Buburra Reid & Beatson

Reid, C. A. M. & Beatson, M., 2013, A new genus and species of Bruchinae, with a key to the genera from Australia (Coleoptera: Chrysomelidae), Zootaxa 3599 (6), pp. 535-548 : 537-541

Buburra Reid & Beatson , gen. nov.

( Figures 2–25 )

Type species: Buburra jeanae Reid & Beatson , this designation.

Diagnosis. Frons without median ridge; eyes small, with moderately deep canthus, approximately ⅓ greatest eye diameter; eye facets small; temples long, ½–⅔ eye length, posteriorly rounded; antennomeres not sexually dimorphic, not conspicuously serrate; venter of head without well-defined submental area; pronotum subrectangular, entirely laterally marginate; prosternal process long and narrow, visible and strongly arched between coxae and terminating behind them; mesepimeron broad, evenly narrowing from anterolateral edge to posteromedial edge; apex hind femora with ventral pecten of 6–9 large blunt spines on outer margin; fore and mid tibiae with 2 short apical spurs; hind tibia ventral surface without basal tubercle, apex without spurs; first ventrite as long as 2–4 combined; apical lobes tegmen membranous, bilobed and setose at apex; apex penis acute, rigid (strongly sclerotised), without valves; female without spines in bursa copulatrix.

Description. Sexes externally similar. Body ( Figs 2–5 ): small for a pachymerine, total length 3.8–4.5mm (with head flat), length from anterior of pronotum to apex elytra 3.4–3.9mm, elongate-oval; integument mostly reddishbrown, variegated on elytra, generally with covering of adpressed setae, not dense enough to obscure integument, which is mostly densely and finely punctured (conspicuous large scattered punctures absent); two types of setae present, erect and adpressed; adpressed setae variegated on elytra in small pale or dark patches.

Head ( Figs 2–3 , 6 , 17–18 ): elongate, not concealed from above, width at eyes much less than twice (c.1.3x) width at neck; neck, vertex and frons level, without abrupt elevation between neck and vertex; frons without median ridge but midline partially less punctate and microsculptured, shallowly impressed around inner margin of eyes; clypeus almost quadrate; eyes small but extending to venter of head, interocular distance dorsally> dorsal eye width (c.1.3x) and ventrally >> eye width (c. 2.4x); eyes with deep canthus at antennal insertions, approximately ⅓ greatest eye diameter; eye facets small, basal width of second antennomere equal to approximately two facet diameters; temples long, ½–⅔ length eye in lateral view, posteriorly rounded; antennae moderately long, approximately ⅔ body length, inserted laterally, in swellings at junction of clypeus and frons; all antennomeres elongate, 1 ovate with truncate apex, 2–5 relatively narrow with rounded apices, 6–10 expanded with truncate apices but not conspicuously serrate, 11 elongate-acuminate, inner edge 7 bluntly lobed at apex; labrum large, semi-ovate; mandibles flat, with acutely unidentate apices projecting beyond labrum; apical maxillary palpomere elongate-fusiform, 1.6–1.8x length penultimate; mentum transversely rectangular (width c. 3x length) with blunt anterolateral lobes; venter of head dull and sculptured from between temples to mentum, without sutures or defined ‘submentum’, smooth and shining posterior to this.

Thorax ( Figs 2–5 , 7–9 ): pronotal dorsal shape subrectangular, slightly transverse, hind angles blunt, basal ⅔ almost parallel, apical ⅓ contracting to prominent trichobothrium at anterior angles; lateral carina (margination) present from base to apex; surface elevated at middle of anterior, slightly depressed either side of disc; prosternal process long and narrow, strongly arched between coxae, flat and slightly expanded at apex posterior to coxae; coxal cavities closed by junction of thin hypomeral lobe reaching tip of prosternal process; scutellum small, acutely triangular with rounded tip; each elytron elongate, covering or almost covering (male) or exposing (female) pygidium, flat at base, without elevated spines or tubercles; 10 deeply grooved striae present, obscurely punctate, 1st, 2nd, 3rd, 8th, 9th straight from elytral base to apex, 4th and 5th usually anastomosed and always terminating ⅔ from base, 6th & 7th usually anastomosed at apex (6 fused with 4+5 on one elytron), 10th adjacent to epipleural margin; upper margin epipleuron distinct at base, evanescent in apical third; mesoventrite with gradually elevated elongate parallel-sided process between coxae, apex truncate; mesepimeron broad, evenly narrowing from anterolateral edge to posteromedial edge, which is c. ½ width anterolateral edge; wing venation relatively complete for Bruchinae , median field of wing with closed elongate basal cell, two apical veins leading off this, short AA4 and long CuA2 reaching wing margin, plus two free veins reaching wing margin (probably MP3 and MP4); metaventrite discrimen distinct on basal ¾; metanepisterna elongate rectangular; procoxae conical but not elevated above prosternal process, mid coxae ovate, hind coxae slightly smaller than hind femora; mid and anterior femora elongate-fusiform without ventral keels; hind femora elongate-ovate, middle ½– ¾ of venter with irregular median row of 15–22 small spines slightly increasing in size towards apex, and apical quarter with pecten of 6–9 large blunt spines on outer margin, the most basal spine slightly largest; fore and mid tibiae thin, without keels, apices with 2 short spurs each c. 0.5x apical tibial width; hind tibia strongly curved, ventral surface sharply keeled along entire inner and outer edges and without basal tubercle, trace of short lateral keel at base, apex with ventral short flat triangular projection, length 0.3–0.5x apical tibial width, without spurs; tarsi 5-segmented, long and thin, hind tarsi almost as long as hind tibiae; first tarsomere elongate and narrow (male = female), third tarsomere transverse, bilobed, lobes 0.3–0.5x total length, claws ventrally bluntly lobed.

