Monday, 5 May 2014

Playing catch-up

The unexpectedly long period of warm weather in April brought everything on very quickly, so we're having what I can only describe as an early and 'strong' spring and early summer. I'm already seeing species that I would not expect until the end of May or start of June, and the Orange Tip butterflies have already laid their eggs:

Orange-Tip butterfly egg
The female lays a single egg (the larvae are cannibals) at the rear of the flower where the seedpod will form. The larva will feed on the seedpods as its sole food until it pupates.

The males are already sedate enough to stop for a photograph: normally they are far too flighty most of the way through May.

Male Orange Tip butterfly
Towards the end of the season - probably around 3 weeks' time - females run out of empty flowers and 'dump' their eggs on plants which already have eggs (or even larvae) in situ. These are doomed to be eaten, but the desperate females rely on the remote chance that their eggs will survive. This shows the importance of synchronisation with the sole foodplant: too early and there will be nowhere to lay; too late and all the suitable flowers will already be occupied.

Fungal rusts are also wasting no time:

Uromyces dactylidis on Creeping Buttercup
In common with most other rusts, Uromyces dactylidis requires an alternate host to live on while the primary vegetation is missing. In this case it's a range of grasses. I always find it intriguing that alternate hosts are rarely closely related to the primary host.

I'm currently working with a number of schools in the Heritage in Schools programme run by the Heritage Council in Ireland. This enables schools to book visits by heritage experts at a lower price than they would normally pay. I'm covering Natural Heritage, and this shot was taken at a visit to a school last week:

Common Frog
During a six-week period, we will count the species in a number of local habitats and draw up a biodiversity map for the local area. This will enable us to determine factors that encourage or inhibit biodiversity.

One early species found last week was the bumblebee-mimicking hoverfly Eristalis intricarius. During the early years of my local survey, this species confined to one small local area, but in recent years I have found it in more and more locations. It must be finding something that is beneficial.

The bumblebee-mimicking hoverfly Eristalis intricarius

No comments: