Myrsidea Waterston

Price, Roger D., Hellenthal, Ronald A. & Dalgleish, Robert C., 2005, The genus Myrsidea Waterston (Phthiraptera: Menoponidae) from tyrant­flycatchers (Passeriformes: Tyrannidae), with descriptions of 13 new species, Zootaxa 1048, pp. 1-20 : 2-3

Genus Myrsidea Waterston

Myrsidea Waterston 1915:12 . Type species: Myrsidea victrix Waterston by original designation.

A thorough characterization of this genus may be found in Clay (1966). We provide here only the diagnostic characters that are of significance in defining the genus as it pertains to the tyrannid lice.

Head ( Fig. 5 ) evenly rounded anteriorly; lacking lateral slit or notch; with long inner occipital setae, minute outer; without ventral sclerotized processes; gula usually with 4–5 setae on each side, less often 3 or 6, with heavier longer posterior seta; hypopharyngeal sclerites well developed.

Thorax ( Fig. 5 ) with pronotum lacking central setae; with 3 short setae at each lateral angle and 6 longer posterior marginal setae. Mesonotum well defined, with 2 minute medioanterior setae adjacent to postnotum and 2 minute setae at posterior margin. Metanotum without central setae, but with 6 short setae around periphery. Prosternal plate well developed, elongate, with 2 short anterior setae; mesothorax with notum, pleura, and sternum fused to form strongly sclerotized ring; metasternal plate prominent, diamond shaped, usually with 6 setae, much less often 5, 7, or 8; venter of femur III with setal brush.

Abdomen with undivided tergites, without anterior setae except for very small seta at corner of each side of tergite I (not included in tergal count); sternite I small, usually without setae; sternite II enlarged, with aster of heavy setae at each posterior corner. Female anus oval, without inner setae; subgenital plate of fused sternites VII–IX, usually with lightly serrated posterior margin. Male subgenital plate of fused sternites VIII–IX; genitalia of characteristic shape ( Fig. 6 ), with spinous sac having distinctively shaped associated sclerite.

Sexual dimorphism is limited to males having smaller dimensions, sparser abdominal chaetotaxy, and differences of the posterior abdomen. Some females may have enlargement of anterior abdominal tergites. Male tergites are unmodified, with pattern of postspiracular setal lengths much as for female. Characters listed above for the genus will not be repeated in the species descriptions.

Figures

FIGURES 1 – 8. 1 – 2, Myrsidea magnidens. 1, Female metanotum and dorsal abdomen. 2, Male genital sac sclerite. 3, M. stenodesma female metanotum and dorsal abdomen. 4 – 6, M. pitangi. 4, Female metanotum and dorsoventral abdomen. 5, Entire dorsoventral male. 6, Male genitalia. 7, M. seversoni female dorsal thorax and abdomen. 8, M. melancholici female dorsal thorax and abdomen.