Cicadas and lacewings - a
association between a lacewing, Italochrysa neurodes (Neuroptera, family
Chrysopidae) and a cicada, Platypleura capensis (Hemiptera, family
Cicadidae) was described a few years ago (van Noort, 1995).
Cicada, Platypleura capensis, feeding
on the host plant, Chrysanthemoides monilifera. The proboscis can
be seen penetrating the branch.
Lacewing, Italochrysa neurodes, feeding
on plant sap.
Cicada and lacewing on a host plant branch.
Plant sap seeping from a puncture in
a host plant branch after the cicada has fed.
This association was first observed in Fernkloof Nature
Reserve in the mountains above Hermanus in the south western Cape during the hot
summer months from November to February. During this period the continuous high
pitched call of P. capensis is a familiar sound. The call however stops abruptly should one approach its
host plant, one of which is Chrysanthemoides monilifera, without extreme
care. The cicada feeds in a near vertical position, facing upwards, on a branch. This
is done by extracting sap by inserting its proboscis into the branch of its host
plant. The lacewing is attracted to the calling and feeding cicada and lands on
the branch near it and
then positions itself above the cicada on the branch, facing it head-on.
the cicada flies off, the lacewing moves toward the puncture made by the
cicada and proceeds to feed on the plant sap.
Sometimes the lacewing makes physical contact by resting its
antennae on the cicada's head which is followed by the cicada 'pawing' the lacewing's
antennae with its forelegs. The lacewing then retreats a few centimetres and
relinquishes contact. The cicada continues to call and feed throughout the
Similar behaviour patterns were observed in Natal
at the end of the 19th century, except in this case, a total of 16 lacewings of
another species formed a semicircle around an unidentified calling cicada's head, occasionally approaching and
It appears that the reason for the lacewing being attracted to
the cicada is probably to gain access to plant sap made available by the cicada
puncturing the plant stem. The question then arises as to how the lacewing
locates the calling cicada. The lacewing could either be using an olfactory
stimulus (smell) as they are attracted to honeydew and the volatiles in the
cicadas excreted waste could attract them. However, this is unlikely as the
cicadas spray their excretement away from themselves and their perches. It is more
likely that the lacewing is using the auditory stimulus of the cicada call. It
has been established that the lacewing subfamily Chrysopinae, to which this
lacewing belongs, has a tympanal groove in the forewing that acts as an auditory
organ. The fact that lacewings use hearing to avoid bat predation would suggest
that it is plausible that these lacewings locate feeding and calling cicadas
using sound. This hypothesis is still under investigation.