The #AncellorProject: Summary of weeks two and three; reflection

Week two:

Day 8: three large carabids, one harvestman, and one little black beetle that looked like this:Image

Day (9,10,11): eight large black carabids, one large blueish carabid (Leistus spinibarbis – see below), two Bembidion-looking carabids (Bembidion tetracolum, possibly), three staphylinids. One more unidentified small black beetle. Fly larvae hatched and very active on the bait.


Day (12,13,14): six large carabids (largest ~17mm), two smaller Notiophilus-looking carabids, one small staphylinid, one larger staphylinid (~9mm). Another one of those little black beetles.

Week Three:

Days 15-21 (total): two small staphylinids, one larger staphylinid, one carabid, another of those little black beetles (maybe some kind of nitidulid?).

While more insects were caught in the second week than in the first, very few were caught in the third week. This could be a result of the increasing attractiveness of the trap to predatory and carrion-associated insects as time progressed, followed by a period of temperatures low enough to inhibit insect activity.

Potential improvements:

  • The box protected the trap and bait very effectively. However, it is possible that it trapped the VOCs associated with decomposition rather than allowing them to spread, meaning that fewer insects were attracted to the trap. Holes in the side of the box, allowing air to pass through it, would eliminate this concern.
  • The bottle trap caught a great number of flies – possibly due to the fact that it contained a small amount of the bait. Being unable to escape from the trap themselves, and difficult to encourage to leave the food source inside it, flies soon overpopulated the trap. In future, no bait will be placed in the bottle trap and the flies caught in it will be collected regularly.
  • The pitfall trap was subject to the usual pitfall trap annoyances – difficult digging a deep enough hole, soil falling into the trap, difficulty ensuring the top of the trap was flat with the soil, and collapse of the hole when removing the pitfall trap to collect captured insects. A slightly more complex trap might remove these annoyances.
    Pitfall trap 2.0:
    Requires two identical pots (e.g. yoghurt pots).
    The first pot is placed in the ground as normal, level with the soil. A centimetre or so of the top of the second pot is removed, and then the second pot is placed within the first. The second pot will be able to be removed without risk of damaging the hole, and replaced without requiring re-leveling of the soil.
  • Both traps were non-lethal. Since several of the insects collected were predatory, it is very possible that more insects were captured than were collected. A lethal trap has its own pros and cons, but could give a more complete picture of the local insect community.
  • It is questionable whether the bait specifically attracted any particular insects, since all of the insects caught were fairly ubiquitous. Bait may not be necessary for future projects – or, alternatively, different baits may be tested to see which are the most effective.
  • I was unable to check the trap daily. This may have resulted in the loss of specimens. Checking traps daily in future is likely to be beneficial.
  • The cold weather is probably responsible for the decrease in the number of insects captured. Projects undertaken in warmer weather may yield better results.
  • Most specimens captured in the pitfall trap were released shortly after collection. Keeping specimens would have allowed easier identification. Which leads me to…
  • Identification to species level. The aim of this project was to identify captured insects to family level. A future project could use lethal traps (or non-lethal traps, followed by collection and freezing of interesting specimens) to collect insects and aim to identify them to species level in the lab.

If anyone’s interested, I’ve found this site to be a really useful resource for beetle identification:

The #AncellorProject: Week One Summary

This first week has seen the capture of a dozen or so beetles in total, and a steady increase in the number of flies present on and around the bait. Here’s a quick summary of what’s been found in the pitfall trap:

Day 1: one large carabid, one small carabid (Bembidion quadrimaculatum), three small staphylinids, two collembola, one tiny spider, (several) woodlice.

Day 2: one small staphylinid

Day (3,4,5): six large carabids, one small carabid-looking beetle, two small staphylinids, one nitidulid beetle, three tiny spiders, two shiny mite-looking things

Day 6: one large carabid, one small staphylinid

Day 7: one large tegenaria spider, one harvestman, one tiny spider

There’s been a noticeable increase in the number of flies present on and around the bait and caught in the bottle trap. Eggs were first visible on day 2, but no larvae have hatched as of yet. The cold weather has most probably been a limiting factor in insect activity. There’s been no noticeable change in the diversity of insects(/arthropods) as the bait has begun to decompose.

The #AncellorProject

Yesterday (09.10.13) I set up a pitfall trap near the Ancellor building. It’s baited with a small amount of liver, and I’m hoping it will attract a few of the various insects associated with decomposition – particularly the beetles.

My intention is to check and empty the trap regularly (every day if possible, but we’ll have to see), ID as far as possible the species found there, and post the results  here at the end of each week. I’ll be leaving the trap set up for three weeks in total, until the end of October.

Suggestions are appreciated, and people are very welcome to join in – I’m more than happy for this to be a group thing. Let me know if you’re interested!


Hopefully the plastic box will keep out the rain and larger animals. Hopefully

Hopefully the plastic box will protect the trap from both the rain and curious vertebrates. Hopefully.

Pitfall trap, small jar of bait, bottle trap containing bait

Pitfall trap, small jar of bait, bottle trap containing bait

Looks pretty classy if I do say so myself

Looks pretty classy if I do say so myself

There's a small gap between the ground and the bottom of the box - hopefully enough to allow arthropod access!

There’s a small gap between the ground and the bottom of the box – hopefully enough to allow arthropod access!