Chrysoperla bolti, 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 : 1629-1631

Chrysoperla bolti , sp. nov.

( Figures 1 (b), 2(b), 4(c) and 6; Table 1, 3, 4)

Holotype. NHMUK010729838 . Male : KYRGYZSTAN: Alamüdün District (42.58°N, 74.48°E), 1950 – 2056 m, 12 July 2016, coll. P. Duelli, BMNH.

Paratypes. Same data as holotype, 7 ♂, 6 ♀, BMNH (specimens NHMUK010729839 – NHMUK010729851 , inclusive), 2 ♀, UCMS; same locality as holotype 25 June 2016: 4 ♂, 1 ♀, UCMS; Chichkan Valley, (42.12°N, 72.80°E), 1750 m, 1 June 1995: 6 ♂, 4 ♀, coll . P . Duelli, UCMS; 30 first-instar, 8 second-instar, and 18 third-instar larvae, reared from parents pooled from Alamüdün paratypes, WFBM .

Etymology

Named for our colleague and fellow insect collector, Mr Daniel Bolt.

Description

Adult. Ground colour uniform dark green on upper surface, paler green on lower surface, pale yellow-white dorsal stripe running along rear of head and length of thorax and abdomen. Stipes marked entirely dark brown or black. Maxillary palp with apical segment yellowish-brown, other segments marked dark brown dorsally. Gena marked dark brown or black. Clypeus lateral edge marked with black-brown stripe, occasionally reddish. Frons marked laterally with reddish stripe and sometimes with small red spot below the outer margin of the antennal base, ground colour of upper half green, lower half yellowish. Scape, pedicel and postocciput unmarked. Pronotal setae mostly pale in females, predominantly black in males. Pronotum marked with indistinct greyish lateral spots. Metatarsal claw basal dilation ratio 2.81 (2.47 – 3.13). Forewing apically symmetrical, narrow and rounded; length 11.55 – 14.40 mm; length: breadth ratio 3.12 (2.79 – 3.33); venation entirely green except basal vein of intramedian cell, the two Cu crossveins, and ends of costal and subcostal crossveins faint black; costal setae short, inclined towards wing apex; basal Rs-M crossvein at right angles to Rs. Abdominal segments 1 – 3 unmarked; abdominal sternites clothed by fine, blond setae, but usually black setae on sternite 8; pleural membrane of second segment usually bearing a thin brown stripe; lip of sternite 8 + 9 in male broad and short above a small chin; tignum as in other carnea -group species.

Courtship song (25 degrees C). Substrate-borne vibrational signals produced by abdominal oscillations; nearly identical in males and females. The SRU usually monosyllabic, always beginning with single volley of abdominal vibration of nearly 1 s duration, sometimes followed (≈ 20% of the time) by atonal rumble of variable duration. In solo ‘ calling ’ context, SRU repeated every 3.8 s. Vibrational frequency of each volley simple, linearly falling from ≈ 80 Hz at start to ≈ 40 Hz at end. Heterosexual duets consist of each individual repeatedly and politely answering single SRUs 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 moderately narrow medium to dark brown longitudinal, dorso-lateral stripes with baso-lateral expansions extending towards eyes and a medium to dark brown lateral stripe of variable width immediately behind the eye; head surface typically showing a darker spot in the dorso-lateral stripe mesad of the eyes, but lacking separate fronto-medial spot. Antennal scape pale to medium brown, sometimes darker medially and occasionally exhibiting a pale longitudinal stripe dorso-laterally; pedicel and basal flagellomere brown in 30% of specimens. Extensive red suffusion present dorso-laterally and laterally on all thoracic and abdominal segments; thorax and first several segments of the abdomen bearing narrow, brown, dorso-lateral longitudinal stripes (prothorax) or spots (meso- and metathoraces and abdomen). Base of coxa and associated pleuron medium brown; distal femoral band broad and brown, darkest apically and paler basad, successively narrower on more posterior legs; tibial base brown.

Larva, earlier instars. Stripes, lateral expansions, and spots on head and prothorax less sharply delineated but often more extensive than in third-instar (mature) individuals. Scape always (second-instars) or often (first-instars) brown; pedicel and first flagellomere brown in 12% of second-instars but unpigmented in first-instars. Meso-and metanota unmarked with brown and showing reduced area and intensity of red suffusion. Red suffusion similarly reduced on abdomen. Femoral pigmentation limited to distal onethird to one-half on all legs.

Life cycle and ecology

A habitat specialist, found in alpine meadows of tall grasses and herbs at elevations greater than 1000 m. Number of generations per year unknown. Stalked eggs oviposited singly rather than in groups. In winter diapause, adults remain dark green but typically acquire enhanced reddish suffusion on genae and frons. Apparently not a nomadic (migratory) species.

Diagnosis/discussion. Chrysoperla bolti sp. nov. can be most reliably separated from other species in the carnea -group by courtship song analysis. However, C. bolti differs from C. shahrudensis and several other Eurasian species in its darker-green body colouration, extensive yellow pigment on the lower frons, and less intense dark markings on the crossveins, but those traits are not absolutely diagnostic. Additional non-diagnostic characters helping to distinguish this species from several other common carnea -group species include a relatively narrow but apically rounded fore wing, intermediate size of the basal dilation of the claw, C. carnea -like proportions of the abdominal chin and lip, and the presence of a thin ‘ lucasina stripe ’ on the pleural membrane of the second abdominal segment ( Henry et al. 1996). Of the two undescribed species that live in sympatry with C. bolti in Kyrgyzstan, C. ‘ downesi-K ’ is morphologically more similar to it than is C. ‘ carnea-K. ’ In particular, C. ‘ downesi-K ’ is darker green and has a yellow frons and relatively narrow wings, whereas C. ‘ carnea-K ’ has broad wings and prominent black tips on the crossveins, two traits shared with C. shahrudensis (S.J.B., unpublished data).

The simple SRU of C. bolti’ s vibrational song, consisting of just one relatively long volley (or volley plus rumble), superficially resembles that of C. shahrudensis in Iran and more exactly resembles that of C. adamsi in western North America. However, the C. bolti volley has a simple, smoothly descending frequency structure that differentiates it clearly from C. shahrudensis , while C. bolti’ s longer volley period (≈ 3.8 s) consistently separates it from true C. adamsi (≈ 3.2 s). There are no known members of the global carnea -group other than C. shahrudensis and C. adamsi that have duetting songs similar to the song of C. bolti .

Limited and simple head markings characterize the larva of C. bolti , but do not distinguish it absolutely from any other Eurasian species of the carnea -group. However, the brown antennal scape and serially graded extent of femoral pigmentation are potentially diagnostic traits, although they need 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. bolti include only the two undescribed species informally known as C. ‘ carnea-K ’ and C. ‘ downesi-K, ’ each of which has acoustical, morphological and ecological characteristics that delineate it from C. bolti .

Distribution. Northern Kyrgyzstan (central Asia) at elevations> 1000 m.

Taxon abbreviations: C., Chrysoperla ; z., zastrowi ; shahrud, shahrudensis ; nippon, nipponensis Locality abbreviations: RSA, Republic of South Africa; C, central; N, northern; S, southern; W, western; SE, southeastern; SW, southwestern; Switz, Switzerland; Pfyn, Pfynwald region of Switzerland; CA, state of California, USA; WA, state of Washington, USA; OR, state of Oregon, USA; ID, state of Idaho, USA; Inv, Inverness, CA, USA (San Francisco Bay area).

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.