Ittys ceresarum (Ashmead)

George, Jeremiah N., 2007, Review of the species of Ittys (Chalcidoidea: Trichogrammatidae) occuring in the United States, with the description of four new species, Zootaxa 1581 (1), pp. 53-68 : 56-60

Ittys ceresarum (Ashmead)

( Figs 1–7 )

Trichogramma ceresarum ( Ashmead), 1888: 107 . Neotype male designated here in USNM.

Ittys ceresarum ; Girault, 1911: 25–26.

Abella nympha Girault, 1911: 197–198 . Holotype female, in USNM examined. New synonymy.

Abella perditrix Gahan, 1918: 25–26 . Holotype female, in USNM examined. New synonymy.

Paracentrobia (Ittys) ceresarum ; Doutt and Viggiani, 1968: 565.

Ittys ceresarum ; Viggiani, 1971: 198.

Diagnosis. TSS widest just posterior to anterior margin; terminal spine submedial and at posterior margin of appendage, terminal spine attaining apex of aedeagus, volsella with distinct digital spine ( Figs. 6–7 ).

Description. Length: Male 0.59–1.04 mm, female 0.67 – 0.98 mm (without ovipositor 0.60 – 0.73 mm).

Color: Both sexes light yellow to light brown with variation as follows: head light to dark yellow; preorbital carina light to dark brown; malar depression and mandible dark brown to brown. Antenna with scape yellow; pedicel yellow darkening from light brown to brown apically; F1 usually brown, F2 light yellow usually lighter than F1; C1 brown to dark yellow, C2 usually lighter than C1, yellow to brown, C3 brown to yellow. Pronotum yellow with anterior dorsolateral and anterolateral margins with brown band; propleuron usually with distinct pair of brown medial bands. Mesoscutum and scutellum yellow to light yellow. Legs with coxa light brown; remaining parts of legs light yellow. Metasoma usually with two distinct posterior brown metatergal bands (Mt5 and 6); some specimens with additional anterior brown lateral tergal bands (see comments).

Male: Head 0.78 as long/wide, interocular distance 0.60 head width. Antennae with scape widest medially; A2 relatively large and appressed to F1; C1, C2, and C3 0.32, 0.42, 0.46 total club length, respectively;F1- 0-1 BPS; F2- 1-2 BPS; C1, C2 and C3 each with 1 ventral BPS; C1- 0-1PS extending length of segment and 0-1PS extending from C1-C2; C2- 0-1PS extending the length of segment; C3- 2-4PS extending the length of segment with a slight apical extension beyond end of club; club segments with relatively sparse CHS, C2 with ca. 3 evenly distributed CHS, maximum length 0.033 mm.

Mesosoma: Mesoscutum ca. 0.97 wide/long. Scutellum ca. 1.4 wide/long. Forewing 0.43 as wide /long; venation attaining ca. 0.5 length of wing; occurrence of vein tracks as follows; RS2, r-m, M, CU2, and A present, distinct; RS1 distinct with ca. 6 setae; CU1 present but indistinct; fringe setae short, 0.21 maximum width of wing; relative length of submarginal, premarginal, marginal and stigmal veins, 1.7, 1.1, 1.2, 0.7, respectively; postmarginal extension negligible; submarginal narrow, widest at basal end; premarginal short, wide relative to submarginal. Legs with relative length of coxa, trochanter, femur, tibia and (tarsomeres) as follows: fore leg- 7.0: 3.4: 12.0: 9.6: (4.6: 4.4: 5.8); middle leg- 5.6: 3.6: 10.8: 13.8: (5.5:4.3: 4.8); hind leg- 9.0: 4.5: 11.5: 14.6: (5.5: 4.3: 6.0).

Metasoma: TSS triangular with terminal spine at posterior apex ( Figs. 6–7 ); apex of terminal spine approaching posterior end of aedeagus ( Fig. 7 ). Genitalia with volsellae distinctly sickle shaped with a pronounced digital spine; length of genitalia to HTL 0.80–0.83; length of apodemes to total aedeagus length 0.33–0.44; length to width of anterior dorsal aperture 0.51–0.95; AD to length of genitalia 0.25–0.31( Fig. 7 ).

