Journal of Threatened
Taxa | www.threatenedtaxa.org | 26 February 2023 | 15(2): 22677–22685
ISSN 0974-7907
(Online) | ISSN 0974-7893 (Print)
https://doi.org/10.11609/jott.8005.15.2.22677-22685
#8005 | Received 03
May 2022 | Final received 07 February 2023 | Finally accepted 15 February 2023
Notes on morphology and bionomics
of Urolabida histrionica
(Westwood) (Heteroptera: Urostylididae)
from Assam, India
Sachin Ranade 1 & Hemant
V. Ghate 2
1 Vulture Conservation Breeding
Center, Rani, Kamrup, Assam 781131, India.
2 Post-Graduate Research Centre,
Department of Zoology, Modern College of Arts, Science & Commerce
(Autonomous), Shivajinagar, Pune, Maharashtra 411005, India.
1 sachinranade@yahoo.com, 2 hemantghate@gmail.com
(corresponding author)
Abstract: Illustrated redescription
of a colourful bug Urolabida
histrionica (Westwood 1837), along with comments
on bionomics, is presented for the first time from an Indian population. The
host plant for this bug was identified as Ficus
hispida L. f. (Moraceae).
Keywords: Bug, male and female genitalia,
eggs, Ficus hispida,
northeastern India, nymphs.
Editor: Hélcio R. Gil-Santana, Instituto Oswaldo Cruz, Rio de
Janeiro, Brazil. Date of
publication: 26 February 2023 (online & print)
Citation: Ranade, S. & H.V. Ghate (2023). Notes on morphology and bionomics of Urolabida
histrionica (Westwood) (Heteroptera:
Urostylididae) from Assam, India. Journal of Threatened Taxa 15(2): 22677–22685. https://doi.org/10.11609/jott.8005.15.2.22677-22685
Copyright: © Ranade & Ghate
2023. Creative
Commons Attribution 4.0 International License.
JoTT allows unrestricted use, reproduction,
and distribution of this article in any medium by providing adequate credit to
the author(s) and the source of publication.
Funding: Self-funded.
Competing interests: The authors
declare no competing interests.
Author details: Sachin Ranade works in the Vulture Conservation
Breeding Centre, Assam. His interests include study of diversity of Mantodea and Cassidinae. H.V. Ghate retired as Head of the Department of Zoology but continues to work
on Heteroptera. Earlier he worked on Mantodea, Cerambycidae, aquatic beetles and freshwater
sponges.
Author contributions:
SR did all fieldwork and relevant observations, HVG studied morphology; both completed the manuscript.
Acknowledgements:
SR is thankful to Bombay Natural History Society for support and
encouragement. HVG is indebted to Dávid Rédei (National Chung Hsing University,
Taiwan) for continuous support with literature and comments on the images; we
also thank Ge Deyan (Chinese Academy of Sciences, Beijing, China) for helping
us with literature. We sincerely thank Kaiqin Li
(Kunming Natural History Museum of Zoology, Kunming Institute of Zoology,
Academia Sinica, China) for translating part of the
Chinese text from the paper cited here. We also thank Ms. Sayali
Sheth for preparing photo plates. HVG is grateful to
the authorities of Modern College for facilities and encouragement.
INTRODUCTION
Urostylididae are an Old-World group of bugs
distributed from India through the Oriental region and into Japan and
southeastern Asia. The family currently includes eight genera and over 170
species but information on the bionomics of these bugs is meagre; urostylidids have been recorded from a variety of plants,
but there seems to be a preference for various tree species (Rider et al.
2018).
Atkinson (1889) had earlier
documented the various species of Urostylididae (in
British India), under the family ‘Urostylina’, and
also given information about these species under three genera; this work
included eight species under the genus Urochela
Dallas, 1870, eight species under Urostylis
Westwood, 1837, and seven under Urolabida Westwood,
1837 with a key to genera (total 23 species). Distant (1902) subsequently
included 22 species under the same three genera: Urostylis
(8 species), Urochela (8 species), and Urolabida (6 species) under the subfamily ‘Urostylinae’, six of these were new species and the
remaining were briefly redescribed. Subsequently,
Distant (1908) redescribed two more species of Urostylis. Thus the Fauna of British India volumes
by Distant recorded 24 species under ‘Urostylinae’ sensu Distant. Although some additional species have been
described in later years, e.g., by Yang (1938a), from India and some of the
species listed in Fauna are not in the present Indian territory, some have
undergone nomenclatural change, there is neither an updated list of the species
of this family for India (the former lists being for ‘British India’); there is
no updated list for the world either and this lacuna was pointed out by Rider
(2006) in the catalogue of Urostylididae of the
Palearctic. As pointed out by Berger et al. (2001), the family name Urostylididae Dallas, 1851 is the grammatically correct
spelling because it is based on the genus Urostylis
Westwood, 1837 and the stem from which family name is to be derived is Urostylid and so the correct name would be Urostylididae; acceptance of this family name also removes
homonymy with Urostylidae Bütschli,
1889 (in Ciliophora, Hypotrichia).
