Chrysoperla zastrowi sillemi (Esben-Petersen), 2010

Henry, Charles S., Brooks, Stephen J., Johnson, James B., Venkatesan, Thiruvengadam & Duelli, Peter, 2010, The most important lacewing species in Indian agricultural crops, Chrysoperla sillemi (Esben-Petersen), is a subspecies of Chrysoperla zastrowi (Esben-Petersen) (Neuroptera: Chrysopidae), Journal of Natural History 44 (41 - 42), pp. 2543-2555 : 2552-2554

Chrysoperla zastrowi sillemi (Esben-Petersen) stat. rev.

Chrysoperla sillemi Esben-Petersen, 1935: 234 . Holotype. Female , India: Kashmir , Karakorum, Maralbashi, 110 m, 20 March 1930 coll. Sillem. ITZ [examined]. Stat. rev.

Chrysoperla sillemi (Esben-Petersen) ; Brooks, 1994: 149.

Chrysoperla zastrowi arabica Henry et al., 2006 . New synonym.

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 middorsal 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 forewing. Pronotum marked with median pale yellow stripe; lateral setae mostly short, black. Tarsal claw basal dilation ratio 3.5–5.1. Forewing 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 predominantly bearing black setae, although Indian specimens often have a mixture of blond and 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) (updated from 2006). Song consisting of a single-volley SRU 1.1 s (minimum within solos) to 3.4 s (maximum within duets) in duration, usually repeated several to many times with a period of 1.8 s (minimum within solos) to 6.4 s (maximum within duets); carrier frequency is a pure (single-frequency) tone, falling from a range of 55–73 Hz to 17–30 Hz during the course of the volley. Amplitude peaks sharply as the volley begins, then declines smoothly but usually 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 dark, longitudinal dorsolateral brown stripes with narrow basolateral expansions extending towards the eyes; sometimes (26%) with variably prominent darker spot in dorsolateral stripe mesad of eyes; elongate frontomedial spot usually (85%) present; pair of variably prominent submedial spots behind frontomedial spot uncommonly (16%) present; lateral stripe present behind eye. Thorax pale cream coloured; pronotum with tan, longitudinal, dorsolateral stripes; mesonota and metanota with small brown spots near mid-length. Abdomen pale cream coloured, unmarked, except tubercles sometimes tan.

Second instar. Similar to third-instar except as follows. Head with dorsolateral 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 dorsolateral stripes usually more prominent, mesonotal and metanotal spots smaller. Abdomen with tubercles sometimes darker.

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

Remarks. Chrysoperla zastrowi sillemi can be separated with certainty from the nominate subspecies only by courtship song analysis. However, in most cases adult C. z. sillemi can be distinguished from C. z. zastrowi by the angle of the basal Rs-M cross-vein, which in C. z. zastrowi always leaves Rs at an oblique angle; in most specimens of C. z. sillemi , 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 C. z. sillemi is best distinguished from that of C. z. zastrowi by its shorter volley duration and shorter volley period: each of these features is at least 1.6 times longer in the nominate subspecies than in C. z. sillemi . The song of C. z. sillemi 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 rises rather than falls during the course of each volley.

Larvae of C. z. sillemi and C. z. zastrowi are similar, but can usually be distinguished from each other by the frequent presence in C. z. sillemi of a frontomedial spot, which is absent in all C. z. zastrowi . Another distinguishing feature is the absence in most C. z. sillemi of a darker spot in the dorsolateral stripe mesad of the eyes, which is always present in the nominate subspecies. A third feature that is useful for C. z. sillemi larvae from India is the common occurrence of the pair of submedial spots. None of the C. z. sillemi larvae examined from any region simultaneously lacked the frontomedial spot yet possessed the darker spot in the dorsolateral stripe, which is the universal condition in C. z. zastrowi . The larva of C. z. sillemi 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). Even the two submedial spots that distinguish the Indian larvae of C. z. sillemi are shared with some C. carnea larvae from Berchtesgaden, Germany; Zürich and Brissago, Switzerland; and Tammela, Finland ( Henry et al. 2002), as well as with C. lucasina from Berchtesgaden, Germany ( Henry et al. 1996).

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