Zeodera Laporte, 1867

Kipling, Will, 2020, Phylogeny and classification of the genus-group taxa of Loxandrina (Coleoptera, Carabidae, Abacetini), Deutsche Entomologische Zeitschrift 67 (2), pp. 151-182 : 151

Genus Zeodera Laporte, 1867

= Poeciloidia Tschitschérine, 1891. Type species Feronia iridescens Laporte, 1867: 132 (sensu Tschitschérine, see Straneo (1937), Moore (1965) and Moore et al. (1987))

Types species.

Zeodera atra Laporte, 1867: 114, by monotypy.

subgenus Haploferonia Darlington, 1962

Type species. Haploferonia simplex Darlington, 1962: 548, by monotypy.

subgenus Homalonesiota Maindron, 1908

Type species. Homalonesiota karawarii Maindron, 1908: 295, by monotypy.

subgenus Nebrioferonia Straneo, 1939

Type species. Nebrioferonia strigitarsis Straneo, 1939: 119, by monotypy.

Selected literature.

Keys to genus-level taxa ( Moore 1965; Baehr and Will 2019), treatment of New Guinea taxa ( Darlington 1962, 1971; Allen 1982), descriptions and key to some Australian taxa ( Sloane 1903).

Described species and range.

Twenty five species are presently described from Australia, New Guinea and Sulawesi.

Adult characteristics.

Medium to moderately large sized beetles (6.0-22.0 mm). Most are black or piceous and some are castaneous or brown. Legs, mouthparts and the ventral surface of the body may be paler than the dorsal surface, but not more than moderately contrasting. The elytra are concolorous and never have distinct pale spots or vittae; at most the elytron may be slightly paler on the first interval and vaguely paler near the apices of the elytra. Many are very glossy and often with a more or less prominent spectral iridescence. Species from the drier interior of Australia are frequently a dull matt from the prominent mesh microsculpture. The apex of the prosternal process has a raised margin in the majority of species. The elytral plica varies from large and well-developed to completely absent. Elytral interval 3 consistently has a single discal puncture. Though most species are very typical looking Loxandrina and so reminiscent of platynines in general body form, the genus also includes forms from very broad, Abax -form as in Z. atra , (Fig. 13 ) to broadly ovoid in Z. lata (Fig. 16 ), and narrow-elongate in Z. longiformis .

Larvae.

No larval descriptions have been published for any Zeodera species. I have examined a larva of Z. longiformis (reared by B.P. Moore). It is a typical looking loxandrine larva, similar to the described larvae of O. velocipes .

Life history notes.

Species of Zeodera are found across habitats from rainforest (uncommonly), closed forests ( Moore et al. 1987), to a wide variety of more open habitat types near permanent and seasonal, lentic and lotic water in arid regions. They are generally very hygrophilous with some species found in stream and river gravel and cobble directly over running water. By far the greatest diversity and abundance of Zeodera is encountered in backwater areas along oxbows, billabongs, near seasonal lakes, in riparian flood areas, and in wet roadside ditches. Typically they are abundant in muddy places with abundant leaf litter flotsam, or tangles of matted grasses. They are nocturnally active and those that fly can be very abundant at lights. A few species are found in open grassland with no apparent surface water ( Guthrie et al. 2010).

Discussion.

There are five genus-level taxa that were recognized by previous authors that are included in the Zeodera clade: Loxandrus , which is herein restricted to New World taxa, Zeodera , Homalonesiota , Nebrioferonia , and Haploferonia . Zeodera has priority as the earliest established genus-level taxon among the four names for taxa in the clade. Darlington (1962) repeatedly noted (as did Allen (1982)) that these genus-level taxa are scarcely different from Loxandrus auct. and proposed that they were derived from that stock and are part of a closely related group in the Australian and New Guinea region. The results of this study confirm Darlington’s intuition. Exemplars included in the analysis for all of these taxa nest within the broader Zeodera clade. To reflect the phylogeny these genus-level taxa are now treated as subgenera of Zeodera .

The four subgenera were all originally established as genera based on overall body shape and a small number of morphological features that in combination distinguish them (see the key). The nominate subgenus of Zeodera only includes Z. atra , which has a distinctive broad body form, short metepisternum and evident elytral interval 10. Zeodera (Haploferonia) simplex (Fig. 14 ) also has a short metepisternum and evident elytral interval 10, but has a more typical elongate body form. Additionally, Z. simplex lacks the elytral plica that is very well developed in Zeodera atra and most species of Zeodera . The presence of the partial interval 10 of the elytra appears independently in various species, including other abacetines such as Cerabilia , Cyrtomoscelis , and outside abacetines in similarly flightless pterostichines such as Lesticus Dejean, 1828, Rhytiferonia Darlington, 1962, Rhabdotus Chaudoir, 1865, and Parhypates Motschulsky, 1866. The short metepisternum in both of these species is consistent with a change in the thorax after losing the ability to fly. Zeodera atra is well-known as a rainforest species ( Moore 1965; Moore et al. 1987) and is not restricted to near water areas. Likewise, Z. simplex is relatively large, flightless, and presumed to be a rainforest species ( Darlington 1962). These species appear to occupy a similar ecological role as the comparable-sized and often flightless Prosopogmus and Lesticus species also found in the region. Other rainforest Loxandrina , such as all Australian and New Caledonian Cerabilia and many Neotropical Oxycrepis , are small to minute with various flight wing development.

