Neotachardiella charruarum Kondo, Peronti & Pacheco da Silva, 2025

Neotachardiella charruarum Kondo, Peronti & Pacheco da Silva , sp. nov.

( Figs 2B–E View FIGURE 2 , 4 View FIGURE 4 and 5 View FIGURE 5 )

Proposed common names. Español: Insecto laca de los Charrúas; Portuguese: Cochonilha laca dos Charruas; English: Charrua lac insect.

Material studied. Holotype: adult female, labeled as follows: “ Neotachardiella / charruarum Kondo , / Peronti, Pacheco da Silva / ex twig of Myrrhinium / atropurpureum var. / octandrum, URUGUAY / Montevideo, Malvin / 34°53’41”S, 56°06’16”W / 14.ix.2018, No. 150 / coll. V.C. Pacheco da Silva ” ( FCE-HE): Catalogue No. FCE-HE 0742 , 1(1). GoogleMaps

Paratypes: Same data as holotype: 2(5: 5 adult females) ( CTNI) GoogleMaps ; same data except: Montevideo, Sayago , 34°50ʹ11ʺS, 56°13ʹ14ʺW, 24.iv.2018, No. 1, 8(38: 27 adult females + 9 first-instar nymphs) ( CTNI) GoogleMaps ; same data except: 34°50’12.7”S, 56°13’13.2”W, 24.v.2023, 2(7 adult females) GoogleMaps ; same data except: 34°50ʹ23ʺS, 56°12ʹ45ʺW, ex Eugenia uniflora , 22.ii.2020, No. 2, 26(150: 77 adult females + 73 first-instar nymphs) ( CTNI) GoogleMaps ; same data except 14.iv.2018, 7(7 adult females) ( FCE-HE 0743-0749 GoogleMaps ; same data except: Montevideo, Prado , 34°51ʹ28ʺS, 56°11ʹ59ʺW, ex Psidium guajava twig, 30.iv.2020, No. 218, 7(28: 27 adult females + 1 parasitoid pupa) ( CTNI) GoogleMaps ; same data except: 34°51’34.6”S, 56°12’02.9”W, ex twig of Blepharocalyx salicifolius , 24.v.2023, 2(8 adult females) GoogleMaps ; same data except: ex twig of Psidium cattleyanum , 19.iv.2024, 1(2 adult females), coll. T GoogleMaps . Kondo and V . C. Pacheco da Silva; Montevideo, ex twig of Luma apiculata , 30.iv.2018, No. 220, 6 (21: 15 adult females + 6 parasitoid pupae) ( CTNI), coll. V . C. Pacheco da Silva ; same data except: ex twig of Myrceugenia glaucescens , 24.v.2023, 1(3 adult females) ; same data except: 34°54’20.6”S, 56°11’10.0”W, ex twig of Myrcianthes pungens , 06.iv.2023, 2(10 adult females); GoogleMaps Canelones, Sauce , 34°39ʹ51.2ʺS, 56°06ʹ36.3ʺW, 11(11 adult females); GoogleMaps ex twig of Eugenia uniflora , 22.ii.2020, coll. V.C. Pacheco da Silva, Catalogue No. FCE-HE 0750-0759 GoogleMaps ; Maldonado, Punta Colorada , 34°52’08.9”S 55°14’20.2”W, 3(8 adult females), ex twig of Eugenia uniflora , 04.i.2024, coll. V GoogleMaps . C. Pacheco da Silva , Catalogue No. FCE-HE 0760 .

Adult female

Unmounted material ( Figs 2B & C View FIGURE 2 ). Resinous test purplish red to dark purplish brown, sometimes with tinges of orange, often appearing brown or black due to sooty mold; tests of adjacent females becoming fused when crowded on infested twigs and branches of host. Test of individual (not fused) specimens hemispherical, each with 4‒10 poorly developed marginal lobes, each lobe rounded, older specimens often becoming spherical; first-instar test incorporated into adult test on mid-dorsum, inconspicuous; adult test also with a circular opening present on an elevated area just posterior to first-instar test. After the removal of the resinous test, the body is ovoid, with a constriction at the stigmatic areas and anal tubercle protruding ( Fig. 2E View FIGURE 2 ).

