Arhyssus nigristernum ( Signoret, 1859 )

Swanson, Daniel R., Taylor, Steven J. & Heads, Sam W., 2017, Nine true bugs (Heteroptera) newly-discovered in Illinois, Zootaxa 4269 (4), pp. 571-585 : 580-582

Arhyssus nigristernum ( Signoret, 1859) ; Aufeius impressicollis Stål, 1870 ; and Niesthrea louisianica Sailer,

1961 ( Rhopalidae : Rhopalinae ). In the early summer of 2014, a single male ( Fig. 7 ) and single female of the scentless plant bug Arhyssus nigristernum were collected via sweep-net within a shrub prairie in the Fogelpole Cave Nature Preserve ( Fig. 14 ). The specimens bear the following label data: ILLINOIS: Monroe Co., Fogelpole Cave Nat. Preserve, shrub prairie, 30 June 2014, 38.1964°N 90.1294°W, 640 ft., D. R. Swanson et al., #47, det. D. R. Swanson 2014 [1 male, 1 female] . This specimen was taken in the shrubby transition zone between the prairie vegetation and the wooded sinkhole. The female has been vouchered in the Illinois Natural History Survey Insect Collection ( INHS Insect Collection 780,163), and the male has been retained in the first author's collection (DRS). A search for corroborative material in INHS revealed several additional specimens : ILLINOIS: [Clark Co.], Parker, sweepings, 18 May 1908, [no collector], INHS Insect Collection 569,605 [1 male] ; [Jackson Co.], Makanda, Giant City [ State ] Park, 10 May 1932, H. L. Dozier, INHS Insect Collection 569,607 [1 female] ; [Jackson Co.], Grand Tower, 12 May 1932, H. L. Dozier, INHS Insect Collection 569,001 & 569,615 [2 males] ; [Pope Co.], Golconda, 22 June 1932, Ross, Dozier, Park, INHS Insect Collection 569,610 [1 male] ; [Union Co.], Cobden, 26 June 1905, [no collector], INHS Insect Collection 569,606 [1 female] ; [Union Co.], Jonesboro, 6 May 1932, H. L. Dozier, INHS Insect Collection 569,612 [1 male] ; [Vermilion Co.], Batestown, 16 June 1908, [no collector], INHS Insect Collection 569,614 [1 male] ; [Vermilion Co.], Danville, 3 July 1911, [no collector], INHS Insect Collection 569,603 [1 male] ; [Washington Co.], Dubois , sweepings from grass, 3 July 1909, [no collector], INHS Insect Collection 569,608 [1 female] ; [Washington Co.], Dubois , 21 May 1917, [no collector], INHS Insect Collection 569,604 [1 male] ; and [Washington Co.], DuBois , 9 Aug. 1917, [no collector], INHS Insect Collection 569,609 [1 female]. All of the supplemental specimens were identified as Arhyssus bohemonii [sic] by Harris in 1945.

In the eastern states, A. nigristernum resembles many other rhopalines, generally requiring examination of the pronotum and metapleuron under a microscope to confirm the genus. However, dark individuals (such as the pair caught here) are distinctive among eastern species of Arhyssus . In past literature, this species was often listed under a junior synonym, Corizus bohemani Signoret, 1859 . Henry (1988) recorded A. nigristernum from Arkansas , Connecticut , Florida , Indiana , Kansas , Kentucky , Louisiana , Maine , Maryland , Massachusetts , Michigan , Mississippi , Missouri , North Carolina , New Jersey , New York , Ohio , Pennsylvania , Rhode Island , Tennessee , Texas , Virginia, and West Virginia, as well as Washington, D.C. , Ontario, and Quebec . Parshley (1917) included New Hampshire . Chopra's (1968) distribution map included dots for several specimens from Illinois (as well as Alabama, Georgia, Oklahoma, and South Carolina ), although these states were not listed under "Material Examined", and we are unaware of any other literature records for A. nigristernum in these states. The current known distribution of the species north of Mexico is summarized in Fig. 20 .

The unreported status of Illinoisan records for this species was overlooked in Heads et al. (2015), and there are a few reasons that could account for this species going previously unnoticed. It appears to be less common than Arhyssus lateralis ( Say, 1825) , and pale individuals of A. nigristernum could easily be confounded with the former, as well as other rhopalines. Furthermore, A. nigristernum is not considered economically important (inferred from absence in Schaefer & Kotulski 2000).

Two other new state records are here conveniently reported, based on material housed in the INHS, in order to more fully flesh-out the rhopalid diversity of Illinois. Furthermore, both species can be considered beneficial in that they feed on plants often considered pests ( Schaefer & Kotulski 2000).

