Larvae of this species are green in colour. It feeds on grasses. There is no variation reported for larval colour feeding on different grasses. Check larval stages on this website
Yes dry means low relative humidity. It can be provided through insect growth chambers.
Can you explain more about Insect growth Chambers?
Seems like a new term for me!
Insect growth chambers are used to culture insects/ conduct experiments in laboratories. One can control variables of light, humidity and temperature in these. If you need to correlate the effect of these variables in your experiment or reduce bias which would normally be encountered if the experiment is carried out in un-controlled conditions one could use insect growth chambers.