Ima Tindale
Creators: name: Connors, Matthew G.
name: Yeeles, Peter
name: Lach, Lori
name: Rentz, David C. F.
Publisher: name: Zenodo
Year: 2023
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Mantodea
Nanomantidae
Ima

description: Ima Tindale
Ima Tindale, N.B. 1924, Review of Australian Mantidae. Part II. Records of the South Australian Museum (Adelaide), vol. 2, pp. 547–552 [549]. Type species: Ima fusca Tindale, by original designation.
Differential diagnosis. Small, rather slender and delicate, male macropterous, female moderately brachypterous. Body colour brown or grey with darker mottling, with a distinctive line of dark and pale patches along the tegmen. Eyes moderately dorsoventrally compressed, juxtaocular bulge prominent. Pronotum elongate, more than 2.2 times as long as wide, without strong paired tubercles. Abdomen unmodified, without projections. Male genitalia with pda a short robust spine, L4A without other projections, afa rather small and not strongly bifurcate. Ima can be distinguished from all other Australian Fulciniinae by the lack of tubercles on the pronotum, the pronotum being more than 2.2 times as long as wide, and the lack of dorsomedian abdominal projections in the female, and the pda of the male genitalia being present as a single robust spine.
Description. External morphology is strongly conserved in this genus, and the only consistent difference between the two species is the form of the male genitalia.
Head. Head subtriangular, wider than pronotum, approximately 1.7 times as wide as high in male, approximately 1.6 times as wide as high in female, compressed, finely shagrinate. Clypeus subrectangular, transverse, with moderately arched, elevated postmedian transverse ridge and two transverse, weakly elevated antemedian ridges, these more prominent in female; posterior margin weakly convex; anterior margin sinuate. Lower frons transverse, six-sided; posterior margin concave, elevated, with corners produced into blunt projections; anterior corners with a small, rounded swelling. Eyes very large, rounded, bulbous, moderately dorsoventrally compressed. Ocellar tubercle prominent, raised in male, weakly elevated in female; in male ocelli large, ovate, median ocellus distinctly smaller than lateral ocelli; in female ocelli smaller, subequal in size. Vertex slightly elevated but not produced into a postocellar process, weakly sinuate, somewhat concave in dorsal view; frontal sulcus feebly indicated laterally but surrounded by a broad depression; juxtaocular bulge prominent, rounded, projecting posteriorly beyond posterior margin of both eye and vertex.Antennae elongate, slender, setose; when directed posteriorly, reaching approximately base of hind coxae in male, reaching approximately base of hind wings in female; scape wide, rounded, slightly kidney-shaped; pedicel narrower, weakly constricted basally; first flagellomere elongate, second short, subsequent flagellomeres gradually becoming more elongate distally.
Thorax. Pronotum moderately elongate, subovate, approximately 2.2 times as long as wide in male, approximately 2.5 times as long as wide in female, broadest anterior to centre but posterior to supracoxal sulcus, surface finely shagrinate, with a few small, scattered tubercles; dorsolaterally with a pair of moderately-defined, undulating longitudinal carinae extending along almost the entire pronotum, these bounding a more flattened dorsal region. Supracoxal sulcus strongly arched, deep on lateral margins of pronotum but only weakly indicated dorsally; median keel almost absent anteriorly, low and weakly-defined on posterior of metazone. Prozone ovate, with sides almost parallel, somewhat elevated anteriorly but with anterior margin sloping downwards, posteriorly with low diagonal ridges along dorsolateral carinae, irregularly tuberculate posterolaterally. Metazone somewhat elongate, broadest anteriorly, approximately 1.7 times length of prozone in male, approximately 1.9 times length of prozone in female, weakly elevated anteromedially and posteriorly such that dorsal surface is weakly undulate, anterolaterally with a short longitudinal ridge of varying distinctness, this generally weaker in female. Lateral pronotal expansion present as a narrow, finely dentate margin (Figure 1A–B, 6A–B). Prosternum very finely granulated; ventral cervical sclerite and intercervical sclerites present as narrow, rounded ridges, the latter especially more prominent in females; postcervical plate broad, subrectangular, with concave anterior margin; T-shaped sclerite narrow medially, slightly broader in male; gustifolium organ small, reduced, rounded, with scattered setae; furcasternite with low median keel anteriorly and with low, rounded ridge along posterolateral margins. Posterior hearing organ is of the DK type in male, of the DNK type in female.
Foreleg spination formula: F = 3DS/10–14AvS/4PvS; T = 7–8AvS/4–7PvS.
