Meligethes matronalis Audisio & Spornraft, 1990

Audisio, Paolo, Mancini, Emiliano & Biase, Alessio De, 2006, A new species of the pollen­beetle genus Meligethes (Coleoptera: Nitidulidae) of the M. aeneus group from Greece, with review of the M. subaeneus complex, Zootaxa 1275, pp. 43-60 : 51-57

Meligethes matronalis Audisio & Spornraft, 1990

( Figs. 4 , 9–10 , 15 )

Diagnosis

Medium­sized (length 2.20–3.10 mm) and moderately variable species, usually dark brown with pale brown to orange­brown legs and antennae, with maximum pronotal width at posterior angles ( Fig. 4 ). Similar to the widespread European M. subaeneus Sturm, 1845 , but with dorsal punctures denser and coarser (less close than in M. epeirosi n.sp.; spaces between punctures 1.2–1.3X diameter), body larger (2.2–3.1 mm in M. matronalis , 1.7–2.8 mm in M. subaeneus ), shiny surface between elytral punctures, pronotum less dull, and different median lobe of aedeagus being longer than M. subaeneus ( Fig. 10 ; ratio LEAE/WIAE [ Fig. 17 f] = 1.95–2.13 in M. matronalis , 1.66–1.78 in M. subaeneus ), and subparallel at sides (in M. epeirosi n.sp. median lobe with maximum width at distal threefifths, distinctly narrowed both distad and proximad: Figs. 11–12 ). Quite distinct from all members of the M. coracinus subgroup due to pronotal maximum width close to the posterior angles. Female ovipositor as figured ( Fig. 15 ), with slightly darker apex.

Geographic distribution

This species is widespread from N Spain (Pyrenean Mts.) westward throughout most of Europe, reaching the Caucasus ( Azerbaijan) eastward ( Audisio, 1993; Audisio et al., 2000, 2005a). This species is rare and local, except for localities from central and northern Europe (southern Germany to southern Finland and Sweden northward), where the present­day distribution is associated with a recent anthropogenic introduction of the larval host­plant (see below) that is widely used as an ornamental (Jalaas & Suominen, 1994; Meybohm, 1995; Renner, 1995; Spornraft, 1998; Ericson, 1999; Schillhammer & Schuh, 2004).

subgroup.

Continued species of the Meligethes coracinus subgroup (see Fig. 17 ).

measurement measurement description

acronyms

Fig 17 a WPR1 pronotal width at posterior angles

WPR2 pronotal width at 1/3 of its length

LEPR pronotal length

LELY elytral length (mean)

WELY elytral width (mean)

Fig 17 b W03J maximum width of 3rd antennal joint

W10J maximum width of 10th antennal joint

Fig 17 c LETI length of front tibiae (mean)

WITI maximum width of front tibiae, excluding teeth (mean)

Fig 17 d LFTA total length of front tarsi (mean)

WFTA maximum width of second tarsal joint of front tarsi (mean)

LLTJ length of last tarsal joint of front tarsi (mean)

WLTJ maximum width of last tarsal joint of front tarsi (mean)

Fig 17 e WITE maximum width of tegmen

WIMN width of tegmen at subproximal narrowest point

ANGT measure (expressed as ratio of the angular value in degrees x 100 over the value of 180°) of the sector defined by the inner edge of the paramera

LETE length of tegmen

DETE depth of tegminal incisure

Fig 17 f LEAE length of median lobe of the aedeagus

LEOS length of the distance between the posterior edge of the aedeagal ejaculatory ostium and apex of the median lobe of the aedeagus

WIAE maximum width of median lobe of the aedeagus

Fig 17 g V length of segment AB (apex of the median lobe of aedeagus)

H length of segment AC (apex of the median lobe of aedeagus)

Biological notes

This species is strictly monophagous, and the well­known larval host­plant is Hesperis matronalis L. ( Brassicaceae Hesperideae ; Audisio & Spornraft, 1990; Audisio, 1993; Audisio et al., 2001a, 2002). Only a few Caucasian localities ( Armenia, Eastern Turkey) had populations associated with Hesperis transcaucasica Tzvelev (unpublished data); however this probably represents a subspecies of H. matronalis ( Davis, 1965) . Meligethes matronalis , at least in natural environments, is strongly associated with edges and clearings of broad­leaved woods (beech, mesophilous oaks, alders, chestnuts, and others), from 200 to 2500 m a.s.l.

Taxonomic observations

This species, except for variation in body size (2.2–3.1 mm), appears to be morphologically homogeneous throughout most of its geographic range (both primary and secondary), except the Caucasian populations are represented by specimens showing relatively duller spaces between dorsal punctures in comparison with W. European specimens. Genetic data available from allozyme analyses ( De Biase, 2000; Audisio et al., 2002), COI gene sequences (unpublished data), and mitochondrial Control Region fragments (unpublished data), indicate a stronger genetic affinity between M. matronalis and M. coracinus , than to M. subaeneus . Despite this genetic evidence, M. subaeneus and M. matronalis are much more closely related to each other in a phenetic space described by morphometric variables ( Audisio et al., 2001a), and Kirejtshuk (1997) erroneously concluded that these two species were synonymous.

Figures

FIGURE 17. Schematic drawings of morphological characters measurements for Meligethes species—a: body shape and pronotum; b: antennae; c: protibiae; d: protarsi; e: tegmen; f: aedeagus; g: aedeagal apex. Refer to Table 2 for list of characters and acronyms.

FIGURES 1 – 4. Dorsal habitus of Meligethes epeirosi n. sp. (♂ paratype from Greece, Katara Pass, Fig. 1), of M. subaeneus Sturm (♂ specimen from Italy, Latium, Rocca di Papa, Fig. 2; ♂ specimen from Spain, Cantabria, Campollo, Fig. 3), and of M. matronalis Audisio & Spornraft (♂ specimen from Italy, Latium, Rocca di Papa, Fig. 4). Scale bar = 2.00 mm.

FIGURES 5 – 12. Tegmen and median lobe of aedeagus (dorsal view) of Meligethes coracinus Sturm (♂ specimen from Italy, Lombardia, Lovero Valtellino, Figs. 5 – 6), of M. subaeneus Sturm (♂ specimen from Italy, Latium, Rocca di Papa, Figs. 7 – 8), of M. matronalis Audisio & Spornraft (♂ specimen from Italy, Latium, Rocca di Papa, Figs. 9 – 10) and of Meligethes epeirosi n. sp. (♂ paratype from Greece, Katara Pass, Figs. 11 – 12). Scale bar = 0.50 mm.

FIGURES 13 – 16. Ovipositor of Meligethes coracinus Sturm (Ψ specimen from Italy, Lombardia, San Giacomo di Teglio, Fig. 13), of M. subaeneus Sturm (Ψ specimen from Italy, Latium, Rocca di Papa, Fig. 14), of M. matronalis Audisio & Spornraft (Ψ specimen from Italy, Latium, Rocca di Papa, Fig. 15) and of Meligethes epeirosi n. sp. (Ψ specimen from Greece, Katara Pass, Fig. 16). Scale bar = 0.50 mm.