Larrisson Menke, 1967

Pulawski, Wojciech J., 2012, A review of the genus Larrisson Menke, 1967, and description of the new genus Larrissa (Hymenoptera, Crabronidae), Journal of Hymenoptera Research 25, pp. 35-82 : 37-41

Genus Larrisson Menke, 1967

Recognition.

In his key to world genera of Miscophini , Menke (1977) differentiated Larrisson from Sericophorus by the length of the occipital carina, which ends before reaching the hypostomal carina in the former and reaches the hypostomal carina in the latter. This character, however, no longer holds, as the occipital carina effaces before reaching the hypostomal carina in three Sericophorus described in Lomholdt and Pulawski (2010): Sericophorus centralis Pulawski, Sericophorus genalis Pulawski, and Sericophorus politus Lomholdt. A useful, although not universal recognition character, is the shape of the posterior propodeal surface: it has no median carina in Larrisson , whereas in the vast majority of Sericophorus there is a well-defined carina below the median sulcus (also present in Lyroda and Sphodrotes ). The carina, however, is only one quarter of the posterior surface long in the holotype of Sericophorus centralis , and absent in the paratype. The essential difference between the two genera is in two male characters: Larrisson have 11 flagellomeres and a well defined volsella, whereas in Sericophorus the antenna has 10 flagellomeres and the volsella is absent.

Menke (1979) recognized two species groups in Larrisson : the monotypic nedymus group and the abnormis group that included abnormis Turner, azyx Menke, and rieki Menke (the latter two known from the male sex only). The twelve new species (armatus, carinatus, latifrons, niger, orbitalis, punctatus, quintus, spinosus, sulcatus, tegularis, tibialis, and variegatus) generally agree well with his diagnosis of the abnormis group except the inner mandibular margin has a tooth near midlength in tibialis (and also in an additional specimen of rieki), the metanotum has no spine or tubercle in armatus, carinatus, niger, punctatus, and tegularis (as in nedymus), mesothoracic venter is conspicuously depressed in punctatus (as in nedymus), the propodeal side is unridged mesally in armatus and most quintus (as in nedymus), male sternum VIII is emarginate apically in armatus, orbitalis, quintus, tegularis, and variegatus (as in nedymus), and gonocoxite has no accessory lobes and no elaborate setal fringe in tegularis (as in nedymus). The twelve species fit well the abnormis groupin all other characters: scapal basin present, impunctate or sparsely to densely punctate (frons uniformly punctate in nedymus), scape longer than flagellomeres I-III combined (shorter than that in nedymus), inner mandibular margin with preapical tooth, with small incision at about midlength in female (without preapical tooth, with two teeth near midlength in nedymus), mesopleuron rounded anteriorly (abruptly angular below pronotal lobe in nedymus), forewing vein M diverging from M+Cu distad of cu-a or interstitial with cu-a (diverging basad of cu-a in nedymus), glabrous area of propodeal dorsum covering entire enclosure except limited to slightly more than median sulcus in tegularis and variegatus (limited to median sulcus in nedymus), male forecoxa and foretrochanter simple (forecoxa with apical spine and foretrochanter emarginate basally in nedymus), basolateral carina of tergum I not expanded into lamella (lamella present in nedymus), apical tergum of female without a narrow, impunctate and asetose marginal lamella (lamella present in nedymus), volsella ending near apex of penis valve or exceeding it (ending at half length of penis valve in nedymus); and head of penis valve not dentate (dentate in nedymus).

Menke (1979) also claimed that the stipes and prementum are shortened in the abnormis group, the prementum being less than twice as long as wide, but not shortened in nedymus, with the prementum little more than twice as long as wide. I cannot confirm this difference: the length of these mouthparts is practically identical in azyx, nedymus, and rieki, although definitely smaller in abnormis.

Prey of Larrisson was unknown until now, but the holotype female of niger is pinned with her prey, an adult mirid 3.6 mm long. The specimen has an additional label that reads "Wasp grasped bug on terete-leaved Acacia ", indicating that the mirid was not placed on the same pin accidentally. Randall T. Schuh (American Museum of Natural History, New York, New York) kindly identified it as a male of the tribe Orthotylini belonging to an undescribed genus and species.

Phylogenetic analysis.

