Rhadalinae from the Baltic Amber (Coleoptera, Dasytidae)

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<ul><li><p>09. 11. 1998 Mitt. Mus. Nat.kd. Berl., Dtsch. entomol. Z. 45 (1998) 2, 255-264 </p><p>Rhadalinae from the Baltic Amber (Coleoptera, Dasytidae) </p><p>K. Majer I </p><p>With 39 figures </p><p>Abstract </p><p>Twenty amber inclusions of Dasytinae, deposited in the Museum fur Naturkunde at the Humboldt University, Berlin, were examined. Following taxa are described as new to science: Aplocehlr gen. nov., A. herendti, A . fiiscipes, A. kunowi spp. n. </p><p>Key words: Dasytidae: Rhadalinae, Baltic amber, taxonomy </p><p>Introduction </p><p>Baltic amber inclusions are pieces of fossil resin originating mostly from Pinus (= Pinites) succini- feru (Goepert). They are dated to the early Ter- tiary, Upper Eocene (Priabonian age), between 40 and 36 million years ago. The main locality of the Baltic amber deposits is the Sambian Penin- sula. The history of the exploration of Baltic amber as well as all related research disciplines, e.g. palaeoecology or palaeogeography are dealt with in detail in a large number of papers. Be- sides those refered to the section on taxonomy below, some of the numerous, very usable Polish contributions should also be mentioned: Kos- mowska-Ceranowicz (1985), Skalski (1985), Ku- licka (1985) and Szadziewski (1988). </p><p>In 1986, I took the opportunity to study the Baltic amber inclusions deposited in the Zoologi- cal Museum at the Humboldt University in Ber- lin. Because of the difficulties in classifying the specimens, it is only now that I am able to pub- lish the results of my investigations. The present study includes only a fragment of numerous ex- isting inclusions scattered among many Eu- ropean museums. </p><p>Material and methods </p><p>Twenty-seven amber inclusions (6 from the Berendt, 21 from the Kunow collection) with insect bodies identified by Dr. F. Hieke (Hieke &amp; Pietrzeniuk 1984) as Dasytidae were loaned to me. Seven of them do not belong to the family </p><p>Dasytidae, the rest, i t . 20 inclusions, were examined when immersed in cedar oil in a small Petri dish. The inclusions were examined under a stereoscopic (providing better re- sults) as well as a compound microscope. Both strong trans- mitted and reflected light was used with the stereoscopic mi- croscope. </p><p>Shape and coloration of each inclusion was a limiting fac- tor when observing specimens; only transparent inclusions with well-visible specimens deemed suitable for description as taxa new for science. Milkiness, air bubbles, dust, pollen grains and other impurities occurring in most of the inclu- sions made their evaluation very difficult. At least integu- ment, eyes, antenna, tarsi and elytra had to be visible when describing a taxon. Taxa belonging to the Rhadalini and Pe- lecophorini were left undescribed until revisions of recent genera have been published. </p><p>All inclusions are illustrated as at least schematic drawings. Remarks on their possible generic placement are given and their observability is recorded, so that a future re-examina- tion and inclusion in a more extensive study on the tertiary Dasytidae is facilitated. </p><p>Taxonomy </p><p>The following taxa of the Dasytidae have been mentioned in papers dealing with the Baltic amber (Spahr 1981b: 69): </p><p>D a sy t i d a e : Bachofen-Echt 1949: 109. - Handlirsch 1925: 232. - Larsson 1965: 141.