Diagnosis of Forcipomyia sahariensis Kieffer ( Diptera : Ceratopogonidae ) with the first description of immature stages

Forcipomyia sahariensis Kieffer, 1923 is diagnosed in all stages. Larvae a nd pupae reared from rotting roots are described for the first time. Forcipomyia tuzeti Huttel et Huttel, 1952 from France and F. acanthophora Remm in Havelka, 1976 from Germany are recognized as new ju nior synonyms of F. sahariensis . A supplemented key for identification of known larvae and pupae of Polish species of the subgenus Forcipomyia s. str. is also provided.

Diagnosis: Immature stages and adults of Forcipomyia sahariensis can be easily distinguished among other species of the subgenus Forcipomyia s. str.by the following combination of characters: Larva: Body seta b and d densely serrated; seta a lanceolate; cuticle covered with short spines; head setae p and q lanceolate (Figs. 1, 2).
Thorax.Prolegs slightly bilobed, hooklets placed centrally.Seta a lanceolate, relatively short, of same shape on all body segments.Seta b and ć/dark, placed on distinct tubercles, seta d slightly curved, serrated, seta b shorter with dense serratings.Seta b on segment 11 devoid of spines, short and slender.Seta c dark with short sparse spines and pointed apex (Fig. 2).Cuticle covered with short spines.
Seta d of anal segment (12) short and slender, setae a and b of similar shape as on other body segments (Fig. 2).Anal papillae bilobed.
Head.Process a absent; b bearing very short apical seta (Fig. 3).Thorax.Processes c, d and e stout and serrated.Process c with short seta.Process /reduced to a small tubercle.Horn short, about twice longer than broad, bulb-shaped, with 12-20 spiracular openings (Fig. 3).Caudomedian prolongation reaching middle of 1st abdominal segment.
Distribution: Forcipomyia sahariensis is widely distributed in the Palaearctic region.It is recorded from Europe (France, Germany, Poland, Slovakia), Middle Asia (Kazakhstan), Far East (Sakhalin), Near East (Caucasus) and North Africa (Algeria).Larvae and pupae live in wet rotting roots of Arctium lappa and Apiaceae.

D is c u s s io n
Preimaginal stages of Forcipomyia sahariensis are described here for the first time.They are very similar to those of F. squamigera.Larvae of both species have similar head setae p and q and thoracic setae -a, b and d (Szadziewski et. al. 2007).The thoracic setae a are short and lanceolate, while b and d serrated and placed on separate tubercles.Pupae of F. sahariensis http://rcin.org.pl and F. squamigera have different number and specific shape of short abdominal processess (see key below).
In the male genitalia of Forcipomyia sahariensis there are characteristic u-shaped parameres and a group of 8-10 small spines on the ventral surface of the gonocoxite.The same diagnostic structures we found in males of F. tuzeti and F. acanthophora described from Europe.We believe that these features properly indicate that all these names concern one species and propose to treat F. tuzeti and F. acanthophora as new junior synonyms of F. sahariensis.Forcipomyia ashantii Ingram & Macfie, 1924 from tropical Africa and F. ventralis Borkent, 1997(=abdominalis Tokunaga, 1940) from Japan have also ventral spines on gonocoxites like F. sahariensis.However, their females have no lanceolate scales on their tibiae.
In the neck region of Forcipomyia radicicola larvae there are three ovoid pillow-like ventral fields of thin and smooth cuticle (Fig. 11).We suggest that they play certainly role in cuticular respiration of apneustic larvae of this species.Such structures in the genus Forcipomyia are observed for the first time.