Ideas For Other Ecological and Physiological
Experiments Using M. sexta
Aside from the effects of elevated
CO2 on herbivory, there are many different
types of experiments which students can perform using M.
sexta. Because the hornworms are so easy to grow, and go
from egg to pupa in just a few weeks, students can ask
questions about feeding and growth on different
Students can compare the growth of hornworms on leaves
from different species of tobacco, leaves from tomato plants
(members of the same family as tobacco), and leaves from
unrelated plant species. Using the same technique for
measuring leaf area as in the
CO2 experiment, they can compare feeding rates
over a shorter time span.
Hawkmoths are also easy to use in experiments; because
they are nocturnal, students can manipulate plants and other
items in flight cages during the day and return the
following day to collect data. The moths will not fly around
during the day unless quite provoked.
As a companion set of experiments to the feeding
experiments, students can look at oviposition choice by
moths; are female moths more likely to lay eggs on tobacco
than on other species of plants? How does oviposition choice
relate to larval feeding?
Moths can also be used for ecological experiments looking
at choice of resting background. If presented with different
backgrounds in a flight cage to rest on, will moths choose
backgrounds which camoflage them? Does light level at night
affect resting choice?