Chironomus nr. sp. parariparius of Martin (2023)

Namayandeh, Armin, Guerra, Sergio, Islam, Natasha, James, Taylor, Hudson, Patrick L., Ghaderi, Edris, Yusuf, Thameena, Vasquez, Adrian A. & Ram, Jeffrey L., 2024, New species and a fascinating diversity of Chironomidae (Diptera, Insecta) in and around an overlooked urban vernal pool, ZooKeys 1208, pp. 133-163 : 133-163

Chironomus nr. sp. parariparius of Martin (2023)

Figs 13 A – E

Material examined.

1 male; USA, Michigan, Detroit, Palmer Park, Pond A ; 42.42766 ° N, 83.11741 ° W; leg. P. L. Hudson; 30. vi. 2022, dep. ARC .

Diagnostic characters.

The adult male of C. nr. sp. parariparius can be separated from other Chironomus species by the combination of the following characteristics: AR 3.1; frontal tubercle present, 12 μm long; wing without any pattern; fore tibia scale 60 μm long; tergite IX with 9 median setae on two adjacent pale patches; superior volsella S-type, with robust apex and base with 5 long setae.

Description.

Male (n = 1). Total length 7.0 mm. Wing 3.6 mm long and 0.90 mm wide.

Coloration of the mounted specimen. Head brown. Thorax brown, with scutellum and humeral region pale yellowish. Abdominal tergites with posterior 2 / 3 rd brown and the anterior 1 / 3 rd pale yellowish (Fig. 13 A ). Halter and wing pale brown.

Head (Fig. 13 B, C ). Antenna with 11 flagellomeres, the last flagellomere with 4 sensilla chaetica (Fig. 13 B ), each of 2 nd – 4 th antennal flagellomere with a pair of long sensilla chaetica; groove starts at 4 th flagellomere, AR 3.1. Eyes bare, with well-extended dorsomedial extension. Frontal tubercle present, 12 μm long. Temporal setae 25, uniserial. Tentorium 201 μm long. Clypeus nearly squared, 130 μm long and 146 μm wide, bearing 36 setae, setae 108 μm long. Palpal segment lengths (in μm): 216, 116, 272, 234, 337. Third palpomere with 7 sensilla clavata.

Thorax. Acrostichals 2, close to antepronotum; dorsocentrals 14 in single row; prealars 5; scutellars 14 in double rows; antepronotals 1. Mid-scutum hump is present.

Wing (Fig. 13 D ). Wing without any pattern. Brachiolum with 1 seta, squama with 17 setae, R with 40 setae, R 1 with 47 setae, R 4 + 5 with 65 setae. Anal lobe developed.

Legs. Mid and hind legs missing. Fore tibia scale 60 μm long. The lengths and proportions of the legs as in Table 8 .

Hypopygium (Fig. 13 E ). Tergite IX with 12 median setae, seven on adjacent small pale patches and 5 more posteriorly without pale patches, all pointing toward anal point. Anal point broad, parallel-sided with a round apex, 119 μm long. Sternapodeme squared, 129 μm long. Phallapodeme 202 μm long. Superior volsella S-type with robust apex, and base with 5 long setae, 83 μm long. Inferior volsella 178 μm long, base slightly bent, apex reaches the mid-section of the anal point. Gonocoxite 111 μm long. Gonostylus 204 μm long, with 5 long setae at apex; HR 0.5, HV 2.6.

Remarks.

The single adult male of the Chironomus species we collected from Pond A closely resembles the Chironomus species Martin (2023) described as Species 2 c. or Chironomus species parariparius. According to Martin (2023), only the images of the adult male are available based on the reared collection of specimens by J. E. Sublette, now kept in the Zoological Museum of the University of Minnesota, St. Paul. Pupa is only described by the caudolateral spur of segment VIII; however, larva morphology and cytology are described by Martin (2023) in detail. Martin (2023) describes the species’ habitat as snow pools, similar to Pond A. The adult male from pond A is quite distinguishable from other species in the C. riparius group based on the characteristics of the hypopygium (Jon Martin, pers. comm. 18 March 2024).

Figures

Figure 13. Chironomus nr. sp. parariparius of Martin (2023), adult male A abdominal tergites III – V B antenna C head D wing E hypopygium. Scale bars: 100 µm.