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Семейство Cerambycidae |
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Last week I traveled to northwestern Tennessee to visit research plots, and on
the way back I took the opportunity to stop by Fort Defiance Park near Cairo,
Illinois. Fort Defiance represents the southernmost tip of Illinois, lying at
the confluence of the Ohio and Mississippi Rivers, and on previous visits I had
thought that the wet bottomland forest remnants present there looked like
promising habitat for the ant-like tiger beetle (Cylindera cursitans). The type
locality of a synonym (Cicindela alata) is in northern Illinois, but the type
specimens are considered to have been introduced and, to my knowledge, no bona
fide records of the species are known from the southern part of the state. I
have taken the species nearby on the Missouri side of the Mississippi River
(MacRae et al. 2011), so I thought the chances were good of finding it here as
well. And find it I did - in good numbers! Success already in hand, I decided to
stick around for nightfall and set up some blacklights to see what other beetles
might be attracted from the surrounding forests.
The color and shape of the body and prominent jaws give the appearance of a
small stag beetle.
Sadly, not much of interest was coming to the lights. Temperatures and humidity
were good, but a waxing moon with clear skies didn't help. Worse, the sheets
were inundated with caddisflies - always a predictable consequence when
blacklighting near large rivers but especially annoying because of their habit
of flying into your face (and up nostrils, down shirts, in earsЕ) when checking
the sheet for other insects. A few longhorned beetles did show up, as did some
male and female reddish-brown stag beetles (Lucanus capreolus), and later a
single coppery tiger beetle (Ellipsoptera cuprascens) also made an appearance.
By 10 pm, however, I had decided enough was enough and went to one of the sheets
to begin taking it down. As I did, I noticed a reddish-brown, large-mandibled
beetle sitting on the sheet that, for all intents and purposes, looked like a
small stag beetle. I wasn't fooled, however, as I knew exactly what this beetle
was - I had previously seen this species in the form of two individuals at a
blacklight in southern Missouri very near to my current location (although it
was 28 years ago!). It was Parandra polita, an usual longhorned beetle belonging
to the archaic subfamily Parandrinae, and those specimens (MacRae 1994) plus
another collected more recently a few miles north - also at a blacklight in wet
bottomland forest along the Mississippi River (McDowell & MacRae 2009) - to date
represent the only known occurrences of this uncommon species in Missouri.
The entire rather than emarginate eyes distinguish this species from Neandra
brunnea,
Linsley (1962) noted the tenebrionid (darkling beetle)-like appearance of
beetles in this genus. Perhaps the glabrous, parallel-sided body recalls the
appearance of some darkling beetles, but I have always thought these beetles
looked more like stag beetles because of the reddish-brown coloration and,
notably, fairly large, forward-projecting mandibles that even show the same type
of size dimorphism as stag beetles - larger in "major" males, smaller in females
and "minor" males. Parandrines differ from most other subfamilies of longhorned
beetles by having the antennae short and equal-segmented and the tarsi
distinctly pentamerous with slender, padless segments. Another small subfamily
of longhorned beetles, the Spondylidinae, shares these characters, but
parandrines are easily distinguished from them by several characters including
the margined pronotum - also a most lucanid-like character.
Parandra polita also has the mandibles contiguous at the base and a narrower,
more flattened body.
Although Parandrines are reasonably diverse in South America and Africa, North
America boasts only four taxa, with P. polita and Neandra brunnea being the only
two occurring in the eastern part of the continent. Annoyingly, I have collected
just as few specimens of the latter as the former, despite the fact that N.
brunnea is considered to be the most commonly encountered of all four North
American taxa. The specimens were all taken in Japanese beetle traps that I ran
while working for the Missouri Department of Agriculture in the 1980s, so I have
never actually seen a live individual of that species. Parandra polita and N.
brunnea are, however, fairly easy to distinguish, as the former has the
mandibles triangular and contiguous at the base while in the latter they are
sickle-shaped and well separated at the base. The former also has the eyes
entire on the inner margin while the latter has them distinctly emarginate, and
in basic gestalt P. polita has a narrower, more flattened body than N. brunnea.
A frontal portrait of this beetle was featured a few days ago in ID Challenge
#23. A few people were fooled by its lucanid- and even cucujid-like appearance,
but Stephen, Harry Zirlin, Nikola Rahme, Jon Quist, and Ben Coulter all
correctly guessed this species. By virtue of being first, Stephen rises above
the 5-way tie to get the win. However, I should note that Harry was the first to
actually provide names for each of the four requested taxa (as did Jon and Ben
subsequently), so he could make a valid claim for the win. Also, nfldkings and
froglady made really nice comments about my blog and the featured photo, so I
award them with honorable mentions!
REFERENCES:
Linsley, E. G. 1962. The Cerambycidae of North America. Part II. Taxonomy and
classification of the Parandrinae, Prioninae, Spndylinae, and Aseminae.
University of California Publications in Entomology 19:1-102, 1 plate [OCLC
WorldCat].
MacRae, T. C. 1994. Annotated checklist of the longhorned beetles (Coleoptera:
Cerambycidae and Disteniidae) known to occur in Missouri. Insecta Mundi 7(4)
(1993):223-252 [pdf].
MacRae, T. C., C. R. Brown & K. Fothergill. 2011. Distribution, seasonal
occurrence and conservation status of Cylindera (s. str.) cursitans (LeConte)
(Coleoptera: Cicindelidae) in Missouri. CICINDELA 43(3):59-74 [pdf].
McDowell, W. T. & T. C. MacRae. 2009. First record of Typocerus deceptus Knull,
1929 (Coleoptera: Cerambycidae) in Missouri, with notes on additional species
from the state. The Pan-Pacific Entomologist 84(4) (2008):341-343 [pdf].
Ted C. MacRae
July 14, 2014