Leucopina nyiaybsa Gaimari & Montes, 2024

Montes-Rodríguez, José Mauricio, Kondo, Takumasa & Gaimari, Stephen D., 2024, Natural enemies of Maconellicoccus hirsutus (Green) (Hemiptera: Coccomorpha: Pseudococcidae), with description of a new species of Leucopina Malloch (Diptera: Chamaemyiidae), Zootaxa 5424 (4), pp. 423-436 : 428-434

Leucopina nyiaybsa Gaimari & Montes , sp.n.

urn:lsid:zoobank.org:act:FCC97B4B-85F0-4443-9A98-8779F2DD22BD

( Figs 2–4 )

Holotype ♂ (point mounted, in excellent condition), deposited in CTNI, with following labels: COLOMBIA, Santander: / Bucaramanga, Barrio / La Aurora, 1010 m / N 7°07′34″ W 73°07′00″ / 10.i.2020 J.M. Montes // En brotes florales y vegetativos / de Malvaviscus sp. ( Malvaceae )- / falso cayeno. Larvas son / depredadoras de / Maconellicoccus hirsutus / ( Pseudococcidae )- cochinilla / rosada del hibisco // HOLOTYPE / Leucopina / nyiaybsa/ Gaimari & Montes.

Paratypes. COLOMBIA: Santander: Bucaramanga: 2 ♂, 2 ♀ ( AMNH), 2 ♂, 2 ♀ ( CSCA), 5 ♂, 7 ♀ ( CTNI), 4 ♂, 4 ♀ ( SDG), 2 ♂, 2 ♀ ( USNM). Same data as holotype, except for: Barrio La Aurora , 07°07′34″N 73°07′00″W, 1010 m a.s.l., 10.i.2020, coll. J. Montes, ex Malvaviscus sp. , larvae predators of Maconellicoccus hirsutus ; 1 ♂, 1 ♀ ( CTNI); Barrio La Aurora , 07°07′33″N 73°06′58″W, Calle 32 29–36, 1011 m a.s.l., 10.i.2020, coll. J. Montes, ex Hibiscus sp. , larvae predators of Maconellicoccus hirsutus ; 1 ♀ ( CTNI); Barrio San Francisco, 07°07′52″N 73°07′19″W, 995 m a.s.l., 14.ii.2023, coll. J. Montes, ex Malvaviscus sp. , larvae predators of Maconellicoccus hirsutus ; 1 ♂ ( CTNI); Barrio San Francisco, 07°07′51″N 73°07′17″W, 998 m a.s.l., 12.ii.2023, coll. J. Montes, ex Hibiscus sp. , larvae predators of Maconellicoccus hirsutus (CTNI) . PERU: Cusco: 1 ♂, 1 ♀ ( CNC), Zea [=Pitumarca, approx. 13°59′17″S 71°25′14″W, ca. 3500 m], 27.v.1958, coll. J.E. Hinton, S.I.R.M. 1845, ex. mealybug on oleander .

Etymology. The word “ nyiaybsa ” is derived from the Chibchan language, spoken by the Muisca people (an ancient culture inhabiting the type locality), “ nyia ” meaning silver + “ ybsa ” meaning fly.

Diagnosis. This species is differentiated from other species of Leucopina by the following combination of characters in the male: the outer vertical seta is absent, whereas the inner vertical seta is tiny; the ocellar triangle is broad and fuzzy, with posterior ocellus within one ocellar diameter to the corresponding edge of the eye, the anterior ocellus is much smaller than a posterior ocellus and is closer to each posterior ocellus than the distance between posterior ocelli (forming an isosceles obtuse triangle); the dorsocentral vitta is distinct through its entire length from the anterior edge of the mesonotum, onto the prescutellum and to the scutellar suture; the mesonotum lacks any median vittae; the abdomen has paired brown pruinose spots on tergite 3 only, and median spots on tergites 3–5; in the genitalia lateral view, the surstylus is broad (sharp in dorsal view), and the phallus is long and gently curved ending at a bluntly rounded tip.

Adults, ♂, ♀. Body ( Fig. 2A ) length 2.11–2.39 mm (♂, 2.15–2.35 mm; ♀, 2.11–2.39 mm).