Female. Similar to male except as follows; F1- 0-1 BPS; F2-1-2 BPS; C1-1 BPS; C2- 1 BPS; C3-1 BPS; C1-PS extending from C1 to C2, C2- 2 PS extending length of C2, C3- 4 PS extending length of segment; C2 with ca. 4 CHS, maximum length ca. 0.045mm. HTL/OL 0.33–0.42.

Distribution. Widely distributed throughout North America.

Biology. Recorded parasitoid of Ceresa borealis (Fairmaire) , C. bubalus (Fabricius) , C. taurina (Fitch) (Membracidae) , Cicadetta montana (Scopoli) (Cicadidae) , Platycotis tuberculata (Fairmaire) (Membracidae) , Pseudatomoscelis seriatus (Reuter) (Membracidae) , and Stictocephala inermis (Fabricius) (Miridae) .

Types. Neotype 1♂ s UNITED STATES. specific locality unknown labeled as “ Ittys ceresarum (Ashmead) 1m, 4f types, 27930,15/18, Type No. 13393 U.S.N.M.”

Ittys ceresarum (Ashmead) (USNM) . 2 female syntypes not located. (see comments).

Paracentrobia perditrix (Gahan) 1♀ s holotype ( USNM Type No. 21699) “Tempe, Arizona V. L. Wildermuth coll. Webst. # 6190 Tempe # 2740” , 4♀, 4♂ paratypes same information as holotype ( USNM Type No. 21699) .

Paracentrobia nympha (Girault) 1♀ s holotype ( USNM no Type No.) “parasite on Diplosis ? in stems of Ambrosia artemisiaefolia issued May 21, 97” indicated in Girault (1911) as from Dr. L.O. Howard, locality unknown .