Lomholdt (1985) placed Larrisson , together with Sericophorus , in the tribe Sericophorini Dalla Torre, that he characterized by a second submarginal cell conspicuously narrowed anteriorly, a synapomorphy. In the following analysis, I have used as outgroups representatives of three other miscophine genera with posteroventrally emarginate mandible that occur in Australia ( Lyroda , Sericophorus , and Sphodrotes ) and that appear to be more closely related to Sericophorus than the non-Australian genera. Sericophorus was used below as a sister taxon of Larrisson , and Sericophorus relucens Rayment, a relatively unspecialized species of the genus, was selected as the first outgroup. Sphodrotes punctuosa Kohlwas selected as the second outgroup, and Lyroda venusta Bingham as the root taxon. Since females are known for only nine species of Larrisson (out of the total of 15), whereas the males are known for 13 species, the analysis was based entirely on male characters, and Larrisson latifrons , niger, and punctatus (known from the female only) were excluded. Autapomorphies were included. The following is the list of characters.

1. Frons: 0, fully setose. 1, with glabrous scapal basin.

2. Occipital carina: 0, not reaching hypostomal carina. 1, reaching hypostomal carina.

3. Scape: 0, not shortened, length (without radix) at least 1.8 × width. 1, shortened, length about 1.3 × width ( Fig. 25a ).

4. Length of flagellomere I: 0, at least 1.7 × apical width. 1, about 1.3-1.5 × apical width. 2, about equal to apical width. 3, about 0.8 × apical width.

5. Mandible, inner margin: 0, without tooth at midlength of inner margin. 1, with tooth at midlength of inner margin ( Fig. 25a ).

6. Mesopleuron: 0, rounded anteriorly. 1, abruptly angular below pronotal lobe.

7. Mesothoracic venter (shape): 0, inconspicuously concave. 1, conspicuously concave.

8. Mesothoracic venter (sculpture): 0, densely punctate. 1, sparsely punctate.

9. Propodeal dorsum (setae): 0, all setose. 1, median sulcus glabrous. 2, median sulcus and adjacent area glabrous. 3, all enclosure (or nearly so) glabrous.

10. Presence of spine or tubercle behind propodeal spiracle: 0, spine or tubercle absent. 1, present (the spine in Sphodrotes punctuosa is much further from the spiracle and thus nonhomologous with that of Larrisson ).

11. Posterior propodeal surface: 0, without medioventral carina. 1, with medioventral carina.

12. Divergence of forewing vein M from M+Cu: 0, diverging distad of cu-a or interstitial with cu-a. 1, diverging basad of cu-a.

13. First recurrent vein: 0, ending on second submarginal cell ( Fig. 23 ) or interstitial with first intersubmarginal vein. 1, ending on first submarginal cell.

14. Hindtibial outer surface: 0, all or largely punctate and setose (at least sparsely so). 1, impunctate and asetose between spines in dorsal half or along dorsal margin, at least in apical half.

15. Basolateral carina of tergum I: 0, not expanded. 1, expanded into lamella.

16. Setae: 0, appressed. 1, erect or suberect on upper frons, gena, vertex, mesothorax, hindcoxal venter, and hindfemoral venter ( Fig. 27a, b ).

17. Color of gaster: 0, gaster all or largely black 1, gaster all or largely red ( Fig. 19e ).

18. Presence of yellow fasciae on gaster: 0, fasciae absent. 1, fasciae present.

19. Male flagellum (number of flagellomeres): 0, with 11 flagellomeres. 1, with 10 flagellomeres (10 flagellomeres are found in all Sericophorus ).

20. Male flagellum (shape): 0, flagellomeres all cylindrical. 1, flagellomeres I-VI convex ventrally ( Fig. 22c ).

21. Male flagellum (color): 0, black or dark brown or reddish brown ventrally. 1, at least flagellomeres VIII and IX yellow ( Figs 22b, c , 24a ).

22. Mesopleural precoxal carina of male: 0, low, obtuse. 1, projecting as spine.

23. Male metanotum: 0, simple. 1, with median spine or tubercle ( Fig. 16b ).

24. Male propodeum(presence of spine or tubercle behind spiracle): 0, spine or tubercle absent. 1, spine or tubercle present (the tubercle in Sphodrotes punctuosa is minute, and a lower one, large, is nonhomologous).

25. Male forecoxa and foretrochanter: 0, not modified. 1, modified.

26. Male femora, tibiae, and tarsi: 0, not modified. 1, modified ( Fig. 26b-f ).

27. Male midfemur: 0, convex ventrally, not carinate. 1, slightly concave ventrally, with obtuse carina along both anterior and posterior margin ( Fig. 27b ).