Head ( Figs 2B–C ). 1.6–1.9 higher than long; 1.2–1.3 X wider than high. Eye 1.4–1.7 X higher than wide, from anterior view each eye 0.6–0.7 X width of frons at level of antennal base. Sexually dimorphic in characteristics of the ocellar triangle and vertical setae, as follows. In male: ocellar triangle broad, nearly flattened dorsally, forming obtuse isosceles triangle with posterior ocelli farther apart than distance between either posterior ocellus and anterior ocellus, covered with fuzzy pale erect pilosity restricted to ocellar triangle, each posterior ocellus closer to edge of eye than one ocellar diameter; outer vertical seta absent, inner one tiny. In female: ocellar triangle broad, forming nearly equilateral triangle, each posterior ocellus within two ocellar diameters to edge of eye, setulose, with pair of distinct reclinate ocellar setae originating outside of ocellar triangle at level of anterior ocellus, sometimes with additional errant enlarged seta nearby; vertical setae present and strong, outer vertical seta stronger than inner. Frons slightly wider than high, height 1.5–1.9 X lunule height, tapering dorsally with width at level of anterior ocellus 0.6–0.8X width at level of antennal base, fronto-orbital area silvery pruinose, extending through parafacial, frontal vitta (central area between ocellar triangle and lunule) darker greyish pruinose; entirely setulose (setulae tiny in male, slightly stronger in female). Lunule similarly setulose, silvery pruinose, high arching, height 0.5–0.6 X width of lunule at antennal base; height 0.5–0.7 X height of frons from edge of lunule to anterior ocellus. Antenna entirely black; with gap between them wider than width of a single antennal base; area between antennal bases silvery grey pruinose, concolorous with lunule and face; 1st flagellomere short, rounded; arista with distal segment 4.0–4.5 X longer than basal. Face silvery grey pruinose; with shallow antennal grooves. Parafacial silvery grey pruinose, narrow, each about one-quarter width of face. Gena 0.1–0.2 X height of eye, with one strong genal seta in addition to several setulae in row behind and along eye margin. Clypeus silvery grey; small, narrow. Palpus black; spatulate; sparsely setulose. Prementum silvery grey. Labellum small, pale.

Thorax ( Figs2A,2D ). Scutum silvery grey pruinose; 1.2–1.4 X longer than wide; 4.3 X scutellar length; uniformly setulose except lacking setulae in patch at anteromedial edge; with distinct wide and sharply defined dorsocentral vittae extending through entire length, and extending through prescutellum; lacking median vittae. Prescutellum present, silvery grey medially, brown laterally (as extension of dorsocentral vittae). Scutellum darkened, brownish; 1.7–2.0 X wider than long. Pleuron silvery grey pruinose, concolorous with scutum. Chaetotaxy: 0+2 dorsocentral setae, posterior seta about 1.5–1.8 X longer than anterior one; one postpronotal seta (with several setulae); two notopleural setae, subequal, in anterior and posterior corners; one pre- and one postsutural supra-alar seta; two postalar setae; prescutellar acrostichal seta absent; proepisternum, anepisternum and anepimeron lacking setae; one strong katepisternal seta along upper edge, with 2–4 small setulae in row anterior to seta; two pairs scutellar setae, posterior pair stronger. Legs. Coxae silvery grey pruinose, concolorous with katepisternum. Femora dark grey pruinose except for distal tips yellow, fore femur yellowish on ventral surface. Tibiae silvery to brownish grey pruinose, yellow in proximal third. Tarsi dark brown, except basotarsomere and tarsomere 2 yellow. Wing. Length 1.7–2.0 mm (♂, 1.8–1.9 mm; ♀, 1.7–2.0 mm); 2.5–2.8 X longer than high. Hyaline, with veins brown, except yellow basally. Costal vein extends to tip of M 1. Veins R 2+3 and R 4+5 parallel in distal half of wing, with M 1 curving slightly forward. Crossvein r-m located slightly basad of halfway point of wing length, and at 2/3 point of cell dm-cu length. Vein Cu extends to wing margin; apical section subequal to crossvein m-cu. Halter stalk and knob white.

Abdomen ( Fig. 2G ). Tergites uniformly setulose, with setulae slightly enlarged along posterior margin, especially laterally. Syntergite 1+2 dark brown pruinose except silvery-grey pruinose laterally and in a transverse posterior strip. Tergites 3–5 silvery-grey pruinose, except tergite 3 with an anteromedial brown pruinose strip and paired brown pruinose spots, tergite 4 with an anteromedial brown pruinose spot, and tergite 5 with a small anteromedial black (ground color) spot. Syntergite 1+2 and tergite 3 of male with a patch of microtrichiae on lateral edge ( Fig. 2F , also see Gaimari et al. 2008). Sternites silvery-grey pruinose, with sternites 1–5 identical in males and females ( Fig. 3A ). Sternite 1 not seen. Sternite 2 transversely divided, with anterior portion being a small bare sclerite placed within anterior concavity of posterior portion; about half the width of posterior part; posterior part 3 X wider than long, deeply emarginate anteriorly, 1.6–1.7 X wider than sternite 3. Sternites 3 and 4 subequal in size, each as wide as long, slightly tapering posteriorly. Sternite 5 slightly wider than sternites 3 and 4, and slightly longer than wide. Sternites 2–5 setulose in posterior two-thirds (except anterior portion of sternite 2 bare), with longest setulae laterally. Sternites 3–5 with sockets of tiny sensory setae in each anterolateral corner.