Material examined. UNITED STATES. Arizona: (Cochise Co.)- Portal, 1mi NE; 1♀ c; 25-vii-1982; SS; RJL. (Santa Cruz Co.)- Sycamore Canyon; 9mi, W. Peña Blanca Lake; 4100′ el; 1♀, 1♀ c; vii-12-1983; R. Anderson. California: (Calaveras Co.)- Arnold; 1♀ c; viii-1-1986; SS primarily Salix & Lupinus ; JDP. (Glenn Co.)- Elk Creek, 5mi N; 5♀ c; vi-7-1984; SS; riparian; 1♀ c; vi-5-1987; JDP. (Los Angeles Co.)- Altadena; 2♀ c; vi-1/28-1990; 2♀ c; ix-20/ x-7-1989; 1♀ c; iv-2/ v-21-1990; 2♀ c; vi-9-1991; R.H. Crandall. Los Flores Canyon; 1♀ c; ii-9/19-1989; R.H. Crandall. San Pedro, 3171 N. Gaffey Dr. (Defense Fuel Support Point); 2♀ c; v-26/ vii-6-2002; 1♀ c; viii-18/ ix-23-2002; 2♀ c; vii-6/ viii-18-2002; coastal sage scrub; MT; J. George. (Riverside Co.)- Lake Skinner, NE (MET B11); ca. 1580'; 33°36′01′′N, 117° 01′ 58′′W; 1♀ c; viii-15/ 29-1996 33°36′07′′N, 117° 02′ 5′′ W; 2♀ c; vi-4/18-1996; MT; burned sage scrub. Lake Skinner NE (MET UII); 33°35′58′′N, 117°01′58W; ca.1570′; 1♂; iv-24/ v-8-1997 1♀; viii-29/ ix-12-1996; 1♀ vii-2/16-1996; 1♀ c; vi-4/18-1996 1♂; iv-24/ v-8-1997 2♀ c; ix-12/26-1996; MT; (METU4); 33°36′04′′N, 117°02′18W; 1♂; vii-30/ viii-13-1998; 2♀ c; v-22/ vi-5-1997; ex. sage scrub; ca. 1570′ el; 1♀, 1♂; vii-16/30-1998; 1♀ c; vi-2-1998; MT; coastal sage scrub; JDP. Menifee Valley (hills on W. end); 1800′ el; 133°39′N, 117°13′W; 1♀; x-6/11-1981; 1♀, 1♂; standard mesh MT 2♀, 2♀ c; x-fine mesh MT; vi-7/13-1995 1♀ c; vii-19/ vii-1-1995; MT 3♀, 1♂, vii- 19/31-1995; standard mesh MT 3♀, 9♀ c; vi-14/28-1995; MT 2♀, 1♂; vii-19/ viii-1-1995 6♀, 1♂, 4♀ c; vi-28/ vii-12-1995; standard mesh MT 1♀; iii-1/30-1996; 1♀, 1♂ vii-19/ viii-1-1995; fine mesh MT 1♀, 1♂, 1♀ c; ii- 14-1999; YPT; JDP. Rubidoux, Jurupa Ranch County Park; 2♀ c; vi-27-1986; R.J.L. (Modoc Co.)- Warner Mts, 1/ 4 mi W Cedar Pass Campground; 5900′ el; 1♀ c; vii-23-1992; YPT; JDP & GP. (San Bernardino Co.)- Baldy Mesa; 7 mi E. Phelan; 1♂; v-9/15-1981; YPT; J.T. Huber. Phelan, 7.5 mi E. 1♂; v-23/29-1981; YPT; J.T. Huber. San Gorgonio Wilderness, Fish Creek Trail; 8600′el; 1♀; vii-19-1982; JBW. Van Duzen Cyn. Rd.; 0.5 mi N Big Bear City; 1♀; vi-23-1989; SS; R. Velten. Van Duzen Cyn. Rd.; 1 mi N. Big Bear City; 1♀; vii-10-1988; SS; R. Velten. Twentynine Palms; 1♀ c; v-8-1984; SS primarily Prosopis ; J. Huber. Twentynine Palms, Mesquite Springs; 1♂; iv-12-1984; SS; RJL. Granite Mtn. Reserve, Granite Cove Area; 1♀ c; viii-26/ 29-1994; YPT; JDP. Clark Mts. (w. end); 1490m el; 35° 31' 45'' N, 115° 38' 15'' W; 1♀ c; v-21-2001; JDP. (Santa Barbara Co.)- Sedgewick Reserve; 45 km NW Santa Barbara; 34° 44' N, 120°02' W; 500m el; 1♀ c; x- 19-1997; E. Schlinger; (UCD). (Solano Co.)- Cold Canyon Reserve; 11km W. Winters; 2♀ c; v-7-1992; SS Eriophyllum lanatum ; S.L. Heydon; (UCD). Colorado: (Sterling Co.)- along south Platte River; 1♀ c; vii-13- 1986; SS willows & poplar; JDP. Florida: (Alachua Co.)- Gainsville, (near airport); 1♀ c; v-27-1991; GZ & JBW. (Clay Co.)- Gold Head Branch State Park; 4♀ c; v-28-1991; SS; J.B. JBW. (Highlands Co.)- Archbold Bird Res; 1♀ c; ix-18-x-5-1987; MT; D. Wahl. Georgia: (McIntosh Co.)- Sapelo Island; 1♀ c; vii-18-1987; shrubs/sand dunes; L. Dumouchal. Sapelo Island; 1♀ c; viii-20-1 x-9-1987; MT; shrubs/sand dunes; BRC Hym Team. Texas: (Bastrop Co.)- Bastrop State Park; 1♂ c; vi-16-1990; R. Wharton. 1♂ c; iii-22-1996; JBW & GZ. (Brazos Co.)- College Station; Lick Creek Park; 1♀; 2♂; viii-26-1987; JBW & GZ 1♀ c; vii-30-1987; SS; JBW 1♀ c; viii-4/26-1987; MT/Interc.; J. Heraty & JBW 8♀ c; viii-26-1987; JBW & GZ. Bryan Hensel Park; 1♀ c; vi-24-1986; J. Heraty; (CNC). (Brewster Co.) Big Bend Nat’l Park, Rosillos Mts., Buttrill Spring; 1♀; vi-15/18-1991; YPT; JBW & GZ. Alamo Spring; 1♀ c; vii-10/21-1991; R. Vogrsberger. Buttrill Spring; 1♀ c; vii-10/17-1991; MT; R. Vogrsberger. Rosillos Mt.; 3900' el.; 1♂ c; vi-17-1991; SS; JBW. Rosillos Mt., Mt. Lodge; 1♀ c; iii-18/21-1992; YPT; JBW & R. Wharton. (Burnet Co.)