Saturday, 17 May 2014

Moving on

Over the past few years, I have added fewer and fewer new species to my list each year. The main reason for this is my modus operandi, whereby I search for things that I can photograph and identify specimens mainly from those photographs. This process has limitations: many species need microscopic analysis before they can be identified accurately. Since I don't capture specimens there are many species that I see that I cannot identify. This is a lost opportunity in a number of ways:

  • Potential records are not being added to the national database, so the overall picture of what is where is wrong.
  • I research the natural history of the species that I identify, and if I don't know what something is, I can't find out what it does.
  • All species have loose or tight associations with other species and their habitat(s). I am missing opportunities to find out these associations, and hence my ability to add to our knowledge is reduced.

Basically, I am limiting my knowledge and I am limiting my ability to add to the greater knowledge. So I have decided to start sampling specimens. This will enable me to identify specimens beyond "a tachinid" or "a lesser cranefly". It's a logical progression, and hopefully it will add to your knowledge as well as mine.

On Friday I attended a beginner's course on spider identification. Spiders are an area that I have largely ignored for a number of reasons, and I think it's time to embrace them and begin to record them properly. The literature isn't cheap, but there are hundreds of species out there, and I'm sure I can make some progress in this very under-recorded group.

During the fieldwork we found this harvestman:

The harvestman Platybunus triangularis
Platybunus triangularis is one of the few harvestmen that can be found as an adult at this time of year. The pose with one leg held out as a trigger is typical of harvestmen, since they don't make webs, but pounce on passing insects.

New to my species list.

This Green-veined White butterfly is rather interesting:
Green-veined White butterfly
The obvious oddity is the fact that the patterns on the two wings are different. The left wing is clearly a female wing (it has plenty of dark spots), but the right wing has only a faint, single spot. The wings of male Green-veined White can vary a little, but I have seen identically-marked males. So the question is: is this a gynandromorph (half female, half male)? Another thing to notice is that the abdomen is not straight: it has a distinct kink in it. This is a feature I have seen on images of confirmed gynandromorph specimens. The jury is out, but I'll report back later.

My first collected specimen is a Water-measurer - Hydrometra stagnorum:
Water-measurer - Hydrometra stagnorum
Hydrometra stagnorum is a water-walking bug that can be seen in the company of other water-walking species, but it's a lot smaller (12 mm.) One notable feature is the very long head: this is thought to be used to reach food below the water surface.

New to my species list.

No comments: