Bull. Inst. r. Sei. nat. Belg. Bruxelles 31-XII-1973 Bull. K. Belg. lnst. Nat. Wet. Brussel 1 ENTOMOLOGIE 49 9 1 1 STUDIES ON THE COMPARATIVE MORPHOLOGY OF SCENT APPARATUS AND ALIMENTARY ORGANS OF SOME STINK BUGS (PENT ATOMIDAE : PENTAT OMINAE) OF PAKISTAN WITH REFERENCE TO PHYLOGENY BY lMTIAZ AHMAD & SHAFAT AHMAD KHAN SYNOPSIS An attempt is made to study the comparative morphology of the scent apparatus and of the alimentary organs within the subfamily Pentato minae. The result is compared with the accounts given in the existing literature and the relationship of various group within Pentatomoidea on the basis of these characters is briefly discussed. KEY TO THE LETTERING ACG : accessory gland; C : coxal cavity; CAEC gastric caeca; DEP : ventral depression in the reservoir; DRE : duct of the reservoir (dorsal in position); GL : scent gland; IAM : inner arm of valvular apparatus; LDR : duct of the reservoir (ventral in position); MGS : midgut sac (midguti); M. G. 2 : midgut2; M. G. 3 : midguta; MT : malpighian tubule; N : ganglionic nerve; OAM : outer arm of valvular apparatus; OES : oesophagus; OS : ostiole; P : ileum (pylorus); PAG : pterothoracic abdominal ganglion; PT : pterothorax : RE : reservoir; REC : rectum; S. G. A. : anterior lobe of principal salivary gland; S. G. P. : posterior lobe of principal salivary gland; VES : vestibule; VRE : reservoir ventrally. 2 lMTIAZ AHMAD & SHAFAT AHMAD KHAN 49, 9 CONTENTS Page Introduction 2 Material and Methods 4 Part I. The scent apparatus morphology 4 General aspects of the morphology of the scent apparatus 4 Comparative scent gland morphology . . . . . . . . . . . . 8 Family Pentatomidae (subfamily Pentatominae) 8 Tri be Asopini . . . . . . 8 Tri be Podopini . . . 9 Tribe Eurydemini ... 9 Tribe Aeliini ... . . . 11 Tribe Sciocorini ... 13 Tribe Carpocorini 15 Tribe Pentatomini ... 17 Tribe Eysorcorini . .. 20 Part II. Morphology of alimentary organs . . . . . . . . . . . . . . . . . . 23 General aspects of the morphology of the alimentary organs 23 Comparative morphology of alimentary organs . . . 25 Family Pentatomidae (subfamily Pentatominae) 25 Tri be Asopini . . . . . . 25 Tri be Podopini .. . 27 Tribe Eurydemini ... 29 Tri be Aeliini ... . .. 33 Tribe Sciocorini . .. 34 Tribe Carpocorini .. . 35 Tribe Pentatomini . . . 38 Tribe Eysarcorini ... 42 Phylogenetic considerations based on the characters of scent apparatus and those of alimenrary organs 44 Acknowledgements . 51 Sumrnary 52 References 53 INTRODUCTION During the recent years various aspects of comparative morphology (metathoracic scent gland ostioles, trichobothria, male and female geni talia, eggs, nymphs, male and female interna! reproductive organs, chro mosomes and etc.) are used in order to solve many of the phylogenetic problems within Pentatomoidea. COBBEN's (1968) list of references extensively covers most of these aspects. 49, 9 STINK BUGS (PENTATOMIDAE : PENTATOM!NAE) OF PAKISTAN 3 LESTON (1958 b) in his « higher systematics of shield bugs » probably rightly has claimed « there is agreement amongst specialist's that shield bugs warrant superfamily status as Pentatomoidea. At family level no two authors agree ». M!YAMOTO (1961) has emphasized this on several places, for instance with reference to Acanthosomatidae he has men tioned, « in the current classification of the Heteroptera, some authors (LESTON, 1953; Sournwooo, 1956; PENDERGRAST, 1957; ScUDDER, 1959 and etc.) considered this group as a family but others (CHINA and MILLER, 1955 and 1959) have another opinion». On the lower levels the disagree ments seem to be even greater. LESTON (1958 b) referring to various groups, then according to him excluded from the family Pentatomidae, such as Eurygasterinae and Halyinae has specified that the status of many of these are required to be increased or diminished. After BRINDLE.Y (1930) scent apparatus morphology on comparative basis in respect to the above mentioned problems has never been used within the superfamily Pentatomoidea, although GUPTA (1961 and 1964) and AHMAD and KHANuM (1968) and AHMAD et. al. (in press) have emphasized its importance as a systematic tool. BRINDLEY's work of 1930 included only two species representing two different families namely Acanthosomatidae and Pentatomidae (as they