Nealiolus jaboticaba Shimbori & Wengrat, 2020

Shimbori, Eduardo M., Wengrat, Ana P. G. S., Savaris, Marcoandre, Galvão, William B., Nanini, Frederico, Garcia, Sarah S. P. & Corrêa, Alberto S., 2020, Two new species of Nealiolus Mason (Hymenoptera, Braconidae, Brachistinae) reared from pest weevils (Coleoptera, Curculionidae), Zootaxa 4729 (1), pp. 116-126 : 122-125

Nealiolus jaboticaba Shimbori & Wengrat sp. n.

( Figs 9‒16 , 17 )

M aterial examined. Holotype ♀ (DCBU #370880) “ BRAZIL: São Paulo: Piracicaba, Santa Rita , 22°45.041’S 47°35.324’W, 598 m, 17 Dec 2018, reared from pupae of Conotrachelus sp. in soil, but from fruits of Plinia cauliflora ( Mart.) Kausel ( Jaboticaba) , M. Savaris ”, bottom label “DNA #2”. Point mounted, deposited at DCBU . Paratypes: 3 ♀ s, same data as holotype except “DNA#15” ( DCBU #370881 ), “DNA # 16” and “DNA #18” respec- tively; 1 ♀, same as holotype, different date “ 12 Dec 2018 ”; 1 ♂, same as holotype, except: “no solo, pupa dentro da câmara, “ 10 Dec 2018 ” ( DCBU #370882 ); 1 ♀, top label: “Piracicaba, SP [campus ESALQ /USP—experimental field]; 18/09/2002. Em jaboticaba S. Sánchez , col.”, bottom label “Introduzindo ovipositor em frutos de jaboticaba com larvas de Conotrachelus ”; 1 ♀ “Piracicaba, SP; Novembro/2002; Jaboticaba; S. Sánchez ”; 1 ♂, same data except date, October 2002; 1 ♂ same data except date, “ October 11, 2002 ” and bottom label: “Emergido de larvas de Conotrachelus ”, specimen pinned with cocoon. (All specimens without DCBU collection number are deposited at ESALQ)

Description of ♀. Body length 4.5‒5.4 mm; fore wing length 3.8‒4.6 mm; antenna length 3.8‒4.9 mm.

Color ( Figs 9, 10 ). Head black, clypeus and mandibles yellowish brown; palpi pale yellow. Antenna dark brown, scape and pedicel darker than flagellum. Mesosoma yellowish brown; darker (brown) at propodeum basally, mesopleuron posteriorly and most of metapleuron. Metasoma dark brown; T1 mostly yellowish brown with darker areas medially and near lateral edges. Fore legs yellow; mid legs yellow except coxa and femur brown; hind legs mostly brown, trochanter, trochantellus and apical tarsomeres yellow, tibia dark brown with basal 1/4‒1/5 whitish yellow. Wings hyaline, veins and stigma dark brown; tegula pale brown.

Head ( Fig. 11 ). Transverse in frontal view, face about 2.2‒2.6 × wider than high; distance between tentorial pits 1.3‒1.5 × height of clypeus; eye height 0.54‒0.64 × face width; clypeus transverse, 2.8‒ 3.1 × wider than high; ventral margin nearly straight and without median tooth but with angulation at level of tentorial pits. Face densely punctate, smooth near limit with clypeus, clypeus mostly polished with sparse punctation; mid-longitudinal carina extending from between antennal sockets just to reach upper part of face; gena and temples smooth, vertex punctate, frons smooth and distinctly excavated. Transverse in dorsal view, 2.1‒2.2 × wider than long; eye 1.2‒1.3 × longer than temple; distance between eye and lateral ocellus (OOL) 3.1 × diameter of lateral ocellus (OD), POL (distance between lateral ocelli) 0.38 × OOL; ocellar triangle with a deep central pit. Antenna with 34‒38 flagellomeres, first flagellomere 0.82‒0.86 × longer than second.

