Bursinia genei (Dufour, 1849)

Davranoglou, Leonidas-Romanos, Malenovský, Igor, Soh, Zestin Wen Wen, Schlepütz, Christian M. & Wilson, Michael R., 2022, Fig. 11 in Fig. 6. A in A New Species of Bleeker, 1876 (Teleostei: Scorpaenidae) from Taiwan., Zoological Studies 61 (51), pp. 1-15 : 10-14

Diagnosis of B. genei

Bursinia genei shares the following combination of characters with other members of the subgenus Bursinia s. str. ( Emeljanov 2009): apical swelling (apical callus) of cephalic process longer than broad; lateral carinae of frons complete (distinct throughout their length); area between intermediate and lateral carinae of frons with three rows of sensory pits apically ( Fig. 2C ). These characters should distinguish it from six species currently classified in the subgenus Struthionia ( Emeljanov 2009) .

According to Emeljanov and Drosopoulos (2004), B. genei is “close or identical” to B. hemiptera Costa, 1840 , described from southern Italy; both species should share smooth tegmina, with reticulation very faint or entirely absent. Based on Horváth (1910) and Melichar (1912), B. genei differs from B. hemiptera in lateral carinae of frons that are joining lateral carinae of vertex subapically, at a clear distance from apex of cephalic process ( Fig. 2C ); in B. hemiptera , the lateral carinae of frons are extended up to the apex of cephalic process ( Costa 1840: pl. 1, fig. 4; Horváth 1910: fig. 3; Melichar 1912).

According to Horváth (1913), B. genei differs from B. breviceps Horváth, 1913 , described from southern Spain, by a much longer cephalic process (which is short and broad, and parabolic in dorsal view in B. breviceps ).

According to Horváth (1913), B. genei can be easily distinguished from B. latipes Horváth, 1913 , described from eastern Spain, by its slender fore femora and tibiae (they are enlarged and lamellate in B. latipes ) and uniformly coloured tegmina (bearing a broad, transverse, contrasting white band apically in B. latipes ).

According to Emeljanov (1972), B. genei differs from B. rugosa Emeljanov, 1972 , described from central and southern Spain, in the sensory pits between lateral and intermediate carinae of frons present up to very apex of cephalic process. Based on a comparison of our material of B. genei with the holotype male, a paratype female and three additional males of B. rugosa (labelled as from “Hispania” and “Ribas”, all specimens deposited in MMBC), we can add that those sensory pits on frons are also smaller in B. genei than in B. rugosa , and that B. genei also differs from B. rugosa in a more slender body and smooth tegmina (the body is distinctly broader and tegmina distinctly reticulate in B. rugosa ).

Compared with B. galaxia Emeljanov and Drosopoulos, 2004 , described from southern Portugal, the body size of B. genei is smaller and its cephalic proces in dorsal view is slightly broader and with more or less smoothly arcuate, not angular lateral margins subapically ( Emeljanov and Drosopoulos 2004).

Unfortunately, the original descriptions of B. carinata Horváth, 1936 , B. discolor Horváth, 1936 , B. fallax Horváth, 1936 , B. griseola Horváth, 1936 (all described from Spain), and B. pithyusa Emeljanov, 1972 (described from Ibiza) are not accompanied by clear diagnoses from other previously described taxa or illustrations ( Horváth 1936; Emeljanov 1972). These taxa need to be redescribed, illustrated and compared with other Bursinia spp. based on their type specimens in future studies.

Horváth (1910) also described B. genei var. parvula Horváth, 1910 from central Spain (Espinar), which he distinguished from the typical form of B. genei based on a smaller body size and more elongated cephalic process ( Horváth 1910: fig. 6). Horváth (1936) elevated this variety to species rank. In our opinion, the body size and the length and shape of the cephalic process in B. genei are quite variable ( Figs. 1 , 2 ) and B. parvula is likely to fall within this range, but future studies based on a more numerous material, particularly from Spain, should come to a more solid conclusion.

