Bioacoustics of Ichneumonopsis

description · Plazi

Redescription Extremely ichneumonid-like species, with elongate body and antennae, petiolate abdomen ( Figs 20–21 ), contrasting dark (brown or black) and yellow or white markings on all body parts, and usually dimidiate wing pattern (anterior 0.4 of wing yellow, remaining part hyaline ( Fig. 18 ), although in I. taiwanensis sp. nov. ( Fig. 19 ) there are additional dark areas on posterior half of wing); sexes not conspicuously dimorphic. Chaetotaxy reduced, with many major setae lacking or small, setula-like; one pair of (apical) scutellar setae present; entire body with pale (mostly yellow, sometimes brown or blackish) setulae not strongly contrasted with background. Microtrichia indistinct. Head ( Figs 5–6 ) STRUCTURE. Distinctly higher than long, with high and transversely convex face and narrow and shallow antennal fovea (groove), frons sloping, frontofacial angle about 100 o- 120 o ; gena high, about 0.33 times as high as eye; occiput rather flat dorsally, swollen ventrally; antenna longer than face, with all three segments at least somewhat elongate, including scape which is distinctly porrect, with1 st flagellomere about 4–5 times as long as high, rounded apically; arista short plumose, plumosity about as wide as 1 st flagellomere height. COLOURATION. Primarily yellow, with black or blackish parts as follows: orbital plate, ocellar triangle, both sometimes united, irregular spot on anterior part of frons, genal spot, small spot laterally on face at mid-height, small spot around and ventral to base of lateral vertical seta, and long vertical spot extending over most of ventral part of occiput to genal margin, latter sometimes indistinct. In addition, face almost entirely black or with elaborate pattern of numerous small spots; these spots variable in number and expression, often asymmetrical, sometimes lacking. CHAETOTAXY AND VESTITURE. Frontal setae 0–2, if present then small (anterior frontal) or setula-like, barely distinguishable from adjacent setulae; anterior orbital seta small but distinct; posterior orbital seta present or lacking, if present, then small, setula-like and barely distinguishable from adjacent setulae; medial and lateral vertical setae present; ocellar seta lacking; postocellar seta indistinguishable from adjacent setulae; genal seta present; postocular setae tiny, inconspicuous. Setulae mostly fine and rather sparse, more spine-like and blackish around occipital foramen. Thorax ( Figs 7–9 ) STRUCTURE. Scutum narrow, length to width ratio 1.33–1.40; scutellum small, about 0.22–0.27 times as long as scutum (n = 7 for both ratios); clear overlap between the three species, moderately convex. COLOURATION. Mostly yellow, with complex dark (brown to black) pattern. Scutum generally with five longitudinal brown to black vittae, including (single) median, (pair) dorsocentral and (pair) notopleural vittae, the latter vitta not extending along entire scutum, the former two vittae often entire, connected across posterior margin, hence scutum without distinct yellow or white prescutellar markings; postpronotal lobe mostly yellow, sometimes slightly dark (brown to black anteriorly); scutellum entirely yellow; pleural pattern complex; see description of I. burmensis for details. Subscutellum and mediotergite mostly yellow to brownish, laterally and dorsally brown. CHAETOTAXY AND VESTITURE. Notopleural setae 2, postsutural supra-alar, postalar, anepisternal and one pair (apical) scutellar setae present; scapular, postsutural dorsocentral and katepisternal setae present or absent, scapular setae entirely lacking in the two specimens of I. hancocki sp. nov. , but present in the two other species, although median pair lacking in all specimens of I. taiwanensis sp. nov. and sometimes also in I. burmensis . Lateral pair variable in size but usually distinct in the two latter species. Presutural dorsocentral, postpronotal, acrostichal and intra-alar setae lacking, median part of scutum with 10–16, but usually not less than 12 rows of setulae, although in I. sp. nov. scutum presuturally appears to have sparser setulae. Legs ( Figs 13–17 ) STRUCTURE AND CHAEOTAXY. Elongate, without overt features except spinose femora in both sexes. In two species ( I. burmensis and I. taiwanensis sp. nov. ) only forefemur spinose, with single row of 2–5 blackish spines ventrally on distal half, and other femora without any spines or setae, only setulae, whereas in I. hancocki sp. nov. all femora spinose, in two rows and much more extensively; midtibia with one apicoventral spine. COLOURATION. Pattern complex and variable, with legs comprising whitish, yellowish, brownish and blackish parts. In I. taiwanensis sp. nov. legs more uniformly yellow probably due to immersion in