- Hieke &amp; Petrzeniuk 1984: 313. Dasytes: Bachofen-Echt 1949: 109. - Berendt 1845: 56. - Giebel 1852: 655. - Giebel 1856a: 104. - Giebel 1856b: 181. - Handlirsch 1908: 741, 1355. - Klebs 1910: 237. - Larsson 1978: 150. - Scudder 1885: 796. - Scudder 1886: 75. - Scud- der 1891: 508. Aplocrzemirs: Bachofen-Echt 1949: 109. - Klebs 1910: 237. - Larsson 1978: 150. Microjiilistus: Bachofen-Echt 1949: 109. - Klebs 1910: 237. - Larsson 1978: 150. P.si1ofhri.x: Klebs 1910: 237. - Larsson 1978: 150. </p><p>Osova 4, 62500 Brno, Czech Republic. Received December 1996, accepted January 1998 </p></li><li><p>256 Majer, K., Rhadalinae from the Baltic Amber </p><p>Subfamily Rhadalinae </p><p>Only Dasytidae-Rhadalinae were found in the Baltic amber inclusions, corresponding very well with their recent bionomy and the palaeoecology of the Upper Eocene. In general, larvae of the Dasytidae are at least partly carnivorous, preying on larvae of small xylophagous insects. Seconda- rily (apotypically), the larvae are also partly sa- pro- or xylophagous. Imagines are rather polini- vorous, to a lesser extent carnivorous. </p><p>Concerning bionomy, the Rhadalinae are the most ancestral Dasytid subfamily, as their imagi- nes are very often also carnivorous. Most of the species develop under decaying bark, preferably of coniferous trees. After emerging, imagines often do not leave their host trees (they are col- lected on the foliage or in blooming male cones), while others are found as feeding polinivorously on vegetation (blooming flowers or shrubs) in their proximity. </p><p>The Rhadalinae seem radiated from Laurasia into the northern part of South America, the Afrotropical region and, eastwards through the Oriental region to Borneo; they have not yet been desribed from the Australian region. A gen- eric synopsis of this subfamily was provided by Peacock (1987), but her contribution is of rather limited use as it lacks a character analysis and the examination of the terminalia but it includes very useful checklists of species. The subfamily Rhada- linae was re-defined in my latest paper on major taxonomy of the Melyridae s. 1. (Majer 1994). </p><p>Aploceble gen. n. </p><p>Type species Aploceble berendti sp. n. By present designation. Gender: neutrum. Derivatio nomi- nis: erected by combining Aplo (from Aploc- nernus) and ceble (from Trichoceble). </p><p>Generic autapomorphy within the Rhadalinae: membranous appendages fully developed but weakly sclerotized (Fig. 10). </p><p>Homoplasies within the Rhadalinae: eyes pub- escent, tarsomere 3 but particularly 4 smaller than adjoining, epipleura reduced. </p><p>Key to species: </p><p>Plesiomorphy within the Rhadalinae: Visible sterna 1 and 2 apparently freely articulated (symplesiomorphy with the genus Dasyrhadus Fall, 1910). </p><p>D e s c r i p t i o n. Outline Dasyres-like, rather cylindrical, pronotum narrower than elytral base. Vestiture of long, numerous hairs. Eyes mostly pubescent, moderately large and prominent, inner margins almost straight. Antennomeres loosely serrate. Pronotum bordered, rounded at sides, more or less narrowed forwards, perimeter not explanate, strongly bordered, disc evenly convex. Metendosternite unknown but very likely with lamina. Epipleura indistinct along hind third. Visible sterna 1 and 2 apparently freely articulated. Tarsomeres elongate, especially hind 1 and 2 very long, 3 and 4 distinctly shorter (Fig. lo), claws long, membranous appendages fully developed, slightly sclerotized (Fig. lo). </p><p>R e m a r k s . This extinct genus is erected upon the combination of elongate tarsi and fully devel- oped, slightly sclerotized claw appendages. Con- nate sternites 1 and 2 are not observed, they are very likely indeed freely articulated or at most partly connate only, nevertheless this character is not well-visible and thus not fully reliable. The combination of pubescent eyes, fully developed membranous appendages and elongate unequal tarsomeres would be sufficient to erect a tribe. Similarly, a sublateral carina is apparently evi- dent but it could be a matter of a light refrac- tion. The weakly sclerotized appendages may in- dicate a trend to their subsequent reduction as an independent transformation series. Even if Aploceble was a very primitive