are generally regarded now) and even after her in various specific descriptions of scent apparatus only five species representing three families Dinidoridae, Cydnidae and Pentatomidae including three tribes Pentatomini, Eurydemini and Halyini of the latter have been covered, whereas the descriptions of GUPTA (1960) for Aspongopus janus (FABRICIUS) (Coridius) and RAI and TREHAN (1964) for Bagrada cruciferarum ICIRKADL Y are erroneous and misleading. The early works of DUFOUR, 1833; KUNCKEL, 1866; KuLWIEC, 1898; GULDE, 1902; KERSHAW, 1907 and MurR, 1907 covering various features of scent apparatus in various species of the superfamily Pentatomoidea are in addition to the works reported above. REMOLD (1962) covers func tional aspects. On the contrary, with reference to alimentary organs, after MIYAMOTo's (1961) famous work on « comparative morphology of alimentary organs of Heteroptera with the phylogenetic considerations » which jncluded an observation of alimentary orgails of forty species, alone from the families Pentatomidae and Scutelleridae and several species representing Phyllocephalinae (Phyllocephalidae of MIYAMOro), Urostylidae, Dinidoridae, Plataspidae, Cydnidae and Acanthosomatidae, apart from specific descriptions of alimentary organs with reference to functional aspects (DUFOUR, 1833; GLASGOW, 1914; SAREL-WHITEFŒLD, 1929; MALOUF, 1933; :HAMNER, 1936; ELSON, 1937, :HARRIS, 1938; KRETOVICH et. al., 1943; STROGAYA, 1950; VOJDANI, 1954; GooDCHILD, 1963 a; 63 b and 66; R.ASTOGI, 1961; 1965 and 1966) which have appeared from cime to time in the existing literature. The phylogenetic considera tions on the basis of the comparative salivary glands morphology alone are in addition to those referred above (KUNCKEL, 1866; BuGNION & POFF, 4 IMTIAZ AHMAD & SHAFAT AHMAD KHAN 49, 9 1908; 1910; BAPTIST, 1941; NuoRTEVA, 1954 and 1956; SouTHWOOD, 1955; KuMAR, 1962, 65, 69 a and b). In order to add to the descriptions of the scent apparatus and those of alimentary organs within the subfamily Pentatominae and in order to bring together the existing literature for a comparison and for a philogenetic considerations of these characters in correlation with each other, the present study was undertaken. MATERIAL AND METHODS Adult pentatomine bugs (Table No. 1) were collected mainly on lucerne (Medicago sativa; Papilionaceae), young rawasan (Sesbania sesbans; Papilionaceae), and bushes (Sueda monica; Chenopodiaceae) from various parts of Sind during spring and summer of 1969 and 1970 (April to September). For anatomical studies both, preserved (in CARNOY fixative, 3 parts absolute alcohol and one part glacial acetic acid) and live speci mens were clissected under Leitz binocular but good results were only obtained with freshly killed specimens. The structure of the scent appa ratus was studied after removing the overlying viscera. Morphological diagrams were made using ocular grid on graph papers. For all measure ments ocular micromillimeter graticule was used. PARTI. - THE SCENT APPARATUS MORPHOLOGY General aspects of the morphology of the scent apparatus Scent apparatus. After removing the crop and the over lying viscera, a pair of white racemose, glands are exposed attached to the anterior sicle (lateral ducts) of a reservoir. On its ventral surface lies usually the convoluted accessory gland which also opens in the lateral ducts of the reservoir. Lateral ducts of each sicle in between the meso and metathoracic coxal cavities open in their respective semitransparent membranous vestibules. The opening on each sicle is guarded by a valvular apparatus. In turn each vestibule opens to the exterior through an opening located slightly lateral in between the mesa and metathoracic coxal cavities on the metasternum. The glands. The glands are racemose spongy in appearance. Each gland lies sym metrically adjacent to the pterothoracic abdominal nerve, facing each other. The glandular tissue is shining white and is easily distinguished TABLE 1 Common name 5'è Species examined Locality Botanical name of the host plants \0 Family P ENTAT 0 Ml D A E "' .z.-j Subfamily l : PENTA T 0 MIN A E ;>; ctl:::l C"l Tribe I : ASOPINI "..,' zt'1 Species 1 : Andrallus spinidens (FABR.) ... ... ...... 1 Malir gardens 1 Lucerne 1 Medicago sativa ..