Tag Archives: Insects

The dermestid mystery: solved

About a year ago, I noticed Amos frequently and obsessively scratching himself, and, after some searching, I discovered a single flea.  I promptly treated him, but often felt something crawling on my legs and arms in my bed when I went to sleep.  I would usually panic a bit – oh no! fleas in my bed! –  but invariably, I would find that the insect responsible for disturbing a few leg hairs were Dermestid beetles.  Beetles in this family are frequently used to strip flesh from carcasses and clean bone and are not known to be harmful or even bite.

I couldn’t figure out where they came from, but I was glad they weren’t fleas.  The problem disappeared shortly after I started noticing them, but recently returned.  I was still without an answer to the beetles’ origins, until yesterday.  I moved an ottoman away from my bed, and discovered this milk bone, covered in holes and the little dermestid beetles running out of them.  Amos is a peculiar dog: he will often hide his treats, rather than promptly eating them, and apparently, he forgot about this one.

Without a microscope but with Google Image Search, I managed to tentatively identify the beetles as Lasioderma serricorne, cigarette beetles, which are Anobiids, not Dermestids (the ‘furriness’ suggested to me that they were dermestids at first).  In any case, I’ll be sure Amos isn’t allowed to hide his treats any longer.

Dermestid beetles - 09.21.2013 - 13.02.19

Dermestid beetles - 09.21.2013 - 13.02.34

Cowkiller Velvet Ant

The mutillids, like this Dasymutilla occidentalis, are abundant this year, possibly because of this cool connect:

These solitary wasps are hyperparasitoids (i.e., parasites of parasites) on cicada killers (like this Sphecius speciosus, which are themselves parasitoids of cicadas… and this year saw a large emergence of 17-year cicadas.

The individual here is a female – males have wings and are not as vibrantly orange – and wasp vibrating as I photographed her.  I discuss cicada killers and velvet ants in lecture, but I was unaware they had such an awesome  natural history connection…

Cow Ant - Mullidae - 09.13.2013 - 14.00.42

Cow Ant - Mullidae - 09.13.2013 - 13.59.54

 

Another tettigoniid

At least I think this is another long-horned orthopteran.  There are several families in the tropics of Orthopterans that I don’t know, so it could be something entirely different. This individual has a short-horned grasshopper appearance (Acrididae), but extremely long antennae, which is a characteristic of the tettigonids (i.e., katydids).  The tympana location differs between the two families too: it should be on the tibia of the fore-legs in tettigonids as seen here.

Juvenile katydid

Juvenile female leaf-mimicking katydid (Tettigoniidae).  Females have the large, sword-like, ovipositor at the end of their abdomen, and adults have full wings that cover the entire body.

I also ran into this, which I took in another part of Costa Rica a few years ago.

Orthoptera Tettigoniidae - 20130714 - 11

Katydid with nuptial gifts

Found another katydid (Tettigoniidae) with spermatophores/nuptial gifts present, as I mentioned observing here!

The little white bubbles at the tip of this female’s abdomen (about halfway down the length of the wings; there are two, but only one is visible on this shot), can contain various amounts carbohydrates and proteins as a gift from a mate along with sperm.

Orthoptera Tettigoniidae - 20130714 - 10