Mangled or Beautiful?

Sorting through specimens sent to me by Tom Murray as photo-vouchers, one of the beetles included was very unusual.

An individual of Disonycha caroliniana, pictured below, had a pretty cool deformity.  The right elytron has an indentation apically while the left elytron is grossly inflated, almost like a bubble.  In addition, some of the pigment of the red vittae bleeds into adjacent areas.  I suppose it was caused by an accident during pupation.  It’s quite unique looking, certainly like nothing I’ve seen before.

Renovation Entomology

My brother bought the condo next to his place in Indianapolis for a really good deal, although the place is a mess.  I was over there today helping him clean it out (filled a dumpster, and need to get a second!!) and found my first BMSB (Brown Marmorated Stink Bug, Halyomorpha halys), just waltzing around on one of the trash bags.  I was pretty excited to find it, even though I’m sure I’ll be seeing many, many more in the coming years.  I was kind of surprised to only find one though.

It was a pretty warm fall day, the kind when lots of insects are cruising around looking for the perfect spot to spend the winter.  Boxelder bugs, Boisea trivittata, were swarming on the sunny side of the building.  Billbugs, Sphenophorus parvulus, were lumbering across the sidewalks, and quite common too.  I also saw a couple Sitona joining them.  The quicker sidewalk bugs included a Geocoris uliginosus and a nice winged female Bethylid (Holepyris sp.) that I scooped up with a leaf (I’ve learned my lesson about handling them, they pack a mean sting, and man is her stinger big).  Also nabbed a tachinid fly that wasn’t very interested in running away from my fingers.  Unfortunately she dropped a few legs when I put her in my vial.

Oh yeah, there is a hornet nest, in the FREAKING wall.  It’s big too, probably bald-faced hornets.  Luckily the inhabitants were all gone.  I’ll have to take pictures of it next weekend.

EDIT: Turns out the wasp nest was from German yellowjackets (Vespula germanica).

 

Chicago

I’ve been in Chicago for about the last week.  Unfortunately I didn’t have time to do any collecting while there, but I didn’t go away empty handed.  I found a female Anisodactylus harrisii under a stone in my cousin’s backyard.  Next time I’ll have set aside some time and find somewhere to look for bugs!

Pterostichus stygicus vs coracinus

Genitalia of Pterostichus stygicusGround beetles in the genus Pterostichus, subgenus Euferonia, are common woodland beetles in the eastern U.S.  Almost all have reduced wings, so are unable to fly.

I’ve collected a number of specimens that fit into this species pair, but have struggled with separating them with existing keys.  Lindroth noted that “the infraspecific variation of external characters is considerable” and has resulted in many unnecessary names, especially by Casey.

The characters that separate P. stygicus from P. coracinus are the presence of a “tubercle” in the basal fovea of the pronotum and the elytra usually being somewhat iridescent.  The iridescence isn’t hard to see, but the “tubercle” is very subjective.  It appears to be referring to a low ridge or convexity within the fovae, hardly tuberculate in my opinion, and quite variable.  Fortunately, I recently collected a pair of males and decided to consult Lindroth, who illustrates the genitalia of the species.  The shape of the penis is very distinct between the two species: symmetrical in P. stygicus and asymmetical in P. coracinus.  This led to the reevaluation my previously collected specimens, which turned out to be all P. stygicus.

Now I just need to find P. coracinus!

The Latridid that broke the camel’s back

It’s that time again, when an excess of specimens requires the splitting up of a specimen box.  Not that this is a bad thing; actually it’s great, as long as you have an extra box sitting around.

I’ve been putting away some identified specimens, but I just couldn’t find any room for some new Latridiidae.  So its time to split it up, which I’ve been putting off for awhile.  Actually, I probably have four or five boxes that need splitting now that I think about it….

