Thursday, May 5, 2011

Life in the cracks and crevices

In the past, taking pictures was a challenge and most of our records were only textual notes that we exchanged when we met, and things have changed so much. For the old-time naturalists, photography has been more of a tool rather than an end and it is remarkable how good even the average photograph with a low-end digital camera is these days. One does regret not having these gizmos in the past. Most of these pictures were taken using a rather low-end aim-and-shoot digital camera (A 3.2 megapixel Nikon CoolPix E3700). Putting together these old pictures surprised me a bit especially to see the total volume of images which have a way of accumulating rapidly. out of control. Fortunately I release most of my images under creative commons licenses and include notes and metadata. Posting them on Wikimedia Commons, allows me to keep notes and categorize them while many get identified or go through revisions when group experts find them and these images  take a life of their own, making their way into books and newspapers with enquiries landing at your desk from around the world. The benefit to illustrate Wikipedia articles naturally does not need explication and such material is longer lived than the average blog, personal  or even organizational website. Anyway, here is a random assortment of free critter images (read that as you may) that have visited and live alongside. None of these are rare (in Bangalore) and are probably right around your home as well.
Ramanella variegata

A couple of years ago we had Ramanella variegata breeding in our water sump - one of these pretty frogs had a favourite PVC tube into which he would croak like a Tuvan throat singer in the mornings. The acoustics inside the tube were perhaps enjoyable, although some studies on frogs have suggested that males might try to cheat in the competition for mates by choosing locations where they sound mightier.  Unfortunately,  these frogs have not turned up this year even after the first few rains but still look forward to having these pretty residents breeding around.
Scanning you with advanced spectrometry
Jumping spiders are lynx eyed although the term "lynx spider" is used for the Oxyopidae. They turn around to take a close look at you but the most interesting times are when they meet others. That is when you see them wave their palps and forelegs in well defined semaphore patterns. They have extremely sharp vision and are said to have the ability to distinguish colours (extending to UV) and detect polarization as well. One rather fascinating species named Bagheera kiplingi is even thought to break from the basic spider characteristic in being herbivorous.

Heterorrhina elegans - no green pigment
The rainy weather brings numerous insects that have a short breeding period. These include brilliant beetles that have led the largest part of their lives underground as curly white grubs. Some can appear in rather large numbers especially when they swarm at chosen trees. Among these are the emerald green scarabs. It is amazing that they have evolved such cuticular microstructures that produce green colours entirely without the need for specific pigments. 

A change in the angle of lighting turns emerald to gold. The colour is produced by diffracting incident light, amplifying some frequencies, decimating others and letting only a part reach your eye. Naturally lots of people want to be able to replicate such microstructures for applications in human life such as for car exteriors but that would not be much of an innovation as it would still be for attracting mates.

A lycid beetle
I never seem to get the Lycidae identity right at first go. These rather soft-bodied beetles are found mainly on plants. As adults some are thought to feed on nectar or not to feed at all. The larvae are predaceous and bear a strong resemblance to the larvae of the firefly beetles and their rather primitive appearance has given them the name of "trilobite larva". The Lycidae belong to the same groups as the click-beetles and the thorax ends in a sharp point in this particular specimen although it does not function as in the click-beetles for flipping them back on their legs.

Camponotus sericeus under a rock
The space under pots and stones is  great for species that need a well regulated temperature and humidity.  Here one can often find numbers of land crustaceans, annelids and insects. This colony of ants lived in the space below a rock. The queen was apparently somewhere and the workers at the centre were taking care of larvae and pupae. The entire nest is just planar and in the narrow space, perhaps ideal as a study species.

Myrmicaria brunnea at sugar lick
Some ants have a taste for sugar - Myrmicaria brunnea - apparently just cannot resist it. A little water around a crystal of sugar attracts them in droves and they line up along the edge of the sweet waterholes and lap them up. Their sweet tooth leads them to harvest honeydew secreted by bugs. Apparently most members of the genus hold the gaster facing downwards as evident in the picture.

Mantis nymph (2 mm long)
Ants are so successful that numerous other tiny insects have evolved to appear like them. This effectively keeps away predators, and even tiny predators at like this nymph of a mantis are at risk. These are not the only ant like predators. Invariably to be found running on the wall, are also the ant mimic spiders.

Delias eucharis
Flying insects tend to be more interesting, as they can come in from much further off and are not dependent on the food resources within your home. This Common Jezebel butterfly Delias eucharis appears to be freshly emerged. The larvae breed on the parasitic mistletoe plants, the trees around my home are devoid of mistletoe, so it is a bit of a mystery.

Wasp possibly Phimenes sp.
Potter wasps are beautifully marked. Despite their distinct colours, the taxonomy of the Indian species is uncertain. I recently found one picking up clay from an older nest for use in a fresh nest. A leaky tap or a watery patch in the soil is a great attraction for them.

Camponotus with micro-livestock
A recent outbreak of scale insects led to a number of species of plants being covered in scales. These scale insects suck up fluid from the plants and share their secretions with ants. The ants keep away predators and move the scales around to new plants leading to a rather effective utilization of the vegetation by the ants.

Spalgis epius
But the defence by ants of these scale insects does not seem to be perfect. Their livestock, sooner or later become the target of pathogens, parasitoids and predators. One of the predators of these scales is, rather surprisingly, the caterpillar of a butterfly called the apefly. The name comes from the appearance of its pupa.

Platynotus excavatus doing a headstand
Coming down to ground level introduces us to a number of other visitors.  This Tenebrionid beetle was on the ground in the typical posture that many take. Some species in the Namib desert, adopt this posture termed as "fog-basking" to let moisture condense on their elytra. Some species even have ridges along the sides that lead the drops of water right to their mouths. The idea has even been adopted in some parts of the world to squeeze water out of the morning breeze to meet the water needs of people. Perhaps this beetle has something to offer for thirsty Bangalore.

Acknowledgements
The identification of insects is tricky and it takes a long while to orient oneself with the basic groupings and things get better over time.  Many thanks are due to the faculty and friends, especially Prof. C. A. Viraktamath, at the department of entomology at the University of Agricultural Sciences in Bangalore for many of the species level identifications above.

5 comments:

  1. The evolution of Wikimedia Projects unseen continues. It is in the way people choose to use the Commons. The images are placed there as if Commons were a permanent biodiversity repository. Some of us find inexorable logic in uploading all our biodiversity images, none excluded, onto Commons. It is here that our images are most available to the world which interacts with the images, uses them and enrich the context they are held in. Commons not just as a repository but as a path to knowledge!

    ReplyDelete
  2. Lovely to have someone doing the hard taxonomy work for me, all I need to do is to enjoy your posts..I really am not too much into names; just love the beauty of these little critters.

    Bagheera kiplingi! Must go and google for it now...which Jungle Book lover named that, I must find out.

    ReplyDelete
  3. Yet another wonderful informative article, Shyamal! Thank you. Does this mean that anyone can upload their pics to Wikimedia Commons?

    ReplyDelete
  4. Yes Indeed, Uma. Anyone is most welcome to contribute to the Wikimedia commons - all you need is a login at http://commons.wikimedia.org and the willingness to license your images for free usage (under a creative commons license with the condition of attribution) or releasing it into public domain unconditionally.

    ReplyDelete
  5. Very nice and informative article. Enjoyed it. Bright colored cars used primarily to attract mates? Indeed! :)

    ReplyDelete