Description of Hexamermis philaeni n. sp. (Enoplea: Mermithidae), a parasitoid of the meadow spittlebug Philaenus spumarius (Hemiptera: Aphrophoridae) in Italy.

A new species of the genus Hexamermis, Hexamermis philaeni sp. n., was described analyzing specimens isolated from nymphs and adults of the meadow spittlebug Philaenus spumarius in Italy. The combination of the following morphological characters identifies this novel species: terminal mouth opening; the presence of six cephalic papillae; six hypodermal cords at midbody; vulvar opening wide and visible without lips, vulvar cone developed, vagina bend at connection with the uterus; spicules paired, developed, separated and equal in size, slightly curved near the distal end and shorter than the width of the body at the level of the cloaca; genital papillae surrounding the cloaca, surpassing the base of the spicules and arranged as follows: 24 pre-cloacal, 5 ad-cloacal, and 50 postcloacal. Bayesian phylogenetic analysis based on 18S data placed H. philaeni within Hexamermis-Agamermis mixed clade. To our knowledge, this work represents the first record of a Hexamermis species parasitizing P. spumarius.