Male pregenital segments and genitalia ( Figs 2G–H , 3B–E ). Tergite 6 saddle-shaped, slightly wider than epandrium, about 2 X wider than long, with setae in posterior part; sternite 6 not evident. Syntergosternite 7+8 a narrow undivided membranous strip. In lateral view, epandrium convex posterodorsally, with 6–8 strong setae on each side, and extending evenly into surstylar lobe; surstylar lobe broad, with small bump dorsodistally, and small setulae on inner surface. In dorsal view, epandrium broadly rounded, evenly extending into incurved tapering surstylar lobes, with setulae of inner surface most evident. Cercus large, covered with fine hairs and short setulae, and with several longer setae distally. Hypandrium subrectangular in ventral view with anterior edge rounded, slightly longer than wide; wide boomerang-shaped in lateral view. Pregonite long (shorter than postgonite), tapering, with small lateral setulae in distal half; in lateral view tapering to pointed tip, in dorsal view more blunt. Postgonite longer than pregonite; tapering to narrow tip; slightly curved in lateral view; straight until outcurved tip in ventral view; with sparse small setulae dorsally and laterally. Phallapodeme subequal in size to hypandrium, subtriangular in lateral view; bone-shaped from dorsal view. Phallus from ventral view with bulbous basal half, tapering gradually to slightly widened blunt tip; length 4.3 X width of bulbous base; in lateral view with basal part bluntly rounded, then widest near midpoint of length where distinctly curved (ca. 45°), then tapering slightly recurved to blunt tip.

Female terminalia. Tergite 6 about 2.3 X wider than length through middle, length through middle subequal to that of tergite 5, and slightly shorter than that of tergite 4, setulose in posterior third, longest along posterior edge; sternite 6 ( Fig. 3A ) enlarged, 2.4 X wider than length through middle, width 2.1 X that of sternite 5 and 1.5 that of sternite 7, length through middle 0.9 X length of sternite 5, with setulae in posterior third, longest along posterior edge, with paired sockets of tiny sensory setae placed near anterior edge at about 1/4 width on each side; tergite 7 ( Fig. 3A ) a transverse sclerotized bare strip anteriorly, with corresponding patch of long setulae on membrane behind; sternite 7 ( Fig. 3A ) small (0.4 X length and 0.7 X width of sternite 6), nearly 4 X wider than long, with deeply emarginated anterior and posterior margins, with setulae on membrane posterior to sternite, with sockets of tiny sensory setae in each anterolateral corner.; tergite 8 elongate, deeply emarginate anteriorly, slightly narrower than sternite 7, lightly sclerotized, sparse tiny setulae in posterior half; sternite 8 absent, entirely membranous, with corresponding patch of tiny setulae. Hypoproct tapering evenly to rounded tip, with tiny setulae, a few longer. Epiproct subtriangular, with sparse tiny setulae, a few longer. Cercus small, pad-like, bearing uniformly short setulae. Internally, spermathecae 2+2, round ( Fig. 2I ).

Immature stages. General characteristics consistent with other leucopines as described by Gaimari & Turner (1996). First two instars light pink to pink in color ( Fig. 4A ). First-instar larva with body length 1.0– 1.2 mm; anterior spiracles absent; posterior spiracles on paired short, tubular stalks, each bilobed. Second-instar larva ( Figs 4B ) with body length 1.6–1.8 mm; anterior spiracle bilobed; posterior spiracle trilobed and mounted on a short, wide, raised, quadrangular prominence. Third-instar larva ( Fig. 4D ) white, with body length 1.9–2.0 mm; anterior spiracles bilobed (as in Fig. 4G , puparium); posterior spiracles on prominent stalks (as in Fig. 4H ) of 0.13–0.17 mm length. Density of chaetoids (small conical protuberances on the body surface) increases with larval development; in second instar scarce and dispersed; in third instar dense, especially on dorsum of posterior segments. In transition to puparial stage, spiracular stalks in third instar begin to sclerotize first ( Fig. 4E ). Puparium ( Fig. 4F ) with length 2.5– 2.7 mm; retaining spiracular condition and chaetoids of mature third-instar larva, with some chaetoids becoming more spine-like during sclerotization.

