Bioacoustics of Notomulciber

Host plants. Two beetles were collected on Helicteres isora L. ( Sterculiaceae ). Although there were adult feeding symptoms on the leaves and stem, the host association could not be confirmed during the field collection. The symptoms of damage involved typical Lamiinae adult feeding patterns: leaves were fed along the veins from underside ( Fig. 33 ) and sometimes vein clearing was also observed, while the outer surface of the petiole and stem were gnawed longitudinally ( Fig. 34 ). Another adult was picked up while it was resting on the leaf blade of Zingiber zerumbet (L.) Sm. ( Zingiberaceae ). However, no such feeding symptoms were noticed on the plant. Based on the circumstantial evidences, it may be that H. isora is the adult host plant of N. viraktamathi sp. nov. Behaviour. Adults were inactive during day and were found idle in a characteristic resting posture ( Figs. 36– 37 ). Legs were held adducted to the body with tibiae closely appressed to the femora. The front and mid-legs were held close to each other near to the pronotum, substantially apart from the hind legs, thereby creating an illusion of the hind legs as the ‘fore legs.’ The antennae, held closely appressed to the body, emerge from beneath the elytra and extend beyond the elytral apex. Further, the postmedian circular bright eyespots on the elytra look like deflection marks besides creating an illusion of broad ‘false head’. This whole arrangement may give the beetle an illusion of moving in the direction opposite to its actual orientation. Silberglied & Aiello (1976) define this behaviour of reversed orientation as “Tergiversation.” Apart from this, when the adults were hand-picked from the plant surface, they resorted to stridulation by constantly nodding their head to rub the pronotal ridges on the stridulatory plate to produce sound.