Antistrophus meganae Tooker & Hanks, 2004

Nastasi, Louis F., Tooker, John F., Davis, Charles K., Smith, Cecil N., Frey, Timothy S., Hatfield, M. J., Presnall, Tara M., Hines, Heather M. & Deans, Andrew R., 2024, Cryptic or underworked? Taxonomic revision of the Antistrophus rufus species complex (Cynipoidea, Aulacideini), Journal of Hymenoptera Research 97, pp. 399-439 : 399-439

Antistrophus meganae Tooker & Hanks, 2004

Fig. 6

Antistrophus meganae Tooker & Hanks, 2004 in Tooker et al. 2004: 132. ♀, ♂ (type locality: East St. Joseph Railroad Prairie, Iroquois Co., Illinois, USA).

Material examined.

Holotype (deposited at INHS). USA • ♀; Illinois, Champaign County, St. Joseph , roadside prairie; J. Tooker leg.; reared from stem of Silphium terebinthinaceum , emerging in June 2000; INHS Insect Collection 52830.

Paratypes (14 ♀ and 8 ♂). Deposited at INHS: USA • 8 ♀ and 4 ♂; same data as for holotype; INHS Insect Collection 52831–52837 • 4 ♀ and 3 ♂; Illinois, Ford County, Paxton, Paxton Railroad Prairie ; J. Tooker leg.; reared from stem of Silphium terebinthinaceum , emerging in June 2000; INHS Insect Collection 52838–52844 .

Deposited at USNM: USA • 2 ♀ and 1 ♂; Illinois, Ford County, Paxton, Paxton Railroad Prairie ; J. Tooker leg.; reared from stem of Silphium terebinthinaceum , emerging in June 2000; USNMENT 01790188 – 01790190 .

Other material

(10 ♀ and 17 ♂). Deposited at PSUC: USA • 1 ♀; Illinois, Champaign County, St. Joseph , roadside prairie; JF Tooker and AR Deans leg.; 40.113, - 88.064; galled plant material collected 10 Nov 2020; reared from stem of Silphium terebinthinaceum , emerging in June 2021; PSUC _ FEM _ 248429 • 1 ♀ and 1 ♂; Illinois, McLean County, Chenoa, Weston Cemetery Prairie ; 40.725, - 88.606; galled plant material collected 11 Nov 2020; reared from stem of Silphium terebinthinaceum , emerging in June 2021; PSUC _ FEM _ 248165–248166 .

