Like clockwork

On Monday I wondered when the parasites of the Nematus pavidus sawfly larvae would appear. The answer is: today.

This is the primary parasite: Campodorus sp. This specimen was examining the larvae very closely, but it's clear that they aren't large enough yet. I'd guess that Monday or Tuesday next week should see a flurry of egg-laying.

This exotic-looking Forest Shieldbug - Pentatoma rufipes - struck a striking pose, so I gratefully took the shot:

Another new moth for me: Small wainscot - Chortodes pygmina. The larvae feed on sedges and grasses, but the adults don't feed at all.

I wasn't at all surprised to see this migratory Silver Y moth after all the migrant hoverflies I've seen in the last few days.

Just for the record, the Frosted Orange - Gortyna flavago - emerges just as the leaves are turning brown:

A miscellany

Every tree has its set of dependent species. Horse Chestnut has fewer than most, but I strongly suspect that the number of dependent species is closely related to the length of time that a particular species of tree has been resident in a particular place: it will always take some time for the dependents to follow the presence of the host. Horse Chestnut is a relatively recent addition to our fauna, and would almost certainly have been introduced by man. I must see if it's possible to detect a statistical correlation between duration of residence of host plant and number of dependent species.

The fungal rust on this Chestnut leaf is Guignardia aesculi, which affects most specimens of Chestnut in our area.


Moths are still coming to light, but in smaller numbers, which is to be expected as we get colder. This Black Rustic - Aporophyla nigra - is a new species for me:


Occasionally I get an Ichneumonid or two as well. This red one is worth showing:


Shield bugs are usually found very close to their particular habitat. This Forest Shield Bug - Pentatoma rufipes - is always found in old deciduous woodland, but the other night this specimen was blown onto my windowsill. It can always fly back.

Colourful Bugs

True bugs - Hemiptera - are largely overlooked, perhaps because many are small, some are dull and they change their appearance dramatically as they mutate through several nymph stages, making them far too tricky to identify. Some of them are, however, absolutely stunning.

This is a nymph stage of Cicadella viridis, one of the leaf-hoppers, about 8mm long. The stunning purple-blue colour is absolutely accurate. The adult is a wonderful powdered turquoise, and I'll show it soon.

My first reaction on seeing the following shot was 'bird-dropping, full of seeds', but it quickly resolved into a cluster of nymphs of the Forest Shieldbug - Pentatoma rufipes. These are common enough, but I hadn't seen the 'huddling' habit before.


My next thought was that they were on some common prey, such as a caterpillar, but no: as I touched the leaf they dispersed, leaving nothing behind. Lurking close-by I found a later nymph stage of the same Shieldbug:



This is Calocoris stysi, one of the Mirid bugs: