The goal was to determine the potential impact of photoperiod on feeding behavior and larval growth rates. Larvae from six different families of the eastern swallowtail butterfly, Papilio glaucus L. (Lepidoptera: Papilionidae) were placed into 3 different photoperiod regimes (long days at 18:6 h, short days at 12:12 h, and total darkness at 0:24 h, all at 27°C) as neonate first instars and reared to pupation. The initial 11 days reflected very slow growth of the larvae in darkness (only half the weight of the long day larvae). No differences in survival at 4 days or 11 days or until pupation were evident between any treatments. Average time to pupation ( = total larval duration) was statistically identical between the treatments. However, despite their slow start during the first two instars, the larvae in complete darkness were able to increase their growth rates in the final 3 instars to such magnitude that they grew to the same final pupal size as those in the long day (and bigger than those in the short day) treatments. Such compensatory feeding and growth as a result of photoperiod has not previously been reported. Potential additional causes for such behavioral/physiological compensatory growth rates in caterpillars of other species are discussed.
Muehlhaus, Jennifer and Scriber, J. Mark
"Compensatory Feeding and Growth Responses of Papilio Glaucus (Lepidoptera: Papilionidae) Larvae Reared in Darkness.,"
The Great Lakes Entomologist, vol 39
Available at: https://scholar.valpo.edu/tgle/vol39/iss2/5