Update on mite situation

So I mentioned my bouncing bundle of a billion-or-so surprises that I found in Cambridgea eggs to my supervisor about a fortnight ago. He was unsure of what they would be but recommended that I send some down to a colleague of his at Canterbury museum who is their resident “mite guy”. So had another dig around in the egg cases, pulled some mites out and dropped them into a vial of ethanol to send down.

When working with animals <1mm long, surface tension is the bane of my existence. i.e. very small animals stick to damp surfaces like Gollum to the one ring and any you really just want to squash the damn thing and then you do by accident and feel bad.


So last week I got an email back from mite expert. He had mounted them (the notion of mounting these suckers blows my mind) but doesn’t have the appropriate microscope to properly identify them with certainty to anything below family level(1).

So the mites were identified as to the order Sarcoptiformes (the only thing I can find in my Greek dictionary for this name is that they have fleshy bodies?). Matt (mite expert) also believes that they are of the family Acaridae and says that there are several genera of this family which will colonise mouldy grain or rotting carcasses of invertebrates. “If humidity is high enough they can colonise virtually anywhere” he says.

When I mentioned that the mites were found inside the egg cases, he also raised the point that they breed explosively and, if they are parthenogenic(2). then only a very small number of females would have to make it into the egg sac.
So it’s basically it’s not clear whether the mites were feeding on the eggs themselves or on mould or something similar. When I asked about the dusty contents of one of the egg cases (Fig. 1) he said that it could be bits of the eggs themselves although they could also just be mite faeces. Which makes the granola analogy even “better”.

Egg e4
Fig. 1: Photographs of C. foliata egg case and mites going nom nom nom


 Notes that are longer than original post:

Tangent 1: Pretty much everyone is familiar with the idea of binomial nomenclature even if you didn’t know that that’s what it’s called: i.e. all species have a unique pair of latin names such as Homo sapiens. These two words designate different levels of classification.

e.g. In this case Homo refers to a specimen’s “genus” (plural “genera”) which is a broader level of classification which will contain several species while sapiens is the “species” proper. So Homo neanderthalensis is in the same genus as modern humans but is a different species. There are several higher level groupings are used in taxonomy (The practice of classifying species. “taxis” (ταξις) referring to arrangement and “nomos” (νομος) referring to a practice or convention). Genera are nested with families and families within orders etc. From the most broad to the most specific, these taxonomic levels are Kingdom, Phylum, Class, Order, Family, Genus, Species.

Also known as King Phillip Came Over For Grilled Sausages.

(NB: There are several other classifications between these main ones such as “tribe” and the names of the classifications can differ between botanists and zoologists.)

So humans are, in full:

Kingdom: Animalia

Phylum: Chordata

Class: Mammalia

Order: Primates

Family: Hominidae

Genus: Homo

Species: H. sapiens

Tangent 2: Parthenogenesis is a form of asexual reproduction in which females produce only daughters without having to mate with males (παρθένος = parthenos = maids or young women. I can’t figure out whether it’s implying that parthenogenesis only generates females or whether it is reproduction by unmated females/maids). It occurs in several invertebrates but at significant physiological cost for the female. In the springbok mantis (Miomantis caffra), females readily laid egg cases without mating with males and these did produce viable young. However, in a species from the same genus, the nymphs (young) produced from these egg cases often didn’t make it to adulthood or were in poorer condition. Even with this cost parthenogenesis can be a powerful way for females to rapidly generate identically (or virtually identical) young who will succeed provided that the environment is relatively stable