Mesosoma . Mesonotum mostly smooth with very weak punctation; notauli deep and crenulate, meeting posteriorly in a distinct median carina; median lobe of mesoscutum distinctly higher than lateral lobes, weakly rugose and bordered by carina just posteriorly; scutellar sulcus with median carina, smooth otherwise; mesoscutellar trough mostly smooth with few crenulae near scutellum. Metanotum mostly smooth with roughly triangular carinate area medially and few carinae laterally. Propodeum strongly carinate over a rather smooth background; areola distinct and pentagonal, basal transverse carina strong and sinuate, meeting a diagonal carina at mid-length; areas defined by carinae posteriorly with sparse rugae ( Fig. 12 ). Pronotum mostly smooth, with some transverse carina anteriorly and a few longitudinal carina posteriorly. Mesopleuron smooth with distinct and crenulate sternaulus.

Legs. Inner spur of hind tibia 0.37‒0.43 × longer than basitarsus, inner and outer spurs sub-equal; hind femur 3.2‒3.3 × longer than wide ( Fig. 9 ).

Wings. Fore wing ( Fig. 13 ): vein r/2RS = 0.52‒0.63; r/(RS+M)b =1.2‒1.3; stigma width/height = 3.2‒3.6; R1/ stigma length; = 1.25‒1.28; veins 1a and 2a present. Hind wing: M+CU/1M = 3.1‒3.4; 1M/r-m = 0.7-0.8.

Metasoma ( Fig. 14 ). T1 distinctly widening apically, apical width 1.6 × its length and 1.4‒1.6 × longer than basal width just basal to basal expansions; dorsal carina strong and complete, delimiting a higher roughly triangular area which is mostly smooth except for superficial rugosity posteriorly; lateral areas longitudinally costate; remainder carapace entirely rugose-costate, transverse sulcus between T2 and T3 fine but distinct. Ovipositor about 2.0‒2.1 × longer than metasoma.

Male. Body length 4.4‒4.5 mm; fore wing length 3.5‒3.6 mm; antenna 4.2 mm. Very similar to female, except antenna relatively longer and narrower, nearly as long as body, and with 34 antennomeres, apical antennomeres slightly longer than wide as compared with nearly quadrate segments in females (F14 1.0 × wider than long in females, ~0.7 × in males). Mesosoma with more extensive dark color, mesopleuron and propodeum nearly entirely dark brown to black, whereas in females mesopleuron and propodeum are usually brownish yellow with some dark spots posteriorly and medially, respectively.

Diagnosis. The new species is similar to N. acutulus and N. mexicanus , the two species included in the mexicanus- group by Martin (1959), which is characterised by the relatively large body (4.5‒6.0 mm), the strongly sculp- tured carapace, with T3 fully sculptured, and antenna with at least 34 antennomeres (35 in females; but unknown for N. mexicanus because known females have broken antenna). Within the mexicanus- group, N. jaboticaba sp. n. is most similar to N. mexicanus , by the longer ovipositor (about 2.0 × longer than metasoma) and the absence of a ventral longitudinal carina at face (which is present in N. acutulus ). The new species differs from N. mexicanus , in having a distinctly areolate propodeum (areola indistinct in N. mexicanus ), a mostly brown mesosoma (black in N. mexicanus ), smooth clypeus (rugose in N. mexicanus ), and a much wider T1, about 1.5 × wider apically and long, as compared with 1.2 × in N. mexicanus .

Comments. The DNA barcode sequences were compared with public and private records on Barcode of Life Database (BOLD) and GenBank. The four sequences obtained for the new species are nearly identical and do not match any of the sequences available in the databases ( Fig. 18 , Table 1 ). GenBank accession numbers: MN1781119; MN178120 ; MN178121 ; MN178122 .

