May 14, 1874] 



NATURE 



31 



LARV.-E OF ME MB R AC IS SERVING AS 

 MII.K-CATTLE TO A BRAZILIAN SPECIES 

 OF BEE 



lY/fV letter in Nature, vol. viii. p. 201, was in- 

 ■'■'-'- complete so far as the names of the Brazilian 

 insects alluded to are concerned, but I am now enabled 

 accurately to name boih the supposed milk-cow and the 

 supposed milker. With regard to the former, Mr. Rogen- 

 hofer, of Vienna, has had the kindness to compare my 

 specimens of Membracis with the collection in the museum 

 of that metropolis, and informs me that my Membracis 

 belongs to the genus Potnia of Stiil [Umbonia of Fair- 



FiG I.— Cacafogo, worker (sid 



maire), the species most probably being indicator Fairm, 

 As to the Trigona species referred to in the above letter, 

 I have in the meantime received numerous good speci- 

 mens, not only a number of workers, but also some males, 

 and even one queen. Mr. Frederick Smith has been good 

 enough to compare my specimens with the collection in 

 the I5ritish Museum and has found that they belong 

 to an undescribed species. Having worked through 

 the literature on Trigona and Melipona a-, completely as 

 possible, and after perusing the descriptions of about one 

 hundred species, not having found a single one of which 

 all three kmds of individuals arc known, I think it will 



Ije welcome to -flie readers of this journal who are in- 

 terested in entomology, if I do not restrict myself to 

 mcrJy mentioning the name and diagnostics of my new 

 Trit ona species, but give a description of its workers, male 

 and" queen, adding a brief account of its peculiar habits 

 and economy from my brother's (Fritz Miiller) observa- 



'tior s. 



Trigona cagafogo* 

 Length of the workers and males 5—5!, of the queen 



■6— 7 mm. Males and workers' are almost alike in size, 

 colour, and outline of the body, and are distinguished from 



• I call the species Cngafogo, using the vernacular n.ime for the specific 

 ■cne. 



most other species of the same genus by the breadth of their 

 head and the narrowness of their abdomen, which, in the 

 workers, scarcely exceeds half the breadth of the head. 

 In the males the abdomen is equally slender, but the 

 head somewhat less broad ; in the queen the head is of 

 the same size and form as in the workers, but the abdo- 

 men is so much dilated as to reach one and a half times 

 the breadth of the head. 



The head, tegute, scutellum, and abdomen, in all three 

 kinds of individuals, are ferruginous, smooth and 

 shining, the posterior margins of the vertex, of the scu- 

 tellum and of the last segments of the abdomen have a 



Fig. 3.- -Cacafogo, queen. 



black pubescence ; the re;t of the thorax, together with 

 the legs, is black with black pubescence ; the antenna; 

 black, the greatest part (v ) or the whole ((J ) of the scape 

 rufo-piceous, the flagellum fuscous beneath. The wings 

 by far exceed the abdomen ; the basal portion and 

 radical cell of the anterior wings dark fuscous ; their 

 apical portion and the posterior wings subhyaline ; the 

 stronger nervures brown, the feeblest ones pale ferruginous ; 

 no cubital cell at all. The mandibles with two teeth at their 

 apex. The tibia; triangular, their outside pubescent from 

 the base to the middle, towards the apex slightly exca- 



tX'V^ 



vated, smooth, shining, and naked. The whole body 

 destitute of feather-like hairs. The unguicuke of the 

 males are, in this as in other Trigona and Melipcna 

 species, two-cleft ; whilst those of the workers and femaks 

 are simple. The queen, besides her larger size and the 

 much dilated abdom.en, differs from the workers by the 

 colour of the head being somewhat paler, the antennae 

 longer, the thorax stronger, its anterior and lateral 

 margins and two longitudinal streaks rufo fuscous, the 

 anterior wings provided with a completely closed cubital 

 cell, the legs larger and more robust, especially the 

 anterior and middle tibiae much thicker, the outside of 

 the posterior tibix slightly convex and pubescent nearly 



