

 out finding lumibeis of them in nearh 

 everv sorus. 



A first ghmce at them suggests that 

 the insects mav be some species of 

 riirips, hut the resemblance vanishes 

 on closer examination. Their motions, 

 as a general thing, are less rapid than 

 those of Thrifis. and a hand-lens at 

 once shows them to be some sort of 

 dipterous lar\ ae. With a higher power 

 the hreast-lione. ciiaracteristic of ceci- 

 ilomyid larvae, is distinctly seen. Vari- 

 ous attemjits have been made to bring 

 them to maturitw but so far without 

 success, so that it is as yet impossible 

 to say anything definite about the spe- 

 cies to which the\- belons- 



The constant presence of these insects 

 on the fruit of the fungi led me to watcli 

 their movements from time to time, and 

 the reascjn for their presence was soon 

 seen in the altered appearance of the 

 sori where they were most numerous. 

 Their relish for the Spores is entirely 

 disproportionate to the size of their mi- 

 nute bodies. The fact that they feed 

 on the spores aflbrds a simple explana- 

 tion of their presence on the aecidial 

 and uredo fruits, rather than in the te- 

 leutosporic sori of the rusts, since the 

 spores of the latter are more frequently 

 thick-walled and hard. 



The fungi on which I have most often 

 observed the larvae in question are Acci- 

 J/inii ca/ad/i. the cluster cup of Ari- 

 sa cilia and other aroids. Coleosporiiiin 

 soiicJii-ai-vciisis. the common rustof ^4,v- 

 tcr and Solidago. and Cacoma iiiteiis. 

 the destructive red-rust everywhere 

 abundant in spring on leaves of the 

 blackberr\ :uk1 raspberry (Rtihtis). 



Mr. C. \'. Rilev informs me that he 

 has also found the same larvae on a fun- 

 gus (Exolmsidii/iii vacciiiii?') growing 

 on Az<7/ra. wmy that the\' have been 



