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Trisecodes Delvare & La Salle, 2000

 
   
T. agromyzae, male
  T. agromyzae, female
     
   
 
 
     
     

Distribution

     

Biology

     

Comments

     
       
           

Classification

 

Subfamily

Tribe

Entedoninae

Entedonini

           
 
 
 

Diagnosis

 


   
 
Tarsi 3-segmented.
Submarginal vein (SMV) with 1 single seta dorsally. Postmarginal vein and stigmal vein very short. More than two lines of setae originating from stigmal region (R, Rs1, Rs2 & r-m).
Flagellum with one anellus; funicle and club with 3 segments in both sexes. Male flagellum with whorls of long hairs.
Frons with distinct scrobal sutures which extend dorsally to the frontal sutures and define a median strip; fronto-facial suture V-shaped.
Mesosoma with distinct raised reticulation. Pronotum without transverse carina. Notauli complete and straight. Mesoscutum and scutellum with wide median groove. Scutellum without sublateral grooves or lines and with 3 pairs of short hairs. Propodeum with spiracular groove hardly impressed, without subspiracular tubercle and median carina.
Petiole not distinct.
Body colour mainly dark, with slight bluish reflections.

 
         
     
 
 

Distribution


 

This new genus has been recognised only in the Neotropical Region (Noyes, 2001).

         
 
 

Biology

     

T. agromyzae Delvare & La Salle, the only species described by now, is a larval parasitoid of leafminers belonging to the genera Liriomyza Mik, Calycomyza Hendel and Ophiomyia Brazhnikov (Agromyzidae) (Noyes, 2001).

       
                                       
 
 

Comments

 
Trisecodes is the only eulophid genus with tarsi 3-segmented. Up to its discovery and description, the only Hymenoptera known to have 3-segmented tarsi in both sexes were members of the family Trichogrammatidae. However, many of the derived states found in Trisecodes are found in some eulophids, for example the shape and placement of the frontal sutures, the reduced number of tarsal segments, the reduced number of setae on the submarginal vein, the very short postmarginal vein, and the presence of line of hairs on the forewing. The fore tibial spur is also similar to the spur present among eulophids. Moreover, some characters, as reduced number in antennal segments, special structure of the fore tibial spur and petiolate gaster with phragma restricted to mesosoma and not entering metasoma, are definitely characters recognizable in the family Eulophidae. Finally, all the trichogrammatids are egg parasitoids of several insects, while Eulophidae (as Trisecodes) include many larval or/and pupal parasitoids of agromyzid leafminers. Therefore, thanks to all the reasons above reported, Delvare and La Salle (2000) placed Trisecodes as a member of the family Eulophidae, instead of putting it among trichogrammatids. It seemed also reasonable placed Trisecodes, considering the currently recognized subfamilies, within Entedoninae by the combination of two characters: frontal suture clearly separated from anterior ocellus and V-shaped, and lines of setae from stigmal vein. Those characters are in fact present in Asecodes, which thus could be closely related to Trisecodes. However, Trisecodes doesn’t have many typical characters usually reported for Entedoninae (see Boucek, 1988; Schauff, 1991), as the scutellum with a pair of setae, submarginal vein with 2 setae, male scape with sensory pores at the ventral edge, propodeum with a subspiracular tubercle; it has in fact 3 pairs of small setae on scutellum, a single seta on submarginal vein, notauli complete and doesn’t have a tubercle on propodeum and sensory pores on male scape.
Finally, the combination of the 3-segmented tarsi and the condition of head and thorax definitely separate this genus from all the others included in the key.
                       
                                                             
                         
 
                                                             
     
 
 

 

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