Other Common Names
Big-footed or Big-legged Plant Bug
Explanation of Names
ACANTHOCEPHALA: from the Greek "akantha" (thorn or spine) + "kephale" (head) - refers to the spine on the front of the head in this genus.
"Acanthocephala" is also a taxon of parasitic worms (Spiny-headed Worms) historically considered a separate phylum, but recently classified as a
subtaxon of rotifers (Rotifera). - [RM]
Numbers
Nearctica.com and Arnett
(1) list five species in North America.
Size
From 20-22 mm (A. terminalis) to 25-28 mm (A. femorata)
Identification
Large, dark brown or almost black.
Tylus (beak) flattened from side-to-side and prominently pointed.
Based on the distribution data in the Range section below, any Acanthocephala individual found north of North Carolina must be A. terminalis.
Except for
A. thomasi, which occurs only in AZ CA TX, the 4 other
Acanthocephala species in North America can usually be identified using the key at the bottom of
this U. of Florida page.
See also this side by side comparison of the two species most easily confused where both occur, A. confraterna and A. terminalis.
Note: In states other than AZ, CA, FL, GA, and TX there are only three species to choose from. They may be eliminated easily if compared in this order: A. declivis has a distinctive right-angled hind leg flange and broad pronotum. A. femorata has uniformly red antennae. A. terminalis has red-tipped antennae.
Orange antennae and dark body could be mimicry of a Pompilid wasp, but these bugs do exude a foul-smelling liquid, so it may be Mullerian mimicry.
Range
A. declivis - North Carolina to Florida, west to Arizona
A. confraterna - known only from Alabama, Florida, Georgia, and Texas
A. femorata - North Carolina to Florida, west to Oklahoma and Texas
A. terminalis - from Texas and Colorado east to Michigan, through southern Ontario to New England states, and south to Florida
(all the above distribution data taken from PDF docs on
U. of Florida page)
A. thomasi - Arizona, California, and Texas (
U. of Florida)
Habitat
Deciduous forests, also fields, etc.
Food
Nymphs and adults suck plant juices.
See Also
Leptoglossus. The expansion of the lower hind leg is generally longer in Acanthocephala, shorter and often wider in Leptoglossus.
Print References
Arnett, pp. 254-255, figs. 20.18-19
(1)
Slater, p. 58, figs. 88, 89
(2)
Milne, p. 481, plate 103--A. femorata
(3)
Brimley, p. 64, lists A. declivis, A. femorata, and A. terminalis for North Carolina
(4).
Internet References
key to species [at bottom of page] of the 4
Acanthocephala species occurring in Florida (U. of Florida)
Insect Images--
A. declivis
North Carolina State University Entomology Collection lists for that state, with number pinned:
declivis (27),
femorata (107),
terminalis (204).
Hemiptera of Oklahoma lists
declivis, femorata, and
terminalis.
Arizona Hemiptera lists
A. terminalis (but no specimens were collected in Arizona).
