Geoscience Reference
In-Depth Information
bends when the hair is moved and sends off a nerve signal. In the case of
Notiophilus
,
this signal causes it to dart forward until it touches its prey with the two sensory short
horns on its upper lip, or labrum, when its jaws snap together.
F
IG. 32
A Half-grown larva of large blue butterfly
Maculinea arion
with adult ants and ant brood of
Myrmica
sabuleti
. (Photograph J.A. Thomas.)
These details of behaviour were watched and analysed by Thomas Bauer in Ger-
many using a high speed camera to reveal details. He also described the attacks made
by another collembolan specialist
Loricera pilicornis.
This beetle uses its eyes to hunt
by day but it is also able to catch prey in total darkness with the use of its anten-
nae. These are unusual in that the nearer segments each bear several strong bristles
which project downwards and inwards and help to sweep prey towards its jaws. When
L. pilicornis
detects a springtail, visually or by antennal contact, it moves forward
quickly with its antennae held about 80 degrees apart until it touches the springtail
with its palps. The antennae are then struck together within 12 milliseconds and the
mouthparts grasp the prey. The springtail species that Bauer studied had an average
reaction time of 25 milliseconds after being touched, and often an individual managed
to jump clear (
Fig. 31
), but when there was a cluster of them around a food source the
antennal bristles swept several together at the same time and one at least was often
trapped.
A
NTS AND ANT-HILLS
