Necremnus leucarthros, (NEES)

Gebiola, Marco, Bernardo, Umberto, Ribes, Antoni & Gibson, Gary A. P., 2015, An integrative study of Necremnus Thomson (Hymenoptera: Eulophidae) associated with invasive pests in Europe and North America: taxonomic and ecological implications, Zoological Journal of the Linnean Society 173 (2), pp. 352-423 : 408-411

publication ID

https://doi.org/ 10.1111/zoj.12210

persistent identifier

https://treatment.plazi.org/id/293AD62E-FFA8-3419-10F2-FE2CFC69FE8C

treatment provided by

Felipe

scientific name

Necremnus leucarthros
status

 

NECREMNUS LEUCARTHROS (NEES) View in CoL ( FIGS 139–150 View Figures 139–144 View Figures 145–150 )

Eulophus leucarthros Nees View in CoL ab Esenbeck, 1834: 172. Described ♀ (type status and location unknown).

Eulophus cornu copiae Förster, 1841: 44 . ♂ syntypes (Vienna, Munich). Synonymy by Boucˇek (1959: 151).

Eulophus Anaxippus Walker, 1846b: 182 View in CoL . ♀ lectotype (BMNH, here designated). Synonymy by Graham in Boucˇek & Askew (1968: 65).

Eulophus teratocerus Förster, 1861: 37 View in CoL . ♀ and ♂ syntypes (location unknown). Synonymy by Bouček & Askew (1968: 65).

Necremnus leucarthros View in CoL ; Thomson, 1878: 234.

Eulophus cornucopiae Förster View in CoL ; justified emendation by Boucˇek (1959: 152).

Necremnus arthos Yefremova, 2007: 31 . Lapsus calami for N. leucarthros View in CoL .

Type material

We did not examine type material of N. leucarthros , which apparently is lost. Gahan (1941: 201) formed his concept of N. leucarthros in North America based on ‘specimens identified by Thomson, Ruschka, and Schmiedeknecht’, although he incorrectly recognized N. hippia as a junior synonym of N. leucarthros . Bouček (1959) stated that he saw several syntypes of Eulophus cornucopiae in Vienna and Munich and confirmed their synonymy with N. leucarthros . Boucˇek & Askew (1968) synonymized Eulophus teratocerus under N. leucarthros , but did not provide any reason or information about type material. The type material of E. anaxippus consists of a single, card-mounted female ( Fig. 140 View Figures 139–144 ) in the BMNH that has the following four rectangular labels: (1) a handwritten label with ‘ Anaxippus ’; (2) a ‘Ch. Ferriere det.’ label with ‘= Necremnus leucarthros Ths. ’ handwritten; (3) a label with ‘ Eulophus anaxippus Walker LECTOTYPE: ♂ [sic] M. de V. Graham det. 1958’ partly printed and handwritten; and (4) a label with ‘B.M. TYPE HYM. 5.2505’. As Graham did not validly designate a lectotype through publication under ICZN rules, in order to stabilize the concept of the name we designate this female as the lectotype of E. anaxippus . The lectotype is entire except for lacking its right set of wings and having a small portion of the right hand side of the gaster missing within its basal half ( Fig. 140 View Figures 139–144 ). It fits our concept of N. leucarthros , including having the combined length of F1 + anelli about 1.7 × length of the pedicel ( Fig. 139 View Figures 139–144 ), the propodeal spiracles slightly separated from the posterior margin of the metanotum ( Fig. 143 View Figures 139–144 ), a comparatively broad fore wing speculum ( Fig. 144 View Figures 139–144 ), and a line of six minute setae ventrally in the basal cell near the submarginal vein.