Several specimens, including a large series, of Aufeius impressicollis ( Fig. 8 ) were discovered in the collection. They bear the following label data: ILLINOIS: [Champaign Co.], Champaign, 31 October 1906, Hart & Hood, det. Harris 1945, INHS Insect Collection 568,581–568,588 & 568,601–568,607 [7 males, 6 females]; Champaign Co. , Urbana , 13 Nov. 1915, [no collector], det. Harris 1945, INHS Insect Collection 568,595 [1 male]. Henry (1988) recorded A. impressicollis from Arizona, Arkansas, California, Colorado, Idaho, Indiana, Iowa, Kansas, Maryland, Missouri, Nebraska, New Mexico, Ohio, South Dakota, Texas, Utah, and Washington . Wheeler (1988) added South Carolina , and Wheeler (2002) added Georgia, North Carolina , and Oklahoma . The current known distribution of the species north of Mexico is summarized in Fig. 21 . Given this range, it is unsurprising to find this species in Illinois. Aufeius impressicollis feeds on various Amaranthaceae , including smooth pigweed ( Amaranthus hybridus L.) ( Wheeler 1984, 1988, 2002; Schaefer & Kotulski 2000).

A single specimen of Niesthrea louisianica ( Fig. 9 ) also was present in the INHS. The specimen bears the following label: ILLINOIS: S . Illinois [no further data], Andreas Bolter Collection, det. D. R. Swanson 2016, INHS Insect Collection 754,415 [1 female] . However, the presence of N. louisianica in Illinois is corroborated by an individual photographed in Fairfield, Wayne County, Illinois on 3 November 2005 and posted to BugGuide.net (http://bugguide.net/node/view/36397). Henry (1988) recorded this species from Alabama , Arizona , Arkansas , Florida , Georgia, Iowa , Kansas , Louisiana , Maryland , Mississippi , Missouri , New Jersey, New Mexico, New York , North Carolina , Oklahoma , South Carolina , Tennessee , Texas , Utah , and Virginia. The current known distribution of the species north of Mexico is summarized in Fig. 22 . Finding this species in Illinois was not surprising, particularly in the southern part of the state. Niesthrea louisianica is known to feed on velvetleaf ( Abutilon theophrasti Medikus ), which plant can be pestiferous in monocultures of corn, soybean, cotton, and sorghum ( Schaefer & Kotulski 2000).

With the addition of A. nigristernum , A. impressicollis , and N. louisianica , eight species of scentless bugs are known from Illinois; the other five species are: Arhyssus lateralis ( Say, 1825) ; Boisea trivittata ( Say, 1825) ; Harmostes fraterculus ( Say, 1831) ; Harmostes reflexulus ( Say, 1831) ; and Jadera haematoloma (Herrich- Schaeffer, 1847). The following key was constructed using Hoebeke & Wheeler (1982) and Swanson (2011). Three additional species, i.e., Brachycarenus trigrinus ( Schilling, 1829) ; Liorhyssus hyalinus ( Fabricius, 1794) ; Stictopleurus punctiventris ( Dallas, 1852) , may yet be found in Illinois, given their presence in other surrounding Midwest states (Henry 1988).

Figures

FIGURES 1 – 9. Dorsal habitus of nine Heteroptera newly reported for Illinois: (1) Neuroctenus pseudonymus, adult female; (2) Nannium pusio, adult female; (3) Metacanthus multispinus, adult male; (4) Anasa repetita, adult male; (5) Chelinidea vittiger, adult female; (6) Phymata fasciata fasciata, adult male; (7) Arhyssus nigristernum, adult male; (8) Aufeius impressicollis, adult female; and (9) Niesthrea louisianica, adult female. Scale bar = 1 mm.

FIGURES 10 – 14. Various collection sites of nine Heteroptera newly reported for Illinois: (10) near Brasher Cave, Pope County (Neuroctenus pseudonymus) (image © Matthew L. Niemiller); (11) Fogelpole Cave Nature Preserve, Monroe County (Metacanthus multispinus, Phymata fasciata fasciata); (12) Kidd Lake Marsh, Monroe County (Anasa repetita, Phymata fasciata fasciata); (13) White Rock Nature Preserve, Monroe County (Chelinidea vittiger); and (14) Fogelpole Cave Nature Preserve, Monroe County (Arhyssus nigristernum).

FIGURES 15 – 22. Current known distribution of eight Heteroptera newly reported for Illinois by state / province within the U. S. A. and Canada: (15) Neuroctenus pseudonymus; (16) Metacanthus multispinus; (17) Anasa repetita; (18) Chelinidea vittiger; (19) Phymata fasciata fasciata; (20) Arhyssus nigristernum; (21) Aufeius impressicollis; and (22) Niesthrea louisianica. Being known from only two states, the range of Nannium pusio is not depicted.