Deposited at WIRC: USA • 2 ♀; Wisconsin, Columbia County, Mass Rd. ; galled plant material collected Fall 2008; reared from stem of Silphium terebinthinaceum , emerging in June 2009; WIRC 00171156 ; 00171166 • 2 ♀ and 2 ♂; Wisconsin, Dane County, Co A and Oak Ridge ( Anthony Branch F. A. ); 42.892454, - 89.320011; galled plant material collected 15 Apr 2009; reared from stem of Silphium terebinthinaceum , emerging in June 2009; WIRC 00170514 ; 00171140; 00171154–00171155 • 1 ♂; Wisconsin, Dane County, Kelly Road and RR , roadside; galled plant material collected Fall 2008; reared from stem of Silphium terebinthinaceum , emerging in July 2009; WIRC 00170513 • 1 ♂; Wisconsin, Dane County, Malone Road ; galled plant material collected 17 Apr 2009; reared from stem of Silphium terebinthinaceum , emerging in June 2009; WIRC 00171112 • 1 ♂; Wisconsin, Dane County, Noll Valley ; galled plant material collected 5 Apr 2012; reared from stem of Silphium terebinthinaceum , emerging in June 2012; WIRC 00171114 • 1 ♂; Wisconsin, Dane County, Prairie Ridge City Park ; galled plant material collected 3 Apr 2012; reared from stem of Silphium terebinthinaceum , emerging in May 2012; WIRC 00171124 • 1 ♀ and 1 ♂; Wisconsin, Dane County, Sugar Ridge Savanna ; galled plant material collected 20 Mar 2012; reared from stem of Silphium terebinthinaceum , emerging in May 2012; WIRC 00171122 ; 00171134 • 1 ♂; Wisconsin, Dane County, TNC Waubesa Wetland ; galled plant material collected 22 Nov 2008; reared from stem of Silphium terebinthinaceum , emerging in May 2009; WIRC 00170515 • 1 ♂; Wisconsin, Jefferson County, Bluejoint Prairie ; 43.163398, - 88.938815; galled plant material collected 16 Apr 2009; reared from stem of Silphium terebinthinaceum , emerging in July 2009; WIRC 00170517 • 1 ♂; Wisconsin, Jefferson County, Bluejoint Prairie ; 43.163398, - 88.938815; galled plant material collected 16 Apr 2009; reared from stem of Silphium terebinthinaceum , emerging in May 2009; WIRC 00170512 • 1 ♀ and 2 ♂; Wisconsin, Jefferson County, Cold Spring Prairie ; 42.872556, - 88.770194; galled plant material collected 15 Apr 2009; reared from stem of Silphium terebinthinaceum , emerging in June 2009; WIRC 00171109 ; 00171137; 00171141 • 3 ♂; Wisconsin, Walworth County, Skoponong Prairie ; 42.829155, - 88.620586; galled plant material collected 4 Oct 2011; reared from stem of Silphium terebinthinaceum , emerging in May or June 2012; WIRC 00170749 ; 00171113; 00171120 • 1 ♀; Wisconsin, Walworth County, Young Pr. East Annex ; 42.839419, - 88.63002; galled plant material collected 16 Apr 2009; reared from stem of Silphium terebinthinaceum , emerging in June 2009; WIRC 00170750 • 1 ♀ and 2 ♂; Wisconsin, Winnebago County, Oshkosh-Larsen Trl mid (B); 44.13912, - 88.624272; galled plant material collected 10 Oct 2011; reared from stem of Silphium terebinthinaceum , emerging in June 2012; WIRC 00171115–00171116 ; 00171118 .

Diagnosis.

A. meganae is the only species of the rufus complex in which the mesoscutellar foveae (Fig. 6 F ) are long and ovate, reaching nearly halfway across the mesoscutellar disc. A. meganae also differs from most other members of the rufus complex by the POL (Fig. 6 C ), which is longer than the OOL in A. meganae and A. minor but shorter than the OOL in the other species.

Description.

