On the behavioural biology of a morpho-variant of Myrmaplata plataleoides (O. Pickard-Cambridge, 1869) (Araneae: Salticidae) with taxonomic notes

Abstract

We hereby report an isolated population of a rare morpho-variant of the ant-mimicking jumping spider Myrmaplata plataleoides (O. Pickard-Cambridge, 1869) from Hazaribagh Wildlife Sanctuary, Hazaribagh, Jharkhand, India, which is also the first record of this species from the state of Jharkhand, India. Descriptions of both male and female spiders, the female’s exuviae, its eggs and habitat are presented. We have studied its moulting, feeding and sexual behaviour in detail, and have recorded various behavioural aspects that were never documented before, such as debris-rolling behaviour, photokinetic response, starvation response and oxygen deprivation response. We here report the occurrence of this spider near the colonies of the ground-nesting ant Camponotus compressus (Fabricius, 1787). This spider is known to mimic the Asian weaver ant Oecophylla smaragdina (Fabricius, 1775), which are greenish orange to red in colour. Specimens collected by us are dark brown to black in coloration whereas the commonly reported specimens are often greenish orange to red. We propose that the darker coloration would have been naturally selected in this isolated population of M. plataleoides as an adaptation to coexist with C. compressus, which is also black in coloration and abundant around the spiders. Study of the moulting behaviour of the morpho-variant further reveals the display of a novel mechanism of ant mimicry among these spiders which we have named as temporal myrmecomorphy. Temporal myrmecomorphy has been proposed to be a protective mechanism used by a harmless mimic against the attacks of the aggressive models so that it can co-exist with the models. Present study establishes the usefulness of a morpho-variant as an important model in understanding the evolution and behaviour of a species holistically.