3
Several snail-killing flies (Sciomyzidae) were also in evidence, including the distinctive
Pherbina coryleti and several species of Tetanocera which will need the male genitalia
examining under a microscope before a name can be applied.
Several other flies were collected and await examination.
Dragonflies and damselflies were also few, with only three species notd ... Ishnura
elegans, Enallagma cyathigerum and Calopteryx splendens. Grasshoppers and crickets
included Conocephalus dorsalis, Pholidoptera griseoaptera and the two common
species Chorthippus brunneus and Ch. parallelus.
A dead tree trunk attracted some attention as ruby-tailed wasps Chrysis sp. (as yet
unidentified females) were watched investigating holes in the timber, some of which
contained nest chambers of the solitary wasp Trypoxylon attenuatum. Ruby-tailed wasps
are cleptoparasites (nest parasites) of solitary bees and wasps and are sometimes called
cuckoo-wasps, laying their eggs in the host nest. The parasite egg hatches first, destroys
the host egg and then uses the food provided by the host for its own larva. After
development, the cuckoo-wasp, rather than the host wasp, emerges from the nest-
chamber.
A disappointing day for accumulating insect records, but nevertheless an interesting one
from the point of view of investigating the changing populations of insects within the
county.
Colin W. Plant
* Editor's note: There was some consternation and excitement during the morning when a
foal was found stuck in one of the dykes. It had obviously been there for some time and
its efforts to escape from the deep water had thrashed the vegetation in a large circle to
the extent that it appeared to have fallen into a pond rather than a dyke. Even though the
foal was obviously getting very tired it was still making desperate efforts to get out, and
so it was with some trepidation and care that we managed to pull it out safely. The horses
feeding nearby immediately all arrived to surround and protect the foal and take it off to
safety. Without our appearance the foal would certainly not have survived.
Spider report
Spiders recorded were all widespread, the most interesting and local being the Theridiid
spider Theridion instabile. This is a characteristic but rather local species of marshes and
sedge beds.
Species recorded
Dictyna arundinacea Enoplognatha ovata
Dictyna uncinata Tetragnatha montana
Clubiona phragmitis Araniella cucurbitina
Xysticus cristatus Larinioides cornutus
Philodromus cespitum Gnathonarium dentatum
Pardosa amentata Hypomma bituberculatum
Pardosa palustris Oedothorax tuberosus
Pardosa prativaga trigone atra
Pirata piraticus Erigone dentipalpis
Theridion bimaculatum Bathyphantes approximatus
Theridion instabile Kaestneria pullata
Theridion sisyphium
Peter Harvey