A species of Urostylididae
collected from Assam was identified as Urolabida
histrionica (Westwood 1837), based on the keys
and descriptions in Distant (1902). Urolabida
differs from the other two allied genera (Urostylis
& Urochela known from India) by absence of
ocelli. The colouration of the dry mounted specimen
of this species is very different than that of the live insect; while the live
insect shows large bands of yellow colour on green
pronotum, scutellum, & hemelytra, and a pair of elongate black spots on
corium (Image 1A), the dried insect appears uniformly brownish-yellow, with
green tinge at places; only elongate black spots on corium and the fuscous
areas on antennae remain unaffected by drying (Images 1B & 1C).
Distant (1902) had noted that
this species is highly variable in hue and all the markings, except for the
elongate black spot on the corium. The semicircular yellow band around posterior
part of pronotum and scutellum was (presumably) responsible for the specific
name semicircularis earlier given by Herrich-Schäffer (1839), who described and illustrated this
species as Typhlocoris semicircularis.
In recent years, Ahmad et al. (1992) studied a few species of Urostylididae (name used by these authors: Urostylidae) and carried out cladistics analysis based on
four genera and five species and added details of male / female genitalia of
some species, including that of U. histrionica (incorrectly
spelled at places as ‘historionica’). Kumar
(1971) also added information to the structure of male genitalia of this and a
few other Urostylididae.
The present short note is based
on the field observations on a population of this bug from Assam. The entire
life cycle was completed on the host plant Ficus
hispida L.f. (Moraceae). A brief photo essay of life history of this
species is presented here which includes live photos of the bugs, their eggs,
and nymphs as well as images of dried specimens illustrating morphology. A
series of images of the male genitalia is also provided.
MATERIALS AND METHODS
Insects were photographed in the
field (Kamrup, Assam: between December 2015 to
October 2021 by S. Ranade) in natural condition using a digital SLR camera
(Nikon D 850). Specimens were sent to Pune for further examination.
Morphological study was carried out using Leica MZ 6 microscope with attached
Canon PowerShot S50 camera (in Modern College, Pune).
Measurements were done with Erma stage, ocular micrometer, and an accurate
scale. The pygophore was detached from the body after
treating the last two abdominal segments with hot 10% potassium hydroxide (KOH)
solution. The pygophore was further boiled for 3
minutes in 10% KOH and the phallus and the parameres
were separated in distilled water. The phallus was briefly stained with diluted
methylene blue for examination. Subsequently, phallus and parameres
were mounted in polyvinyl lacto-glycerol (PVLG) with
lignin pink dye, and photographed. Each microscopic image presented here is
prepared by photo-stacking several images taken at various focal planes, by
using Combine ZM freeware.
RESULTS
Classification based on Rider
(2006)
Taxonomy
Urostylididae Dallas, 1851
Urostylidinae Dallas, 1851
Urolabidini Stål,
1876
Urolabida Westwood, 1837
Urostylis histrionica Westwood, 1837
Typhlocoris semicircularis Herrich-Schäffer,
1839
Urolabida binotata Walker, 1867: 415
Urolabida histrionica (Westwood, 1837)
Bionomics
The observations given below were
carried out by one of us (SR) in Kamrup District,
Assam, opportunistically between December 2015 to October 2021. All of these
are incidental observations and so some details are not available. Eggs or
nymphs were not collected, only a pair of adults was collected in May 2016 for
dissection. Subsequently, in October 2021 another pair (one male & one
female) was collected for additional observations. Thus, two males and two
females were preserved for subsequent morphological study at Modern College,
Pune.
These bugs were first located
during December 2015, on Ficus hispida plant that was about 100 cm tall. A few nymphs
in III and IV instars were also present at that time, indicating that mating
and egg laying probably happened in November. Subsequently, in late March 2016,
some mating pairs were again located on the same plant (Image 1D); sometimes,
IV instar nymphs were found with adults (Image 1E), confirming that this is the
host plant.
The egg mass was observed on the
underside of leaves, once in 2019 and thrice in 2020. On 11 May 2020, the act
of egg laying was observed for the first time. Eggs appeared as pale-yellow
translucent mass, with about 27 to 30 eggs in one mass. There was some opaque,
cream coloured substance, deposited by the female, on
top of each egg (Image 2A). Hatching took place in 4 days on 15 May. These
first instar nymphs were oval, translucent with only three somewhat opaque
marks on dorsal side. These bugs were feeding on the substance left over on the
eggs for the next forty-eight hours, before molting on 17 May (Image 2B). In
two days, these nymphs had turned brownish with very dark head, pronotum and
antennae; there were prominent marks on abdominal tergites, mid-dorsally (scent
gland area) and laterally. These nymphs still remained together around the egg
mass and appeared to be feeding on host plant on the fourth or fifth day after
hatching. The II instar onward the nymphs were seen in small groups (3 to 5
individuals or larger group, see Image 2C) at the base of leaves, sometimes
accompanied by the adults (Image 1E). Actual metamorphosis, especially from V
instar to adult change could not be observed.