Dimensions of adult female test: young adult female 1.5–2.2 mm long, 1.5–2.2 mm wide, 1.0– 1.5 mm high; older adult female 2–3 mm long, 2–3 mm wide, 1–2 mm high (n = 10 specimens). Resin texture very hard, brittle and shiny. Often with white waxy filaments projecting from dorsum of test, corresponding to locations of brachial plates and anal tubercle.

Slide-mounted specimens ( Fig. 4 View FIGURE 4 ) (described from 20 specimens in good condition). Adult female subcircular, oval or elongate oval to broadly pyriform, often with a constriction at level of anterior stigmatic areas. Body 0.8–3.0 (holotype 1.7) mm long, 0.7–2.7 (holotype 1.6) mm wide ( Fig. 4 View FIGURE 4 ).

Dorsum. Derm membranous. Dorsal setae and macroducts absent. Microducts scarce, scattered; diameter of duct rim 2.0 µm. Spermatoid ducts each 5−6 µm wide at widest point, scattered throughout dorsum. Brachia short, each 75−158 µm long, basal part membranous, with area that touches brachial plates becoming a sclerotized wall with longitudinal furrows at maturity; sclerotized area 27–75 µm long, measured from base of brachial plate to membranous area of brachia. Brachial plates circular, oval to broadly oval, each 130–165 µm long, 102–145 µm wide; brachial crater opening situated towards body margin, with 2 or 3 (usually 3) setae on anterior margin and 2 or 3 (usually 2) setae on posterior margin (high magnification needed to detect); brachial crater: pore area width 7−9, pore area length 14−18. Brachial pores heavily sclerotized, each 4−6 µm wide, loculi not visible in most pores but probably quinquelocular. Ratio of length of brachial plate to length of first marginal duct cluster (mdc-i) 1.7–2.4 (2.2): 1. Anterior spiracles situated on dorsum, large, each surrounded by a spiracular sclerotization, 112−163 µm long, 90−140 µm wide; width of anterior spiracular peritreme 31–45 µm; spiracular pores of similar structure to brachial pores, loculi on each pore usually not visible, each pore 3−4 µm wide; numerous, with (31–73) pores around each spiracle. Anal tubercle tapering, highly sclerotized, 175–303 µm long; pre-anal plate 53–165 µm long, 220–293 µm wide; supra-anal plate 103–148 µm long, 188–225 µm wide; with no setae observed on pre-anal and supra-anal plates. Dorsal spine well developed, 105–125 µm long, 66–93 µm wide at base; dorsal spine duct of dendritic type. Anal fringe entire, with 4 innermost lobes bifurcate, each 57–105 µm long; the 2 lobes on each lateral margin usually spiniform, innermost lobes longer, straight or bent, usually with a pointed apex, rarely bifurcate, each 52–80 µm long; outermost lobes shortest, each 32–53 µm long with a pointed apex. Anal ring 95–108 µm wide, divided into 4 separate sections, bearing a total of 10 setae, each seta 158–263 µm long, tips of setae surpassing anal fringe. Eyespots absent.