- Inks Lake State Park; 1♂ s, 2♂ c; iii- 22-1986; JBW & GZ. (Hays Co.) San Marcos, 5 mi W. 1♀ c; iv-19-1984; J.C. Shaffner. (Hidalgo Co.)- Bentsen-Rio-Grande St. Park, River Hiking Trail; 2♀ s, 1♂ s, 5♀ c, 1♂ c; vi-19-1986; SS; JBW. Bentsen-Rio-Grande St. Park, Singing Chaparral Trail, 1♂ c; vi-19-1986. (Hunt Co.)- Clymer Meadow; 1♂; vii-9-1991; JBW. (Jeff Davis Co.)- Davis Mtns., Limpia Cyn.; 5600′el.; 1♀ s; vii-25-1992; YPT; 1♂ c; SS grasses and flowers; JBW. (Jim Wells Co.)- Ben Bolt, 8 mi N.W., La Copita Res. Station; 1♀ s, 1♂ s, 5♀ c; ix-28/30-1990; MT; Wharton & JBW 4♀ c, 1♂ c; v-20-1987; JBW. Ben Bolt, 8 mi W., La Copita Res. Station, (area 8 near pond); 4♀ c, 2♂ c; ix- 29-1990; SS; JBW. Ben Bolt, 8 mi NW., La Copita Res. Station, 6♀ c; ix-28/30-1990; MT; Wharton & JBW. Ben Bolt, La Copita Res. Station,. 5 mi S. of tank; 4♀ c; iii-24-1990; SS; GZ. La Copita Res. Station, North Fence Pasture 52; 1♂ s; iii-23-1990. La Copita Res. Station, exclosure; 1♀; viii-29-1989. (Presidio Co.)- Big Bend Ranch, SNA Agua Adentro; 1♀, 2♀ c; vi-18/23-1991; R. Wharton. Big Bend Ranch, SNA; 5♀ c; vii-7/ 94-1991; YPT; JBW & GZ. Big Bend Ranch, SNA; 1♀ c; vi-21-1990; SS; JBW & GZ. Big Bend Ranch, SNA, 0.9 mi E. McGuirks Tank; 3640′ el; 1♀; vi-20-1990; desert willow; JBW & GZ. Big Bend Ranch, SNA, 0.9 mi E. McGuirks Tank; 29° 30′ 20′′N, 103° 52′ 15′′W; 4400′ el; 1♂ s; vi-22-1990; JBW & GZ. Big Bend Ranch, SNA,. 9 mi E. McGuirks tank; 29° 30′ 45′′N, 103° 51′ 56′′ W; 1♀ s; viii-7/9-1991; YPT; GZ & JBW. (Robertson Co.) Hearne, 8 mi E.; 1♀ s, 1♀ c; x-3/ x27-1990; MT post oak savanna / 3♀ c; iv-1/21-1991; M. Hallmark. (Starr Co.)- Falcon Lake State Park; 1♀ c; xii-15-1983; JBW & H. Browning. Indiana: (Posey Co.)- Indianapolis; 1♀ c; ix-6-1983; J. & D. Huber. Illinois: (Champaign Co.)- Urbana; 1♀ s; 4♀ c; ix-3-1983; SS; J. & D. Huber. (Montgomery Co.)- Litchfield; 1♀ c; ix-3-1983; SS; J. & D. Huber. (Marion Co.)- Centralia, (downtown E. Kell Rd.); 1♀ c; YPT in yard; ix-13/17-1995; S. Triapitsyn. Kansas: (Mitchell Co.) - Waconda Lake; 2mi W. Glen Elder; 1♀ c; viii-28-1985; JDP. Oregon:(Harney Co.)- Mann Lake, 7 mi S, (ca. 3mi NE Alvord Ranch); 2♀; vii-10-1999; SS Salix along creek; JDP. Mississippi: (Forrest Co.)- Petal; 2♀ s; 1♂ s; ix-23-1983; SS; JDP. Missouri: (Boone Co.)- Columbia, Hinkston Creek; 1♀ c; ix-8-1987; SS; JDP. (Springfield Co.)- Springfield; 2♀ s, 2♂ s, 3♀ c; viii-19-1983; SS; JDP. (Wayne Co.)- Williamsville; 2♀ s, 1♂ s, 6♀ c; vii-1987; 2♀ c; ix-1987; MT; J.T. Becker. Tennessee: (Cockle Co.)- Hartford; 1♂ s, 1♀ c; vii-24-1986; SS; JDP. Utah: (Garfield Co.)- Ticaboo, 7.2 mi S. (Cane Springs Desert); 1♀ s, 1♂ s, 1♀ c; v-20-1995; SS desert flowers; JDP. (Washington Co.)- Shivwits, 14 mi, SW; 1♀ c; iv-19-1994; SS; desert vegetation; JDP. (Wayne Co.)- Hanksville, 2.5 mi S.; 1♀ s, 1♀ c; v-20-1995; SS Astragalus . Hanksville, 15.6 mi N.; 1♀ c; v-20- 1995; SS desert flowers; JDP. Hanksville, 2.7 mi SE; 38°20.26′N, 110° 41.26W; 4570’ el; 3♀ s, 1♂ s, 6♀ c; v- 9/10-2000; YPT; JDP. Virginia: (Montgomery Co.)- Blacksburg, 8km. NW; 1000 m; 1♂ s; viii-1/17-1987; MT; BRC Hym. Team. Blacksburg, 8 km NW; 1♀ c; BRC Hym Team. (Page Co.)- Shenandoah Nat. Pk., Big Meadow; 1300m; 1♀ c; v-5-vi-5-1987; MT; natural meadow; BRC Hym Team. Washington: (Kittitas Co.)- Cle Elum; 4♀ c; vii-20-1988; S willow; JDP. (Yakima Co.)- Yakima, N. river; 1♀ c; vii-20-1988; S riparian veg. (willows etc.); R.K. Velton. Wisconsin: (Milwaukee Co.)- Milwaukee, Fox Point suburb; 1♀ c; ix-2- 1983; SS; J.T. Huber. West Virginia: (Cabell Co.)- Barboursville; 1♂ s; vii-8-1998; SS along railroad track; JDP.