Female (Fig. 6 A ) – Body length: 1.8–3.2 mm (x ̄ = 2.5 mm; n = 25; holotype = 2.3 mm). Color: Antenna color: red brown throughout, at most slightly darker distally than proximally. Head color: vertex and occiput dark red brown, mandibles red brown basally to darker red brown apically, rest of head red brown throughout. Mesosoma color: pronotum and propodeum red brown laterally to dark red brown medially, mesoscutum dark red brown with distinct posterolateral red brown spots, scutellum dark red brown, and mesopleuron dark red brown dorsally and ventrally but red brown medially. Wing membrane color: hyaline throughout. Wing vein color: light brown. Leg color: red brown throughout, except for apical tarsomere which is conspicuously darker. Metasoma color: red brown to dark red brown. Antennae (Fig. 6 B ): Antennomere count: 13. F 1 length: 2.6 × as long as wide. F 2 length: 3.6 × as long as wide. F 2: F 1 length ratio: 1.4. Placodeal sensilla on F 2: absent; sensilla present only on F 3 and following antennomeres. Head (Fig. 6 C ): Upper frons sculpture: reticulate. Gena posterolateral projection in anterior view: distinctly projecting past compound eyes. Facial radiating striae: distinct and complete, reaching compound eyes. Supraclypeal area sculpture: reticulate. Supraclypeal area projection: slightly projecting. OOL vs POL: POL distinctly longer. OOL vs LOL: OOL less than twice LOL. POL vs LOL: POL twice LOL. LOL vs DLO: LOL longer. Vertex sculpture: reticulate throughout. Clypeus sculpture: reticulate. Mesosoma (Figs 6 D – F ): Pronotum pilosity: densely pilose along anterior margin and with only sparse setae elsewhere. Pronotum excluding pronotal plate sculpture: reticulate. Pronotal plate sculpture: reticulate. Mesopleuron excluding speculum sculpture: reticulate with fine intermediate striae. Speculum sculpture: reticulate. Mesopleuron pilosity: ventral margin and mesopleural triangle densely pilose and bare elsewhere. Mesoscutum pilosity: sparsely pilose. Mesoscutum sculpture: reticulate. Apparent length of anterior parallel lines: reaching one third across mesoscutum. Morphology of anterior parallel lines: narrow, distinct throughout perceptible length. Apparent length of parapsidal grooves: reaching halfway across mesoscutum. Morphology of parapsidal grooves: narrow, distinct throughout perceptible length. Morphology of median mesoscutal impression: apparent as a shallow impression extending across most of mesoscutum. Notauli completeness: incomplete, distinct posteriorly to indistinct in anterior third. Morphology of notauli: appearing as wide indentations with sloping edges throughout distinct portions. Metapleural sulcus: meeting posterior mesopleuron at about one third of its height. Lateral propodeal carinae: distinct and subparallel. Metapleuron sculpture: reticulate. Mesoscutellar foveae distinction: distinct, relatively deep anteriorly to shallower and inconspicuously delimited posteriorly. Mesoscutellar foveae sculpture: reticulate. Mesoscutellar disc sculpture: rugose-reticulate, primarily reticulate, but with distinct rugose-reticulate sculpture seemingly restricted to outer margins. Mesoscutellar foveae length: long, reaching nearly halfway across mesoscutellar disc. Mesoscutellar foveae shape: ovate, slightly longer than wide, separated by a subtriangular carina slightly wider posteriorly than anteriorly. Mesoscutellar disc shape: subcircular, about as wide as long. Wings: Marginal cell length: 3.3 × as long as wide. Fore wing distal fringe of marginal setae: absent. Metasoma: Punctation of metasomal terga: T 3 punctate only in posterior third and with T 4 and following punctate throughout.

Male (Fig. 6 G ) – Same as female except for the following: Body length: 1.3–2.5 mm (x ̄ = 2.1 mm; n = 25). Antennae: Antennomere count: 14. F 1 length: 2.5 × as long as wide. F 2 length: 3.0 × as long as wide. F 2: F 1 length ratio: 1.4 (as in female). Placodeal sensilla on F 2: present. Wings: Fore wing distal fringe of marginal setae: present. Metasoma: Metasoma size: conspicuously smaller than in female.

Biology.

Antistrophus meganae induces inconspicuous, externally imperceptible galls in stems of Silphium terebinthinaceum (Fig. 6 H ) ( Tooker et al. 2004; Nastasi and Deans 2021).

Distribution.

Tooker et al. (2004) reported this species only from several prairie sites in Illinois ( USA). Nastasi and Deans (2021) did not report additional localities; however, the specimens we examined revealed novel records from Wisconsin (Suppl. material 1: table 1). We also sequenced DNA barcodes for individuals from Ohio (Suppl. material 1: table 6), and a series of specimens identified using the key represents a new state record from Michigan (see Discussion; Suppl. material 1: table 1). Known and potential distribution are summarized in Fig. 9 .

Figures

Figure 6. Antistrophus meganae Tooker & Hanks, 2004 A female lateral habitus (PSUC _ FEM _ 248165) B female proximal antennomeres (PSUC _ FEM _ 247325) C female dorsal head (PSUC _ FEM _ 247325) D female dorsal mesosoma (PSUC _ FEM _ 247230) E female dorsal mesoscutum (PSUC _ FEM _ 247230); not = notaulus F female dorsal scutellum (PSUC _ FEM _ 247230); scf = mesoscutellar fovea G male lateral habitus (PSUC _ FEM _ 248498) H gallss and larvae of A. meganae in a stem of Silphium terebinthinaceum Jacq.

Figure 9. Known and potential distributions for species of the Antistrophus rufus complex. Host plant distribution follows Kartesz (2015). States in green reflect established distribution, while states in yellow reflect potential distribution based on records of the host plant.