Tag Archives: parasite

Cooler Temperatures

Autumn conditions this year began almost exactly with the Autumn Equinox and temperatures have become steadily cooler since then. There are still green leaves on many trees but much of the foliage is yellow or red and showers of cold rain and some northern breezes have reduced temperatures a lot.

Lower temperatures slow the growth of plant life, but also have an immediate effect on insect populations, killing many of them and sending others into torpor or hibernation. Despite this there are still some hardy species to be seen around, including some rarities, such as the very rare and beautifully marked Juniper Shieldbug (Cyphostethus tristriatus). I found this one last weekend, and it is the first recorded in Ireland since 2016. There were only 15 recorded in Ireland before this one:

They are probably far more common than the recorded numbers suggest. Keep an eye out for them.

There are many other insects which are very numerous in Autumn, such as the 22-spot Ladybird (Psyllobora vigintiduopunctata), which seems very at home in the Autumn landscape:

Although temperatures are usually hovering around 10°C, on sunny days some butterflies reach the 15°C necessary in order to fly. Today I found a Red Admiral flying about, feeding on the few remaining blooms of Butterfly Bush:

Some insects are very obvious, such as the handsome little 22=spot Ladybird (Sometimes you might not realise you are looking at an insect, or insect activity. If you can find an oak tree of any size, see if they have oak “apples”. As everyone knows acorns are the fruit of the oak tree. Oak apples are not fruit but look far more like fruit than acorns do:

   Oak apples are actually growths caused by tiny insects, oak gall wasps, which somehow create them by making a change happen at a molecular level. These growths are protective pods in which the insect grubs grow and develop. Eventually they hatch out, fly away, mate, and lay eggs on an oak tree.

Although there are fewer insects there are still lots of attractive birds about, and in autumn it’s often easier to get close to them than in summer, as they are forced to forage closer to human habitation. One particularly difficult bird to see is the Little Grebe (Tachybaptus ruficollis), but as foliage surrounding ponds and lakes begins to die back they become more apparent:

One bird that is very easy to spot because of it’s bold white colouration is the Little Egret (Egretta garzetta). This bird was very rare in Europe and almost extinct up until the 1950s. The reason for its rarity was due to overhunting for its head plumes, which were used in ladies’ hats back in the days when ladies wore ridiculously ornate hats on a daily basis. In fact, the Royal Society for the Protection of Birds, the RSPB, was originally set up with the aim of protecting the few remaining individuals of this species living on the island of Great Britain:

How did such a rare species come to be living in Ireland, of all places. Incredibly this species is no longer rare. In fact, they can be found all across Europe in huge numbers due to the decline in the fashion for ridiculous hats. For reasons which are not yet understood they migrated into Ireland and can now bee seen in huge numbers along the coast, or on rivers and lakes.

It’s a Bee thing…

As promised, a few words and photos about the Tawny Mining Bee, Andrena fulva. The first time this species was recorded in Ireland was 1927, in Kilkenny. But last year another, also an individual bee, was found in the same area, and it became only the second recorded in Ireland. But this species has been in my garden here in Wicklow for at least a number of years, I just didn’t know it was so rare in Ireland. And furthermore, there were loads of them, and they had dug hundreds of nests all over an aerated area of the lawn.

A female Tawny Mining Bee resting on a shrub just behind the complex of nest mines.
A female Tawny Mining Bee resting on a shrub just behind the complex of nest mines.

Only two weeks ago nesting Tawny Mining Bees were discovered in Kilkenny, so it is definitely a resident species. At the moment the National Biodiversity Data Centre is looking for any reports they can get of this bee, especially of nests. So here is a little bit about them.

Firstly, look out for their mines. There are a number of different species of mining bee found throughout Europe, and in Ireland, but none looks quite like the Tawny, and none builds nests exactly like it either. Firstly, the female bee is like a very small bumblebee, and her nest is basically a 2 cm high by 4 or 5 cm wide cone like a miniature volcano. The hole at the top is 1 cm wide. Most other mining bees are much smaller as are their nests.

Nest of the Tawny Mining Bee, as it usually appears on a lawn. These bees like rich soils, not sand.
Nest of the Tawny Mining Bee, as it usually appears on a lawn. These bees like rich soils, not sand. The flower behind it is a violet.

 

A female Twany Mining Bee at rest in her mine.
A female Tawny Mining Bee at rest in her mine.

If you have Berberus in your garden you are especially likely to have these bees, as they love Berberus blossom, which is due to open soon. Now, there are a number of mining bee species around, and another that also makes a volcano-like cone is the closely-related Andrena haemorrhoa. This bee is smaller than the Tawny Mining Bee, and the female has special hairs on her hind legs for collecting pollen, but which look like cowboy chaps.

Andrena haemorrhoa is a lovely little mining bee, and probably the most common in Wicklow, and Ireland. This female is collecting pollen from a daisy, which gives you an idea of how small she is. The male is even smaller.
Andrena haemorrhoa is a lovely little mining bee, and probably the most common in Wicklow, and Ireland. This female is collecting pollen from a daisy, which gives you an idea of how small she is. The male is even smaller.

One of the most interesting things about solitary bees (bees that don’t live in colonies) is that almost every species is targeted by a special parasite, a “cuckoo bee”. There are many different species and types of cuckoo bee, and like the cuckoo bird, they lay their eggs in the nests of their host species. But, most importantly, the larvae of the cuckoo bee eat the larvae of the hosts. Mining bees are usually parasitised by very small, wasp-like bees of the Nomada family. These bees are becoming rare across Europe due to pesticide use, but they are still thriving in Wicklow.

This species of cuckoo bee was searching all of the Tawny Mining Bee burrows and can be seen beside one in this photo. According to naturalist John Fogarty, it appears to be Nomada leucopthalma, a species which normally parasitises a different species of mining bee, Andrena clarkella. Anyhow, a little more research and we will know for certain.
This species of cuckoo bee was searching all of the Tawny Mining Bee burrows and can be seen beside one in this photo. According to naturalist John Fogarty, it appears to be Nomada leucophthalma, a species which normally parasitises a different species of mining bee, Andrena clarkella. Anyhow, a little more research and we will know for certain.