Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
Clickable Guide
Moths Butterflies Flies Caterpillars Flies Dragonflies Flies Mantids Cockroaches Bees and Wasps Walkingsticks Earwigs Ants Termites Hoppers and Kin Hoppers and Kin Beetles True Bugs Fleas Grasshoppers and Kin Ticks Spiders Scorpions Centipedes Millipedes

Calendar

TaxonomyBrowseInfoImagesLinksBooksData
Photo#278586
Very small Phasmid? - Pseudometapterus umbrosus

Very small Phasmid? - Pseudometapterus umbrosus
Nashville, Davidson County, Tennessee, USA
May 21, 2009
Size: 14 mm
By cropping off the antennae, lots of extraneous pixels were lost, and the small format jaggies were reduced. I didn't realize that the assassin's beak was so prominent in this shot, or I wouldn't have guessed Phasmid.

Images of this individual: tag all
Very small Phasmid? - Pseudometapterus umbrosus Very small Phasmid? - Pseudometapterus umbrosus Very small Phasmid? - Pseudometapterus umbrosus

Probably not P. umbrosus.
Although this does look like it is in the tribe Metapterini, I do not think this is P. umbrosus. Looks like it could be an immature Emesya sp. I wrote the most recent descriptive work on P. umbrosus. I would be happy to send you a copy of that manuscript if you so wish.

 
I'll certainly admit...
that I sometimes fail to consider the possibilities of teneral or immature individuals (as I did here). And certainly individuals of Emesinae are extremely difficult to ID from photograph alone. But I have to ask Dr. Bradshaw, what makes you doubt this identification? What are the visual cues in these photographs that might suggest to someone that it has been misdiagnosed? I ask simply because it is always my desire to understand and learn from these types of situations.

As a side note, I have copies of and have read both Hagerty, McPherson & Bradshaw (2001) and Bradshaw & McPherson (2002) concerning E. b. brevipennis and P. umbrosus, respectively.

 
ID considerations.
There are a couple reasons to doubt this identification, at least based on this images here. The general color should look a lot darker, much like Barce spp. Although, this specimen does look like it is Metapterini, there are no white, adult Metapterini (not that I recall). In fact, to separate Pseudometapterus from Barce one ultimately has to measure some distances of the bases of spines on the forelegs. Otherwise, it will look like Barce. Also, the general pattern of spines is wrong for Pseudometapterus (see my publication with the illustration of the 5th instar, it should look very similar to the adult). Furthermore, if you view the image with the close-up of the forelegs closely, you will see no small spine basad of the first large spine of the first large spine of the posterodistal series of spines on the forelegs (again see my pub and note the tiny spine at the base of the largest spine on Fig. 17). If it is Pseudometapterus, it should have this spine. And it can't be an immature P. umbrosus, because it would be more equal in size to the psyllid prey in this photo. Hope that clears things up a little. Thanks for requesting clarification.

 
A few more points to consider...
The metapterines (for this is surely its tribal assignment) to be considered include an immature Emesaya as you suggested, an adult species of Barce or an adult species of Pseudometapterus. I do not regard the single species of the neotropical Ghinallelia as a valid possibility in Tennessee.

The color is admittedly problematic since you are correct in that there are no known pale adult members of Metapterini other than the sometimes stramineous color of Barce neglecta. As such, the pale color should be treated as an aberration or as an artifact of the photograph and cannot rule out P. umbrosus any more than it can rule out any other metapterine. The pattern itself, when considered independent of depth of color, is reasonably close to P. umbrosus (as illustrated in your publication) though some Barce do have a similar pattern as well.

E. brevipennis is the only real contender within Emesaya though it matters little since the evidence still holds for other species. Emesaya can be ruled out for several reasons. The first and second instar nymphs (and to a lesser degree the third) retain a much wider, slightly oval abdomen. The insect in the photo has an extremely skinny, parallel-sided habitus suggesting it is much closer to adulthood. At 14 millimeters, this insect would be a bit small for a penultimate or ultimate instar nymph. I feel this is further corroborated by the time of year the specimen was photographed. According to the E. brevipennis study (the TN locality should make little difference), the first through third instars of E. brevipennis are the ones that will be found in late May. P. umbrosus, as your study shows, is out as an adult in May. Another point to consider involves the wings. Macropterous individuals are considered typical in Emesaya as no short-winged individuals have been found (to my knowledge) whereas microptery/aptery are considered the much more typical condition in Pseudometapterus (and Barce). Lastly, the profemoral spines do not match Emesaya, even more so than Barce or Pseudometapterus. In Emesaya, the forelegs appear extremely skinny and the spines don’t start distinctly before the midpoint of the segment. Comparatively, Pseudometapterus and Barce both have the series starting distinctly before the middle of the article. Given all these factors, it seems fairly safe to rule out Emesaya.

On to Barce. The size eliminates a nymph of Barce since 14 mm is on the extremely large size even for the adults. It is, without a doubt, not B. aberrans; the profemoral spines start too far distad of the procoxa. I cannot see a distinct clypeal spine in the closeup which would rule out neglecta, uhleri and the subspecies of fraterna though this photo makes that conclusion rather tenuous. The short procoxal length (not twice as long as the protibia) eliminates B. husseyi. Additionally, the color pattern on the head, if darkened, still doesn’t match that of B. werneri or B. husseyi. Still, Barce remains the most likely genus if it is not Pseudometapterus. As a side note, you can also separate Barce and Pseudometapterus by the claw characteristics of the meso- & metatarsi. Not helpful for the photo here, I know, but still another character.

Now here’s my issue with the diagram of the foreleg. That large basal spine is of course part of the posteroventral series but the other small one is supposed to be part of the anteroventral series and Wygodzinsky (1966) remarks how both genera have the posteroventral series typical of other metapterines. However he does mention how Barce is the genus with the anteroventral process being placed basad of the large basal posteroventral spine. Pseudometapterus has the process placed distad of the large spine. This seems to be in conflict with what is shown in the diagram.

 
thanks, Dr Bradshaw
pls send the paper to vmarfus on gmail, it will be highly appreciated. =v=

Comment viewing options
Select your preferred way to display the comments and click 'Save settings' to activate your changes.