Description

Female

Body length 1.7–2.5 mm. Head comparatively bright green ( Fig. 145 View Figures 145–150 ) to bluish-green ( Fig. 149 View Figures 145–150 ) or more blue to purple dorsally, usually without coppery lustre. Antenna ( Figs 139 View Figures 139–144 , 149 View Figures 145–150 ) with scape similarly dark as flagellum; length of flagellum + pedicel about 1.1 × width of head; flagellum with length of F1 + anelli about 1.9– 2.5 × as long as wide and about 1.3–1.8 × length of pedicel, second at most 1.8 ×, third funicular at most 1.5 ×, and clava about 2.6–2.9 × as long as wide. Mesosoma comparatively bright green to blue, usually without but at most with only very limited, inconspicuous coppery lustre ( Figs 140, 141 View Figures 139–144 , 145, 146 View Figures 145–150 ); tegula uniformly dark brown or with slight metallic lustre ( Fig. 142 View Figures 139–144 ). Mesonotum with scutellum reticulate; scutellum longitudinally reticulate-imbricate on either side of midline ( Figs 141 View Figures 139–144 , 147 View Figures 145–150 ). Fore wing hyaline; speculum usually quite obviously broadly bare dorsally ( Fig. 148 View Figures 145–150 ); basal cell apically and speculum posteriorly delineated by complete rows of setae, and mediocubital fold with two to seven setae basal to basal fold, often over at least about apical half of basal cell; subcubital line of setae, except very rarely, consisting of only one row of setae over at least its basal half ( Fig. 148 View Figures 145–150 ); basal cell with at least three and often five or more spots in line adjacent to submarginal vein, including in ventral view usually short but quite distinct setae, particularly apically toward basal fold, and rarely with single seta dorsally; postmarginal vein 1.5– 1.6 × length of stigmal vein. Legs ( Figs 140 View Figures 139–144 , 145, 146 View Figures 145–150 ) dark except protibia dorsolongitudinally, knees narrowly, and basal tarsomeres of meso- and metatarsi pale, although rarely second tarsomeres brownish to white. Metanotum ( Figs 143 View Figures 139–144 , 147 View Figures 145–150 ) with dorsellum meshlike coriaceous to reticulate-imbricate or rarely shallowly reticulate. Propodeum ( Figs 143 View Figures 139–144 , 147 View Figures 145–150 ) with median carina over most of length; often somewhat more finely sculptured than dorsellum, alutaceous to mesh-like coriaceous; spiracle obliquely oval, usually slightly separated from metanotum but if touching then with uniformly developed rim. Gaster ( Figs 140 View Figures 139–144 , 145 View Figures 145–150 ) variably extensively green to blue or purple dorsally with posterior margins of basal four tergites at least broadly brownish along posterior margins and tergites 2–4 sometimes entirely brown to coppery-brown; about 1.8–2.3 × as long as wide and subequal in length to combined length of head + mesosoma; syntergum short.

Male

Similar to female. Antenna with dense mps on all rami and short setae at most about as long as width of rami ( Fig. 150 View Figures 145–150 ); position of sensory pores on scape not determined.

Distribution

Palaearctic and Nearctic (see Noyes, 2013); we sequenced specimens from France and Switzerland.

Hosts

See Noyes (2013). Some of the hosts listed require confirmation of the parasitoid identification, especially those from Lepidoptera , as the species in N. tidius group are associated with Coleoptera .

Discussion

Males of N. leucarthros are easily identified by their antennal structure, all three rami being covered with very short setae and dense mps ( Fig. 150 View Figures 145–150 ). Males of other species all have long, hair-like setae regardless of whether all or some of the rami have mps. Females can be more difficult to distinguish. Recognition of N. leucarthros females in North America is discussed under N. duplicatus . In Europe, females of N. hippia and N. aenigmaticus have the propodeal spiracles slightly overlapped by the metanotum or if touching the metanotum then the anterior rim of the spiracle is somewhat depressed or sinuate. Females of N. leucarthros usually have the propodeal spiracle slightly separat- ed from the metanotum ( Figs 143 View Figures 139–144 , 147 View Figures 145–150 ), but at least the rim is uniformly developed as in N. tidius . Both Boucˇek (1959) and Graham (1959) separated females of N. leucarthros from N. tidius by the former having a dark green body and the latter a bronze or greenishbronze body. Askew (1968) separated them also by the extension of the speculum, and length of gaster. Although N. leucarthros females are typically a bright- er green there sometimes is very little difference in colour of individuals of the two species. Females usually are much more readily distinguished by the fore wing disc being more extensively setose in N. tidius than in N. leucarthros . As a result, the speculum is narrower in N. tidius and the subcubital setal line consists of two or more rows of setae over most of its length ( Fig. 168 View Figures 165–171 ). The subcubital setal line usually consists of only one row of setae over about its basal half ( Fig. 148 View Figures 145–150 ) in N. leucarthros , although rarely there are two rows. Furthermore, some N. tidius females have the tegulae yellowish along the inner margin adjacent to, although sometimes concealed by, the mesoscutum, and often have noticeably more oblong funiculars, although this latter feature is quite variable and not always distinctive. If the length of the postmarginal vein relative to the stigmal vein is not observable, females could also be confused with those of N. cosconius except for an often subtle difference in fore wing colour pattern (see Discussion under latter species).

Kingdom

Animalia

Phylum

Arthropoda

Class

Insecta

Order

Hymenoptera

Family

Eulophidae

Genus

Necremnus

Loc

Necremnus leucarthros

Gebiola, Marco, Bernardo, Umberto, Ribes, Antoni & Gibson, Gary A. P. 2015
2015
Loc

Necremnus arthos

Yefremova ZA 2007: 31
2007
Loc

Necremnus leucarthros

Thomson CG 1878: 234
1878
Loc

Eulophus teratocerus Förster, 1861: 37

Forster A 1861: 37
1861
Loc

Eulophus Anaxippus Walker, 1846b: 182

Walker F 1846: 182
1846
Loc

Eulophus cornu copiae Förster, 1841: 44

Forster A 1841: 44
1841
Loc

Eulophus leucarthros

Esenbeck CG 1834: 172
1834
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