Biology. Oviposition is directly into the PHM colony, with eggs and first two instars hard to detect within an ovisac of PHM due to similar coloration, and in the case of first instars, similar in size to PHM eggs ( Fig. 4A ). Second instars are somewhat more easily detected due to larger size ( Fig. 4C ). When the third instar is sufficiently developed, they leave the mealybug ovisac to pupariate on plant surfaces, often between young leaves and shoots, or within the wax of the PHM infestation. Although not observed, some may drop into the soil as is typical for other chamaemyiids. Although species of Leucopina are known to feed on eggs inside the ovisacs of species in several genera of mealybugs and scales ( Gaimari 2010), none were recorded preying on the PHM before this one. This is the first potential biological control agent of the PHM originating from the Neotropics, although more extensive sampling of other mealybugs and scales will help determine how broad is the host range for the chamaemyiid. In Peru, this species was found parasitizing a mealybug on oleander ( Nerium oleander ).

Distribution. In Colombia, this species has only been reported in the urban area of the city of Bucaramanga in the department of Santander from 995–1011 meters above sea level, although its presence in southern Peru suggests it is much more widespread in the Andean Region. The locality in Peru from which it is known is considerably higher in altitude, at about 3500 m, so this species is likely quite widespread in this region. The new species represents the southernmost record for the genus, the first described species of Leucopina for South America, and the first record of the family Chamaemyiidae in Colombia. The other described species of the genus are known to occur from Canada into Mexico, and among the known undescribed species very few are known to occur south of Mexico.

Notes. There are six described species, including this one, and many more await description by Gaimari. In comparison with the other described species of Leucopina , the new species differs from them in diagnostic characters of males described above as follows: L. bella (Loew) has an outer vertical seta, and the ocellar setae are on an ocellar plate that is not fuzzy and not so broad (the posterior ocellus is more distant from the corresponding edge of the eye); L. bellula (Williston) has paired spots on tergites 3–5; L. bivittata (Malloch) has a large outer vertical seta; L. ocellaris (Malloch) is unknown as a male, but the female differs in having the ocellar setae set in line between the anterior and posterior setae (in the female of the new species, the ocellar seta is well outside the ocellar triangle); L. verticalis (Malloch) has the ocelli forming an equilateral triangle, and the phallus is more strongly curved.

Figures

FIGURE 2. Adult Leucopina nyiaybsa Gaimari & Montes, sp. n. A. Male habitus, lateral view. B. Male, frontal view of the head. C. Female, frontal view of the head. D. Male, dorsal view of the thorax. E. Male, dorsal view of the abdomen. F. Male, lateral view of syntergite 1+2 and tergites 3 and 4 (arrows to patches of microtrichia). G. Male, posterior view of terminalia (arrow to tergite 6). H. Male, ventral view of terminalia (arrow to syntergosternite 7+8) I. Female, dorsal view of macerated abdomen, showing spermathecae. Scale bar represents 0.5 mm.

FIGURE 3. Adult Leucopina nyiaybsa Gaimari & Montes, sp. n. A. Female abdominal sclerites, ventral view. B–E. Male genitalia.B. Entire,lateral view.C. Phallus and phallapodeme,lateral view.D. Entire (phallus, phallapodeme, and cerci removed), nearly ventral view, oriented to maximize view of pre- and postgonites and surstyli (note, hypandrium angled downward). E. Phallus, phallapodeme, and hypandrium, nearly ventral view, oriented to maximize view of hypandrium. Abbreviations: c = cercus; e = epandrium; h = hypandrium; ph = phallus; php = phallapodeme; pog = postgonite; prg = pregonite; ss = surstylus; s2–s7 = sternites 2–7; t7 = tergite 7. Scale bar represents 0.1 mm.

FIGURE 4. Immature stages of Leucopina nyiaybsa Gaimari & Montes, sp. n. A. A small first-instar larva inside an ovisac of PHM (white arrow). B. Close-up of a second-instar larva showing its relative size compared to the small eggs of the PHM. C. A second-instar larva inside an ovisac. D. A third-instar larva between young leaves of Hibiscus sp. E. Third-instar larva during pupariation, the spiracular stalks begin to sclerotize. F. Puparium. G. Anterior spiracles of puparium. H. Posterior spiracular stalk and spiracles of puparium. Scale bars represent 1.0 mm (A), 0.5 mm (B–F), 0.1 mm (G–H).