Silo chrisiammos Malicky 1984

Waringer, Johann, Graf, Wolfram, Sipahiler, Füsun & Malicky, Hans, 2017, The larvae of Silo chrisiammos Malicky 1984 and Lithax musaca Malicky 1972 (Trichoptera: Goeridae), including a key to the Goeridae larvae of the Eastern and Hellenic western Balkan regions, Zootaxa 4306 (1), pp. 67-80 : 68-72

publication ID

https://doi.org/ 10.11646/zootaxa.4306.1.3

publication LSID

lsid:zoobank.org:pub:059A9922-B98D-4E1D-B026-415F1573BA13

DOI

https://doi.org/10.5281/zenodo.6030231

persistent identifier

https://treatment.plazi.org/id/03ACBE39-0176-FFC0-85FF-FAD92D53816B

treatment provided by

Plazi

scientific name

Silo chrisiammos Malicky 1984
status

 

Description of the final instar larva of Silo chrisiammos Malicky 1984 View in CoL

Biometry. Body length ranging from 6.7 to 8.6 mm, head width from 0.86 to 1.00 mm (n = 3).

Head. Head capsule roundish, with strongly protruding eyes and orange to reddish brown coloration; surface coarsely granulated ( Figs. 1–3 View FIGURES 1 – 6 ). In lateral view, head profile rounded ( Fig. 3 View FIGURES 1 – 6 ). Pale ring around each eye ( Fig. 3 View FIGURES 1 – 6 ). Head capsule with complete set of 18 pairs of primary setae and small number of tiny pale secondary setae in occipital region. On each parietal, 10 dorsal and 2 ventral primary setae present, frontoclypeus with 6 pairs of primary setae. Antennae originating within small dents halfway between anterior eye margin and anterior head capsule margin ( Fig. 1 View FIGURES 1 – 6 , arrow), each consisting of 1 short cylindrical base and 1 short flagellum. Labrum brown, with 3 pairs of primary setae at anterolateral corners; anteriorly, with 1 small median and 2 large lateral lobes, the latter fitted with long setal brushes ( Fig. 2 View FIGURES 1 – 6 ). Ventral apotome very narrow and elongate, amphora-shaped, orange, postgenal suture approximately 39% of apotome length; horn-like, curved anterolateral lobes present ( Fig. 4 View FIGURES 1 – 6 ). Mandibles black, lacking terminal teeth along edges as well as lacking ridges in central concavity ( Fig. 4 View FIGURES 1 – 6 ).

Thorax. Pronotum enlarged, coarsely granulated, with lateral yellowish-brown semicircular and plate-like extensions ( Fig. 5 View FIGURES 1 – 6 ); the latter extended anterolaterally, pointed, and partially divided by short oblique transverse suture at two-thirds distance from anterolateral angle ( Fig. 5 View FIGURES 1 – 6 s). Central pronotal section medium to dark brown, fitted with single, nose-like dorsal hump widest along anterior pronotal border and fading in height and width when approaching the posterior pronotal border ( Figs. 5 View FIGURES 1 – 6 n, 6n), thereby creating two dark brown lateral dents ( Figs. 5 View FIGURES 1 – 6 d, 6d). In anterior view, anterior pronotal border steeply sloped dorsally, shaping a semicircular retraction space for the head capsule ( Fig. 1 View FIGURES 1 – 6 ). Pronotal muscle attachment spots dark brown, each lacking border of dark-pigmented dots present in other Goeridae larvae.

Mesonotal sclerites coarsely granulated, medium brown, arranged in 3 closely-fitting pairs with suture clearly visible between sclerites arbitrarily numbered 1 and 2 ( Fig. 7 View FIGURES 7 – 12 ). With dorsal transverse hump anterior of posterior borders of mesonotal sclerites number 3. (The larva blocks its case opening against predators with its pronotum and anterodorsal and anterolateral mesonotum (= operculum sensu Wiggins 1996; figs. 16.1A, 16.1B) when it withdraws its head.) Mesepisterna (= mesopleurites) each with long and pointed anterior process projecting free from body and fitting against lateral pronotal margin ( Fig. 7 View FIGURES 7 – 12 m).

Metanotum covered by 4 pairs of coarsely granulated, light-to-medium brown sclerites with sclerite #2 small and relatively weakly sclerotized ( Fig. 7 View FIGURES 7 – 12 ).

Legs orange to light brown; coxa of each foreleg wider than those of mid- and hind legs ( Figs. 8–10 View FIGURES 7 – 12 ). Coxae of all three legs with ventral groups of dark setae; additional face setae lacking on all femora. Ventral edge of 1 st femur with 2 pale straw-colored spines and 1 dark seta, 2nd femur with 2 dark ventral-edge setae and 3rd femur with 2 dark long and 1 short pale setae. Proximal sections of trochanters without setae. Tarsal claw of each leg curved, with strong basal seta originating from conical base ( Figs. 8–10 View FIGURES 7 – 12 ).

Abdomen. Abdominal segment I with 1 dorsal and 2 lateral fleshy protuberances, latter with weak semicircular posterior sclerotization and sclerotized bar extending posterodorsad ( Fig. 11 View FIGURES 7 – 12 ). Setal areas sa 1, sa 2, and sa 3 (sensu Wiggins 1996) fused, thereby creating continuous transverse row of setae anterior of dorsal protuberance to dorsal section of each lateral protuberance; small setal group present posterior of dorsal protuberance; setal area sa 3 covering dorsal section of each lateral protuberance ( Fig. 11 View FIGURES 7 – 12 ). On abdominal sternum I, setal areas sa 1, sa 2, and sa 3 fused, creating continuous row of setae with basal sclerites minute and inconspicuous; setal number 58–62 ( Fig. 12 View FIGURES 7 – 12 ).

Gills consisting of 2–4 filaments and additional single filaments ( Fig. 13 View FIGURES 13 – 17 ). Dorsal gills present at most from 3rd segment (postsegmental position) to 7th segment (postsegmental position). Ventral gills ranging from 3rd (presegmental) to 7th segment (postsegmental). Lateral gills lacking. Lateral fringe extending from posterior 1/4 of abdominal segment III to end of abdominal segment VIII.

Posterior margin of abdominal segment IX with 18 setae, 6 of them long and remainder short to medium in length ( Figs. 14, 15 View FIGURES 13 – 17 ). Unsclerotized basodorsal section of anal proleg with group of 6–8 short and 3 large, dark setae. Anal proleg lateral sclerite with dark dorsal stripe; anal claw with yellow base and dark brown apical section and with tiny accessory hook ( Figs. 14, 15 View FIGURES 13 – 17 ).

Case. Fifth instar larval case flattened, 7.1–9.2 mm long, width at anterior opening 3.9–5.1 mm, at posterior opening 3.0– 3.1 mm, height 2.1–2.4 mm (n = 3), made of mineral particles and consisting of wing-like, large ballast stones up to 5 mm long and 1.7 mm wide along each side, connected by bottom and roof sections made of much smaller sand grains 0.3–1.0 mm in diameter. Compared with other Goeridae , the lateral wing-like extensions (= ballast stones) are small ( Fig. 16 View FIGURES 13 – 17 ). Posterior case membrane of prepupae with 5 narrow, oval apertures arranged in a semicircular pattern ( Fig. 17 View FIGURES 13 – 17 ).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Trichoptera

Family

Goeridae

Genus

Silo

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