Eurekapnia Stark & Broome, 2019

Broome, Hannah Jean, Stark, Bill P. & Baumann, Richard W., 2019, A Review Of The Genus Bolshecapnia Ricker, 1965 (Plecoptera: Capniidae), And Recognition Of Two New Nearctic Capniid Genera, Illiesia 15 (1), pp. 1-26 : 16

Eurekapnia Stark & Broome , New genus

Type species: Capnia maculata Jewett, 1954 = Eurekapnia maculata (Jewett) by monotypy.

Male characteristics: 1. The male epiproct is almost uniformly slender from base to apex except for an apical area capable of being folded laterally to increase the apical width ( Figs. 37, 40-42 ). 2. The ventral and lateral margins of the finger-like epiproct are formed by a pair of thick sclerites that are separated along the dorsum by a wide groove ( Figs. 37-40 ); width of the groove varies based on position of the sclerites (compare Figs. 51-52 ). 3. Abdominal tergum 9 bears a pair of conical knobs separated by a gap slightly wider than the folded epiproct tip ( Figs. 37-38, 40 , 43, 45). 4. The ventral vesicle is almost circular in outline and is attached to the intersegmental membrane between sterna 8 and 9 (Figs. 47-48). The vesicle surface is covered with thick setae.

Female characteristics: 1. The subgenital plate is uniformly pigmented and extends across the entire width of sternum 8 between the two pleural membranes ( Figs. 35-36 ). 2. The posterior margin of the plate is rounded and scarcely exceeds the posterior margin of sternum 8.

Wings: 1. The venation of E. maculata , the only known species, is very similar to that of Bolshecapnia and Sasquacapnia , however the wings of Eurekapnia have scattered brown maculations that give them a distinctive appearance.

Larval characteristics: Undescribed.

Currently recognized species: E. maculata

Distribution: Known only from California ( DeWalt et al. 2018).

Etymology: The generic name, Eurekapnia , is based on the California state motto, “Eureka”, a Greek word whose literal meaning is defined as “I have found it”. This word was supposedly uttered by Archimedes after he discovered a successful method for estimating the purity of gold.

Figures

Figs. 37-42. Eurekapnia maculata, male reproductive structures. All localities in California, Alameda Co., Arroyo Mocho. 37. Male epiproct and terminal abdominal segments dorsal. 38. Epiproct lateral. 39. Epiproct base dorsal. 40. Epiproct apex unexpanded dorsal. 41. Epiproct, with apex expanded dorsal. 42. Epiproct apex expanded dorsal.

Figs. 49-54. Eurekapnia maculata, variation in male epiprocts. All localities in California. 49. San Benito Co., Chalone Creek male epiproct unexpanded. 50. Sacramento Co., Cosumnes River epiproct partially expanded. 51. Butte Co., Little Chico Creek, epiproct apex slightly expanded. 52. San Luis Obispo Co., Santa Rita Creek, epiproct apex slightly expanded. 53. Napa Co., Wragg Creek epiproct apex unexpanded. 54. Napa Co., Knoxville Creek, exposed fusion plate at epiproct base.

Figs. 31-36. Bolshecapnia spenceri (31-34) and Eurekapnia maculata (35-36) male and female reproductive structures. B. spenceri localities in British Columbia, Consolation Lake., and E. maculata localities in California, Alameda Co., Arroyo Mocho. 31. Male abdominal sternum 9 and vesicle. 32. Male vesicle. 33. Female subgenital plate. 34. Subgenital plate detail. 35. Female abdominal sterna 7-10. 36. Subgenital plate detail (sgp = subgenital plate, ve = vesicle).