-j and Hyderabad ;i. 6 ~ 0 Tribe 2 PODOPINI ;i. t'1 Species 2 : Tarisa fraudatrix (HoRvÂTH) ............ [ Thatta [ Bush [ Sueda monica 'zt"'1d ..-j ~ Tribe 3 : EURYDEMINI ~ z .; Species 3 : Bagrada hilaris (BuRM.) . . . . . . . . . . . . . .. 1 Malir gardens, 1 Lucerne and Mus tard Medicago sativa Tan do-jam Brassica campestris .,, 0 and Mirpurkhas '"d ;i. Species 4 : Stenozygum speciosum (DISTANT) ... ··· 1 Werh and Mirpurkhas 1 Green creeper of Sind Salvadora prisica CS "' ..-j Species 5 : S. pseudospeciosum GHAURI . . . . . . ... . . . Thatta Plant without leaves Capparis decidua ~ and Malir gardens Tribe 4 : AELIINI Species 6 Aeliomorpha lineaticollis (WESTWOOD) . , Malir gardens, Thatta, 1 Lucerne, Rawason Medicago sativa V, Hyderabad and Suburbs Sesbania sesbans 1 TABLE 1 (contd. and end) 0\ Common name Species examined Locality Botanical name of the host plants Tribe 5 : SCIOCORINI Species 7 : Sciocoris lewisi (DISTANT) . . . . . . . . . .. . . .. 1 Thatta 1 Bush 1 Sueda monica Tribe 6 : CARPOCORINI ~ Spec'.es 8 : Dolycoris indicus (STAL) . .. . . . . . . . .. . . · 1 Malir gardens 1 Lucer~e Medicago sativa N > Spec1es 9 : Croantha ornatula (H. ScH.) . . . . . . . . . . . . Thatta Cholru, Bush Amaranthus viridis ~ Sueda monica ~ i<:' Tribe 7 : PENTATOMINI :"i': > Species 10 : Nezara viridula L. var. smaragdula ~ (FABR.) ........ . Malir gardens, Lucerne, Rawason Medicago sativa > Thatta and Hyderabad Sesbania sesbans ~ > Species 11 Acrosternum graminea (FABR.) Pipri and Thatta Indigofera, Rawason Indigofera oblongifolia 0 Sesbania sesbans ~ Species 12 : Piezodorus rubrofasciattts (F.) .. . .. . .. . Malir gardens, Lucerne, Rawason Medicago sativa Thatta and Hyderabad Sesbania sesbans Tribe 8 : EYSARCORINI Species 13 : Eysarcoris inconspicuus (H. ScH.) .. . .. . Karachi University Lucerne, Rawason Medicago sativa Campus and Malir Sesbania sesbans gardens -~ Species 14 : E. modestus (DISTANT) .............. . Malir gardens Niazbu Ocimum basilium \D and Hyderabad 49, 9 STINK BUGS (PENTATOM!DAE: PENTATOMINAE) OF PAKISTAN 7 from the surrounding fat bodies which resemble loose mass of aggregate cells. Each gland opens in the lateral ducts of the reservoir through usually an unmarked very thin membranous duct. The reservoir. The reservoir is usually located medially in the depression of the metasternum. Anteriorly it is continued into relatively narrow, mem braneous ducts which lie on each sicle immediately posteriad to the mesosternal ridges and adjacent to the anterior ridges of the metathoracic coxal cavities. The wall of the reservoir appears thicker and more cuti cular as compared to the glands. It is very slightly depressed dorso medially and dorso-laterally and ventrally has the ridges and the furrows. ln the freshly killed specimens the reservoir seems to be full of secretion and its walls show remarkable smoothness. The accessory gland. The accessory gland usually appears like convoluted and coiled tube on the ventral surface of the reservoir usually occupying median position of the reservoir, having almost the same colour as that of the reservoir. lt is only distinguishable from the ventral wall of the reservoir as the raised tubular structure. Usually on the postero-ventral sicle of the reser voir it is very well fitted in the ventral groove and is very hard to recognize. It opens on each sicle in the lateral ducts of the reservoir adjacent to the ventro-medial depression. The vestibule. The vestibules are semimembranous, whitish, tubes lying on each sicle between the ridges of the meso and metathoracic coxal cavities and slightly laterad to them. On their proximal end these are connected with the distal portion of the ducts of the reservoir through valvular apparatus. When pressed at the base, the secretion appears moving in their cavities. At their distal end these open through an aperture or ostiole. The vertical lunate ridge of the ostiole is absent. The valvular apparatus . The valvular apparatus is usually a semi-lunate, flap-like structure fitted nicely underneath the ridges of each metathoracic coxal cavity. Each valvular apparatus lies on the anterio-lateral sicle of the duct of the reservoir and governs the flow of the secretion from the lateral ducts of the reservoir into the vestibules. The apex of the outer arm