Legs. Forecoxa elongate, narrow, keeled and finely toothed along dorsal margin, with strong, tuberculate median keel posteriorly; coxal lobes broad, convergent. Forefemur elongate, broadest slightly basal to tibial spur groove, narrowing anteriorly, with scattered tubercles and setae; dorsal keel strong, elevated; posterior keel present, sometimes low and poorly-defined; tibial spur groove with prominent distal edge but poorly-defined basally; femoral brush ovate; middle discoidal spine largest, distal smallest, distal discoidal spine directed distally; anteroventral forefemur spines alternating between large and small basally, with distalmost spine always large but penultimate one to four spines small, sometimes with distinct gap between penultimate and ultimate distalmost spines; a row of minute spines along a ridge between the anteroventral and posteroventral spines, this extending from near the base of the forefemur to the femoral brush, interrupted by the discoidal spines; genicular spurs strong, well-developed. Foretibia slender, elongate, with scattered setae; a distinct gap between ultimate and penultimate basalmost posteroventral foretibial spines in most specimens, this gap sometimes replaced by a very small spine; tibial spur long, gently curved. Foretarsus longer than foretibia, unmodified. Mid and hind legs moderately long, sparsely setose, unmodified; genicular spurs absent; tibial spurs short; tarsi relatively long.
Wings. Tegmina elongate, with sides subparallel, reaching or just exceeding end of abdomen in male, almost reaching end of fifth abdominal segment in female; veins reticulate, especially distal to stigma; basal area between anterior branch of anterior cubitus and posterior cubitus with many crossveins. Hind wings broad, shortened in female, marginally exceeding end of tegmina in male, in line with or marginally exceeding end of tegmina in female; anterior cubitus unbranched (Figure 1A–B, 6A–B).
Abdomen. Abdomen unmodified, moderately elongate, slightly broader in female; with scattered setae, these denser posteriorly; sometimes with very small, bluntly triangular posterolateral projections on posterior tergites. Cerci elongate, cylindrical, setose, segments gradually lengthening distally (Figure 2, 7). Supra-anal plate of male short, triangular, lateral margins slightly concave, not reaching posterior edge of subgenital plate. Supra-anal plate of female moderately elongate, triangular, tip slightly blunted, marginally exceeding tip of subgenital plate. Subgenital plate of male subtriangular, lateral margins slightly convex, broadly incised at posterior tip between styli, slightly asymmetrical such that the base of the right stylus is more posterior than the left; styli short to moderately long, cylindrical, setose, sometimes with right stylus shorter than left (Figure 2B, 7B). Subgenital plate of female subtriangular, lateral margins slightly convex; ventroterminal lobes elongate, triangular, with lateral regions curled upwards and directed dorsally, tips slightly blunted (Figure 2A, 7A).
Genitalia. Male genitalia with L4A ovate to subtriangular; pda a short, blunt, finely shagrinate spine, directed to the right; afa rather small and not bifurcate, poorly to strongly sclerotised, positioned rather posteriorly; paa poorly sclerotised, elongate, curled dorsally, bent strongly to the left, with rounded tip; loa very small, rounded, directed posterodextrally; fda rather broad, setose posteriorly, sometimes slightly constricted basally; pia a small, strongly sclerotised, rounded to angulate tubercle directed sinistroventrally; pva an elongate, strongly sclerotised projection narrowing abruptly to a blunt point, this directed ventrally and curving evenly along its length such that the apex is directed posteriorly (Figure 1C–D, 6C–D).
Colour. Body colour brown or grey with darker markings, pattern relatively consistent but very variable in intensity. Some specimens very pale grey-brown or orange-brown with few darker markings, others dark brown with bold, almost black patterning.
Head pale to mid brown with dark mottling on labrum, clypeus, mandibles, and around circumantennal sulcus; anterior 2/3 of lower frons dark, forming a transverse stripe, posterior 1/3 very pale; vertex and ocellar tubercle with scattered dark dots, denser around parietal sulcus; ocelli orange-yellow; antennae entirely pale. Eyes distinctly patterned with lateral stripes, consisting of two curved, thin, dark stripes on dorsal surface separated by a very pale region; a thicker, pale cream stripe beneath; a broad dark stripe laterally, concurrent with dark markings on lower frons; a thin, cream stripe beneath, and a curved, thin, dark stripe on ventral surface; extreme dorsal and ventral regions slightly darker than ground colour of head; these markings often fading after death.
Pronotum pale to mid brown; dorsal surface with scattered, dark dots and short streaks, occasionally with a pair of thin, dark longitudinal lines along midline extending along almost entire length of pronotum, slightly divergent posteriorly; lateral surface with two broad, dark, longitudinal lines, on metazone these almost touching the dorsolateral longitudinal carinae, on prozone separated from carinae by a broad pale region; the region between these dark lines usually heavily mottled dark brown, sometimes entirely dark such that only a single, very broad dark line is present; lateral margin of metazone with a pair of short, thin, curved, dark lines anteriorly, on widest section of pronotum; lateral pronotum margin pale cream. Prosternum mostly unicolourous with some dark markings on the intercervical sclerites and T-shaped sclerite, furcasternite often with dark lateral margins and a dark transverse band posteromedially.