Besides external and morphometric characters, future revisions of Bursinia should take into account also male genitalia (including their inflatable elements), which are likely to provide diagnostic details for individual species as in other groups of Dictyopharidae and related Fulgoridae ( Seidel and Wessel 2013; Song et al. 2017 2018). These characters, as well as the female genitalia, have been neglected in Bursinia so far and are described in detail for B. genei for the first time here.

Description of the jumping muscles

Most Auchenorrhyncha are capable of jumping, by using mechanisms that likely evolved independently in the Cicadomorpha and the Fulgoromorpha ( Ogawa and Yoshizawa 2017). The mechanism of Fulgoromorpha is characterised by a greatly enlarged IIIpcm5 muscle, which inserts on a distinct funnel-shaped tendon and is the principal jumping muscle ( Emeljanov 1981 1987; Ogawa and Yoshizawa 2017; Sander 1957). This mechanism is also present in B. genei ( Fig. 9 ). However, the micropterous condition of this species has rendered its wings non-functional, as most of the associated dorsoventral and dorsal longitudinal muscles have disappeared ( Fig. 9 ). As a result, most of the space in the thorax that was dedicated to flight is now occupied by a greatly enlarged jumping muscle ( Fig. 9 ). This suggests that the jumping ability of B. genei might be greater than in macropterous dictyopharids. Bursinia genei has a similar body shape and only a slightly smaller body size compared to another micropterous dictyopharid species, Engela minuta Distant, 1906 ( Dictyopharinae : Dyctiopharini) from South Africa. The jumping capacity of E. minuta was studied in detail by Burrows (2014) who reported a very high take-off velocity of 5.8 m s-1, which is the fastest achieved by any insect described to date, and predicted E. minuta to be able to jump to a distance of more than 3 m, i.e., 500 times its body length. This was longer than jumps predicted for three other, larger macropterous dictyopharid species studied in detail as well ( Burrows 2014). In general, Dictyopharidae are very strong jumpers probably due to a power amplification mechanism in a catapult-like action (described in some other planthopper groups but not detailed in Dictyopharidae yet) and streamlined body including the cephalic process which further improves jumping performance by reducing drag ( Burrows 2014).

Snapping organ and capacity for vibrational communication

All planthoppers have been found to possess a snapping organ, which they use to generate substrateborne vibrational signals ( Davranoglou et al. 2019). Members of Orgeriinae have been shown to communicate with vibrational signals (Tischechkin 2003), although no recordings from Bursinia spp. are available. We have found that B. genei possesses a fully developed snapping organ ( Fig. 10A, B ). By virtually dissecting the specimen, we revealed hypertrophied dorsal longitudinal muscles ( Fig. 10C ), which are the primary operators of the snapping organ, suggesting that it is certainly functional. Unlike most other planthoppers, the apodemes for the snapping organ muscles are fused into a single central apodeme ( Fig. 10B ), which is visible only in microtomography scans and macerated specimens. Upcoming research (Davranoglou and Malenovský, in preparation) will show that a fused apodeme of the snapping organ is a synapomorphy of the Fulgoridae-Dictyopharidae clade.

Habitat and ecology

The two specimens of B. genei from Greece were collected under flat stones from a disturbed xerothermic locality in the outskirts of the town of Konitsa. The locality is at the edge of a Pinus nigra forest that is intersected by a rural road ( Fig. 11 ). During the day, temperatures reached up to 36°C, and the stones that the specimens were collected from were scorching hot. These conditions are congruent with previously known collecting data in the literature ( Emeljanov 2003; Mazzoni 2005) – B. genei is a xerothermic species that can be found at a range of altitudes (40–1300 m), primarily in open areas with sparse herbaceous vegetation and sparse trees, Mediterranean macchia, or at the edge of forests.

