Scelotrichia willcairnsi, Cairns & Wells, 2008

Cairns, Andi & Wells, Alice, 2008, Contrasting modes of handling moss for feeding and case-building by the caddisfly Scelotrichia willcairnsi (Insecta: Trichoptera), Journal of Natural History 42 (41 - 42), pp. 2609-2615 : 2612-2614

publication ID

https://doi.org/ 10.1080/00222930802354308

persistent identifier

https://treatment.plazi.org/id/74798784-112B-FF83-DCBA-FAB62E27F9FD

treatment provided by

Felipe

scientific name

Scelotrichia willcairnsi
status

sp. nov.

Scelotrichia willcairnsi sp. nov.

( Figures 1A,B E View Figure 1 , 2A–C View Figure 2 )

Holotype

Male, North Queensland, Fishery Falls , south of Cairns , 17 ° 119S 145 ° 529E, 10–11 November 2007, A. Cairns, A. Wells, W. Cairns, ANIC.

Paratypes

Eight males, three females, same data as for holotype .

Other material examined

Larvae, pupae, North Queensland, Fishery Falls, south of Cairns, 17 ° 119S 145 ° 529E, 20 November 2004, A. & W. Cairns, ANIC; larvae, pupae, same locality, 10–11 November 2007.

Male

Body densely covered with black setae; antennae 18-segmented; anterior wing length 2.5–2.7 mm; wing with elongate costal fold extending about half the length of the wing (1.5 mm long), and lined with simple flat androconia.

Genitalia ( Figure 2A–C View Figure 2 ): Abdominal segment VIII laterally with dense long black setae, obscuring much of genitalia ( Figure 1E View Figure 1 ); segment IX covered middorsally by fine microtrichia. Dorsal plate (tergite X) V-shaped distally. Aedeagus with a pair of sharply pointed, mesally directed spines at apex. Inferior appendages in ventral view simple, elongate, closely aligned, fused to ventral abdominal segments VII to IX, apically rounded, mesal margin smooth, ventral gland prominent; in dorsal view obliquely truncate apically; in lateral view almost parallel-sided in distal half, upturned and pointed apically.

Female

Paler than male, antennae 18-segmented; anterior wing length 2.3–2.5 mm, wings unmodified. Genitalia: abdominal segment VIII stout, more than twice the diameter of segment IX, segment X narrow, rounded apically with pair of cerci apically; internally a V-shaped toothed chitinous structure within bursa.

Etymology

The species is named for Will Cairns who, with the aid of a long-handled net, collected the moss with its associated microcaddisfly larvae from the waterfall at Fishery Creek.

Remarks

Scelotrichia willcairnsi is distinctive in having the inner margin of the inferior appendages smoothly rounded apically, close-pressed and lacking mesal teeth, and the aedeagus tipped by a pair of fine spines. Separately, similar attributes are seen in some of the South-east Asian–New Guinean species, but not the set.

Early-instar larvae are probably plesiomorphic, having tergites on the thoracic nota only and none on the abdominal segments; a few equal-length, moderately long setae on the abdominal segments; no microtrichia or anal gills; and long and slender anal claws. The fourth, or final, instar larvae ( Figure 1B View Figure 1 ) are also plesiomorphic, being slightly flattened laterally, with tergites on thoracic nota only, and without accessory hooks on the anal claws. Conceivably, the feeding and case-making behaviour of Scelotrichia are plesiotypic. Marshall (1979) in her review of Hydroptilidae genera postulated an early dichotomy leading to the subfamilies Ptilocolepinae and Hydroptilinae, but this was basically an unresolved comb among Hydroptilinae groups. Wells (1984), on the basis of antennal sensilla and setal arrangement, suggested that Stactobiini are probably an early branch among the Hydroptilinae. For the present, however, no studies are available that might indicate whether use of moss in this and probably other Scelotrichia species is a plesiotypic or a derived condition.

ANIC

Australian National Insect Collection

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