genus, the species examined here cannot represent direct ancestors of recent genera, as, for instance, the derived rhadaline genera occur already together with the Aploceble. </p><p>It seems that this genus was widely distributed over all Laurasia, as it is represented by a dis- tinct majority of the inclusions. </p><p>D is t r i b u t i o n. Europe (Eocene, Baltic amber) </p><p>1 Puncturation of elytra coarse and dense, eyes bare (Figs I , 2) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1. A. kunowi sp. n. - Puncturation of elytra much finer and sparser, eyes more or less pubescent (Figs 5.8) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 2 Extremities black.. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2. A. berendti sp. n. - Extremities light brown . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3. A.fuscipes sp. n. </p></li><li><p>Mitt. Mus. Nat.kd. B e d . Dtsch. entomol. Z . 45 (1998) 2 257 </p><p>Aploceble kunowi, sp. n. (Fig. 1 ) </p><p>Types. Holotype (Fig. l), '?(?), No. 534 (Coll. Kiinow). Inclusion: extraordinarily clear and light, 4 x 2 x 2 mm; specimen: very well-visible from all sides, length 2.8 mm, width 1.1 mm. </p><p>Figs 1-6. 1. Aplocrblr kuno- wi. sp. n.. side view (No. 534, Holotype, ;). 2. No. 535, side view. 3, 4, Aploceble ,fir.scipe.y sp. n. (No. 539, Holotypc 2 ) : 3. side view (setae invisible, omitted): 4, terminal segment of maxillary palp. 5 , 6. Aploce- hle hereridti sp. n.(No. 525. Paratype. +): 5 , side view; 6. head, frontal view). Scale bars: A = 1 - 3 . 5 : B = 6 : C = 4 </p><p>tered over all upper body surface. Puncturation on pronotum composed of irregular, well-spaced to contiguous punctures, coarse and relatively dense on elytra. Eyes bare, without ocular notch; antennomeres serrate. Pronotum finely bordered on perimeter, outline nearly semicircular, side margins scarcely crenate, nearly glabrous. Epi- </p><p>D i a g n 0 s i s. Easily recognizable by coarse punt- pleura strongly defined U P to apex. Legs with turation and bare eyes. slightly incrassate femora, front tarsomeres mod- </p><p>erately transverse, almost as in Aplocrzemiis D e s c r i p t i o n. 9. Black. Body strongly convex, Stephens. Middle tarsomeres more elongate subcylindrical. Pubescence dual: (a) semi-erect (posterior ones unobservable); claw appendages pale fuscous rather sparse setae; (b) strikingly nearly as long as claws, semi-membranous, weakly long and semi-erect to erect darker setae scat- sclerotized. </p></li><li><p>258 Maier. K., Rhadalinae from the Baltic Amber </p><p>The following specimen may belong to A . ku- nowi: No. 535 (Fig. 2, Coll. Kiinow). Inclusion: light, 5 x 2 x 2 mm; specimen: length 2.8 mm, width not measurable. Very likely conspecific with No. 534 but very poorly observable from all sides. ' </p><p>Aploceble berendti, sp. n. (Figs 5-11) </p><p>T y p e s . Holotype (Figs 7-9), d, No. 528 (Coll. Berendt). Inclusion: relatively dark, rhomboidal, length 21 mm, each side 13 mm, height 2-3 mm; specimen: very well-visible from both sides and ventrally, dorsally only partly so, length 4.1 mm, width not measurable. </p><p>Figs 7-11. 7, 8, 9, Aplocehle berendri sp. n. (No. 528, Holo- type, 3); 7, sublateral view: 8, </p><p>B 1 mm antennomeres 1-10; 9, hind tarsomere. 10, A. herendti, sp. n. (No. 527, Paratype, 2 ) . 11, No. 532, lateral. Scales: A = 8, 9; B = 7 , 10, 11 </p><p>A 0 2 m m </p><p>Paratype (Figs 5-6), 9, No. 525 (Coll. Berendt). Inclusion: relatively dark, 19 x 7 x 3-4 mm; spe- cimen: very well-visible laterally, but less so dor- sally and ventrally (due to the form of the inclu- sion), length 3.9 mm, width not measurable. </p><p>Paratype (Fig. lo), 9, No. 527 (Coll. Berendt). Inclusion: relatively dark, 17 x 15 x 3 mm; speci- men: extraordinarily well-visible [no trace of milkiness or bubbles but thickly coated with dust (pollen?) layer], length 4.3 mm, width not mea- surable. </p><p>D i a g n o s is. Recognizable by fine puncturation and dark extremities. </p><p>D e s c r i p t i on . Black. Body strongly elongate, cylindrical, feebly convex. Pubescence fine, </p></li><li><p>Mitt. Mus. Nat.kd. Berl.. Dtsch. entomol. Z. 45 (1998) 2 259 </p><p>6 1 mm </p><p>r. 0 5 m m </p><p>Figs 12-22. Unidentified inclusions. 