Chrysoperla shahrudensis, Henry & Brooks & Johnson & Mochizuki & Mirmoayedi & Duelli, 2018

Henry, Charles S., Brooks, Stephen J., Johnson, James B., Mochizuki, Atsushi, Mirmoayedi, Alinaghi & Duelli, Peter, 2018, Distinctive but functionally convergent song phenotypes characterize two new allopatric species of the Chrysoperla carnea-group in Asia, Chrysoperla shahrudensis sp. nov. and Chrysoperla bolti sp. nov. (Neuroptera: Chrysopidae), Journal of Natural History 52 (25 - 26), pp. 1603-1635 : 1627-1629

Chrysoperla shahrudensis sp. nov.

( Figures 1 (a), 2(a), 4(a,b) and 5; Table 1, 2, 3)

Holotype. NHMUK010729670 . Male : IRAN: Shahrud (36.37°N, 54.99°E), 1296 m, 7 August 2014, coll. P. Duelli, A. Mirmoayedi and D. Bolt, BMNH.

Paratypes. Same data as holotype, 4 ♂, 8 ♀ (specimens NHMUK010729671 , NHMUK010729672 , NHMUK010729673 , NHMUK010729674 , NHMUK010729678 , NHMUK010729679 , NHMUK010729680 , NHMUK010729681 , NHMUK010729682 , NHMUK010729683 , NHMUK010729684 and NHMUK010729685 ) . IRAN: Shahrud (36.60°N, 54.98°E), 1286 m: 3 ♂, 1 ♀, coll . same as holotype, BMNH (specimens NHMUK010729675 , NHMUK010729676 , NHMUK010729677 and NHMUK010729686 ); Pass Qazvin to Alamut Valley (36.38°N, 50.21°E), 2267 m, 5 August 2014: 3 ♀, coll . same as holotype, BMNH (specimens NHMUK010729687 , NHMUK010729688 and NHMUK010729689 ); 6 first-instar, 6 second-instar and 12 third-instar larvae, reared from parents pooled from Shahrud paratypes, WFBM .

Etymology

Named for the type locality: Shahrud , Iran .

Description

Adult. Ground colour uniform bright or light green on upper surface, paler green on lower surface, pale yellow-white medial dorsal stripe running along rear of head and length of thorax and abdomen. Stipes with apical 25 – 75% marked dark brown or black. Maxillary palp unmarked or basal segment marked dark brown dorsally. Gena marked black, but sometimes red-brown or red. Clypeus lateral edge marked with black-brown stripe, occasionally red. Frons marked laterally with small red spot below outer margin of antennal base, ground colour entirely green. Scape, pedicel and postocciput unmarked. Pronotal setae pale in most specimens, occasionally with some black setae. Pronotum marked with indistinct greyish lateral spots. Metatarsal claw basal dilation ratio 2.50 (2.28 – 3.17). Forewing apically symmetrical, broadly rounded, and not tapered; length 11.7 – 15.75 mm; length: breadth ratio 2.89 (2.59 – 3.12); venation entirely green except basal vein of intramedian cell, the two Cu crossveins, and ends of costal and subcostal crossveins black; costal setae short, inclined towards wing apex; basal Rs-M crossvein usually at right angles to Rs but occasionally obtuse. Abdominal segments 1 – 3 marked with dorso-lateral rectangular black spots; abdominal sternites clothed by fine, blond setae, occasionally 50% black setae on sternite 8; pleural membrane of second segment usually unmarked but rarely showing a faint band; lip of sternite 8 + 9 in male broad and short above a small chin; tignum as in other carnea -group species.