While Z. simplex is placed within the Zeodera clade its relationship to other species remains uncertain. It is only known from the single female holotype and the character data available for analysis is very limited. Darlington (1962) described the "scutellar strioles" of Z. simplex as "absent or nearly so", but then later refers to them as simply absent (pg. 548). The basis for this confusion seems to be that there are very small, slightly impressed marks on each elytron of the holotype in a position almost corresponding to the angular base of stria 1. However, the marks are much too close to the midline and base of the elytron to truly correspond to the angular base of stria 1. Developmental aberrations of this type are known, but rare, in various South American Oxycrepis ( Will 2008). When present the impressions are short, or may appear as a nearly fully developed angular base of stria 1 but always only unilaterally or unequally if there is any indication on both sides. The elytral marks in Haploferonia are not interpreted as indicating the presence of the angular base of stria 1. Since only one specimen is known for this species, the true extent of variation for this character is unknown.

Homalonesiota (Fig. 17 ) and Nebrioferonia (Fig. 15 ) were treated as closely related by Allen (1982) with the configuration of the sulci of the tarsomeres and setae on the mesocoxa given as synapomorphies. I did not find support for a sister-group relationship and there appears to be some confusion regarding morphological character states for these species. Initially Straneo (1939) described Nebrioferonia to include the single species N. strigitarsis . Subsequently, Darlington (1962) described a second species, N. straneoi , that he later ( Darlington 1971) transferred to Homalonesiota placing it together with Maindron’s H. karawarii . An additional species, N. intermedia was then described by Allen (1982). In his paper, Allen attempted to clarify apomorphic and synapomorphic characteristics to substantiate the genus-level taxa. He proposed that Nebrioferonia and Homalonesiota share synapomorphic state of having quadri-sulcate meso- and metatarsomeres 1-4 and a trisetose mesocoxa. I have examined more than a dozen specimens of species from each of these subgenera, including paratypes for Z. (Homalonesiota) straneoi and Z. (Nebrioferonia) strigitarsis and the holotype and paratype of Z. (Nebrioferonia) intermedia , and found that Homalonesiota specimens constantly have only one anteriolateral and one posteriomedial mesocoxae setae (bisetose) and Nebrioferonia constantly have two anteriolateral and one posteriomedial meoscoxal setae (trisetose) counter to what is reported by Allen (1982) that all of these species were trisetose. A trisetose mesocoxa (Character 38) is constant in Nebrioferonia , and there are scattered occurrences across carabids of apparently fixed multiple mesocoxal anteriolateral setae, for example in some Calathus Bonelli, 1810 species ( Schmidt and Will 2020), but this state is otherwise only known from loxandrine species that are polymorphic for mesocoxal setae number ( O. cordata and O. semperfidelis ).

Darlington (1962) states that "The first 3 segments of the middle and hind tarsi are 4-sulcate (5-costate) above in N. strigitarsis ; broadly 2-sulcate (3-costate) in N. straneoi ". He again confirms this difference in his description of H. straneoi and redescription of H. karawarii Maindron ( Darlington 1971). However, Allen (1982) enumerates the characteristics of Nebrioferonia , including quadri-sulcate tarsi, and then adds "These characters also apply to the genus Homalonesiota ." In his discussion of character states and proposed phylogenetic relationships, quadri-sulcate tarsomeres are considered synapomorphic for Nebrioferonia and Homalonesiota . I have examined specimens of both species of Nebrioferonia and Homalonesiota straneoi and find that Darlington’s description of the tarsi is correct.

Aside from the trisetose mesocoxae in Nebrioferonia and the notably elongate antennomere 1 in Homalonesiota , there is no significant difference between these species and other Zeodera species. There is also no clear evidence that these taxa form a clade within Zeodera . The New Guinea Zeodera species are scattered across the clade suggesting that there are multiple connections, possibly dispersal events, between Australia and New Guinea.

Figures

Figures 12 - 15. Habitus. 12. Zeodera australiensis (Sloane); 13. Z. (s. str.) atra Laporte; 14. Z. (Haploferonia) simplex (Darlington) (holotype); 15. Z. (Nebrioferonia) strigitarsis (Straneo).

Figures 16 - 20. Habitus. 16. Zeodera lata (Darlington); 17. Z. (Homalonesiota) straneoi (Darlington); 18. Cerabilia (s. str.) striatula (Broun); 19. C. (Feronista) storeyi Will; 20. C. (Biliacera) klingonorum Will.