trolls are born from a giant bug with wings. it's called the Mother Grub. not a huge surprise that some mutants among them would carry the same adaptation!

insect reproduction is actually a lot more complex than many people give it credit for, and a lot of our understanding of how it works has been historically shaped by the assumption that they're like us - a male and a female come together to make a baby. but really, a lot of these social insects have more than two biological sexes; is an infertile worker really somehow the same sex as a fertile queen? this is kind of the basis of my interpretation that troll castes are a lot more like genders than we give them credit for. the word "caste", when applied to insects, is really just another word for sex!

an example of insect gender weirdness: among the yellow crazy ants, which are invasive in places all across the world, the worker and queen ants are actually of two different genetic lineages (called W and R). but how can this be, if only the queen ants can reproduce?? surely only the R lineage could survive! that's where the "males" of the species come in - they're actually chimera, formed from both W and R cells. so when they mate with the queen, they have a chance to create RR or WW offspring, or another RW hybrid like themselves. isn't that fascinating!

https://www.ias.ac.in/article/fulltext/jbsc/049/0017

some years ago New Scientist published an article about bees that I thought was especially relevant to troll reproduction, because people make a lot of assumptions about how trolls and their relationship to the mother grub "must" work based on how they assume insects mate:

"[Q]ueens mate with at least 10 males to produce new colony members, and more than one sperm enters each egg. In a few rare instances, individual bees can end up with some tissue derived from the fertilised egg, which is female, and some from extra sperm, which is male.

...

Genetic tests revealed the gynandromorphs’ unusual family histories. Nine of them had two or three fathers and one mother. One had no mother and two fathers, resulting from the fusion of two sperm."

https://www.newscientist.com/article/2186602-some-honeybees-have-four-parents-or-no-mother-and-we-dont-know-why/

in the wide and wacky insect world, trolls reproducing with more than one quadrant-mate - and across sexes - doesn't really seem to be that strange!