AMERICAN DIPTERA. 299 



BIOLOGICAL NOTES ON DIPTERA. 



(Galls on Solidago.) 



BY R. OSTEN SACKEN. 



Five galls, produced by N. Americaa Diptera on the golden rod 

 (^Solidago) have hitherto been described; the history of three of them 

 is complete, as the insect, producing them, has also been described ; 

 (^Trypeta solklaginis Fitch, Cecid. solklaginis Lw ; C'cc. Jn'rtipes 0. S.); 

 two have been named in anticipation of the discovery of the insect 

 (^Cec. racemicola O. S. and Cecid. carhonifera 0. S.). 



To this number I can now add three more galls from which T have 

 bred the following insects; Tri/peta polita Lw., Asphundnlia monavha 

 n, sp. and Cecidomyia anthophda n. sp. 



These eight galls, produced by Diptera on Solidago^ may be classi- 

 fied as follows : 



1. — Smooth swelling of stem or branch ; Trt/peta solidaginis Fitch ; 

 Cecidomi/ia hirtipcs 0. S. 



2. — Accumulation of leaves in consequence of the arrest of growth 

 of stem or branch; Trt/peta jiolita Lw., Cecidomyia solklaginis J^w.^ 

 Asphondylia monncha n. sp. 



3. — Enlargement of bud on flower, amongst the racemes; Cecid. ra- 

 cemicola O. S., Cecid. antliopliila n. sp. 



4 — Hardened spot on the leaves; Cecid. carhonifera 0. S. 



(The descriptions of the two Trypetse^ as well as that of the above 

 mentioned Cecidomyise and their galls, may be found in the first vol- 

 ume of the Monographs of North America Diptera^ 



ASI'HONDYLIA MONACHA, n. Sp. 



The gall of ^^1. monacha, like that of Cecidomyia solidaginis. consists 

 of an accumulation of leaves upon a stem or branch the growth of 

 which has been stunted by the operation of the insect. Several branch- 

 lets being stunted in this way alongside of each other, form a more or 

 less elongated head, sometimes several inches long, consisting of an ac- 

 cumulation of leaves. This head, at least the specimen which I have 

 before me, is more elongated, less stout than the heads of Ccc. solida- 

 ginis which I have seen. But the principal difference lies in its inner 

 structure. The leaves forming the inner part of the gall of Asph. mo- 

 nacha although stunted in their growth, have none of the character- 

 istic appearance of the numerous narrow ribbond-like leaves, surround- 

 ing a central cell, in the gall of Cec. solidaginis ; (compare Mono- 

 graph, etc., 1. c. Tab. 1, f. 9, 10). 