Venter. Derm membranous; mid-areas of venter posterior to mouthparts with microtrichia. Antennae small, each 67–98 µm long, 30–50 μm wide at base, with segmentation poorly defined, about 3 or 4 segmented; each segment membranous; fleshy setae totaling about 3, each 10–23 µm long, present only on last segment when 3 segmented or on last 2 segments when 4 segmented (1 on penultimate segment, and others all on terminal segment); slender setae totaling about 3 or 4, present only on last segment, each 3–6 µm long. Clypeolabral shield 127–158 µm long, 107–120 µm wide. Labium 1 segmented, 55–75 µm long, 55–80 µm wide; bearing 4 pairs of setae. Legs each reduced to a remnant claw; each claw 9–36 µm long, with prothoracic claw remnant smallest, sometimes absent or not detected, metathoracic claw remnant largest. Canella composed of a linear group of 16–33 pores extending from each dorsal spiracle towards mouthparts; canellar pores each 5–6 µm wide, loculi on pores very hard to detect, but with about 5 loculi (only visible under 100x objective). Ventral setae slender, each 5.0–12.5 µm long, present in pairs on mid-areas of abdomen, about 1 pair present anterior to each meso- and metathoracic leg, and submarginally around marginal duct clusters, often with some setae inside marginal duct clusters. Posterior spiracles much smaller than anterior spiracles, each with spiracular peritreme 25–35 µm wide; with 3–8 (mostly 5) spiracular pores present alongside spiracle, each pore quinquelocular, 4–5 µm wide. Marginal duct clusters (mdc) each subcircular to oval; number and distribution as for genus; length and width of each marginal duct cluster (in µm), the number of macroducts in each cluster, and the number of spermatoid ducts in each submarginal group (when present) as follows: mdc-i: 60–85 long, 48–75 wide, with 5–9 macroducts and 0–2 (rarely up to 8) spermatoid ducts; mdc-ii: 63–95 long, 53–80 wide, with 5–9 macroducts and 0–4 (rarely up to 8) spermatoid ducts; mdc-iii: 73–103 long, 63–83 wide, with 4–10 macroducts and 0–3 spermatoid ducts; mdc-iv: 68–103 long, 65–88 wide, with 5–10 macroducts and 0–3 (rarely up to 8) spermatoid ducts; mdc-v: 73–120 long, 58–93 wide, with 4–12 macroducts and 0–5 spermatoid ducts; mdc-vi: 63–98 long, 55–88 wide, with 5–10 macroducts and 0–3 spermatoid ducts; rim of each macroduct 4–6 µm wide. Spermatoid ducts similar in size and shape to those on dorsum, scattered, densely packed in each mdc. Ventral duct clusters (vdc) each subcircular to elongate, composed of large-sized microducts (lsm), each 3–5 µm wide, totaling 4 pairs: 2 pairs on mid areas of head, and each side with 1 present submedially on area lateral to mdc-iii, and 1 present submedially on area lateral to mdc-v; number of large-sized microducts in each ventral duct cluster as follows: vdc-1, 10–38; vdc-2, 9–30; vdc-3, 10–38; and vdc-4, 21–56; vdc-4 represented as an elongate cluster which is usually constricted or subdivided into 2 parts. Microducts present, similar to those on dorsum, each with rim about 2.0 µm wide, present marginally and submarginally on venter. Perivulvar pores and perivulvar pore clusters absent.

Note. Specimens exhibit a range of sizes. In smaller individuals, sclerotized structures, including marginal duct clusters, the dorsal spine, and brachial plates, appear disproportionately larger relative to their body size (see illustration of a smaller specimen in the bottom left corner of Fig. 4 View FIGURE 4 ). Conversely, in larger specimens, these structures appear smaller in proportion to the increased body size ( Fig. 4 View FIGURE 4 , main illustration). Measurements revealed a significant overlap in the actual sizes of these structures across specimens of different sizes, and counts of pores and microducts do not support any substantial differences between large and small individuals.

First-instar nymph

Unmounted material ( Fig. 2D View FIGURE 2 ). Test elongate oval, with segmentation visible dorsally, body tapering towards posterior apex, about 0.5 mm long, 0.3 mm wide; orange to orange-brown, with small dots covering the entire dorsum under high magnification; with white cottony wax protruding from spiracular areas, and short waxy filaments protruding from anal ring (n = 10 specimens). Eyes well developed, reddish brown. In older specimens, the resin becomes visible around the margins of the insect.

Slide-mounted specimens ( Fig. 5 View FIGURE 5 ) (described from 10 specimens in good condition). Body elongate oval, narrowing towards posterior end. Body 440–550 µm (ca. 0.4–0.5 mm) long, 200–250 µm (ca. 0.2–0.3 mm) wide.

Dorsum. Derm membranous, dorsal segmentation clearly visible. Dorsal spine absent. Supra-anal plates each irregularly rectangular, narrowing at outer angles, each plate 20–28 µm long, 10–19 µm wide; dorsal surface with a pair of ligulate lobes, each lobe 15–20 µm long; with a very long apical seta, as long as body length; ventral surface of supra-anal plate with a pair of ventral marginal setae, each seta 14–18 µm long. Anal ring 23–28 µm wide, bearing 6 setae and an irregular row of translucent wax pores. Dorsal microducts each with rim about 2.0 µm wide, present on body margin of most segments, with about 9 microducts on each side. Spermatoid ducts present, marginally and on mid-dorsum, difficult to detect, 4.0–4.5 µm wide at widest point. Dorsal setae absent.

