Rhinusa neta (Germar, 1821)
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https://dx.doi.org/10.3897/zookeys.1195.112328 |
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publication LSID |
lsid:zoobank.org:pub:617FBE9C-72D1-479D-8336-1E9325D74B93 |
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persistent identifier |
https://treatment.plazi.org/id/AC465478-41D1-5C0E-9C8F-AA6D6977706D |
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scientific name |
Rhinusa neta (Germar, 1821) |
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12) Rhinusa neta (Germar, 1821) View in CoL
Material examined.
21 mature larvae; 7 ♂ and 12 ♀ pupae. Serbia, Zemun , ex Linaria vulgaris , 15.08.2017, leg., det. I. Toševski.
Redescription of mature larva
(Figs 54A, B View Figure 54 , 55A-E View Figure 55 , 56A-C View Figure 56 ). Measurements (in mm). Body length: 4.60-7.00 (avg. 5.20). The widest place in the body (meso- and metathorax) measures up to 1.50. Head width: 0.62-0.75 (avg. 0.70).
General. Body elongate, moderately slender, curved, rounded in cross section (Fig. 54A View Figure 54 ). All thoracic segments equal in size. Meso- and metathorax each divided dorsally into two folds (prodorsal fold distinctly smaller than postdorsal fold). Pedal folds of thoracic segments isolated, conical, and prominent. Abdominal segments I-III of similar size, next segments tapering towards posterior body end. Abdominal segments I-VII each divided dorsally into two almost equal in size folds; postdorsal folds only slightly higher than prodorsal folds. Segments VIII and IX dorsally undivided. Epipleural folds of segments I-VIII conical. Laterosternal and eusternal folds of segments I-VIII conical, weakly isolated. Abdominal segment X divided into four folds of equal size, lateral folds each with a single minute seta. Anus situated ventrally, almost completely covered by ninth segment.
Thoracic and abdominal spiracles unicameral; thoracic spiracles (Fig. 54A View Figure 54 ) placed laterally close to mesothorax; abdominal spiracles (Fig. 54A View Figure 54 ) placed medially on segments I-VIII.
Colouration. Dark yellow to brown head, medial parts of epicranium less sclerotised (Fig. 54B View Figure 54 ). All thoracic and abdominal segments whitish, premental shield only slightly darker than the rest of prodorsum (Fig. 54A View Figure 54 ). Cuticle covered with asperities.
Vestiture. Setae on body thin, yellowish, different in length (very short or medium).
Head capsule (Figs 54B View Figure 54 , 55A View Figure 55 ). Head suboval, endocarinal line present, reaching more than the 2/3 of the length of frons. Frontal sutures on head partially indistinct, wide. Frons covered with knobby, dark asperities. Single pair of stemmata in the form of small black spots (st) placed laterally, close to the end of the frontal suture. Des1 short, located in middle part of epicranium; long des2; long des3 located anteriorly, almost on the border of the frontal suture; minute des4 located laterally; and long des5 placed anterolaterally above stemma (Fig. 55A View Figure 55 ). Fs1 short, located posterolaterally; fs2 and fs3 absent; fs4 medium, located anteriorly; and long fs5 located anterolaterally, close to antenna (Fig. 55A View Figure 55 ). Les1 and les2 medium; two short ves. Epicranial area with three pes.
Antennae placed distally of the frontal suture, on the inside; membranous and distinctly convex basal article bearing one conical elongate sensorium, plus a single sensillum basiconicum and single sensillum ampullaceum (Fig. 55B View Figure 55 ).
Clypeus (Fig. 55C View Figure 55 ) trapezoidal, ~ 3.5 × as wide as long with two medium cls, localised posterolaterally, with one sensillum between them; basolateral parts distinctly more sclerotised than the middle part; anterior border slightly curved towards the inside.
Mouth parts. Labrum (Fig. 55C View Figure 55 ) ~ 2.5 × as wide as long, with three piliform lrs, variable in length; lrs1 and lrs2 elongated, located medially, lrs3 short, located anterolaterally; anterior border bi-sinuate. Epipharynx (Fig. 55C View Figure 55 ) with three relatively elongated finger-like als, identical in length, three piliform ams variable in length and single short finger-like mes; labral rods (lr) elongated, close to kidney shaped. Mandibles (Fig. 55D View Figure 55 ) bifid, cutting edge smooth; two medium piliform and short mds, both located close to lateral border. Maxillolabial complex: maxilla brownish sclerotised (Fig. 55E View Figure 55 ), stipes with one stps, two pfs and one very short mbs and one sensillum, stps and both pfs1-2 relatively long; mala with six finger-like dms variable in length; four piliform vms, medium to short in length. Maxillary palpi two-segmented; basal palpomere distinctly wider and slightly longer than distal one; basal palpomere with short mpxs and two sensilla, distal palpomere with a group of four apical sensilla in terminal receptive area. Prementum (Fig. 55E View Figure 55 ) close to oval-shaped, with one long prms; ligula with slightly sinuate margin and two medium ligs; premental sclerite weakly sclerotised, only lateral parts well visible. Labial palpi one-segmented; each palp with a single pore, and a group of three apical sensilla basiconica on terminal receptive area; surface of labium smooth. Postmentum (Fig. 55E View Figure 55 ) with three pms, medium pms1 located anteromedially, long pms2 located laterally, and medium pms3 located anterolaterally; membranous area covered with knobby asperities.