Distribution. Neotropical. Known only from type locality Piracicaba, São Paulo, Brazil ( Fig. 17 ). Natural history. All specimens in the type series are associated with the weevil Conotrachelus sp. ( Coleoptera , Curculionidae , Molytinae ), that feeds on fruits of jaboticaba— Plinia cauliflora (Mart.) Kausel (Myrtaceae) . Saúl Sanchez Soto observed one female [paratype] ovipositing in jaboticaba fruits infested with larvae of Conotrachelus sp., and reared one male [paratype] reared from the same host larvae. Soto & Nakano (2004) reported Nealiolus sp. [= N. jaboticaba sp. n.] as the main parasitoid found in Conotrachelus sp., corresponding to 95% of the parasitoids, and parasitising nearly 1/3 of the weevil larvae. More recently, in samplings made in 2018, we found adults of Conotrachelus sp. foraging on fruits of jabuticaba, searching for oviposition sites. In addition, we observed larvae leaving fallen fruits on the ground and penetrating the soil for pupation. We dug about 20 cm of soil below the fallen fruits for pupal chambers made by the larvae ( Figs 15, 16 ). The larvae pupated around 4 to 12 cm deep in the soil, and the parasitized chambers were recognisable by the presence of a silk cocoon ( Fig. 15 ). The parasitoid makes a hole in the cocoon ( Fig. 16 ) and digs up the ground with the mandibles to reach the surface. Based on these observations, we conclude that females of N. jaboticaba sp. n. locate and oviposit in larvae of Conotrachelus sp. inside the jaboticaba fruits. The parasitoids complete their development after the host finish the construction of the pupal chamber in the soil, just before its pupation.

Etymology. From the tupi name given to the fruits of Plinia cauliflora (Mart.) Kausel (= Myrtus jaboticaba Vell. ), a plant species native from Brazilian Atlantic Forest that produces highly appreciated round fruits directly from its trunks and branches.

DNA Barcoding. We successfully sequenced the DNA barcode region of Nealiolus jaboticaba Shimbori & Wengrat sp. n. (658 bp; GenBank accession numbers: MN1781119- MN178122 ) and Nealiolus chayohtli Wengrat & Shimbori sp. n. (658 bp; GenBank accession numbers: MN178123 - MN178124 ). We found two haplotypes for N. jaboticaba , H1 (n = 3) and H2 (n = 1) with a genetic distance of 0.005 between them. The Bayesian phylogenetic tree suggests the monophyly of N. jaboticaba and N. chayohtli ( Fig. 18 ). The genetic distance of the COI barcode region between N. jaboticaba and N. chayohtli ranged from 0.106 to 0.110. When compared to other Nealiolus COI barcodes collected in BOLD System, the lower genetic distance among N. jaboticaba and Central/North American species was 0.084 and among N. chayotli and Central/North Americas species was 0.094 ( Table 1 ). The estimated genetic distances ( Table 1 ) and Bayesian phylogenetic tree ( Fig. 18 ) within the available COI barcodes confirm the identity of the two new species in South America ( Fig. 18 ), however, none of the barcodes available in public databases are identified at species level. Therefore, comparison with known species and the decision to describe the two entities as new species relies entirely on their morphological and biological features. Nevertheless, our results highlight the COI universal barcoding region as a useful tool for species identification in the genus Nealiolus .

Figures

FIGURE 17. Distribution map for new species of Nealiolus from Brazil: (★) Type locality of N. chayohtli Wengrat & Shimbori sp. n., Amparo, São Paulo. (■) Type locality N. jaboticaba Shimbori & Wengrat sp. n., Piracicaba, São Paulo.

FIGURE 18. Bayesian phylogenetic tree of COI gene fragment of Nealiolus specimens. Branch lengths are drawn to scale; nodal support values below 0.50 were not recorded in the tree; and nodal support values are given as posterior probabilities above the branches in cases with values higher than 0.90. The scale bar corresponds to the expected number of substitutions per site.

FIGURES 9‒16. Nealiolus jaboticaba Shimbori & Wengrat sp. n., ♀: 9‒10, habitus, lateral; 11, head, frontal. 12, propodeum, dorsal; 13, fore wing; 14, metasoma, dorsal; 15‒16, pupal chamber of Conothrachelus sp. constructed in the soil: 15, parasitoid pupae within silk cocoon; 16, empty parasitoid cocoon with the exit opening.