Leiophron uniformis (Gahan)

Goulet, Henri & Mason, Peter G., 2006, Review of the Nearctic species of Leiophron and Peristenus (Hymenoptera Braconidae: Euphorinae) parasitizing Lygus (Hemiptera: Miridae: Mirini:), Zootaxa 1323 (1), pp. 1-118 : 29-32

Leiophron uniformis (Gahan)

( Figs. 36 , 41 , 67 , Table 4)

Euphoriana uniformis Gahan, 1913: 433 . Type locality: USA, Maryland, Hagerstown. Holotype, male (USNM), labelled: [White] “Hagerstown, Md., 18.vii.1912 ” [White] “Webster No. 5967 ” [Red] “Type No. 16351 USNM” [White and framed] “ Euphoriana uniformis ♀ Type Gahan ”. Condition: right flagellum missing last flagellomere.

Leiophron trigonotylidis ; Loan, 1974a: 834; (ex parte).

Diagnosis. Vein RS+M absent, head and thorax straw coloured, transverse microsculpture on posterior half of discal area of mesoscutum lacking or little developed, and males generally with 14 flagellomeres.

Description. FEMALE. Colour. Body generally very light reddish brown; in many specimens propodeum, metanotum and on metasomal tergum 1 brown (as in Fig. 1 ); face and clypeus straw coloured (as in Fig. 14 ) (metasomal tergum 3 is as pale as preceding tergum, but appears brown due to telescoping of the more apical segments under it). Appendages straw coloured (as in Fig. 1 ); brown on mesotarsomere 5 and metatarsomere 5; fading to brown in apical 0.5 of metatibia and in apical half of flagellum (as in Figs. 1 , 34 ). Forewing clear except for two lightly coloured bands (in old specimens bands not visible) aligned with 1 st discal cell and below apical 0.7 of stigma (as in Figs. 1, 2 , 50, 55 ) (apical band fading to clear toward apex); radial cell clear but surrounded by apical dark band. Veins light straw coloured except for brown on forewing veins 1M, 1cu­a, RS and R1, and on apical 0.7 of stigma.

Structure. Flagellum with 12 or 13 (99% of specimens) or, rarely, 14 (1% of specimens) flagellomeres. Clypeus with two short and blunt teeth along anterior margin near middle (as in Fig. 14 ). Length of gena behind eye 1.3–1.6 times as long as length of eye. Height of eye 1.3–1.5 times as long as minimum distance between inner eye margins. Maximum width of head behind eyes subequal (0.96–1.02) to maximum head width at eye level. Occipital carina in dorsal 0.3 developed or reduced gradually (often outlined with transverse and parallel microsculpture on gena near carina). Mesoscutellar fovea about 2–3 times as wide as long and with about 2–8 septa ( Fig. 41 or as in Fig. 40 ). Metasomal tergum 1 with lateral margins slightly convergent (posterior margin 1.3–1.7 times as wide as narrowest width near base), elongate (length 2.3–2.6 as long as maximum width), and not meeting ventrally in anterior 0.3 (as in Fig. 69 ). Vein RS+M absent (as in Figs. 50, 55 ). Basal cell of forewing with 0–15 setae in apical 0.5 of cell, clearly less setose than 1 st discal cell (as in Fig. 53 ). Subbasal cell of hind wing narrow: vein 1M 3.0 times as long as vein cu­a (as in Fig. 65 ).

Sculpture. Punctures on vertex, frons and mesoscutum about 10 µm in diameter (similar to diameter of ommatidia). Punctures 20–60 µm apart on vertex and frons, 30–60 µm apart on mesoscutum, 60–80 µm apart on mesopleuron except posteroventrally where often 10 µm apart, as on face and legs. Clypeus generally glabrous except for row of long setae along anterior margin. Notaulus not outlined in anterior 0.5 or outline suggested by wide impression ( Fig. 41 ). Metasomal tergum 1 with about 6–8 longitudinal ridges, but these anastomosing in centre and forming a puncture­like sculpture ( Fig. 67 ).

Frons and anterior portion of vertex very rarely with outlined isodiametric meshes of microsculpture (about 7 µm in diameter). Discal portion of mesoscutum in posterior half with microsculpture usually smooth or with a weak and restricted development of irregular transverse and convex ridges. Ventral 0.5 of mesopleuron smooth or with parallel ridges slanted downward anteriorly and more or less slanted horizontally posteriorly. Remaining body surface smooth.

MALE. Colour. Propodeum and posterior section of metathorax very light reddish brown.

Structure. Height of eye subequal to minimal distance between eyes: 0.89–1.0 times as long as minimum distance between inner eye margins. Otherwise, structure and sculpture as in female.

Geographical variation. Across most of its range except in the northeastern part of United States, the propodeum of females is as pale or almost as pale coloured as males. Many females are brown on the metanotum. From Virginia northward, the propodeum colour shifts from reddish brown to brown in females, and more males are brown on the metanotum.

Taxonomic notes. Adults of L. uniformis occur in two sizes that are associated with host size (Day, 1990). Reared specimens from Halticus bractatus (Say) are smaller than those reared from Lygus lineolaris and Adelphocoris lineolatus (Goeze) . The following measurements of L. uniformis females differ by more than 2 standard deviations between small and large hosts: maximum head width at level of eyes on average = 425 µm (1 SD = 9.8 µm) from Halticus , and 517 µm (1 SD= 25.5 µm) from Lygus and Adelphocoris ; maximum head width at level of genae on average = 432 µm (1 SD= 9.9 µm) from Halticus , and 521 µm (1 SD= 25.6 µm) for Lygus and Adelphocoris . The following measurements of L. uniformis males differ by slightly less than 1 standard deviation between small and large hosts: maximum head width at level of eyes on average = 400 µm (1 SD= 20.3 µm) from Halticus , and 450 µm (1 SD= 37.1 µm) for Lygus and Adelphocoris ; maximum head width at level of genae on average = 403 µm and (1 SD= 20.4 µm) from Halticus , and 466 µm (1 SD = 42.6 µm) from Lygus and Adelphocoris .

