Dictyogenus, Klapalek, 1904

Reding, Jean-Paul G., Launay, Bertrand, Doaré, Jacques Le, Ruffoni, Alexandre & Vinçon, Gilles, 2019, Two New Species Of Dictyogenus Klapálek, 1904 (Plecoptera: Perlodidae) From The Jura Mountains Of France And Switzerland, And From The French Vercors And Chartreuse Massifs, Illiesia 15 (2), pp. 27-64 : 51-52

publication ID

https://doi.org/10.5281/zenodo.4761285

publication LSID

lsid:zoobank.org:pub:C9602772-1A3A-4C43-AA2D-534DF8D79AEB

DOI

https://doi.org/10.5281/zenodo.4764642

persistent identifier

https://treatment.plazi.org/id/352C87AB-0078-FFD0-F5F6-FCC158E07946

treatment provided by

Felipe

scientific name

Dictyogenus
status

 

Morphological key to mature larvae) (> 8 mm) of Dictyogenus

The larva of Dictyogenus fontium was first described by Kühtreiber (1931), but erroneously listed under the name of D. alpinum , as the same author later (1934) recognizes when providing descriptions of both species. The single major criterion used by him for separating both species hinges on the presence ( D. alpinum ) or absence ( D. fontium ) of a row of erect medio-dorsal setae on the pronotum. This criterion, however, only separates the larvae of the Dictyogenus fontium species complex from the group composed of D. alpinum , D. jurassicum and D. muranyii . As can be inferred from the descriptions of the two new species in the present contribution, the setation patterns of the medio-dorsal row of setae on the pronotum as well as on the mesonotum, metanotum and abdominal terga in the genus Dictyogenus are far more complex. We have also noted that early instar larvae continue to undergo important morphological changes prior to reaching 8 mm body length. Prior to this size they are impossible to identify to species.

1 Pronotum with medio-dorsal setae ( Figs. 13 View Figs , 40, 41 View Figs , 65, 71 View Figs ). Postero-dorsal edge of the femora and tibiae with a fringe of dense silky hair setae ( Figs. 15 View Figs , 42 View Figs , 70 View Figs ) …………………… 2

1’ Pronotum devoid of medio-dorsal setae ( Figs. 85, 86 View Figs ). Postero-dorsal edge of femora and tibiae with a fringe of sparse silky hair setae ( Fig. 87 View Figs ) ……….. Dictyogenus fontium species complex (not keyed)

2 Medio-dorsal setae on pronotum, mesonotum, metanotum and abdominal terga very long, erect, dense and continuous, extending to the occiput of the head ( Figs. 65, 71 View Figs ). Interocellar area with a wide yellow patch, trident-shaped ( Figs. 62 View Fig , 63 View Figs ). Lateral ocelli with circum-ocellar yellow patch ( Fig. 63 View Figs ). A large, elliptical, yellow patch above each lateral ocellus ( Figs. 62 View Fig , 63 View Figs ). M-line curved and well visible ( Figs. 62 View Fig , 63 View Figs ). Upper margin of stipes with numerous (7- 25) spines arranged in several rows ( Fig. 69 View Figs ). Pronotum markedly trapezoidal with straight sides ( Fig. 63 View Figs ). Paragenital plates, in ventral view, with numerous spines (3-20, average 15) per side ( Fig. 68 View Figs ). Cerci with medio-dorsal row of swimming hairs of dense and compact, twice as long as the width of the cercus ( Fig. 67 View Figs ) …………………………... Dictyogenus alpinum

2’ Medio-dorsal setae on pronotum, mesonotum, metanotum and abdominal terga less dense, often with interruptions ( Figs. 13, 14, 15 View Figs , 40, 41 View Figs ). Postero-medial part of head without setae, but only with a few long spines ( Figs. 40, 41 View Figs ). Upper margin of stipes with fewer spines (1- 13) arranged in a single row ( Fig. 45 View Figs ). Paragenital plates, in ventral view, with fewer, generally unpaired, spines or else devoid of spines ( Figs. 17 View Figs , 44 View Figs ). Cerci with medio-dorsal row of swimming-hairs only slightly longer than the width of the cercus ( Figs. 16 View Figs , 43 View Figs ) …………………………………… 3

3 Medio-dorsal setae on pronotum short and scattered, arranged as two loosely demarcated rows ( Fig. 13 View Figs ). Interocellar area pale yellow, narrow with well demarcated contours ( Figs. 10 View Fig and 11 View Figs ). Pronotum ovoid in shape ( Fig. 11 View Figs ). Endemic to the Jura Mountains ...................................... Dictyogenus jurassicum

3’ Medio-dorsal setae on pronotum longer, but dense, sometimes covering only its lower half ( Figs. 40, 41 View Figs ). Interocellar area with wide, pale yellow, keyhole-shaped area ( Fig. 37 View Fig , 38 View Figs ).

Pronotum nearly trapezoidal in shape ( Figs. 37 View Fig , 39 View Figs ). Endemic to the Chartreuse and Vercors massifs ………. Dictyogenus muranyii

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Plecoptera

Family

Perlodidae