Courtship song (25°C). Substrate-borne vibrational signals produced by abdominal oscillations; nearly identical in males and females. Shortest repeated unit usually disyllabic and iterative, always beginning with single primary volley of abdominal vibration of ≈ 0.75-s duration, usually followed (> 80% of the time) by atonal rumble of ≈ 0.50-s duration. In solo ‘ calling ’ context, SRU repeated every 2.40 s. Frequency structure of each volley is complex (bipartite), starting at ≈ 76 Hz, falling quickly to ≈ 35 Hz, rising again to ≈ 60 Hz at end. Heterosexual duets consist of each individual repeatedly and politely answering single SRUs (volley-plus-rumble units) of its partner without overlapping; duets have slightly slower repetition rates than solos.

Larva, third-instar. Background of head, body and legs cream-coloured. Dorsum of head with pair of relatively narrow pale- to medium-brown longitudinal, dorso-lateral stripes with narrow baso-lateral expansions extending towards eyes and medium-brown lateral stripe of variable width immediately behind the eye; head surface rarely (17% of larvae) exhibiting a fronto-medial spot, but nearly always bearing a brown spot dorsomedially on scape. Pronotum usually with narrow, pale brown, longitudinal dorso-lateral stripes; meso- and metanota usually, and abdomen always, unmarked. Coxa bearing two small, medium-brown spots laterally; distal femoral band and base of tibia pale brown.

Larva, earlier instars. Stripes, lateral expansions, and spots on head, thorax and abdomen less sharply delineated but often more extensive than in third-instar (mature) individuals. Femoral and tibial markings remain well-defined or are often darker.

Life cycle and ecology

A habitat generalist, associated broadly with crop fields and field margins within primarily deciduous rather than coniferous niches, at elevations greater than 1000 m. Number of generations per year unknown. Stalked eggs oviposited singly rather than in groups. Adults turn light sandy-brown colour in winter diapause. Possibly a nomadic (migratory) species.

Diagnosis/discussion. Chrysoperla shahrudensis sp. nov. can be most reliably separated from other species in the carnea -group by courtship song analysis. However, the presence of two small red spots on the frons is a diagnostic morphological trait that will usually delineate C. shahrudensis from other species in this genus, except C. bolti . Additional characters that help to distinguish this species from other carnea -group species, but which are not diagnostic, include relatively pale green body colouration; a frons that is mostly or entirely green; symmetrical, broadly rounded apex of the fore wing; intermediate size of the basal dilation of the claw; and C. carnea -like proportions of the abdominal chin and lip.

The simple SRU of the C. shahrudensis vibrational song, consisting of just one relatively long volley (or volley plus rumble), superficially resembles that of both C. bolti sp. nov. in Kyrgyzstan (Asia) and C. adamsi in western North America. However, the C. shahrudensis primary volley has a complex, bipartite frequency structure that differentiates it not only from C. bolti and C. adamsi but also from all other species of the carnea -group.

Limited and simple head markings characterize the larva of C. shahrudensis , but do not distinguish it absolutely from any other Eurasian species of the carnea -group. Only the dorso-medial brown spot on the antennal scape is potentially diagnostic, although this needs to be verified using larger larval sample sizes of all species.

Species of the Chrysoperla carnea -group that have been collected in sympatry with C. shahrudensis include C. carnea , C. agilis , C. pallida , C. zastrowi sillemi and C. heidarii . Of these, only pale green C. pallida is relatively easy to separate from C. shahrudensis based on overall appearance, although all can be unambiguously assigned to species based on song phenotype.

Distribution. Northern Iran (western Asia) at elevations ≥ 1000 m.

Figures

Figure 1. Oscillographs (lower of each pair of traces) and sonographs (upper traces) of (a) a solo vibrational song of Chrysoperla shahrudensis sp. nov. from northern Iran and (b) a solo vibrational song of Chrysoperla bolti sp. nov. from Kyrgyzstan, Asia, illustrating convergent song phenotypes in these two Asian species. Each song was recorded at 25 ± 1°C and is drawn to the same time scale of 12 s. Start, middle, end, and rumble sections of an individual volley are marked by the arrows, while duration and period of the primary volley are bracketed.