28. Male hindfemur: 0, without process. 1, with ventral preapical process ( Fig. 27b ).

29. Outer surface of male hindtibia (shape): 0, not swollen. 1, swollen in basal third or so ( Fig. 21a ).

30. Transverse swelling on male sternum II: 0, absent or rudimentary. 1, well defined.

31. Tergum VII: 0, without basolateral tooth. 1, with basolateral tooth ( Fig. 2d ).

32. Longitudinal carina on male sternum II: 0, carina absent. 1, carina present in basal half ( Fig. 22f ).

33. Male sternum VIII (apex): 0, not emarginate apicomesally. 1, emarginate apicomesally.

34. Male sternum VIII (apicolateral emargination): 0, absent. 1, present ( Fig. 2d , 12e , 19d ).

35. Gonocoxite: 0, with simple, short setae. 1, with elaborate, setal fringes ( Fig. 5 , 14 ).

36. Volsella: 0, minimal to absent. 1, present, about half length of penis valve. 2, present, about as long as penis valve.

37. Penis valve: 0, not dentate. 1, dentate.

The following data matrix ( Table 1 ) was constructed using Winclada version 1.00.08 ( Nixon 2002). Multiple character states were treated as additive.

The above data matrix was analyzed using the Willi Hennig Society edition of TNT ( Goloboff et al. 2008) with 1,000 replications and 1,000 trees to be held. An equal weight analysis resulted in 18 equally parsimonious trees, each of 73 steps, consistency index = 0.575, and retention index = 0.613. An implied weight analysis (k = 3) produced three trees, and the strict consensus tree ( Fig. 1 ) had 74 steps, consistency index = 0.568 , and retention index = 0.600. Critical in the analysis was the position of Larrisson nedymus that appeared as the sister species of Sericophorus relucens , and not a part of the clade encompassing the remaining Larrisson . The same position was retained in another analysis, in which Aha ha Menke was added as another outgroup. This result demonstrates that Larrisson nedymus is not congeneric with the remaining Larrisson and that it either should be transferred to Sericophorus or that it belongs to a genus of its own. Given the degree of differences between Larrisson nedymus and Sericophorus , I believe it should be treated as a separate genus. A new genus, Larrissa is established below for the species.

Figures

Figure 1. Strict consensus cladogram of the species of Larrisson based on male characters (Larrisson latifrons, niger, orbitalis, and punctatus, known from the female only, are omitted). Character numbers are placed above circles, with the state number below. Black circles indicate an unambiguous change, open circles indicate homoplastic change.

Figure 2. Larrisson armatus: a female clypeus b male antenna c male tergum I in dorsolateral view (arrow indicatesbasolateral emargination) d apexof male gaster in dorsal view (upper arrow indicates basolateral tooth of tergum VII, lower arrow indicates sternum VIII).

Figure 5. Larrisson carinatus: male genitalia dorsally.

Figure 12. Larrisson quintus: a female clypeus and mandible b male clypeus and mandible c female pygidial plate d male tergum VII e male sternum VIII in ventral view f male genitalia in ventral view.

Figure 14. Larrisson quintus: male genitalia dorsally.

Figure 16. Larrisson spinosus ♂: a clypeus and mandible b metanotum in lateral view.

Figure 19. Larrisson tegularis: a female head in frontal view b tegula (arrow indicates concave inner margin) c pygidial plate of female d apical sterna of male in ventral view e female gaster in dorsal view.

Figure 21. Larrisson tibialis ♂: a hindtibia in dorsal view b hindtibia in lateral view.

Figure 22. Larrisson variegatus: a female head in frontal view b male head in dorsal view c male antenna d male tergum I in dorsal view e male tergum I in oblique lateral view f gastral base of male in lateral view.

Figure 23. Larrisson variegatus: forewing (arrow indicates first recurrent vein).

Figure 24. Larrisson rieki, ♂ from South Australia: a head in frontal view b midfemur in ventral view.

Figure 25. Facial portraits: a Larrissa nedyma ♀ b Larrisson rieki ♂ c Larrisson azyx ♂ d Larrisson abnormis ♀. From Menke, 1979, reproduced with the author's permission.

Figure 26. Apical gastral terga: a Larrissa nedyma ♀ b Larrisson abnormis ♀ c Larrisson azyx ♂ d Larrisson rieki ♂. From Menke, 1979, reproduced with the author's permission.

Figure 27. Larrisson azyx ♂: a head, thorax, and propodeum in lateral view b hindfemur in lateral view.