Polyozus tridens, WEIRAUCH, 2007

WEIRAUCH, CHRISTIANE, 2007, Revision and Cladistic Analysis of the Polyozus Group of Australian Phylini (Heteroptera: Miridae: Phylinae), American Museum Novitates 3590, pp. 1-64 : 55-58

Polyozus tridens , new species figures 2 , 7 , 9 , 11 , 13 , 17–20

HOLOTYPE: AUSTRALIA: South Australia: 8.8 km S of Oakbank, 33.11264 ° S 140.5524 ° E, 100 m, 08 Nov 1996, Schuh and Cassis, Senna stowardii? (S. Moore) B.R. Randell ( Fabaceae , Caesalpinioideae ), det. PERTH staff 05236541, 13 ( AMNH _PBI 00087403) ( AM).

DIAGNOSIS: Recognized by the small size, elongate ovoid body, uniformly pale yellow coloration, and characters of the male genitalia, most notably the large vesica, with tubular dorsal apical process without proximal process, ventral apical process almost straight, not connected to strap of vesical body, and the well-sclerotized median apical process, consisting of one stem with two small teeth at about middle of process. Habitus and genitalia similar to P. furcilla , but distinguished by the structure of the vesica, with the median apical process with two teeth at about the middle in P. tridens .

DESCRIPTION: Male: Small and elongate ovoid, total length 2.47–2.77, length apex clypeus–cuneal fracture 1.58–1.78, width across pronotum 0.84–0.89. COLORATION ( fig. 2 ): General coloration pale with yellow tinge, suffused with orange on pronotum, mesonotum, and scutellum. Head: Uniformly pale yellow, fasciae indistinct. Antennal segments pale and gradually infuscate toward apex, with brown ring subbasally on segment 1. Labium pale, infuscate toward apex. Thorax: Pronotum, mesonotum, and scutellum pale orange. Pleura pale yellow, partly suffused with orange. Legs: Uniformly pale with tarsi infuscate, very small dark spots on femora, tibial spines dark with very small dark bases. Hemelytra: Corium and cuneus uniformly pale, membrane pale, veins yellowish. Abdomen: Pale green. SURFACE AND VESTITURE: Dorsum weakly shining, with moderately stout, subadpressed, dark, simple setae, and flattened, adpressed, silvery setae. STRUCTURE: Head: Short, vertex slightly wider than width of one eye, clypeus slightly produced, and maxillary plate sunken, eye large, as high as head. Antennal segment 1 moderately slender and slightly surpassing apex of head, segment 2 of moderate length and diameter, of slightly smaller diameter than segment 1, segments 3 and 4 slender, segment 3 about as long as segment 4. Labium slender, apex of labium surpassing base of mesocoxa. Thorax: Pronotum wider than long and anterior margin slightly sinuate. Legs: Claws slender and of moderate length, and pulvilli of moderate size. Hemelytra: Hemelytra slightly convex laterally, cuneus elongate triangular. Abdomen: Stout, reaching to about middle of cuneus. GENITALIA: Parameres: Right paramere as in figure 7 ; left paramere ( fig. 9 ) with short and slender anterior process, posterior process long, slender, bent ventrad, and slightly truncate at apex, body with large, straight, almost horizontal lobe. Phallotheca ( fig. 11 ): External portion irregularly tubular, only slightly tapering toward truncate apex, anterior surface basally with large horizontal flange, opening ventral, slitlike at base and extended toward apex. Vesica ( fig. 13 ): Large, with tubular dorsal apical process without proximal process; ventral apical process almost straight, not connected to strap of vesical body; median apical process well sclerotized, consisting of one stem with two small teeth at about middle of process.

Female: Coloration similar to male, size about same as in male. Total length 2.30–2.50, length apex clypeus–cuneal fracture 1.57–1.74, width across pronotum 0.83–0.97.

ETYMOLOGY: Named for the shape of the median apical process of the vesica, after Latin adjective ‘‘tridens, -entis’’, meaning having three teeth or prongs.

HOST (appendix 1): The only known host was recorded as Senna , probably Senna stowardii ( Fabaceae , Caesalpinioideae ).

DISTRIBUTION: Known from one locality near Oakbank, South Australia ( fig. 17 ).

DISCUSSION: This species is close to P. furcilla , but it is distinguished by the shape of the median apical process of the vesica.

PARATYPES: AUSTRALIA: South Australia: 8.8 km S of Oakbank , 33.11264 ° S

140.5524 ° E, 100 m, 08 Nov 1996, Schuh and Cassis, Senna stowardii? (S. Moore) B.R. Randell (Fabaceae) , det. PERTH staff 05236541, 13 (AMNH_PBI 00087646), 6♀ (AMNH_PBI 00087404, AMNH_PBI 0008- 7647–00087651) (AM).