Here is the before picture.  Yeah, sloppy I know.  Kudos if you can guess all 12 families I have stuffed in this box.

old latridiidae etc

A touch of Laboulbeniales

A recent post on BugGuide brought to my attention to a group of fungi known as Laboulbeniales that infect insects.  I knew I had seen these before, but I had never really paid them much attention.  Sorting through some Carabidae I had collected this summer, I noticed one of the strange growths on the elytron of a Clivina americana.  After posting an image of this beetle to BugGuide, I continued sorting the sample.  To my surprise, I found the fungal hyphae on a large number of specimens.  Once I had seen the first, they became fairly easy to spot (despite all the moth scales floating around in the alcohol).

I contacted the author of the Laboulbeniales post, Danny Haelewaters, now a doctoral student at the Farlow Herbarium, Harvard University.  He is studying Laboulbeniales fungi, so I’ll be sending the specimens to him for his research.

The Carabidae that appeared infected included Clivina americana, Perigona nigriceps, Elaphropus xanthopus, Acupalpus partiarius, Acupalpus indistinctus, Bradycellus rupestris, Stenolophus lecontei, and Stenolophus ochropezus.  There were also infected Homaeotarsus cf. bicolor (Staphylinidae) and Melanophthalma sp. (Latridiidae).

Below are images of some infected beetles (Homaeotarsus, Melanophthalma, Elaphropus xanthopus, and Stenolophus ochropezus):

HomaeotarsusMelanophthalma

Elaphropus xanthopusStenolophus ochropezus
UPDATE: Danny Haelewaters has informed me that the parasite on the Homaeotarsus is Corethromyces cryptobii, a new record for Kentucky.  Hopefully more to come.

Neobisnius is Srzbisnius

Neobisnius jocosus (Horn), photo by Tom Murray

I was fortunate this summer to take a short series of Neobisnius specimens while black-lighting in Kentucky.  Some species are quite colorful and have a very similar color pattern to the toxic Paederus, and may well be mimics.  Luckily there is a thorough monograph of this genus by JH Frank (1980).  Males are fairly easy to key out using external characters, although examination of the aedeagus is probably advisable.  The tricky part is that males and females aren’t terribly different externally.  The front tarsi are somewhat dilated in both sexes!  The keys do not work for females, and there are reproductions of Frank’s key that fail to mention it is based on males (*cough*Downie&Arnett*cough*).

I recommend a quick dissection before mounting this group to determine sex.  If a male, the aedeagus is usually easily evertable and left attached to the beetle, or it can be glued to a point below the specimen.

Head of Neobisnius, showing small fovea. Look for the dense tuft of setae arising from the fovea on the front margin.

There are five species of Neobisnius in the midwest that have this Paederus-like color pattern (referred to as “parti-colored” by Horn): N. jocosus, N. jucundus, N. occidentoides, N. paederoides, and N. terminalis. An additional similarly colored species, N. ludicrus, occurs in the east, but appears restricted to the coastal states of the Southeast.  A quick key to males of the 5 ‘parti-colored’ species is as follows, but genitalia should always be checked when possible:

  1. Head with a fovea on head between antennae.  2
        Head without such a fovea.  3
  2. Eyes large, almost 1/2 length of head … N. occidentoides Frank
        Eyes smaller, only about 1/3 length of head … N. jucundus (Horn)
  3. Pale apical elytral band about 1/4 length of elytra … N. terminalis (LeConte)
        Pale apical elytral band very narrow.  4
  4. Less than 5 mm, sides of head rounded; base of abdominal tergum 7 reddish … N. paederoides (LeConte)
        Larger than 5 mm, head more parallel-sided; abdominal tergum 7 entirely black … N. jocosus Horn

In the series mentioned earlier, out of 13 specimens, 6 were female and 7 were male.  Of the males, 2 were Neobisnius paederoides (LeConte) and 5 were Neobisnius occidentoides Frank.  The females remain unidentified to species.

Useful literature:
Frank, J.H. 1981. A revision of the new world species of the genus Neobisnius Ganglbauer (Coleoptera: Staphylinidae: Staphylininae). Occ. Papers of the Florida State Collection of Arthropods, 1: vi + 60 pp.