Adults of L. uniformis are most similar to those of L. lygivorus , and differ in the microsculpture development on the discal portion of the mesoscutum, the colour pattern on the propodeum in females, and the almost allopatric range (narrowly sympatric in southern Ontario). A summary of measurement differences between L. lygivorus and L. uniformis is given in Table 4.

Adults of L. uniformis differ from those of L. australis by the body colour pattern, and forewing venation. Because only one male and one female are known, the measurements in Table 1 are not discussed further.

Adults of L. uniformis differ from those of L. simoni by the forewing venation, notauli development, and the anterior mesoscutellar fovea proportions. A summary of measurement differences between L. simoni and L. lygivorus is given in Table 3.

Host and biological notes. Reared specimens have been recorded mainly from Halticus bractatus , but they have also been reared successfully from Adelphocoris lineolatus , Lygus lineolaris , L. elisus Van Duzee , Trigonotylus caelestialium , T. tenuis Reuter , and Pseudatomoscelis seriatus (Reuter) . Adults occur from May until August. This is a bivoltine species with two generations a year.

Material examined and range. 287 (79♂, 116♀ and 102♂ / ♀) adults were studied. Of these, 208 were reared from Miridae and 78 were field collected. The species is known across the warm temperate regions of North America from southernmost Ontario to Mexico .

CANADA. ON: Foxboro (1♂); London (3♂, 10♀); Talbotville (1♂, 2♀) . USA. AZ: Cochise Co., Huachuca Mtn. (1♀); Yuma (1♀; USNM) . CA: Imperial Co., Calexico (12♂, 7♀; USNM) ; Imperial Co., Brawley (4♂, 4♀; USNM) ; Riverside Co. (2♂, 10♀; USNM) ; Riverside Co., San Jacinto (4♂, 4♀; USNM) . DE: Newark (11♂, 13♀, 67; USDA) . KS: Balwin (1♂; USNM) ; Garden City (1♂; USNM) ; Wellington (1♀; USNM) . LA: Logansport (1♂; USNM) . MD: Howard Co. (3♂; USNM) ; Montgomery Co., 4 mi S

Ashton (1♀; USNM) ; Beltsville (1♀; USNM) ; Cabin John (1♀; USNM) ; Funkstown (3♀; USNM) ; Glen Echo (1♀; USNM) ; Hagerstown (1♂; USNM) ; Patuxent (1♂; USNM) . MO: Boone Co., Columbia (5♀; USNM) . MS: St. Louis Co., St. Louis (1♀; USNM) ; Tunica Co., 3 mi N Tunica (2♂, 3♀; USNM) . NH: Hillsboro Co., Milford (1♀; USDA) . NJ: Moorestown (1♂, 4♀; USNM) ; Blairstown (21♂, 31♀, 35; USNM, USDA) ; Woodstown (1♂; USDA) ; Warren Co., Harmony Twp. (1♂; USDA) . NY: Rensselaer Co., Coomer (1♂; USDA) ; Rensselaer Co., White Church (1♀; USDA) ; Tompkins Co., Ithaca (1♀); Washington Co. 43 o 10.362'N 73 o 30.025'W (2♂); Wayne Co. (2♂; USNM) . OH: Lucas Co., Adams Twp. (2♀; USNM) . PA: Carbon Co., Lake Harmony Lehigh Co. , (1♂; USDA) ; Lynnville (1♂, 1♀; USDA) ; Walawana (1♀; USNM) . UT: Karob (1♀; USNM) . MEXICO. TAM: Tampico , Victoria Hwy (1♂; ITMM) . “ Flying over the country” (1♀; USNM) .

Figures

FIGURES 25–36. 25–27. Dorsal view of head with insert to show sculpture. 28–31. Lateral view of head. 32–33. Posteroir view of head. Code: “a” dorsal end of occipital carina. 34. lateral view of antenna. 35–36. Last five flagellomeres in lateral view.

FIGURE 37–49. 37. Lateral view of antenna. 38–39. Last six flagellomeres in lateral view. 40–44. Dorsal view of mesosoma. 45–49. Lateral view of mesosoma.

FIGURES 67–78. 67–68. Dorsal view of metasomal tergum 1. 69–70. Ventral view of metasomal segment 1. 71–72. Lateral view of seven last flagellomeres. 73–74. Lateral view of first three flagellomeres. 75–76. Dorsal view of protarsus. 77–78. Lateral view of metasoma.

FIGURES 1–5. Habitus with frontal view of head. Codes: “a” clypeal colour; “b” metatibial colour; “c” metacoxal colour; “d” forewing colour; “e” mesoscutal colour.

FIGURES 13–24. 13–22. Frontal view of head. Code: “a” ventral edge of clypeus. 23–24. Dorsal view of head.

FIGURES 50–58. 50–52. Forewing. 53–54. Basal and subbasal cells of forewing. 55–58. Radial cell and stigma of forewing.

FIGURES 59–66. 59–63. Radial cell and stigma of forewing. 64. Hind wing. 65–66. Basal and subbasal cells of hind wing.