Legs pale to mid brown; forelegs with small, scattered dark dots; forecoxae sometimes with longitudinal stripes on posterior surface; forefemoral and foretibial spines with dark brown tips; foretarsi pale. Mid and hind legs usually with dark bands of variable intensity, distal section of mid and hind femora usually very dark.
Tegmina mostly opaque, pale, mottled with darker patches; costa and basal half of anterior radius pale cream, the latter sometimes with faint dark bands, most other veins brown; pterostigma surrounded by an elongate, almost white patch, with dark ovate patches basal to and distal to the pterostigma, the former sometimes extending as a thin streak posterior to the pterostigma, beyond these an ovate pale patch and then an ovate dark patch, forming a banded line along anterior radius and media, these patterns sometimes somewhat obsolete distal to pterostigma; with many irregular dark markings adjacent to sectors but separated from them by a thin pale border. Hindwing mostly hyaline; veins mostly brown; costal region pale, mostly opaque; usually with irregular dark patches adjacent to distal 1/10 of anterior radius, posterior radius, media, and anterior cubitus.
Dorsal and ventral surface of mesothorax, metathorax, and abdomen pale to mid brown with scattered, dark dots; dorsal surface also with short, irregular, dark, longitudinal lines, these sometimes aligned as longer stripes; cerci pale, sometimes with faint dark mottling (Figure 1A–B, 4, 6A–B, 9).
Remarks. Species of Ima are widespread across the northeast coast of Australia, and although they can be very abundant where they occur they are often highly localised. It is not uncommon for multiple individuals of different life stages to be found on just one or two suitable trees whilst being absent from all other trees in a small area. For this reason the species are seldom encountered by most collectors, and winged males that have been attracted to lights make up the majority of museum specimens.
Oothecae of both Ima fusca and Ima corymbia sp. nov. are extremely cryptic and are laid in narrow gaps between bark where they are well-hidden from potential threats (Figure 3, 8). Adult females insert the distal half of their abdomen into a gap in the bark of their host tree, and deposit a flattened ootheca that is attached to the bark on both the dorsal and ventral surfaces (Figure 4D). The elongated, triangular subgenital plate of the females of Ima spp. likely aids them in finding a suitable crevice and probably also in enlarging an existing crevice, enabling the oothecae to be deposited well away from the surface of the bark (Figure 2A, 7A). The oothecae are thus extremely well-hidden and have only been collected from the wild on rare occasions; even oothecae laid by captive females have proven difficult to find.
Adults and nymphs alike display similar hunting behaviour. Typically, a mantis will stand facing downwards on a vertical tree trunk with its body raised above the bark. Once prey is sighted, usually from a few centimetres away, the mantis actively runs towards it and catches it with its forelegs. Unlike more robust mantises, Ima typically catch only very small prey, and the impact of the forelegs alone is often enough to completely immobilise prey. Sexual cannibalism has not been recorded in any species of Ima, although adult Ima corymbia sp. nov. have been observed preying on conspecific nymphs.
Ima rely on their cryptic colouration as a primary defence, and the variation in colour and pattern between individuals aids in camouflaging them against different shades of bark. Upon being disturbed, however, individuals will run a short distance away, often to the other side of the trunk in smaller trees. Initially facing downwards, the mantis turns to a diagonal or horizontal position, runs to a new position, and then turns to face vertically again. Upon reaching this new position, individuals frequently flatten themselves against the trunk as an additional attempt to evade attention. The entire sequence is so rapid, however, that it is often not obvious to the naked eye that the mantis has turned. Figure 5 shows such a sequence, in which a male Ima fusca travels approximately five body lengths to a new position on a tree trunk. The entire process takes just over a quarter of a second, and as it runs the mantis reaches a relative speed of approximately 34 body lengths per second.
Despite their similarities, Ima fusca and Ima corymbia sp. nov. are apparently entirely allopatric and show a distinct difference in habitat preference, with Ima fusca preferring wetter coastal areas and Ima corymbia preferring drier inland areas. Only a single species has been recorded at any one locality, although they have been recorded from sites just a few kilometres away from each other in the vicinity of Cooktown. Both species may occur at Davies Creek (Figure 15E) where distinct segregation of individuals by habitat and host tree occurs, however we have been unable to examine any specimens from this locality to confirm this.
As female Ima fusca and Ima corymbia sp. nov. cannot be distinguished morphologically, female specimens have been identified via molecular sequencing or have been tentatively identified based on association with male specimens.A number of female specimens could not be confidently identified; these are mapped using white circles in Figure 14.
description: Published as part of Connors, Matthew G., Yeeles, Peter, Lach, Lori & Rentz, David C. F., 2023, A revision of the genus Ima Tindale (Mantodea: Nanomantidae: Fulciniinae) with the description of a new genus, pp. 201-226 in Zootaxa 5380 (3) on pages 202-205, DOI: 10.11646/zootaxa.5380.3.1, http://zenodo.org/record/10224417