82 E. E. TURNER. 



Microdus diatraeae, sp. nov. 



$. Nigra ; segmento mediano, abdoniine, segmento apicali excepto, coxis posticis, 

 f emoribusque posticis, apice excepto, ruf o-f errugineis, alis fuscis, stigmate cellulisque 

 mediana cubitalibusque prima secundaque pallide flavis, palpis testaceis. 



Long. 11 mm. ; terebrae long. 12 mm. 



$. Face subopaque, finely and very closely punctured, much broader than long ; 

 vertex shining, sparsely punctured, front shining, concave, the marginal carinae of 

 the concave area low and indistinct. Thorax strongly narrowed anteriorly, shining, 

 the parapsidal furrows deep ; the median lobe of the mesonotum almost smooth, 

 with a distinct longitudinal carina, the lateral lobes distinctly, but rather sparsely 

 punctured. Mesopleurae, sides of the median segment and coxae finely and very 

 closely punctured. Median segment rather finely rugose at the base, becoming 

 distinctly reticulate towards the apex, with two distinct, but not very strong, 

 longitudinal carinae close to the middle, running from near the base to the apex. 

 First tergite nearly twice as long as its apical breadth, twice as broad at the apex 

 as at the base, irregularly obliquely rugose-striate, with a distinct longitudinal 

 carina from the base to the middle, the apex smooth and shining. Second tergite 

 nearly two-thirds of the length of the first, smooth and shining, with an oblique 

 groove on either side from the base to the lateral margin, the space at the angle 

 bounded by the grooves very small ; a broad transverse groove crossing the segment 

 near the middle, the groove closely longitudinally striated ; second suture smooth. 

 Third tergite smooth and shining, with a shallow, smooth, transverse groove which 

 is obsolete in the middle ; the remaining segments smooth and shining. Spur of hind 

 tibia scarcely more than one-third of the length of the hind metatarsus ; ungues 

 simple. Second cubital cell triangular, not petiolate ; the radius reaching the costa 

 a little nearer to the apex of the wing than to the apex of the stigma. 



British Guiana : Lusignan, Non Pareil and Ogle Plantations, East Coast of 

 Denier ara ; March and April (G. E. Bodkin). 



A parasite of Diatraea larvae. 



In the transverse grooves of the second and third tergites this approaches the 

 genus AeropMlus, Szep., but the general form and the sculpture of the median seg- 

 ment approach much more nearly to Microdus. Nearly related to this species is 

 Microdus macidipes, Cam., 1911 (Cremnops mactdipes, nee Microdus maculipes, 

 Cam. 1887), which I take to be the female of Microdus parvifasciatus, Cam. (described 

 as a Cremnops) ; but the sculpture of the median segment and the difference in the 

 length of the terebra separate the two species at once. Other species described by 

 Cameron in the same paper as Cremnops and really belonging to Microdus are M. nigro- 

 balleatus and M. punctipennis. 