Margin. Outline smooth except for indentation (spiracular cleft) near anterior spiracle on each side. Eyes located on ventral margins, on area posterolateral to each antennal scape. Each spiracular cleft with a pair of pseudospines: 1 anteriorly and the other posteriorly on each side of cleft, each pseudospine 6–8 µm long. Pseudocerarius present marginally near apex of abdomen on each side, anteroventral to supra-anal plates; composed of a pair of pseudospines with derm around their bases slightly sclerotized; each pseudospine 12–23 µm long.

Venter. Derm membranous. Antennae each 135–150 µm long, 6 segmented, with third segment longest; setae as follows: segment I with 3 hair-like setae; segment II, 2 thick setae and a campaniform sensillum; segment III, 1 hair-like seta; segment IV, 1 fleshy seta; segment V, 1 fleshy seta plus 2 very long setose setae; and segment VI with 3 thick setae, 4 fleshy setae and 1 short seta (basiconic sensillum) situated between paired fleshy setae. Mouthparts normal; clypeolabral shield 97.5–107.5 µm long, 62.5–72.5 µm wide; labium 1 segmented, 35.0–47.5 µm long, 47.5–60.0 µm wide, bearing about 8 setae. Legs well developed; trochanter + femur 72.5–82.5 µm long, tibia + tarsus 85.0–97.5 µm long; tarsal digitules of each prothoracic leg dissimilar, one knobbed, 27.5–32.5 µm long, and other spiniform, 7.5–10.0 µm long; tarsal digitules on each mesothoracic and metathoracic leg similar, both knobbed, with longer digitule 35.0–38.8 µm long, shorter digitule 27.5–30.0 µm long. Claws each 15.0–20.0 µm long, with a denticle; claw digitules similar, thin and knobbed, each 17.5–18.8 µm long, with apex of each digitule slightly surpassing apex of claw. Anterior and posterior spiracles similar, each with a well-developed muscle plate, width of peritremes each 6–8 µm. Spiracular pores: each pore about 3.0 µm wide, quinquelocular (but loculi difficult to detect); pores totaling 8–13 in spiracular furrow between anterior spiracle and body margin, and with 1 pore just anterior to each anterior and posterior spiracle in a small depression. Ventral microducts absent. Ventral setae: with a pair of long submedial setae present on each abdominal segment; a seta anterior to each mid- and hind-coxa, each seta 25–35 long; 3 pairs of interantennal setae, each seta 10–30 µm long; a pair of ventral cephalic setae on head, each 7–15 µm long; and ventral submarginal setae slender, short, each 4.0–6.0 µm long, numbering 2 anterior to eye, 2 anterior to spiracular cleft, 1 posterior to each spiracular cleft, and about 4 setae anterior to pseudocerarii.

Etymology. The species is named after the Charrúa, an indigenous people who historically inhabited Uruguay and parts of neighboring Argentina (Entre Ríos) and Brazil (Rio Grande do Sul). The specific epithet charruarum is a combination of “Charrua” and the Latin genitive plural suffix - arum, which is used for feminine nouns. Thus, Neotachardiella charruarum translates to “ Neotachardiella of the Charrúa people.”

Biology. In Uruguay, the largest hatching of first-instar nymphs (crawlers) of N. charruarum was observed at the beginning of summer, typically within a 10-day period from December 15th to 21st, 2023; the highest number of crawlers observed on the 21st. Dead adult females from the previous year remain on branches, while the crawlers move towards the tender shoots or new growth of the current year. A second, much smaller emergence of crawlers occurs towards the end of March. The species overwinters as first-instar nymphs. The female appears to reproduce by parthenogenesis; males have never been observed.

Host plants. Myrtaceae : Blepharocalyx salicifolius , Eugenia uniflora , Luma apiculata , Myrceugenia glaucescens , Myrcianthes pungens , Myrrhinium atropurpureum var. octandrum , Psidium cattleyanum and Psidium guajava . All specimens were collected on twigs.

Distribution. Neotropical realm: Uruguay (Canelones, Maldonado and Montevideo).

Natural enemies. Two sizes of parasitoid wasp exit holes were observed in the tests of N. charruarum . A hyperparasitoid collected was identified as Marietta sp. ( Hymenoptera : Aphelinidae ).

Associated insects. The lac insects were found attended by unidentified ants.