Trophobiosis in a tropical rainforest
on Borneo: Giant ants Camponotus gigas (Hymenoptera:
Formicidae) herd wax cicadas Bythopsyrna circulata
(Auchenorrhyncha: Flatidae)
MARTIN PFEIFFER1* & KARL EDUARD LINSENMAIR2
1 University of Ulm, Institute of Experimental Ecology,
Albert-Einstein Allee 11, 89069 Ulm, Germany,
2 University of Würzburg, Department of Animal Ecology
and Tropical Biology, Am Hubland, 97074 Würzburg, Germany
Abstract: Here we report on a trophobiotic association of
the predominantly nocturnal giant forest ant Camponotus
gigas (Latreille, 1802) with a species of Flatidae, Bythopsyrna
circulata (Guerin-Méneville, 1844) observed in
Kinabalu National Park, Sabah, Malaysia. We investigate task
sharing of the ants and quantify their nutritional benefits. Bythopsyrna circulata, which had no morphological
adaptation to trophobiotic interaction with ants and seems
to be facultatively associated with ants, produced the largest
quantities of honeydew reported up to now. Honeydew output
of larvae was 24 mg/h, of adults 42 mg/h. Time intervals of
honeydew secretion by the Flatidae were significantly shorter
when Hemiptera were tended by ants. Camponotus gigas showed three behavioural patterns during tending of flatids:
“collecting”, “secondary gathering”
and “antennating from ahead”. Workers of C.
gigas switched among different tasks, but usually performed
one task over a longer period of time. All workers exchanged
honeydew by trophallaxis, thus optimizing their load size
(mean load 24.5 mg) before returning to the nest. Although
total colony gain from this association was high at approximately
7.24 g honeydew per night, flatids were not guarded by majors
of C. gigas and were not tended during daytime. In
contrast C. gigas majors guarded the coreid bug Mictis
(cf. longicornis Westwood) sp., an obligate myrmecophile,
which is morphologically adapted to interaction with ants.
These coreids excreted honeydew droplets at a faster rate
than flatids; yet assessment of total output of honeydew was
not possible.