is fitted underneath the raised ridges of the metathoracic coxal cavities whereas the inner arm is free. The two arms are separated through an interlying 8 IMTIAZ AHMAD & SHAFAT AHMAD KHAN 49, 9 membrane. When the apex of the inner arm is pulled, the membranous portion of the valvular apparatus is lifted up and the flow of yellowish liquid may be seen into the vestibules. The tracheation and the nerve supply. From the pterothoracic abdominal ganglion a median nerve and usually 3 pairs of lateral nerves appear to run posteriad into the dorso-medial groove of the reservoir and at the sicles of the ducts of the reservoir respectively. Probably the lateral nerves innervate the muscles of the valvular apparatus. The glands and the reservoir show rich supply of the fine tracheal branches. Mode of action. Secretion probably flows from the glandular cells to the lumen of the glands which ejects it into the reservoir, probably through the cumulative pressure. The accessory gland also discharges its content into the reservoir. The muscular contraction probably pulls the outer arm of the valvular apparatus which releases the valve which in turn allows the secretion to enter into the vestibules from where it is ejected outside through the ostioles. COMPARATIVE SCENT APPARATUS MORPHOLOGY Family PENTA T OMIN AE Sub-family PEN TA T 0 MID A E Tribe ASOPINI (Figs. 1-3) Species examined : Andrallus spinidens (FABRrcrns). Scent glands elongated, narrow somewhat leaflike, placed laterad close to the lateral margins and extending on to the posterior margin of the reservoir; duct of the glands not well marked; reservoir distinctly bilobed, of red rose colour reaching only on to the middle of the metathoracic coxal cavities; accessory glands on the ventral sicle of the reservoir having six or seven convolutions, placed away from the lateral margins; valvular apparatus lunate; vestibules of uniform width, moderately long and curved, handle-like, with very small rounded ostioles. 49, 9 STINK BUGS (PENTATOMIDAE : PENTATOMINAE) OF PAKISTAN 9 Fig. 1. - Andrallus spinidens (FABRICIUS) : scent apparatus entire, dorsal view. Fig. 4. - Tarisa fraudatrix (HORVATH) : scent appararus, dorsal view. Tribe PODOPINI (Figs. 4-6) Species examined : Tarisa fraudatrix (HoRVATH). Scent glands of irregular form, placed dorsad well away from the lateral margins and extending on to the posterior margin of the reservoir; duct of the glands not well marked; reservoir somewhat « V » shaped, tube-like, semitransparant, whitish, membranous in appearance, hanging between the metathoracic coxal cavities and reaching on to before the middle of the cavities; accessory gland on the ventral surface of the reservoir of « V » shape, corresponding to that of reservoir, smooth, without convolution, placed away from the lateral margins but reaching close to them anteriorly; valvular apparatus smoothly lunate; vestibules almost straight, of uniform width, only slightly tapering distad with very minute rounded ostioles. Tribe EUR YDEMINI (Figs. 7 -15) Previous description : RAI and TREHAN (1964). Species examined : Bagrada hilaris (BuRMEISTER); Stenozygum specio sum (DISTANT); S. pseudospeciosum GHAURI. 10 IMTIAZ AHMAD & SHAFAT AHMAD KHAN 49, 9 LOR_ DEP:-_ LOR IAM OAM . 1 3 ---, ,RE i VESI IPT 1mm 1 1 Il r '........i1-1_,.._.....~ _os _GL 5 ----- 0,Smm 6 ---- 1mm Fig. 2. - Andrallus spinidens (FAsrucms) : scent reservoir, showing accessory gland, ventral view. Fig. 3. - Andrallus spinidens (FAsrucms) : scent apparatus, showing valvular apparatus, enlarged, dorsal view. Fig. 5. - Tarisa fraudatrix (HORVATH) : scent reservoir showing accessory gland, ventral view. Fig. 6. - Tarisa fraudatrix (HORVATH) : scent apparatus, showing valvular apparatus, enlarged, dorsal view. Scent glands leaf-like, placed dorsad, near the sicles of the reservoir and usually extending on to the posterior margin; duct of the glands not well marked; colour and shape of the reservoir variable, posterior margin usually somewhat curved, not reaching beyond posterior margin of meta-throracic coxae; accessory gland on the ventral surface of the reservoir usually « V » shaped without loops, away from the lateral margins; valvular apparatus apparently lunate; vestibules convexly curved with very small ovoid ostioles.