Comments. The original description by Ashmead (1888) indicates that I. ceresarum was based on 2 females reared from Ceresa bulbulus , no date or locality information was given. The two female syntypes on which the original description was based have never been identified. Instead, a large series of 35 individuals mounted on tags plus the slide mounted material discussed below with label information identical to that Girault (1911) attributed to Ashmead’s original material are deposited in the USNM. Girault (1911) appears to have selected 1 male and 4 females from this series, placed them on a single glass slide and labeled the slide “Type No. 13,393”. It is not known if the original syntypes are included on this slide. Girault treated additional specimens from this series as cotypes (2♂, 8♀) and mounted them on slides (Accession No. 44,165). He also designated as cotypes 3 males and 1 female collected from Urbana, Illinois and which were never examined by Ashmead (Accession No. 39,120). An additional 35 specimens consistent with Ashmead’s data for the syntypes remain mounted on tags in the USNM. Because the two syntypes examined by Ashmead cannot be located, a lectotype designation is not possible. Additionally, Girault’s types have no standing. The label data associated with the cotypes designated by Girault are as follows. Girault’s cotype series are labeled as paratypes. One slide has a single male indicated as I. ceresarum (ashm) paratype (27930). The second slide has 2 males and 1 female with the same information under a single cover slip. The third slide has 2 male specimens under a single cover slip with no corresponding number but with the following information “ Par. in eggs of Ceresa bulbulus ISS. apr. 1, 5 “86.” Remounted from tags”. Two further slides one of which is attributable to Ashmead were located in the collection of Illinois Natural History Survey. Both slides are labeled as cotypes (both are also labeled as plesiotypes and homotypes). One slide has 3 males and 1 female with no further information except “ no. 39120”. the other slide is indicated as “ USNM specimens labeled “ Trichogramma ceresarum Ashm. ” “17900 Iss. March 22, 25, 30 April 5, 6, 7, 9, 10, 1886” Remounted from tags”. All material examined from the USNM and INHS appear conspecific. A neotype is designated from one of the slides located at USNM. The slide is indicated as “types” and may very well represent specimens Ashmead examined. The slide has one male and four female specimens under one cover slip. The one male is designated the neotype.

