Sunday 17 April 2011

Little differences

Our native butterflies appear in a rather strict sequence depending on whether they overwinter as adults (e.g. Small Tortoiseshell) or as pupae (e.g.Green-veined White), below:
Green-veined White butterfly
This close-up shows that the 'green' veins are actually made up of  minute yellow and black scales under the wings:
Green-veined White closeup
Male Orange Tip butterflies are also out now, in tight synchronisation with their host plant, Cardamine pratensis.  They are patrolling hedgerows at the moment, establishing their territories, and the females will emerge in the next week or so.

If butterflies and moths are around, then their deadly enemy the Tachinid fly is bound to be around, too:
Tachinid Fly
These are parasitic on the larvae of numerous insects, laying their eggs either near the larvae (so they can be accidentally eaten by them) or directly onto them. They then live internally in the larvae, consuming fat reserves and other non-essential parts before emerging to pupate themselves. In field tests around 80% of butterfly and moth caterpillars are found to be parasitised. Tachinids can be differentiated from other larger flies by the long spines and bristles that cover all parts of their body.

Germander Speedwell is opening up all along the hedgerow:

Germander Speedwell

If you're ever in any doubt about a Germander identification, check the stalks. If they have a pair of rows of hairs, then your identification is secure:

Germander Speedwell stalk, showing the twin rows of hairs

Sawflies are a very under-documented part of the bee and wasp family. They take their name from the female's modified stinger, which takes the form of a saw which is used to cut slots in leaves. She then lays eggs in the slots and they hatch out into larvae that very closely resemble the caterpillars of moths and butterflies. Sawflies can be tricky to identify, but if you see a v-shaped suture on the thorax, then you can be pretty sure it's a sawfly.
Adult Sawfly

I checked the lights last night for moths, but it was raining, so there were no moths around. I did, however, spot this snail crossing the step:

4 comments:

Emma Springfield said...

You always have the best pictures. There is a good variety too. Believe it or not I think I like the sawfly best.

The Weaver of Grass said...

I saw my first orange tip yesterday Stuart, together with a couple of Peacocks. (They looked a bit ragged I thought.)

Stuart said...

Weaver, any Peacocks found just now will have overwintered, so I'd expect them to be seriously ragged by now. I think the male Orange Tip is such a beautiful butterfly with its orange wingtips and that licheny underside. They're a big spring marker for me. Butterflies to look out for now in your area would be Green-veined White, Small White and Speckled Wood.

Caroline Gill said...

We also saw our first Orange Tips (about 8) yesterday here in South Wales.