1/19/2023: Big news for Blattids

After a long absence of blog posts I was ready to come back hard with some pictures after a whimsical night wandering about the bug room, but this morning I was gobsmacked with some breaking news on cockroach taxonomy. The last 60 days have been difficult for me with respect to roach phylogeny; shortly after finishing the husbandry guide ectobiidae was split into multiple groups rendering my hard work null. Today there’s news at a familial level, and more interesting announcements about the relationships between multiple blattid taxa.

Based on a myriad of evidence, Periplaneta seems in need of splitting. Perhaps most surprisingly everyone’s favorite, americana, has been argued to be most closely related to a surprising contender: Shelfordella lateralis. In addition to the genetic evidence and morphological notes in the paper, I’d like to add some data to discussion: young Periplaneta americana nymphs are suspiciously unable to climb smooth surfaces, a trait that they share with all life stages of lateralis. This could suggest an inclination for this lineage to have secondarily lost this trait, or merely a likelihood for them to converge on it. Alan Jeon has also pointed out similarities in oothecae between the two.

Though this doesn’t have many implications for keeping these species, it does mean another cascade of nomenclature changes are on their way.

As another fun note without diving into too much detail, it seems Periplaneta japonica is allied more closely with a clade consisting of Archiblatta and Deropeltis, which I find absolutely fascinating. To think a group of taxa that one associates mostly with tropical/subtropical places also contains one of the most cold tolerant cockroaches is incredibly amusing.

To see the data yourself, here’s the link:

https://resjournals.onlinelibrary.wiley.com/doi/full/10.1111/syen.12560

Thank you to both TJ and Chris Snyder for simultaneously ruining and improving my morning!

-Kyle