10/23/2021: Slow but steady success with rainbow tortoise beetles

by Kyle Kandilian · October 23, 2021

Way back in April I did an awkward April fools’ day post about some unbelievable beetles. Absolute hilarity aside, it is time for an update.

For a species with reports of incredible fecundity I haven’t had a landslide of offspring. This could have been to me swapping individuals’ host plants when I could finally stop relying on desperately propagated sweet potato leaves when the native bindweed popped up in my front garden, or maybe could be blamed on the small size of the F1 females. The F2 generation has matured and after gorging on sweet potato leaves (despite their size relative to golden and clavate tortoise beetles I haven’t found their appetite nearly as ravenous) they’re all rather buxom and stately. Despite yeoman’s work selecting for the rainbow individuals (the other color in this population is ladybug-like with a black pronotum and red elytra) out of the last 5 F2s only one female has matured with desired coloration. There must be a simple dominant/recessive mechanism here though I’m ashamed to admit I didn’t track who mated with whom in the F1 so I can’t hazard a proper guess at which trait is what. Some inbreeding should fix that…

With winter approaching fast I’ve started a tiny sweet potato farm indoors so I can feed many hungry mouths in the dark, cold months. I’m dreading having to make some difficult decisions if I start running out of leaves, which wouldn’t be -so- difficult if I had better understanding of the genetics at play. Hardships aside I’m hoping I can gaze into a nice vivarium with dozens of shining rainbow adults by next summer.

The old matriarch of the current lines. At age 4.5 months she’s getting up there and I’ve noticed her colors are faded compared to hardened freshly matures. May we appreciate her tireless devotion to the propagation cause!

-Kyle