Thorax. Prothorax (Fig. 56A View Figure 56 ) with eight medium to short prns; two medium ps; and single short eus. Mesothorax (Fig. 56A View Figure 56 ) with one minute prs, two medium and one minute pds (ordered: minute, medium, medium); one medium as; two medium and single minute ss; one medium eps; two medium ps; and single minute eus. Chaetotaxy of metathorax (Fig. 56A View Figure 56 ) almost identical to that of mesothorax. Each pedal area of thoracic segments with four relatively long and one minute pda.
Abdomen. Segments I-VIII (Fig. 56B, C View Figure 56 ) with one minute prs (segment VIII without); four pds of various length; one minute and one medium ss; three medium eps; one medium ps; one medium lsts; and two short eus. Abdominal segment IX (Fig. 56C View Figure 56 ) with one minute and one medium ds; one medium and one minute ps; and two minute sts.
Description of pupa
(Figs 57A-C View Figure 57 , 58A-C View Figure 58 ). Measurements (in mm). Body length: 2.70-4.20 (avg. 3.25); body width: 1.53-2.26 (avg. 2.10); thorax width: 1.00-1.53 (avg. 1.40); rostrum length: up to 0.73 ♂ and 0.83 ♀.
Body. Integument white, with some parts dark sclerotised; moderately stout, curved. All setae placed on dark brown spots. Head elongated protuberances present (h-pr) on head above eyes. Rostrum elongated, on both sexes almost 4 × as long as wide, reaching over mesocoxae. Pronotum trapezoidal 2.2 × as wide as long. Pronotal protuberances (p-pr) conical, flattened, sclerotised, separated at bases. Meso- and metanotum similar in size. Abdominal segments I-IV almost identical in size; segments V and VI tapering gradually, VII semicircular; segment VIII narrow; segment IX reduced. Abdominal segment VIII dorsally with flattened, weakly sclerotised abdominal protuberance (a-pr). Urogomphi (ur) short, ending with sclerotised, sharp apexes (Fig. 57A-C View Figure 57 ).
Chaetotaxy. Well developed, setae medium to elongated, transparent. Head with one medium sos and one medium os. Rostrum with two rs (Fig. 58A View Figure 58 ). Pronotum with three as, single ls, and three pls all equal in length. Dorsal parts of meso- and metathorax with three setae of various length, placed medially. Apex of femora with a single long fes (Fig. 58A-C View Figure 58 ). Abdominal segments I-VII dorsally with five setae, variable in length: first and third minute, second, fourth, and fifth medium; setae first to fourth placed close to posterior margin of the segment, fifth placed below stigma (on segments VI and VII all setae medium in size). Abdominal segment VIII dorsally with four elongated setae dorsally. Each lateral part of abdominal segments I-VIII with two short setae. Ventral parts of abdominal segments I-VIII with three medium setae. Abdominal segment IX with three short setae ventrally (Fig. 58A-C View Figure 58 ).
Remarks and comparative notes.
This species is very common and has a wide distribution (western, central, and southern Europe, Caucasus, Iran, central Asia; Alonso-Zarazaga et al. 2023). It was accidentally introduced in North America ( Buchanan 1937) but subsequently used as a biological control agent against the dalmatian toadflax ( Linaria dalmatica ) and yellow toadflax ( Linaria vulgaris ) ( Sing et al. 2016). There are no noteworthy morphological differences between various populations living on different species of Linaria . The shape of the rostrum is the most useful character, which allows easy separation at adult stage of R. neta from the other species of the genus with short elytra, except for the western Mediterranean R. incana , from which it can be distinguished only by the shape of the female rostrum, the antennal insertion being located slightly more towards the apex of the rostrum in both sexes, and the scales of the dorsal vestiture being slightly stouter.
The descriptions of the larva and pupa of R. neta given by Ścibior and Łętowski (2018) are generally similar to ours, with some differences probably due to the nomenclature used by these authors. In our opinion, some setae were incorrectly identified in the larva, e.g., as1 instead of ls1. There are also some discrepancies in the interpretation of pupal characters, such as a lack of rs2 or sos instead of os and four abdominal dorsal setae instead of five.
Biological notes.
This is an oligophagous species whose larvae develop on different toadflaxes ( Linaria spp.). The females oviposit eggs from mid-June to the end of September in an already developed seed capsule. The larvae are typical seed feeders. Larval development was recorded on many Linaria species: L. vulgaris , L. genistifolia , L. dalmatica , L. grandiflora Desf., L. angustissima , L. arvensis (L.) Desf., L. corifolia Desf., L. peloponnesiaca Boiss. and Heldr., L. repens (L.) Mill., L. rubioides Vis. & Pancic, L. spartea (L.) Chaz., L. supina (L.) Chaz., and L. vulgaris . Oviposition of eggs and larval feeding do not cause swelling of seeds, but larvae may consume a large proportion of seeds within a capsule, decreasing the seed output but not killing the host plant ( Sing et al. 2016).
Rhinusa vestita group
Adult diagnosis. Rostrum short and stout in both sexes; elytra subquadrate, distinctly flattened on disc; penis with short endophallus beginning just in front of basal third of its body.
No known copyright restrictions apply. See Agosti, D., Egloff, W., 2009. Taxonomic information exchange and copyright: the Plazi approach. BMC Research Notes 2009, 2:53 for further explanation.
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