Simulium chaouikaidi Belqat & Adler, 2024

Belqat, Boutaïna & Adler, Peter H., 2024, The southernmost member of the Simulium venustum species group (Diptera: Simuliidae) in the Old World: a new species from the Rif Mountains of Morocco, Zootaxa 5446 (2), pp. 247-256 : 250

Simulium chaouikaidi Belqat & Adler , n. sp.

Simulium ‘indet.’ Belqat, Adler & Dakki, 2001

Simulium ‘sp.’ Belqat, 2002

Simulium ‘sp.’ Belqat & Dakki, 2004

Simulium ‘sp.’ Belqat, Dakki & Alami, 2005

Simulium ‘sp.’ Belqat, Adler & Crosskey, 2011

Simulium ‘indet. ’ Belqat, Adler, Cherairia & Boudghane-Bendiouis, 2018 Simulium ‘indet.’ Adler, 2022

Simulium ‘indet.’ Adler, 2023

Chromosomal characterization. The three chromosomes in the haploid complement expressed tight pairing of homologues and had well-defined, darkly staining centromere bands within expanded centromere regions, mildly so in chromosomes II and III ( Fig. 1 ) and markedly so in chromosome I. Five of the six chromosome arms had the standard banding sequence for the subgenus Simulium , whereas the sixth arm (IIS) was fixed for inversion IIS-C ( Table 2 ; Fig. 1A, B ).

The sex chromosomes were cytologically undifferentiated; the X and Y were microscopically identical. Autosomal polymorphisms were scarce; only one, a small inversion (IIIL-11), was heterozygous ( Fig. 1C ) in 2 larvae ( Table 2 ).

Diagnosis. Chromosomally, S. chaouikaidi n. sp. is distinguished from all known species of Simuliidae , except S. paramorsitans , by a combination of the fixed IIS-C sequence, standard sequence for IIIL, and microscopically undifferentiated sex chromosomes. The combination of an elongated, narrow ventral plate (2.6 times as long as wide) and finely haired prominence at the base of the gonostylus distinguishes the male from all other species of Simuliidae . The six slender filaments in the same vertical plane and the tightly woven, slipper-shaped cocoon separate the pupa from all other North African Simuliidae . The negative head-spot pattern, arrow-head shaped postgenal cleft, and six-filamented gill histoblast distinguish the mature larva from all other known species of Simuliidae in the Palearctic Region. The female remains unknown.

Figures

FIGURE 1. Chromosomes of Simulium chaouikaidi n. sp. from Morocco (female larva). A. IIS showing the fixed ‘C’ sequence (breakpoints marked with arrows); CII, centromere band. B. Basal portion of IIL and IIS showing the well-defined centromere band (CII) within the slightly expanded centromere region and the proximal breakpoint of the ‘C’ inversion (arrow). C. IIIL showing the standard sequence with one polymorphism (IIIL-11) imposed on it, expressed as a heterozygous knot; CIII, centromere band; NO, nucleolar organizer.