The concept of I. ceresarum has been based on this slide for over a century. All material examined to date appear conspecific with material Ashmead probably had on hand when he described I. ceresarum so there is no potential for confusion.

Ittys ceresarum is the most widely distributed North American species of Ittys , and the coloration throughout its range is highly polymorphic. The brown banding on the metasomal terga is particularly variable. Material examined varies from lacking bands completely to pronounced banding on all segments.

Noticeable geographic trends in genitalic length were also noted. Specimens from the southeastern United States tend to have a longer genital capsule than putative conspecific specimens from the western United States; but no clear pattern emerges. Southeastern specimens also appear to vary from western populations in the number and placement of placoid sensilla on the club. However, accurate counts of PS are difficult to make from slide mounted material. The relatively small amount of material examined from the southeastern United States also makes it impossible to ascertain the importance of this variation. Molecular work indicates the potential presence of multiple cryptic species which in this treatment are subsumed under I. ceresarum due to a lack of defining characteristics (Owen et al. accepted). To better understand this complex more work needs to be done

Variation in the TSS is also apparent in some material. This structure is widest at the posterior margin. With poorly mounted material this can be difficult to ascertain. In slide mounted material the terminal spine appears fairly consistently at the posterior margin of the appendage. When examined with scanning electron microscopy the terminal spine is shown to actually occur slightly anterior to this margin (Figs. 4,6). In a minority of slide mounted material this is also apparent.

The digital spine and sickle shaped volsellae in I. ceresarum are unique and are reliable characters for identification. I. ceresarum can be confused with I. californica and I. macfarlandi . I. californica is readily separated from I. ceresarum by the relatively longer F1 and the longer volsellae which lack the pronounced digital spine. I. macfarlandi can be separated by the TSS which is always maximally expanded medially instead of placed at the posterior margin as in I. ceresarum . I. macfarlandi also lacks the pronounced digital spine present in I. ceresarum .

Synonymy. Abella perditrix was noted by Gahan (1918) in the original description as very similar to I. ceresarum . The type material examined is from Tempe, Arizona, and was reared from Stictocephala festina ( Hemiptera : Membracidae ). Gahan (1918) noted that perditrix was “smaller in size, paler in color and that the forewings were distinctly less strongly ciliated discally” than in ceresarum . What probably appeared as discrete differences between the types of ceresarum and perditrix to Gahan quickly disappear when adequate material is examined, and I am unable to separate the two species. The type series is in reasonably good condition.

Abella nympha Girault was described from a single female specimen. Girault (1911) contrasts nympha with Paracentrobia americana but makes no mention of I. ceresarum . The type was examined and is here considered conspecific with ceresarum . The type locality is noted only as North America. The type is in relatively poor condition and characters for definitive identification of females are limited. The forewings have a slightly longer fringe than is usual for ceresarum but other venation characters agree with ceresarum . The antennae are relatively opaque and positioned poorly but the relative proportions of the funicle and clava agree with I. ceresarum . Although the type of nympha is small it is within the observed range of variation of I. ceresarum .

Figures

FIGURE 1. I. ceresarum male antenna illustrating various antennal sensilla discussed in text.

FIGURES 2–7. I. ceresarum male. 2–3 forewing, 4 lateral view of genitalia with TS and TSS indicated, 6–7 male genitalia.