Kernegaster Schmitz, Barcellos, Eger & Bianchi 2025, gen. nov.
Creators: name: Schmitz, Luís Ricardo
name: Barcellos, Aline
name: Eger, Joseph
name: Bianchi, Filipe Michels
Publisher: name: Zenodo
Year: 2025
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hemiptera
Scutelleridae
Kernegaster

description: Kernegaster Schmitz, Barcellos, Eger & Bianchi gen. nov.
Type species: Pachycoris pinguis Germar, 1839.
Distribution: Southern USA to Argentina (Fig. 3).
General shape and color pattern. Body oval, dorsum strongly convex and venter usually flat or slightly convex. Head. Dorsal surface with at least five pairs of distinct blotches which can be fully present or almost absent. Antennomere I bicolored (first half pale, remaining dark), II bicolored or black, except for K. igneus sp. nov., in which antennomeres I and II are entirely yellow or orange (Fig. 6C; Fig. 7F). Antennomere III dark, yellow, or bicolored, and antennomeres IV and V mainly dark or with just the tip pale. Rostrum with segments I and II always pale, except for Kernegaster multimaculatus sp. nov. in which they are dark. Thorax. Pronotum and scutellum. Species often share the same pattern of dark spots, except for K. pinguis, K. poecilus, and K. diminutus sp. nov (Fig. 4A–D; Fig. 5A). Dark spots are almost absent or markedly present in different numbers and sizes, sometimes forming a cluster. Femora usually with proximal and distal dark blotches, but both can be absent. Tibiae with medial and distal dark blotches. Tarsi usually bicolored. Abdomen. Connexiva mainly pale, usually with dark macula anteriorly and posteriorly on each segment. Ventrally with small dark spots forming larger blotches distributed in at least 3 + 3 rows that can be almost entirely solid or with aggregations of dark spots. Lateral rows are positioned near the lateral line and usually consist of one large spot on each sternite. Median rows with large clusters of spots or well-formed blotches. Inner rows usually wider than the remaining rows, culminated in a large blotch on sternite VII. Stridulatory areas usually without blotches. Sometimes the rows are not evident with the abdomen almost entirely immaculate, this occurs frequently in K. farctus (Fig. 4I). Area adjacent to spiracles dark or concolorous.
Head. Subtriangular, usually wider than long, sometimes with equal length and width. Lateral margins markedly sinuate. Dorsally flat, except for clypeus slightly elevated and longer than mandibular plates. Apex of mandibular plates obtuse, inner and outer lateral margins sinuate. Maxillary plates longer or sub equal to mandibular plates. Ocelli closer to the eyes than to each other. Antenniferous tubercles inserted before eyes and laterally to maxillary plates. Proportions of antennomeres: 1> 2 <3 <4 = 5, antennomere I more robust than the remaining ones. Rostrum surpassing the metasternum. First segment cylindrical and robust, second laterally flat and remaining segments dorso-ventrally flat. Proportion of rostral segments: 1 <2=3> 4.
Thorax. Pronotum about twice as wide as long, anterior margin concave, anterolateral margin slightly convex to slightly sinuous. Humeral angles are rounded or obtuse, slightly to clearly produced, posterolateral margin slightly convex and posterior margin sub-rectilinear. Calli triangular, delimited by impunctate margin. Legs slightly setose, coxae fusiform and laterally flat, femora sulcate ventrally and tibiae sulcate dorsally. Ostiole rounded, positioned medially on the metapleura, oriented posterolaterally; peritreme spout-like, variable in size.
Abdomen. Laterally convex and medially flat, with a medial sulcus attending the length of rostrum. Lateral margins of sternites sub-rectilinear, posterolateral angles acute and slightly produced. Sternites IV–VII trapezoidal. Median length of sternites is about the same except for sternite VII which is more than twice as long as the remaining segments. Stridulatory area present on sternites V–VI. Posterior margin of sternite VII uniformly concave or sinuous medially, always exposing both female and male genitalia.