Abdomen ( Figs 3 , 10, 11 ): pygidium slightly transverse, shape acutely triangle but with tip rounded off (male = female); first ventrite as long as 2–4 combined; male last ventrite apex shallowly concave at middle; female last ventrite apex evenly convex.

Male genitalia ( Figs 12–14 , 19–21 ): apex tergite 8 truncate; sternite 8 minute and Y-shaped; apical lobes tegmen fused, membranous, bilobed and setose at apex, basal strut thin, with low external keel in basal half; penis parallel-sided, not greatly expanded at middle, apex reflexed, acute, rigid (strongly sclerotised), without separately sclerotised ‘valves’; endophallus with dense granular microtubercles in two confused rows, from middle to apex of penis.

Female genitalia ( Figs 15–16 , 22–25 ): ovipositor relatively short; tergite 8 sclerotised across middle and at apex, slightly longer than broad, with strongly concave inner edge and convex apex; sternite 8 strongly sclerotised except middle and apex, transverse, with elongate-triangular truncate spiculum and apical row of long setae; vaginal palpi weakly sclerotised, almost spherical, papillate with 3 long apical setae, each attached internally to long baculus; paraprocts and proctiger weakly sclerotised, poorly demarcated; spermatheca C-shaped, with invagination at entry of duct.

Sexual dimorphism. Sexual dimorphism is slight: antennal proportions similar but male antennae slightly larger ( Figs 17–18 ); elytra generally covering more of pygidium in male; apex male ventrite V slightly concave, apex female ventrite V convex ( Figs 10–11 ).

Distribution and biology. This genus is known from a single species at a single locality in the Victorian Alps, south-east Australia. The larval host is unknown but possibly Acacia alpina (Fabaceae) . See notes under species description for further discussion.

Etymology. Buburra is a recorded name for ‘mountain’ in the extinct language Waywurru (also known as Pallanganmiddang), endemic to the region of occurrence ( Blake & Reid 1999). The gender is to be treated as feminine.

Notes. Buburra shows several plesiomorphic features for a bruchine, by comparison with the sister-group Sagrinae ( Reid 1995, 2000), including: head not abruptly constricted behind vertex; frons without ridge; antennae not sexually dimorphic; prosternal process strongly arched between coxae and meeting hypomeral lobes behind coxae; smooth pronotum and elytra; scutellum triangular; broad mesepimera; relatively complete medial wing venation; 2 apical spurs on anterior and mid tibiae; tibiae without prominent lateral keels; penis strongly sclerotised at tip, without discrete apical sclerites (‘valves’: Nilsson & Johnson 1993, figure 117); endophallus without spines or large sclerites; tegmen without gemmae; ovipositor short, including wellsclerotised female sternite VIII, with short and broad apodeme; bursa copulatrix without spines. The lateral margination of the pronotum cannot be considered plesiomorphic as it shows multiple gains or losses in Chrysomelidae ( Reid 1995) . Buburra shows few apomorphies within Bruchinae , including: long temples; pectinate hind femur; tegminal strut keeled on external surface. The combination of attributes places Buburra in Pachymerini , a tribe defined by a plesiomorphy and body and appendage ratios and therefore likely to be para- or polyphyletic.

There are reviews of the anatomy of all genera of Pachymerini ( Nilsson & Johnson 1993; Johnson, Southgate & Delobel 2004). A Cretaceous fossil has also been placed in Pachymerini ( Reid 2000; Poinar 2005). Comparing Buburra with other Pachymerini we are unable to find any obvious relationship to other genera; the differences in head capsule, tibiae and male and female genitalia are particularly striking. Buburra seems to be an isolated taxon in the Pachymerini and provides further evidence for the non-monophyly of the tribe.

Figures

FIGURES 2 – 5. Buburra jeanae Reid & Beatson: 2, dorsal; 3, lateral; 4, lateroventral of thorax with legs removed, including pro- and mesocoxae; 5, ventral of thorax.

FIGURES 6 – 9. Buburra jeanae Reid & Beatson: 6, head; 7, base of wing; 8 apex mid tibia; 9, hind leg.

FIGURES 10 – 16. Buburra jeanae Reid & Beatson: 10, venter male abdomen; 11, venter female abdomen; 12, male tergite and sternite 8; 13, lateral male genitalia (in fluid); 14, apicolateral male genitalia (dry); 15, ovipositor, ventral; 16, ovipositor, lateral.

FIGURES 17 – 18. Buburra jeanae Reid & Beatson: 17, male antenna; 18, female antenna. Drawn to scale.

FIGURES 19 – 25. Buburra jeanae Reid & Beatson, genitalia drawn from cleared specimens: 19, lateral penis and tegmen; 20, ventral penis; 21, apex tegmen; 22, female tergite VIII; 23, female sternite VIII; 24, ovipositor lateral and apicoventral; 25,