The III to V instar nymphs were
very unlike adults with grayish brown body and symmetrical pattern of dark
brown markings dorsally on head, thorax and abdomen; some markings were pale
magenta; even the antennae and legs showed colouration
that was very different from that of the adult
Both, the adults and the nymphs,
emit pungent smell yet this smell did not deter predatory insects like Asian
Weaver Ant Oecophylla smaragdina
while an unknown species of ant was found attacking the nymphs (Image 2D). The
adults were attracted to the lights at night and were often hunted by spiders
(Image 2E). A good population (8 to 10 individuals) of these bugs was often
seen on this Ficus and was observed to breed
at least twice during the year. The lockdown (of Covid
pandemic) during part of 2020 and 2021 prevented more surveys and, especially
lab work. But the bugs were again noted in October 2021on the same Ficus plants.
Adult colouration
and morphology in brief
Colouration of the live bug is a symmetrical
arrangement of green, bluish-green and yellow stripes on the dorsal side as
shown in Image 1A. All this colouration is lost in
drying, leaving only the black elongate spots in the middle on the posterior
border of the corium. Head is bluish-green in median part while the sides are
green and eyes are black. The first antennomere is usually dark green, the
second is pale green while the remaining three are pale stramineous,
but partly fuscous. A broad yellow semicircular band surrounding a bluish-green
area at the base of the pronotum and continuation of that yellow band on
scutellum, where it surrounds similar bluish-green central area of the
scutellum, appears as a regular feature in all the specimens observed from
Assam. Longitudinal oblique bands of bluish-green, yellow, dark green, pale
green, and again dark green, from clavus to anterior border of the corium, are also
seen in all members of the population. Legs are pale stramineous,
with greenish tinge; all these characters are seen in the photo of the live
bugs. The abdomen beneath is greenish or yellowish-green. Fine, short
translucent setae are sparsely present on some parts of the body; these setae
are especially prominent and relatively more in number on legs.
Structure
Body elongate oval. Head short,
broader than long; clypeus prominent, slightly obliquely projecting in front of
mandibular plates; antenniferous tubercles large,
seen from dorsal side; eyes of moderate size, globular, projecting out of head
profile and widely separated from each other; ocelli absent. Antennae very long
(longer than body, see Images 1A, 1B), five segmented with the third antennomere
shortest, slender except for the first antennomere which is relatively thicker.
Labium slender, just reaching mesocoxae. Prothorax
with pronotum twice broad than long, with distinct collar; pronotal
sides (lateral margin) gently sinuate; humeral angles subprominent;
a shallow but distinct transverse depression in anterior one-third; sparse and
fine punctures present, especially in posterior two thirds of pronotum (Image
3A). Scutellum triangular, longer than broad, finely punctured. Prosternum and
a part of mesosternum tumescent with a shallow median
groove; procoxae closer to each other than meso- and metacoxae (Image 3B).
Metathoracic scent gland prominent, projecting laterally with a tubular spout
like peritreme (Image 4A). Evaporatorium
not well developed. Hemelytra broad and long, passing well beyond abdominal
apex; clavus and corium with fine punctures, opaque; membrane translucent
through which abdominal segments can be seen in fresh specimens.
The abdomen has a distinct ventromedian elevated region in the male, not in the
female. In the male the 7th sternum is deeply emarginated with a setose posterior border. The eighth sternum forms cavity to
accommodate the cup like pygophore; dorsal opening of
pygophore covered over by hemelytra; when hemelytra
are displaced, widely open pygophore reveals dark
brown, partly sclerotized, distal portions of the parameres
(Image 4B). The pygophore
is ventrally tumescent, with two lateral and one median process on the posteroventral border (Image 4C). The various other views
of pygophore in situ as well as of detached pygophore are given here to clarify the position, shape,
setosity and the posteroventral processes. Image 4D–F
show the pygophore in situ in dorsolateral, lateral
and posterior views, respectively. In an in situ position, it is apparent that
eighth sternum is hollowed to accommodate pygophore;
this fact is clear in dorsolateral and posterior views of tip of abdomen .