alcohol. In extremely dark specimens of I. burmensis dark pattern is as follows: coxae entirely or partly blackish; trochanters entirely blackish; forefemur with incomplete narrow blackish ring at base and another preapically, both slightly interrupted ventrally; foretibia blackish; foretarsus blackish except basitarsus mostly whitish, blackish only apically; midfemur with incomplete blackish ring at apical 0.4; midtibia as foretibia, and midtarsus as foretarsus; hindfemur as in forefemur, but rings broader, each about 0.33 times as long as femur; hindtibia brownish-yellow; hindtarsus as in foretarsus. Wing ( Figs 18–19 ) VENATION. Longitudinal veins generally straight, not sinuous; pterostigma about 6–8 times as long as wide; posterodistal lobe of cell bcu slightly shorter than, equal to, or about 1.5 times as long as distal section of vein A 1 +Cu 2 ; stump crossvein present in cell r 1 , either indicated as fold or developed as vein, more or less aligned half way between crossveins R-M and DM-Cu; crossvein R-M aligned with, or slightly basal to, middle of cell dm; crossvein DM-Cu slightly oblique anterodistally; costal spine lacking; vein R 4+5 dorsally with sparse small fine setulae to about level of crossvein DM-Cu. PATTERN. Either dimidiate (in I. burmensis and I. hancocki sp. nov. ), with anterior 0.4 of wing yellowish to brownish, with posterior margin of coloured area often brown, particularly over vein R 4+5 , extending posteriorly only to vein R 4+5 or slightly beyond, and without spots or bands, or pattern type extended dimidiate (in I. taiwanensis sp. nov. ), with additional dark spots on posterior 0.6 of wing, especially over crossvein DM-Cu and distalmost section of vein M; cell bcu yellowish in all species. Abdomen ( Figs 20–21 ) STRUCTURE. Strongly elongate, petiolate; syntergite 1+2 about as long as remaining preabdomen, broadened posteriorly, with distal 0.2 narrowed in dorsal view; tergite 6 of female 0.2–0.3 times as long as tergite 5; oviscape about as long as, or longer than, preabdomen, conical at basal 0.2, remaining part cylindrical. COLOURATION. Abdomen generally banded, with H-shaped or Y-shaped dark pattern on syntergite 1+2, with dark bifurcation always on T1, sometimes also on T2, posterior margin broadly yellow; remaining tergites with more or less discrete, alternating dark (usually brownish or blackish) and yellow posterior transverse bands. CHAETOTAXY AND VESTITURE. Without obvious setae or with one or few at posterolateral corner of last tergite (both male and female), or with few setae posterolaterally on some sternites (females); syntergite 1+2 posterolaterally with large patches of short, dense and erect minute setulae in both males and females, arranged in numerous (ca 30) rows and sometimes with longer coarse dark setulae near these (stridulatory organ?). Terminalia (based on two species) Male ( Figs 22–26 ) Epandrium triangular in lateral view, with elongate surstylus, about 10 times as long as wide, and forming 140 o– 160 o with anterior margin of epandrium; surstylus distally with digitiform prolongation more or less aligned with surstylus, about as long as surstylus width at prensisetae level; proctiger (cerci) slightly to distinctly larger than epandrium, with long and thin hair-like setae, longer, denser and darker (brownish) in one species, shorter and sparser in the other; two small prensisetae; hypandrium and ejaculatory apodeme without overt features, the latter narrow, about 3–4 times as long as wide (at widest place, near apex). Phallus about 1.1–1.2 times as long as abdomen; glans with at least four separate sclerotized plates or structures (from base to tip): first sclerite brown, rather flat dome-like at base; second sclerite opposite first sclerite but slightly more distally, yellow, flat, longer than first sclerite, comprising basal lobe; third structure at middle of glans, cochleate, the most complex and conspicuous sclerotization in the glans; finally small curved brown plate at tip of glans. Female ( Figs 27–30 ) Aculeus flat, about 10 times as long as wide; cercal unit unusually wide, distinctly rounded apically, with or without constriction, with 4 preapical marginal setulae and system of straight or curved longitudinal “canals” crowded toward tip (tip of aculeus illustrated by Hardy 1973 : fig. 58e) or extending more proximally; eversible membrane: with 30–40 dense rows of small yellow denticles; denticles rhomboidal, length equal to width, 209–251 µm , average 230 µm , n = 10; denticles occupying basal 0.25–0.30 of length of eversible membrane, which in most of its length lacks denticles and is translucent grey. Spermathecae – 2, spherical or almost spherical (illustrated by Hardy 1973 : fig. 58c).

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