Grass growing after the rain is a help to some butterfly species

After the rains in Portugal

New grass blades - Photo: Steve Andrews

Drought-stricken Portugal has at last had the autumn rains arrive. The land is swiftly going green again. One type of plant that quickly recovers and shoots from dormant seeds is any one of most species of grass. This is wonderful news for many butterfly species that need grass for their caterpillars.

Speckled Wood - Photo: Steve Andrews

The Speckled Wood (Pararge aegeria)  and Meadow Brown (Maniola jurtina) are two widely distributed butterflies that have larvae that feed on grass. Until recently female butterflies were presented with a major problem because most grass had shrivelled and died in the months of hot sunshine and little or no rain. Much of the countryside had become brown and dusty, and what vegetation that survived was tinder dry and in poor condition. However, millions of seeds have been left to germinate after being activated by the next showers of rain. It always amazes me to see how quickly the greenery returns to barren and dried up land that looks more like a desert. Not just grass but countless weeds and wildflowers swiftly cover the ground with their first shoots and seedling leaves. I delight in seeing so much going green again.

Brown ground going green again - Photo: Steve Andrews

Other butterflies

The Small Copper (Lycaena phlaeas) is another butterfly that was sure to have problems in a drought and that I had seen here. Weeks ago there were many specimens of this pretty little butterfly flying on the scrubland and along paths through the woodland. The vegetation under the trees were all dead and brown and I couldn’t find any leaves of the food-plants this butterfly needs. Species of Sorrel and Dock (Rumex spp.) are the plants the female Small Copper must find to lay her eggs on. Sadly, where I live, as far as I could see, none of them were still growing and what was left was either underground or as seeds. I really don’t know what this butterfly does in such conditions and there are no Small Coppers still about here to take advantage of any new growth. If they have somehow survived I will find out next year. 

Small Copper - Photo: Steve Andrews

Two more butterflies already returning to the countryside here are Clouded Yellow (Colias croceus) and Small White (Pieris rapae). The former needs species of clovers and trefoils, and the latter looks for plants in the Cabbage family but can also use species of Mustard that grow wild. There should be plenty of food-plants for these butterflies in a while, once the seedlings have germinated and started growing again. This is what is happening here now. All plants that have been laying dormant underground as rootstocks or as seeds on the surface are being activated by the so welcome rains. It is wonderful news too, knowing that more rain is forecast for the rest of the week ahead. We need it!

Because butterfly females lay hundreds of eggs it gives them a far better chance of survival but it is still a mystery to me, as to how they get through periods when there are no green plants of the types they need to be found.

The Clouded Yellow