Rhinusa eversmanni (Rosenschoeld, 1838)

Gosik, Rafal, Caldara, Roberto, Tosevski, Ivo & Skuhrovec, Jiri, 2024, Description of immature stages of Rhinusa species (Coleoptera, Curculionidae, Mecinini) with a focus on diagnostic morphological characters at the species and genus levels, ZooKeys 1195, pp. 1-94 : 1

publication ID

https://dx.doi.org/10.3897/zookeys.1195.112328

publication LSID

lsid:zoobank.org:pub:617FBE9C-72D1-479D-8336-1E9325D74B93

persistent identifier

https://treatment.plazi.org/id/298AD9D9-9FDC-546E-A354-7EAA1DB4FB1F

treatment provided by

ZooKeys by Pensoft

scientific name

Rhinusa eversmanni (Rosenschoeld, 1838)
status

 

10) Rhinusa eversmanni (Rosenschoeld, 1838)

Material examined.

9 mature larvae; 4 ♂ and 2 ♀ pupae. Serbia, Didići, ex Linaria vulgaris , 05.07.2017, leg., det. I. Toševski.

Description of mature larva

(Figs 46A, B View Figure 46 , 47A-E View Figure 47 , 48A-C View Figure 48 ). Measurements (in mm). Body length: 2.70-4.10 (avg. 3.10). The widest place in the body (meso- and metathorax) measures up to 1.30. Head width: 0.60-065 (avg. 0.62).

General. Body elongate, slender, strongly curved, rounded in cross section (Fig. 46A View Figure 46 ). All thoracic segments equal in size. Meso- and metathorax each divided dorsally into two folds (prodorsal fold vestigial, postdorsal fold prominent). Pedal folds of thoracic segments isolated, conical. Abdominal segments I-III of similar size, next segments tapering towards posterior body end. Abdominal segments I-VII each divided dorsally into two folds: postdorsal folds much 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, well isolated. Abdominal segment X divided into four folds of equal size. Anus situated ventrally.

Thoracic and abdominal spiracles unicameral; thoracic spiracles (Fig. 46A View Figure 46 ) placed laterally close to mesothorax; abdominal spiracles (Fig. 46A View Figure 46 ) placed medially on segments I-VIII.

Colouration. Dark brown to brown head, medial parts of epicranium less sclerotised (Fig. 46B View Figure 46 ). Prodorsal sclerite brownish. All thoracic and abdominal segments whitish (Fig. 46A View Figure 46 ). Cuticle densely covered with cuticular asperities. All setae of thorax and abdomen placed on dark brown spots.

Vestiture. Setae on body thin, brown, different in length (minute to long).

Head capsule (Figs 46B View Figure 46 , 47A View Figure 47 ). Head suboval, endocarinal line present, reaching to the 3/4 of the length of frons. Frontal sutures on head distinct, very 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 long, located in middle part of epicranium; long des2 located anteriorly; long des3 placed almost on the border of the frontal suture; minute des4, located laterally; and elongated des5 placed anterolaterally above stemma (Fig. 47A View Figure 47 ). Fs1 short, located posterolaterally; fs2 and fs3 absent; fs4 long, located anteriorly; and long fs5 located anterolaterally, close to antenna (Fig. 47A View Figure 47 ). Les1 and les2 medium; two short ves. Epicranial area with four pes.

Antennae placed distally of the frontal suture, on the inside; membranous and distinctly convex basal article bearing one conical, moderately elongate sensorium, plus a single sensillum ampullaceum and two sensilla basiconica (Fig. 47B View Figure 47 ).

Clypeus (Fig. 47C View Figure 47 ) trapezoidal, ~ 2.7 × as wide as long with two short cls, localised posterolaterally, with one sensillum between them; posterior part distinctly less sclerotised than the basal part; anterior border straight.

