COPROPHAGY IN LEPIDOPTERA - OBSERVATIONAL AND EXPERIMENTAL-EVIDENCE IN THE PYRALID MOTH AGLOSSA-PINGUINALIS

Larvae of Lepidoptera are mainly herbivores, and only the larval stage s of Bradypodicola and Cryptoses pyralid moths are known to be special ized coprophages. Here, we report coprophagy as a main feeding habit f or the larvae of another pyralid moth, Aglossa pinguinalis, on the bas is of observational and experimental evidence. The larvae of this moth require two years to complete development, and construct silk tubes c onnecting the food source with a shelter chamber. Larvae of A. pinguin alis were mostly found inside caves, where they were about 700 times m ore abundant than in the open field. Inside the caves, observational r esults indicate that 98% of the larvae fed mostly on excrement and onl y 2% were recorded as eating other kinds of detritus (decayed mushroom s). No larvae were recorded eating plant detritus in the censuses nor in experimental detritus patches. The larvae did not show preferences for different types of excrement in the caves. Experimental dog and sh eep excrement corroborated this result, showing that the abundance of larvae did not differ between these two excrement types over the entir e study. We suggest that habitat selection of A. pinguinalis is ecolog ically similar to the trophic specialization of Bradypodicola and Cryp toses, in spite of the differences in natural history traits among the se moths. Feeding on dry excrement inside caves, or in buried sloth du ng, may reflect the constraints for Lepidoptera successfully to coloni ze excrement: in more exposed excrement, they cannot compete with othe r coprophagous specialists owing to the lack of parental care (e.g. re source relocation) and slow growth rates. We hypothesize that copropha gous Lepidoptera will be restricted to competition-and predation-free habitats and resources, feeding on excrement inside caves and animal b urrows.