Post by eurytides on Dec 17, 2016 15:29:11 GMT -8
A question for the saturniidae experts out there:
So last winter/fall I found a bunch of promethea cocoons. Eclosed some females this summer, one of which attracted a wild male, mated and laid ova. I raised a bunch of these at home, and under warm conditions with plenty of fresh food (Prunus virginiana), the larvae grew really well and in fact skipped an instar (looked like 5th instar larvae when they were 4th). Toward the end, I sleeved them outside so that they can experience natural conditions to induce diapause. I collected 9 pupae about a week later. The pupae were smaller than wild collected ones (i.e. larvae that went through all 5 instars) and all turned out to be male!! The statistical likelihood of this occurring is 1 in 512 (~0.2%). Has anyone ever encountered anything like this, where environmental conditions influence sex determination in C. promethea? That is, if the larvae/pupae aren't of sufficient weight, they become male?
To compare, I've rasied A. polyphemus in the past that went through 4 instead of 5 instars (warm conditions with a good food source, not because of nutrient poor conditions). These resulted in normal sized pupae and adult males and females.
So last winter/fall I found a bunch of promethea cocoons. Eclosed some females this summer, one of which attracted a wild male, mated and laid ova. I raised a bunch of these at home, and under warm conditions with plenty of fresh food (Prunus virginiana), the larvae grew really well and in fact skipped an instar (looked like 5th instar larvae when they were 4th). Toward the end, I sleeved them outside so that they can experience natural conditions to induce diapause. I collected 9 pupae about a week later. The pupae were smaller than wild collected ones (i.e. larvae that went through all 5 instars) and all turned out to be male!! The statistical likelihood of this occurring is 1 in 512 (~0.2%). Has anyone ever encountered anything like this, where environmental conditions influence sex determination in C. promethea? That is, if the larvae/pupae aren't of sufficient weight, they become male?
To compare, I've rasied A. polyphemus in the past that went through 4 instead of 5 instars (warm conditions with a good food source, not because of nutrient poor conditions). These resulted in normal sized pupae and adult males and females.