Mouth parts. Labrum (Fig. 47C View Figure 47 ) ~ 2.4 × as wide as long, with three piliform lrs, various long; lrs1 and lrs2 elongated, located medially, lrs3 medium, located anterolaterally; anterior border bi-sinuate. Epipharynx (Fig. 47C View Figure 47 ) with three elongated finger-like als, almost identical in length; two piliform ams variable in length; single finger-like mes; labral rods (lr) distinct, kidney shaped. Mandibles (Fig. 47D View Figure 47 ) bifid, cutting edge with additional, blunt tooth; two medium piliform and short mds, both located close to lateral border. Maxillolabial complex: maxilla brownish sclerotised (Fig. 47E View Figure 47 ), stipes with one stps, two pfs and one short mbs and one sensillum, stps and both pfs1-2 elongated; mala with five finger-like dms variable in length; four piliform vms, medium to short in length. Maxillary palpi two-segmented; basal palpomere wider and longer than distal one; basal palpomere with short mpxs and single sensillum, distal palpomere with a group of two or three apical sensilla in terminal receptive area. Prementum (Fig. 47E View Figure 47 ) close to oval-shaped, with one long prms; ligula with slightly sinuate margin and two short ligs; premental sclerite well sclerotised, U-shaped. Labial palpi one-segmented; palpi with a single pore, and a pair of apical sensilla (ampullacea) on terminal receptive area; surface of labium smooth. Postmentum (Fig. 47E View Figure 47 ) with three pms, medium pms1 located posteromedially, long pms2 located mediolaterally, and medium pms3 located anterolaterally; membranous area partially covered with knobby asperities.

Thorax. Prothorax (Fig. 48A View Figure 48 ) with 12 elongated to short prns, ten of them placed on dorsal sclerite; two medium ps; and single short eus. Mesothorax (Fig. 48A View Figure 48 ) without prs; with two elongated and two short pds (ordered: short, long, short, long); one long as; two long and single minute ss; one long eps; two long ps; and single minute eus. Chaetotaxy of metathorax (Fig. 48A View Figure 48 ) 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. 48B, C View Figure 48 ) with one minute prs (segments VII and VIII without); four pds of various length; one minute and one long ss; three long eps; one long ps; one medium lsts; and two short eus. Abdominal segment IX (Fig. 48C View Figure 48 ) with two minute and one medium ds; one medium and one minute ps; and two minute sts.

Description of pupa

(Figs 49A-C View Figure 49 , 50A-C View Figure 50 ). Measurements (in mm). Body length: 2.36-2.76; body width: 1.73-2.00; thorax width: 1.03-1.20; rostrum length: up to 0.86 ♂ and 1.23 ♀.

Body. Integument white, stout. Head elongated protuberances present on head above eyes (h-pr). Rostrum elongated, reaching over mesocoxae (almost 4.2 × as wide as long on both male and female). Pronotum trapezoidal 2.5 × as wide as long. Pronotal setae placed on dark brown spots. 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. Urogomphi (ur) short, ending with sclerotised, sharp apexes (Fig. 49A-C View Figure 49 ).

Chaetotaxy. Well developed, setae elongated to short, transparent. Head with one medium sos and one medium os. Rostrum with a single rs (Fig. 50A View Figure 50 ). Pronotum with three as, three ls, and three pls all elongated, 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. 50A-C View Figure 50 ). Abdominal segments I-VII dorsally with four setae dorsally, variable in length: first and third minute, second, short, and fourth medium; setae first to third placed close to posterior margin of the segment, fourth placed below stigma (on segment VII all setae medium). Abdominal segments VII and VIII with four elongated setae dorsally. Each lateral part of abdominal segments I-VIII with one short seta. Ventral parts of abdominal segments I-VIII with three short setae. Abdominal segment IX with four short setae ventrally (Fig. 50A-C View Figure 50 ).

Remarks and comparative notes.

This is an uncommon species with a wide and fragmentary distribution: France, Italy, Germany, Czech Republic, Ukraine, Russia, Kazakhstan, Uzbekistan, and Tajikistan ( Alonso-Zarazaga et al. 2023). At the adult stage, it is easily distinguishable from the other species of the group by the shape and length of the rostrum, especially in the female, which has a longer antennal club than all the other species of the genus.

Biological notes.

The stem galls caused by R. pilosa on L. vulgaris and by R. rara on L. genistifolia or L. dalmatica are niches for the development of R. eversmanni , which is another inquiline weevil. The females oviposit their eggs on fully developed galls, and hatched larvae bore holes towards the central portion of the gall, where larvae of the gall inducer are positioned. Larvae of R. eversmanni are very aggressive, killing all resident larvae inside galls, while competition between them inside galls is pronounced and cannibalism is commonly observed. Over 20 adults of R. eversmanni can develop in the larger gall induced by R. pilosa or R. rara ( Toševski et al. 2015).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Coleoptera

Family

Curculionidae

Genus

Rhinusa