CLADISTIC ANALYSIS OF THE POLYOZUS GROUP OF PHYLINI, WITH REMARKS ON HOST PLANT ASSOCIATIONS AND DISTRIBUTIONS

The cladistic analysis of the 16 ingroup taxa in NONA resulted in eight equally most parsimonious trees (L 5 91; CI 5 67; RI 5 83). The strict consensus of these trees is shown in fig. 18 . The analysis with implied weights using Pee-Wee resulted in two trees (with a fit of 373.3; L 5 92; CI 5 66; RI 5 82), the strict consensus of which is shown in figure 19 . The two trees obtained using Pee- Wee did not correspond to either of the eight trees recovered in the NONA analysis. However, overall topologies of the two analyses are very similar ( figs. 18 , 19 ). The main difference in topology between the two analyses is the placement of Ancoraphylus carolus either as sister group to the remaining species of that genus (unweighted tree) or as the sister group to A. arctous + A. mariala (node 6 vs. 6a in figs. 18 and 19 ). In addition, clade 9 (i.e., monophyly of the Polyozus species excluding P. bulita ) is not supported in the weighted analysis.

Character optimizations are discussed together with the character descriptions in table 2. The discussion is based on the strict consensus obtained through the unweighted analysis ( fig. 18 ). Clades ( figs. 18 , 19 ) with some of their synapomorphies are summarized briefly in the following paragraphs. Unless stated otherwise, unambiguous optimizations are used for the discussion of character distributions.

The Polyozus group ( fig. 18 ; clade 1) is well supported in the present analysis. Among the synapomorphies are a short labium, combination of simple/suberect and flattened/subadpressed setation ( fig. 4 ), J-shaped vesica with process arising close to secondary gonopore, the dorsal apical process bent at a right angle, which renders the apex of the vesica virtually anchor-shaped ( figs. 12 , 13 ), and characters of the female genitalia ( fig. 14 ).

Using fast optimization, synapomorphies of Exocarpocoris (clade 2) are: the flattened shape of the vesical process arising close to the secondary gonopore, the long and coiled shape of this process ( fig. 12 ), the dark Ushaped mark on the hemelytron, and the white color of the cuneus ( fig. 1 ). Within Exocarpocoris , E. aurum and E. tantulus are supported as sister species (clade 3) due to wide vertex and small eyes ( fig. 1 ) and the wide pronotum ( fig. 1 ), but also due to the large left paramere and the horizontal, lobelike extension of the body of the paramere ( fig. 8 ).

The sister group relationship between Ancoraphylus and Polyozus (clade 4) is supported by (unambiguous optimization) the irregular shape of the phallotheca including the basal flange or spine, the orientation of the ventral apical process of the vesica at almost a right angle to the body of the vesica, and the heavy dark punctation of the femora.

The species of Ancoraphylus are united in clade 5 by the type of flattened setae (with parallel rather than oblique ridges as in the other taxa of the Polyozus group; fig. 4 ), the tubercle on the pygophore ( fig. 6A ), and the elongate horizontal lobe of the left paramere ( fig. 8 ). In fast optimization, the dorsal process on the lateral or posterior margin of the left paramere is added to these characters ( fig. 8 ). The position of A. auski and A. carolus relative to each other is ambiguous ( fig. 18 , node 6 and fig. 19 , node 6a). The sister species relationship of A. arctous and A. mariala is well supported, with the greatly enlarged right paramere ( fig. 7 ) and the appendages on the ventral and dorsal apical processes of the vesica among the synapomorphic characters ( fig. 12 ).

Among the apomorphic characters of the genus Polyozus ( figs. 18 , 19 , clade 8) are the large eyes ( fig. 2 ), the notched apex of the right paramere ( fig. 7 ), the short and usually straight process arising close to the secondary gonopore of the vesica ( figs. 12 , 13 ), and the characteristic tree-shaped or forked median apical process of the vesica ( figs. 12 , 13 ).

A sister group relationship of P. bulita with the remaining species (clade 9) is only resolved in the unweighted analysis. It results from the simple phallotheca in P. bulita ( fig. 11 ) and the fact that all other species have at least a smooth lobe in a subapical position on the phallotheca. Clade 10 ( P. furcilla , P. kojonup , and P. tridens ) is recovered in both analyses, but a sister group relationship of P. furcilla and P. tridens is only supported in the weighted analysis. Polyozus mina shares a serrate subapical lobe on the anterior surface of the phallotheca and an additional lobe on the posterior surface with the other species of clade 10 ( fig. 11 ). Clade 12 ( P. kurringai , P. manilla , P. australianus , and P. galbanus ) is supported by the shape of the dorsal apical process, which is fan-shaped and distinctly serrate ( figs. 12 , 13 ).

HOST PLANT ASSOCIATIONS: Unambiguous optimization of host plants on the present analysis of the Polyozus group fails to identify the host plant of the last common ancestor of the entire clade, but fast optimization ( fig. 20 ) treats Acacia as the ancestral host plant.

The genus Exocarpocoris is restricted to Exocarpos aphyllus , pointing to a host switch to that plant and subsequent evolution of this clade on E. aphyllus . Based on available evidence (i.e., cladistic analysis and host plant records), the speciation event that gave rise to the sister species E. aurum and E. tantulus has taken place on E. aphyllus .

