Bioacoustics of Hyphinomos svenhedini

Measurements. Morphometric measurements of H. svenhedini Ramme, 1950 type series and specimens used in this study are listed under Table 1 . Males BL PL PW FW_L FI_L FIII_L TIII_L Holotype 14–15 3.5–3.9 – 2.5 4.4–4.7 10.5–10.7 10.5 M1_Wet 18.2 3.4 4.7 2.4 4.1 10.1 9.7 M2_Dry 14.8 3.3 4.5 2.5 4 9.9 9.7 M3_Dry 14.9 3.6 4.5 2.5 4 10.3 9.6 Females BL PL PW FW_L FI_L FIII_L TIII_L Ovi_L Paratypes 17.5–18 4.5–4.7 – 1.5 5 12–12.5 11.5 11.7–12 F1_Wet 19.1 4.1 5.3 1.9 4.4 11.2 10.4 12.7 F2_Dry 15.3 4 5.2 1.6 4.5 11.8 10.4 12.7 Note: Wet and dry preserved specimens differ probably because of difference in their mode of preservation. Mating behaviour. Like many other insects in alpine zones of high mountains ( Mani, 1968 ) and high altitude crickets ( Gurney & Liebermann, 1975 ), this species is also diurnally active hence mating takes place in the day time. September month seems to be the peak season for them, hence mating pairs were seen everywhere in the areas around Shashi lake. It was an unmistakably common sight. Mating behaviour of this species was studied mostly in the laboratory. A nylon mesh cage of 12”x12”x12”( 30 cm ) dimension was used to enclose a male and a female together. Soon after releasing them together, both the sexes were found to be toppling over each other alternately wherein male was trying to attain the copulatory position by frequently climbing over female’s back. In doing so, male was found to be rubbing his forewings briefly for a couple of seconds to produce high frequency courtship signal. Unlike other orthopterans, attraction and coupling via antennation was absent and pair formation was not preceded by acoustic signalling in this species. Males either leaps abruptly onto the female’s body or simply climbs over her back and holds her abdomen with the help of his legs to restrict her movement since female was always in the process of resisting male and moving away. Males and females exhibit an end-to-end copulation position ( Fig. 12 A&B ) as depicted by Alexander & Otte, 1967 ( Fig. 11–12 ). The final copulatory position was achieved by the male by rapidly repositioning himself by bending abdomen in a c-shape underneath the female, his head facing the ovipositor and then using his pincer like cerci to grip the soft cuticle of the underside of the female’s abdomen and restricting her movement with his mid legs. He would grip the ovipositor with the help of foreleg only for first few minutes (2–4 minutes), eventually the grip of cerci becomes so strong that it allows the male to leave the grip of his foreleg from ovipositor. Apparent resistance by female to copulation was observed where female was seen walking rapidly during mounting and kicked male with her hind legs. On the contrary, females in some cases tend to start copulation and males resist by jumping. Copulation lasted for approximately one hour fifteen minutes in one couple and on separation no spermatophore was found attached to the females abdomen. In an attempt to observe the spermatophore size in this species, copulation between another mating couple was paused after one hour however, no spermatophore was seen. In a third mating pair, copulation lasted for approximately 3.5 hours, suggesting duration of copulation in laboratory condition to be variable. We do not have data on duration of copulation in their natural habitat. However, concluding from the high frequency of mating pairs observed in the field, copulations may either last long or happen quite often or both. Acoustic signals: The calling song is composed of a group of short and long series of impulses where the long series (assumed to be closing hemisyllables) are preceded by shorter ones (assumed to be opening hemisyllables; Fig. 13A–B ). Number of syllables vary between 5–6 per echeme. Duration of short and long hemisyllables are 13 ±1 ms and 41 ±8 ms (mean ± SD), respectively. Period from the onset of short to the onset of consecutive hemisyllable is 23 ± 9ms, from the onset of long to the onset next hemisyllable 56 ± 5ms. Duration and periods of syllables are 65 ±13 ms and 81 ±10 ms resulting in a syllable repetition rate of 12 Hz (at approximately 17.5 ºC; average indoor temperature on 16/09/ 2021 in Kargil). Duration and period of echemes are 406 ±36 ms and 2692 ±789 ms, respectively. The dominant recorded frequency of calling song is 16.8kHz, but may be limited by the recording device ( Fig. 13C ; compare Fig.14C ). Signal produced during mounting attempts by male is composed of separated syllables, differing in structure from that of the calling song ( Fig. 14A–B ) and peak frequency lies between 30–35kHz ( Fig. 14C ).