Chrysoperla zastrowi arabica, Henry & Brooks & Duelli & Johnson, 2006

Henry, Charles S., Brooks, Stephen J., Duelli, Peter & Johnson, James B., 2006, Courtship song of the South African lacewing Chrysoperla zastrowi (Esben-Petersen) (Neuroptera: Chrysopidae): evidence for a trans-equatorial geographic range?, Journal of Natural History 40 (38 - 40), pp. 2173-2195 : 2192-2194

Chrysoperla zastrowi arabica n. subsp.

HOLOTYPE: male, Oman: Al Burymi , 285 m, October 1994, coll. P. Duelli. BMNH.

PARATYPES: same data as holotype, 13 males, 15 females, 15 first-instar, 15 second-instar and 15 third-instar larvae, reared from parents collected x.1994, coll. P. Duelli. 13 males, 15 females, BMNH ; 5 first-instar, 5 second-instar, 5 third-instar larvae, BMNH; 5 first-instar, 5 second-instar, 5 third-instar larvae, CSMNH; 5 first-instar, 5 secondinstar larvae, 5 third-instar larvae, WFBM.

Etymology. Named for its occurrence in the Arabian Peninsula of the Middle East.

Adult. Ground colour uniform pale green. Head marked with broad dark brown band, sometimes outlined in red on gena and clypeus. Maxillary palp marked dark brown dorsally on each segment, occasionally unmarked. Stipes marked with mid-dorsal brown line along its entire length; occasionally, marking restricted to the apical third of the stipes. Clypeus with lateral edge marked with narrow brown or red stripe. Frons marked with brown lateral stripe, or red stripe when the clypeal markings are red. Postoccipital region unmarked. Antennae shorter than fore wing. Pronotum marked with median pale yellow stripe; lateral setae mostly short, black. Tarsal claw basal dilation ratio 3.5–5.1. Fore wing length 11.3– 14.0 mm, length:breadth ratio 2.6–3.4; venation entirely green; costal setae relatively short; basal Rs-M crossvein leaves Rs at right angles or sometimes obliquely. Abdomen bearing black setae on three apical sternites, more basal sternites bearing blond setae; lip of sternite 8+ 9 in male relatively short and narrow with sparse long black setae.

Courtship song (25 ° C). Song consisting of a single-volley SRU 1.8– 3.3 s long, usually repeated several to many times with a period of 2.2– 5.1 s; carrier frequency is a pure (single-frequency) tone, falling from a range of 48–61 to 21–30 Hz during the course of the volley. Amplitude peaks sharply as the volley begins, then declines smoothly but rises again to a broad maximum toward the end of the volley. Volleys of the participants overlap slightly or not at all during heterosexual duets .

Larva, third instar. Head pale tan with a pair of relatively narrow, moderately pale, longitudinal dorso-lateral brown stripes with narrow baso-lateral expansions extending towards the eyes; uncommonly (9.7%) with darker spot in dorso-lateral stripe mesad of eyes; elongate fronto-medial spot usually (84%) present; pale lateral stripe present behind eye. Thorax cream coloured; pronotum with tan, longitudinal, dorso-lateral stripes; meso- and metanota with small brown spots near mid-length. Abdomen cream coloured, unmarked, except tubercles sometimes tan.

Second instar. Similar to third-instar except as follows. Head with dorso-lateral stripes broader relative to width of head, especially anteriad; stripes narrowing more abruptly on medial margin of antennae; frontal spot rarely developed; lateral stripe behind eye darker. Thorax with pronotal dorso-lateral stripes usually more prominent, meso- and metanotal spots smaller. Abdomen with tubercles sometimes darker.

First instar. Similar to second-instar larva except as follows. Head with dorso-lateral stripes broader relative to width of head; baso-lateral expansions sometimes absent; frontal spot absent; lateral stripe behind eye sometimes darker. Thorax with pronotal dorso-lateral stripes variably prominent; meso- and metanotal spots very small, paler. Abdomen with tubercles frequently pigmented.

Remarks. Chrysoperla zastrowi arabica can be separated with certainty from the nominate subspecies only by courtship song analysis. However, in most cases adult C. z. arabica can be distinguished from C. z. zastrowi by the angle of the basal Rs-M crossvein, which in C. z. zastrowi always leaves Rs at an oblique angle; in most specimens of C. z. arabica, this vein is at right angles to Rs. Both subspecies of C. zastrowi can be distinguished from other members of the C. carnea group by the relatively small basal dilation of the tarsal claw (large claw ratio). The tarsal claw ratio is larger in C. zastrowi than in any other western European member of the species group except for western populations of C. mediterranea , but in the latter taxon the claw is hardly dilated at all. Other characters which help to distinguish C. zastrowi from other carnea -group species, but which are not diagnostic (i.e. black setae on pronotum, genital lip characteristics and green venation), are described further in the main Discussion.

The song of Chrysoperla z. arabica is best distinguished from that of C. z. zastrowi by its much longer volley duration and volley period, each of which is longer than that of the nominate subspecies by a factor of 1.6 or more. The song of C. z. arabica is also markedly different from that of any other known song species in the carnea group. The only other lacewing sometimes showing single-volley SRUs of equivalent length is C. agilis , but the carrier frequency in C. agilis has a more complex harmonic structure and increases rather than decreases during the course of each volley.

Larvae of C. z. arabica and C. z. zastrowi are similar, but can usually be distinguished from each other by the frequent presence in C. z. arabica of a fronto-medial spot, which is absent in all C. z. zastrowi . Another distinguishing feature is the absence in most C. z. arabica of a darker spot in the dorso-lateral stripe mesad of the eyes, which is always present in the nominate subspecies. None of the C. z. arabica larvae examined simultaneously lacked the fronto-medial spot yet possessed the darker spot in the dorso-lateral stripe, which is the universal condition in C. z. zastrowi . The larva of C. z. arabica has no features that distinguish it absolutely from that of C. carnea , C. pallida , C. mediterranea , C. agilis or C. lucasina . Its head markings particularly resemble those of C. mediterranea from Carcès, France ( Henry et al. 1999) while those of C. z. zastrowi most closely resemble markings of some C. carnea from Belgorod, Russia ( Henry et al. 2002).

Distribution. Oman, United Arab Emirates, Israel, Iran.