Genital plates. Valvifers VIII subtriangular to sub-rectangular, partially covered, sutural margins posteriorly convex to truncate, posterior margin concave to strongly sinuous. Valvifers IX subtriangular, reduced and fused, partially visible between Valvifers VIII and laterotergites IX. Laterotergites VIII subtriangular, curved with conspicuous spiracles. Laterotergites IX broad, subtriangular to sub-rectangular, with anterior margin convex to markedly convex, posterior margins slightly convex and oblique to the sutural margins; lateral angles round, sometimes produced. Gynatrium. Fecundation canal tubular, posterior opening globose and folded anteriorly; ring sclerites adjacent to the fecundation canal, enlarged, outlined and with inner margin with or without robust sclerites. Posteriorly with an invagination forming a posteromedian gynatrial pouch with a median and intermediate sclerites of variable shape, sometimes with a pair of minor lateral sclerites. Spermatheca. Spermathecal duct uniformly slim, as long as the fecundation canal, bifurcated medially separating the spermathecal dilation and the remaining structures. Spermathecal dilation broad and globose, almost as long as the fecundation canal. Intermediate part shorter and thicker than the spermathecal duct; distal and proximal flanges distinct. Apical receptacle capitate, apically globose with a protrusion (Fig. 11D).
Genital capsule. Subquadrangular, Posterior margin sub-rectilinear to medially excavated, posterolateral angles rounded, sometimes obtuse. Posterior aperture located dorsally and oblique to the body at rest. Ventral rim narrow, convex to concave, lateral expansion of ventral rim broad, with a median protrusion of striated surface (ventrally to parameres), dorsal rim convex. Parameres. Basal apodeme short. Stem elongate, width about twice the base of the crown, outer lateral margin sinuous to concave, distal margin with long setae. Crown hook-like, surpassing or not the width of the stem, apex obtuse, truncated, or acute, inner portion sulcate. Phallus. Phallotheca barrel-shaped (Fig. 14E), ventrally and laterally sclerotized. Aedeagus sensu stricto elongate, about half the length of the conjunctival process II, sometimes almost about the same length, sinuous to dorsally convex in lateral view, apex tapered and curved dorsally to phallus, sometimes abruptly curved (truncated). Conjunctival processes I absent. Conjunctival processes II mostly membranous, well developed, with apex tapered into a sclerotized process with a membranous dorsal branch. Conjunctival processes III basally membranous, distally with a tapered sclerotized process that can be more or less curved.
Etymology: The prefix "Kerne" refers to Justinus Kerner, a German poet, practicing physician, and medical writer who pioneered Klecksography, the art of making images from inkblots, which is used in the Rorschach psychological test. The suffix “gaster” refers to the ventral pattern of the abdomen that resembles the Klecksography painting.
Key to species of Kernegaster Schmitz, Barcellos, Eger & Bianchi
1. Dorsum with pattern of usually black, either small and uniformly distributed or aggregated spots (Fig. 1D–K); humeral angles variable; valvifers VIII shorter, or about the same length, of laterotergites IX (Fig. 9A–H) …. …. …. …. …. …. …. …. …. …. …. …. …. …. ….2. 1’. Dorsum uniformly orange-yellow with medium-sized reddish brown macules which are rather evenly distributed; humeral angles rounded, not projected more than the width of the second antennal segment (Fig. 9I); valvifers VIII clearly longer than laterotergites IX (Fig. 9I) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. … K. chapadanus sp. nov.
2(1). Posterior margin of genital capsule strongly bisinuous, ventral surface of genital capsule with a thickened convex arch on either side of mesial thin triangular area (Fig. 12E); female posterior margin of the seventh sternite broadly convex medially, posterior margin of eighth valvifers acutely angled medially (Fig. 60) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. K. fulvescens sp. nov. 2’. Posterior margin of genital capsule sub rectilinear to strongly excavated, without a thickened convex arcs; Posterior margins of eighth valvifers continuous, without a median acute angle … … … … … … … … … … … … … … … … … ……… … … … … …. ….3.
3(2). Humeral angles of pronotum broadly rounded, produced by less than the width of the second antennal segment (Fig. 4D; Fig. 5A) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …..4. 3’. Humeral angles of pronotum angulate, produced by more than the width of the second antennal segment, usually by about half the width of an eye (Fig. 4A–G) …. …. …. …. ……5.