When detached from body, pygophore
appears dorsally flat with wide posterior (distal) opening and round, large
anterior (basal) opening; parameres as well as
lateral tubercles on the inner wall of pygophore are
visible (Image 5A). The general three lobed appearance and setose
nature of posteroventral border is clearly observed
(Image 5B). Lateral view shows cup-like nature of pygophore
(Image 5C). A faint outline of phallus is also visible through KOH treated
semi-transparent wall of pygophore in all the views.
Dorsal and ventral views of
everted phallus are presented (Image 5D, 5E). Phallus is cylindrical in shape
with the various conjunctival processes [dorso-median
distal process single but bifurcate along entire length (Image 5E-A),
membranous; ventromedian distal process more
sclerotized and bifurcate (Image 5E-B); medio-lateral distal processes (Image
5E-C) and ventro-lateral distal processes are also
present (Image 5E-D)] and are labelled in the ventral view of the phallus. Dorso-lateral distal conjunctival processes are seen in
dorsal view (5D-A). The parameres are curved and
sclerotized in distal third (Image 5F). Female Terminalia as shown in Image 5G.
DISCUSSION
Although the species was
described over 180 years ago, in 1837, there is no published information on the
bionomics of this species. In China the species was recently recorded on Ficus hispida (Peng
et al. 2002). We also record the host plant to be Ficus
hispida, a small tree common in northeastern
India, on which the entire life cycle of this bug is completed. Except for the
report from China (Peng et al. 2002), no plant of Moraceae
has ever been recorded as host plant for any Urostylididae
member so far; host plant of U. histrionica
also is so far not recorded in any part of India (Rider 2015) (David Rider, on
line resource Pentatomoidea Home page website). Thus,
this becomes an additional and confirmed record of the host plant for this
species in India (especially because life history was also completed on this Ficus) and also a confirmed record of a new family
of host plant for the urostylidid bugs.
The deposition of special
secretion / bacterial supplement (symbionts) on to eggs by the female is known
in bugs; symbiotic bacteria in the Pentatomoidea
include several lineages of Gammaproteobacteria that
are vertically transmitted to the next generation by means of egg smearing (see
Schuh & Weirauch 2020). It has been recently
documented (Kaiwa et al. 2014) in two species of Urostylis wherein the female deposited a layer of
jelly, which contains nutrition as well as symbiont bacteria, over eggs.
Detailed work on this egg-covering jelly lead Kaiwa
et al. (2014) to assign the following biological roles to this jelly: (1)
protection of eggs against desiccation and microbial contamination, (2)
immediate food source for nymphs, (3) supporting growth and survival of nymphs,
(4) ensuring survival of the symbiotic bacteria outside the host body, and (5)
ensuring successful vertical transmission of the symbiotic bacteria to the next
generation. It is inferred from the above cited work that the jelly deposition
in U. histrionica must also be serving
the same function and it will be worthwhile to look at the symbionts deposited
in this jelly.
Since it was not possible to
collect and preserve the nymphs, detailed microscopic examination of eggs or
nymphs was not possible during this study as lockdown due to covid pandemic affected this work.
Literature search revealed that
there is a paucity of information on the bionomics of bugs of this family; in
fact, no species found in India has been studied in detail. Even detailed
morphology or redescription of the species present in
India has not been done. Distribution data on most species is wanting and most
species are known from northern or northeastern India.
Very brief description and a few
diagrams of the male and female genitalia of U. histrionica
were first provided by Yang (1938b) but this description was restricted to the
structure of the pygophore and parameres
only; aedeagus was not studied. Subsequently aedeagus was described and
illustrated in detail by Kumar (1971). Ahmad et al. (1992) also gave brief
description and illustrations of pygophore, aedeagus
and parameres. Here we have provided digital
illustrations of the pygophore, before and after
detachment from the body, that clearly show its shape.
The aedeagus in dorsal and
ventral views shows most of the characters described by Kumar (1971), but due
to lack of sufficient material additional views could not be prepared. The
various conjunctival processes are shown and labelled. Parameres
are shown in dorsal and ventral view and are similar to the diagram given by
Ahmad et al (1992) but the view of parameres given by
Yang (1938b) is different and is not shown here.
Roca-Cusachs
et al. (2021), while describing a new species under Urolabida,
have discussed about the problems of taxonomy of Urostylididae
and after examining material belonging to the current three urostylidid
genera mentioned above, they feel that the presently described characters of
these genera are insufficient for their clear delimitation; they even feel that
the genus Urolabida should be redescribed, exclusively on the basis of type specimen, as
the remaining species currently included in Urolabida
may require erection of one or more new genera. We are of the opinion that
molecular work coupled with morphological work may resolve the situation
better.
It is clear therefore that there
is a considerable gap in information about Urostylididae
and so some efforts must be specifically directed at this family to resolve the
various issues.
Measurements: Male (3): TL
9.5–9.7 mm, antennae 11–11.2 mm; Female (1) TL 11 mm, antennae 13 mm.
For images - -
click here for full PDF
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