2000 Volume 51 Issue 3 Pages 215-228
'Sleep' behavior of butterflies at night was observed in 46 individuals belonging to 13 species in 1999 at my house garden. The main sleeping place of Papilio xuthus receives little sunshine, having a high humidity, and is windless compared with the other areas. This species slept hanging from a twig of the tree or at the top of a grass stem 60-150cm high, and usually kept its wings closed. I observed two cases that seemed to be the same individual spending two nights on the same spot. Argyreus hyperbius slept with its wings closed and selected a twig 150-200cm high. This species probably spent two nights at the same spot like P. xuthus. Therefore, I believe that those species had an exact memory of the sleeping place of the previous night, hence they came back to sleep the next evening. Eurema hecabe always slept with its wings closed and hanging from the underside of a leaf of short grass. They preferred a rather dry and open place. Zizeeria maha always slept with both wings closed at the top of a short grass stem 40-50cm high.