12, No. 540; 13, No. 541: 14, No. 542; 15, No. 543; 16-22, No. 549: 16, dorsal view: 17, side view: 18, eye. 19: antennomeres 8-10; 20, detail of pronotal side margin, ventral view: 21, part of elytron; 22, hind claw. Scales: A = 16, 17, 21; B = 12-15; C = 18-20, 22 </p><p>sparse, single; erect light hairs about as long as intervals between punctures. Puncturation mod- erately dense and fine on elytra, pronotal disc with moderately dense punctures having well marked margins, punctures as wide as intervals, punctures form compressed circlets with raised margins on sides of pronotum. Eyes almost bare, with several scattered hairs; antennomeres sharp- ly serrate. </p><p>Pronotum finely bordered on perimeter, side margins slightly crenate, nearly entire. Legs with fine and scattered pubescence. Tarsomeres elon- gate, chiefly on hindlegs, claws slightly incurved, </p><p>appendages as long as claws, also slightly in- curved, sclerotized. </p><p>The following specimens may belong in the proximity of A. herendti: No. 532 (Fig 11, Coll. Kunow), ?(?). Inclusion: light, 5 x 2 x 2 mm; specimen: poorly visible from all sides, with extensive milkiness but eyes distinctly bare, length 3.2 mm, width 1.3 mm. </p><p>No. 540 (Fig. 12, Coll. Kunow), ?(?). Inclu- sion: moderately light, 5 x 4.5 x 2 mm; specimen: with extensive milkiness but membranous appen- dages are well-visible, length 2.8 mm, width 1.6 mm. </p></li><li><p>260 Maier. K.. Rhadalinae from the Baltic Amber </p><p>No. 541 (Fig. 13, Coll. Kunow), ?(?). Inclu- sion: moderately light, 5 x 2 x 2 mm; specimen: with extensive milkiness, it is possibly conspecific with No. 540, length 2.8 mm, width 1.3 mm. </p><p>No. 542 (Fig. 14, Coll. Kunow), ?(?). Inclu- sion: moderately light, 4 x 3 x 2 mm; specimen: very poorly visible, only tarsomeres observable, length 3.1 mm, width 1 mm. </p><p>No. 543 (Fig. 15, Coll. Kunow), ?(?). Inclu- sion: moderately light, 5 x 2 x 2 mm; specimen very poorly visible, length 2.8 mm, width not measurable. </p><p>Aploceble fuscipes, sp. n. (Figs 3, 4) </p><p>Type. Holotype No. 539 (Coll. Kunow), S(?). Inclusion: light, 7 x 2 x 2 mm; specimen: not completely visible from all sides, length 2.8 mm, width 1.1 mm. </p><p>D e s c r i p t ion . Closely allied to A. kunowi from which it differs in light brown extremities and whitish, simple, fine, short semi-erect sparse pub- escence. Puncturation not well-visible but pre- sumably almost the same as in A. kunowi. </p><p>Figs. 23-26. Unidentified inclusions. 23, No. 531, side view. 24-26, No. 524 (Xamerpus ? sp.); 24. part of elytra, ventral view; 25. ventral aspect of body; 26; detail of elytral puncturation. Scales, A = 23, 24; B = 26; C = 25 </p></li><li><p>Mitt. Mus. Nat.kd. Berl.. Dtsch. entomol. Z. 45 (1998) 2 26 1 </p><p>Figs 27-28. X(merpiis? sp. (No. 526). 27, dorsal aspect of body. 28, ventral aspect of </p><p>1 body </p><p>Xamerpus sp. </p><p>The specimens listed below very likely belong in the proximity of the genus Xamerpus Fairmaire, 1886 (synonymized by Peacock 1986, with Mal- thacodes Waterhouse, 1876). They also resemble species near Aplocnemus impressus (Marsham, 1802), but Xamerpus is generally broader, with antennomeres serrate from 5 (Fig. 30). All spe- cies below have black coloration (and probably also black pubescence). Significant characters of recent species of Xamerpus, Malthacodes, Peleco- phoru, etc. ar...</p></li></ul>

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