Host plant distribution using fast optimization on the tree ( fig. 20 ) indicates further that the sister groups Ancoraphylus and Polyozus evolved on Acacia ( Fabaceae , Mimosoideae ), and that within the genus Polyozus species switched to other groups of hosts. The host plant of A. arctous is unknown, but judging from host associations of related taxa and cladistic analysis, it is most likely Acacia . The same prediction could be made for Polyozus bulita , which was so far only collected at light. Within clade 11 of the genus Polyozus , the sister species P. australianus and P. galbanus , both with numerous host records, and P. mina are recorded from species of Acacia . Polyozus furcilla and tridens are recorded from Senna ( Fabaceae , Caesalpinioideae ), and Polyozus kojonup occurs on Jacksonia ( Fabaceae , Papilionoideae ). Although not in the same subfamily, Senna and Jacksonia belong to the same plant family as Acacia , a fact that might facilitate host switching. The host switches that appear to have occurred in P. kuringgai (to Grevillea , Proteaceae ) and P. manilla (to Notelaea , Oleaceae ) in contrast have crossed family boarders.

DISTRIBUTION OF SPECIES OF THE POLYOZUS GROUP ( figs. 15–17 ): Even though Polyozus galbanus was described from New Zealand, the present study provides evidence that P. galbanus , but also other species of this genus and related genera, are of Australian origin (see discussion of P. galbanus ). The species of Polyozus are mostly distributed in the southeast, south, and west of Australia, with the exception of P. bulita , which appears to be restricted to the dry interior of the continent. Due to the limited number of records for most species of the Polyozus group, the range of distribution for most species is poorly known. Some species may be relatively restricted. A notable exception is P. australianus , which extends from the Australian Capital Territory in the east to southern Western Australia.

Compared to Polyozus , the species of Ancoraphylus are more northern and occur mostly in the dry interior of the continent.

The distribution of Exocarpocoris species resembles generally that of Polyozus spp. in being restricted to areas close to the coast. The wide distribution of both E. aurum and E. tantulus from South Australia to Western Australia (in the case of E. tantulus even up to the Shark Bay area) is noteworthy.

Figures

Fig. 2. Habitus photographs of Polyozus spp.

Fig. 7. Right parameres of species of Ancoraphylus, Exocarpocoris, and Polyozus.

Fig. 9. Left paramere of species of Polyozus, shown in dorsal and lateral view. Numbers on illustrations refer to characters and character states in table 2.

Fig. 11. Phallotheca of species of Polyozus, in dorsal and ventral perspective. Numbers on illustrations refer to characters and character states in table 2.

Fig. 13. Vesica of species of Polyozus.

Fig. 17. Distribution of species of Polyozus.

Fig. 18. Phylogenetic relationships of the 16 species of the Polyozus group: The strict consensus of the eight equally most parsimonious trees (L 5 91; CI 5 67; RI 5 83) derived from the character matrix in table 3. Solid circles on the branches indicate uniquely derived apomorphic character states; empty circles indicate homoplastic characters under unambiguous character optimization. Figures above the bars indicate number of character as shown in table 2 and appendix 1; figures below bars indicate the character state. Large figures in shaded circles denominate clades. Branch support values (Bremer support) are given above branches in square boxes.

Fig. 19. Strict consensus of the two most parsimonious trees obtained with the analysis using implied weights. Characters and clades are shown as explained in figure 18.

Fig. 20. Fast optimization of host plants of Phylini of the Polyozus group on the strict consensus of the unweighted analysis.

Fig. 4. Setae comprising hemelytral vestiture. A, Ancoraphylus arctous (AMNH_PBI 00087680); B, Exocarpocoris tantulus (AMNH_PBI 00135796); C, Polyozus bulita (AMNH_PBI 00168436); D, P. furcilla (AMNH_PBI 00099437); E, P. galbanus (AMNH_PBI 00139062); F, P. kojonup (AMNH_PBI 00136470). Scale bar: 50 mm.

Fig. 12. Vesica of species of Ancoraphylus, Exocarpocoris, and Polyozus.

Fig. 14. Female genitalic structures in Ancoraphylus, Exocarpocoris, and Polyozus, comprising bursa copulatrix in dorsal view and posterior wall in ventral view.

Fig. 1. Habitus photographs of Ancoraphylus spp., Exocarpocoris spp., and Polyozus pp.

Fig. 8. Left paramere of species of Ancoraphylus and Exocarpocoris, shown in dorsal and lateral view. Numbers on illustrations refer to characters and character states in table 2.

Fig. 6. Male genitalic structures of A, B, Ancoraphylus arctous; C–E, Exocarpocoris tantulus, and F, G, Polyozus kojonup. Scanning micrographs, scale bar measurements in mm. A, C, F, pygophore in dorsolateral view, B, D, G, detail of parameres and phallotheca, E, ventral surface of left paramere.

Fig. 15. Distribution of species of Ancoraphylus.

Fig. 16. Distribution of species of Exocarpocoris.