4(3). Female ninth laterotergites elongate and strongly constricted laterally, posterior margin of eighth valvifers sinuous (Fig. 9B); parameres with the crown not surpassing the width of the stem (Fig. 12K) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …… K. poecilus (Berg). 4’. Female ninth laterotergites sub-rectangular, not constricted laterally, posterior margin of eighth valvifers concave (Fig. 9D); parameres with crown surpassing the width of the stem (Fig. 12M) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. ….. K. diminutus sp. nov.
5(3). Dorsal pattern of spots aggregated into larger macules (Fig. 4A; Fig. 6A) …. …. …. …. ……6. 5’. Dorsal pattern of spots small and distributed evenly, whether abundant or sparse, sometimes almost absent (Fig. 4G; Fig. 5D; Fig. 6D–G) …. …. …. …. …. …. …. …. …. …. …. …. … 7.
6(5). Dorsal coloration reddish-orange, densely black maculate (Fig. 6A); posterior margin of eighth valvifers sinuous (Fig. 9F); posterior margin of genital capsule strongly sinuous, concave medially (Fig. 12F); …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …… K. igneus sp. nov. 6’. Dorsal coloration more yellowish, black macules more sparsely distributed (Fig. 4A); lateral two-thirds of posterior margin of eighth valvifers rectilinear, middle third strongly convex (Fig. 9A); posterior margin of genital capsule sub-rectilinear to slightly sinuous (Fig. 12A) … … … … … … … … …. … … … … … … … … … … ….… …. K. pinguis (Germar).
7(5). Posterior margin of genital capsule deeply concave (Fig. 12G); posterior margin of female seventh sternite narrowly convex medially and elevated, leaving distinct sulcus above anterior margin of eighth valvifers (Fig. 9G); posterior angle of the sutural margin of the valvifers VIII usually broad rounded; ventral markings dense and in abundance (Fig. 6F) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. K. multimaculatus sp. nov. 7’. Posterior margin of genital capsule shallowly sinuous to rectilinear; posterior margin of female seventh sternite shallowly concave to slightly convex (Fig. 9C–H); posterior angle of the sutural margin of the valvifers VIII slightly round to truncated; ventral markings sparse or less evenly distributed (Fig. 4I; Fig. 6I) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …..8.
8(7). Dorsally with sparsely scattered dark spots, commonly with 1 + 1 pale spots on the anterior portion of the scutellum (Fig. 4G); body ventrally with few blotches (Fig. 4I); head of paramere thick, strongly uncinate, apex acute (Fig. 12L); aedeagus sensu stricto constricted medially, with apex bifid (Fig. 13F); sclerite of conjunctival process II small and strongly curved (Fig. 13G); lateral quarter of posterior margin of eighth valvifers slightly convex, remaining margin usually subrectilinear; inner margin of the ring sclerites without tick leaf-like sclerites (Fig. 10C) …. …. …. …. …. …. ….. K. farctus (Germar). 8’. Dorsally with evenly distributed small spots, lacking 1 + 1 pale spots on the anterior portion of the scutellum (Fig. 6G); body ventrally with numerous dark spots (Fig. 6G); head of paramere thin, elongate, weakly uncinate, apex rounded to obtuse (Fig. 12Q); aedeagus sensu stricto conic, with apex acute (Fig. 14G); sclerite of conjunctival process II large, slightly curved to rectilinear (Fig. 14E–H); posterior margin of eighth valvifers sinuous to subrectilinear; inner margin of ring sclerites with tick leaf-like sclerites (Fig. 11C and D) …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. …. ….. K. rosafloresae sp. nov.
description: Published as part of Schmitz, Luís Ricardo, Barcellos, Aline, Eger, Joseph & Bianchi, Filipe Michels, 2025, Kernegaster gen. nov. (Heteroptera, Scutelleridae, Pachycorinae) and six new species based on genital and polychromatic synapomorphies, pp. 97-123 in Zoologischer Anzeiger 316 on pages 105-111, DOI: 10.1016/j.jcz.2025.03.005