Monday, November 21, 2011

Katydid Asiophlugis species

The intensive work on Orthoptera from the past one year has produced several new findings including some species that are new to science. These are either published already or in the process of being so.

Asiophlugis temasek

One of the new species is a little katydid, named Asiophlugis temasek after the old name for Singapore. This species measures only about 11mm in length and mostly found within our nature reserves. It is cryptic in behaviour, usually roaming on the underside of leaves. This tiny insect is quite charming. It is of emerald green with two large bulging eyes.

Including A. temasek, Singapore has three species from this genus. The other two is Asiophlugis rete and Asiophlugis thaumasia. The marvelous katydid mentioned in the Singapore Red Data book is actually A. thaumasia.
Asiophlugis thaumasia


Because they are so poorly studied, very little is known about their biology. Hence its always interesting to witness aspects of their behaviour. Recently we managed to shot a short video of an A. thaumasia performing a brief waltz dancing. Simply delightful


Actually what it is doing is generating motion parallax. The sideways head movements are means to judge distance and depth perception. In this instance, the head movements allow the little katydid to aim for an accurate targeted jump.

Asiophlugis species are predatory but its still uncertain how they actually hunt. Perhaps they can ambush prey with a mighty leap? It would be very fascinating to document.


Pictures and video taken at: Central Catchment Nature Reserve, December 2010; Bukit Timah Nature Reserve, November 2011


References:

Davison, G. W. H., P. K. L. Ng & H. C. Ho (eds), 2008. The Singapore Red Data Book: Threatened Plants and Animals of Singapore. 2nd Edition. The Nature Society (Singapore), Singapore

Gorochov, A. V. & M. K. Tan, 2011. New katydids of the genus Asiophlugis Gor. (Orthoptera: Tettigoniidae: Meconematinae) from Singapore and Malaysia. Russian Entomological Journal, 20(2): 129–133.

Kral, K., 2003. Behavioural–analytical studies of the role of head movements in depth perception in insects, birds and mammals. Behavioural Processes, 64:1-12.

Tan, M. K., 2011. The species of Asiophlugis Gorochov, 1998 in Singapore (Orthoptera: Tettigoniidae: Meconematinae). Nature In Singapore, 4: 233-239.