Adults of B. genei have been collected from July to September from Acer sp. Linnaeus, Juniperus sp. Linnaeus, Ostrya sp. Scopoli, Quercus sp. Linnaeus, Thymus longicaulis Prest and grasses, as well as in dry leaf litter and herbs at the base of trees ( Horváth 1910; Emeljanov 2003; Mazzoni 2005). Although we did not collect specimens feeding on plants, we should note that the micropterism and cryptic brownish coloration of this species may indicate its preference for a way of life close to the ground rather than on larger trees or shrubs.

Distribution

In terms of biogeography, B. genei is a West- Mediterranean element, spread from the Iberian Peninsula ( Horváth 1910 1936; Lallemand 1929; Emeljanov 2003; this paper) through southern France ( Horváth 1910; Emeljanov 2003; this paper), Corsica ( Emeljanov 2003), Sardinia ( Spinola 1839 – misidentified as Dyctiophora (sic) senegalensis Spinola, 1839 , see Metcalf 1946; Dufour 1849; Servadei 1967) and Italy ( Horváth 1910; Servadei 1967; Emeljanov 2003; Mazzoni 2005), eastwards to the Adriatic coast, and the southwestern Balkans, including northwestern Greece (this paper, new record). The records from former Yugoslavia ( Metcalf 1946; Nast 1972 1987) refer to what is now Croatia ( Horváth 1910; Melichar 1912; Emeljanov 2003; this paper), Montenegro (locality “Sutomore” listed in Horváth 1910 and Melichar 1912), and Bosnia and Herzegovina (“ Herzegowina ” listed by Melichar 1912). The records from “Hungaria” and “ Ungarn ” listed by Horváth (1910) and Melichar (1912), respectively, both refer to the same locality “Zengg”, which is now Senj, a town on the upper Adriatic coast of Croatia. Bursinia genei has not been recorded from what is today Hungary (cf. Györffy et al. 2009). Its records from Hungary in the catalogues by Metcalf (1946) and Nast (1972) are thus based just on erroneous geographical interpretation of historical data. It is very likely that B. genei will be also found in Albania, whereas we doubt it is present in central, southern and eastern Greece where intense collecting efforts by eminent hemipterists (e.g., Sakis Drosopoulos, Pavel Lauterer) for several decades have yielded no results.

Some other hemipteran species have a similar distribution to B. genei and likely followed a similar West-to-East dispersal route from southwestern Europe to the Balkans, e.g., Gardena insignis Horváth, 1887 (Heteroptera: Reduviidae ) ( Putshkov and Moulet 2010).

Figures

Fig. 2. Lateral habitus of male B. genei. (A) Specimen from Murter, Croatia. (B) Specimen from Serres, France. (C) Specimen from Epirus, Greece.Abbreviations: icf = intermediate carina of frons; lcf = lateral carina of forns; mcf = median carina of frons.

Fig. 1. Dorsal habitus of male B. genei. (A) Specimen from Epirus, Greece. (B) Close-up view of head. (C) Specimen from Murter, Croatia. (D) Specimen from Serres, France. (E) Close-up view of head of specimen from Serres, France. Abbreviations: ica = intermediate carina of abdomen; mca = median carina of abdomen; mcv = median carina of vertex.

Fig. 9. False-coloured three-dimensional reconstruction of B. genei from Greece, longitudinal section, lateral view. Abbreviations: bs + ep = basisternum + episternum; fm = femur; IIIpcm5 = musculus episterno-trochanteralis.

Fig. 10. Snapping organ morphology of B. genei. (A) dorsal view of specimen from Serres, France. (B) False-coloured three-dimensional reconstruction of snapping organ of B. genei from Greece. (C) Same, with top part excised to reveal the snapping organ muscles. Abbreviations: apo = apodeme for snapping organ muscles; cn = membranous connector; dlmI = dorsal longitudinal muscle of tergum one; lb = lobe of snapping organ; sp = spiracle; mb = membrane; rg = ridge of snapping organ; t2 = tergum II.

Fig. 11. Collecting locality in Konitsa, Epirus, Greece, where two specimens of B. genei were collected.