The Tribe Scymnini (Coccinellidae: Coleoptera) From Sindh Province, Pakistan

Coccinellids are important natural enemies of aphids, scale insects, mealybugs, whiteflies, jassids and mites. They are being augmented or conserved for population reduction of different agricultural crop pests in the concept of Integrated Pest Management throughout the world. The genera and species in the tribe Scymnini known from Pakistan are revised and redescribed. Two genera including two subgenera and six species among which three species are newly reported, is therefore, a new addition to Coccinellid fauna of Pakistan. Keys to all taxa, descriptions of the higher taxa, species diagnoses, synonymies, and distribution records are included.


Materials and Methods
Coccinellids were collected from different localities of the Sindh Province. The specimens were mounted after boiled in 10% solution of KOH for 10-15 min. Various body parts were separated and mounted in Canada balsam after a brief dip in xylol. Different structures including genitalia were studied under a Kruss Binocullar. Measurements and drawings of the body and other structures were made by using a micromillimeter scale and an ocular grid. The terminologies for various taxonomic structures including genitalia and procedures used by the following scientists were generally followed (Inayatullah andSiddiqui 1978, Gordon 1985). The taxonomic structures especially male and female genitalia after illustration were preserved in microvial with glycerine and pinned with specimen. All diagrams are to the given scales, and all measurements are in millimeters.
All specimens were identified by the author following the checklists, descriptions, and keys given by Chapin and Ahmad (1966), Pang and Gordon (1986), Poorani (2002), Rafi et al. (2005), and with the help of the following website: NBAIR (2009). Identifications were confirmed by Dr. Claudio Canepari, an authority on the family Coccinellidae from Italy. Scymnini Mulsant 1846 Small; elongately oval, moderately convex; dorsal surface pubescent; coloration variable; head with clypeus straight anteriorly, with minute emarginations; antennae short, 8-11 segmented, terminal segments forming distinct club; eyes small, coarsely faceted, pubescent; maxillary palp with terminal segment cylindrical narrow or weakly expanded toward distal end; anterior pronotal margin weakly excavated; anterior margin of prosternum flat, straight never concealing mouth parts, prosternal process with or without longitudinal carinae; elytral epipleura very narrow, without any distinct foveae; tibial spurs present; tarsi trimerous or cryptotetramerous; abdomen with six visible sternite in male and female.

Tribe Scymnini Mulsant
Genitalia: Male genitalia with tegmen short, narrow to broader, sipho elongated, narrow with hammer shaped siphonal capsule; female genitalia with genital plate long, narrow, or short, nearly round; spermatheca present, sign of interrogative shaped.
Head: Clypeus with anterior margin truncate or slightly convex, emargination without setae; antennae 10 or 11-segmented, basal segment stout, about twice as long as wide, slightly curved, second segment slightly shorter than broad but equal in width to basal; third segment slender, about twice as long as broad, fourth and sixth about equal, either shorter than fifth but all about the same width, seventh and eighth segments slightly longer and broader, ninth segment much wider at apex than at base, 10th segment a little broader than long, 11th segment as long as 10th, rounded at apex, the last three or four segments forming a compact club; maxillary palpus with apical segment cylindrical, apex obliquely truncate.
Male genitalia: Median lobe symmetrical or asymmetrical, mostly shorter than paramere; siphon with siphonal capsule not complete hammer shaped, with adjacent arm shorter than opposite arm; trabes curved, mostly broader apically.
Female genitalia: Spermatheca hook shaped, elongated, basally rounded with very small accessory gland with short narrow duct.
Coloration: Body dark brown, lighter in male, eyes brown, pronotum dark pitchy brown to black in middle, anterior, and lateral margins reddish brown and lighter, scutellum dark brown, elytra yellowish to reddish brown, with a dark brown to black sutural stripe starting from basal margin and gradually narrowed toward apex, lateral borders narrowly dark brown to black at middle, elytra and pronotum densely covered with short transparent yellow hairs ventral side reddish to yellowish brown, except pro-, meso-and metasterna and middle of abdominal segments dark brown and covered with fine hair and finely pitted.
Head: Eyes large; labrum with anterior margin convex; ligula with straight margin; terminal segment of labial palp long pointed and converged.
Abdomen: Second to fourth segments narrow medially except the terminal segment; postcoxal line incomplete running parallel to posterior margin to nearly 3/4th of its length and then gently recurved; terminal sternite with posterior margin with hairs entire.
Male genitalia: Sipho bifurcated and broader before the terminal end, terminal end broader and tetragonal, siphonal capsule with inner arm dorsally emarginated forming trigonal shape, outer arm straight and elongated expanded distally; tegmen with trigonal basal piece with no emargination, medial lobe short and broader; parameres straight elongated; trabes medially bended or curved.
Comparative note: It resembles in external appearance with hoffmanni but differs this species from nubilus due to larger in size and the more thickened sutural stripe. The species nubilus belongs to the subgenus Scymnus (Scymnus), whereas the later one belongs to the subgenus Scymnus (Neopullus).
3. Body brownish-black; each elytron with one black spot attached with one patch on each lateral side; sipho terminally with a pointed hook; trabes terminally fin-shaped ------Scymnus (Pullus) syriacus. Coloration: Body glabrous or pubescent; head brownish black; pronotum and elytra shiny dark to bluish in color, scutellum black, two reddish spots on each elytron; color and size variation in spots are common; ventral side brownish black.
Head: Eyes large covering 3 = 4 th part of head; anterior margin of labrum convex; ligula expanded anteriorly with straight margin; labial palp with terminal segment small and pointed. Thorax: Anterolateral margin of pronotum without hairs; prosternal process with carinae reaching to the anterior margin, anteriorly broad; scuto-scutellar suture narrow medially while broader proximally and distally; tibia with dorsal margin distally with small hairs.
Abdomen: Second to fourth segments narrow medially and broader laterally; fifth segment larger in both sexes; postcoxal process bifurcated; postcoxal line complete strongly v-shape; terminal sternite with posterior margin with few hairs.
Male genitalia: Sipho broader, thick, sclerotized and bifurcated terminally and bearing a hook at the starting of this thick part; siphonal capsule completely funnel shaped; basal piece elongated and triangular; parameres slightly diverted; median lobe knife shaped with a deep cutting laterally before the terminal end; trabes straight expanded apically.
Female genitalia: Genital plates larger and slightly tetragonal; lateral plates small and completely trigonal shaped; 10th tergite broader medially and narrow laterally. Comparative note: This species is similar in the external appearance with taiwanus, but in taiwanus, the four spots on elytra are arranged along the lateral margin, differs in shape, and somewhat the body coloration is also slightly variable. The species qaudrillum sometime exactly resembles frontalis having very little differences.
Remarks: It is newly recorded from Pakistan.
Head: Eyes small; anterior margin of labrum slightly notched; ligula with straight margin; terminal segment of labial palp small pointed and converged.
Thorax: Anterolateral margin of pronotum with few hairs; prosternal process with carinae broader toward posterior; scuto-scutellar suture fattened distally and narrower proximally; tibia with dorsal margin distally with minute hairs.
Abdomen: Second to fourth segments equal in size except the terminal segment; postcoxal line complete, semicircular; postcoxal process slightly notched; terminal sternite with posterior margin with hairs entire.
Female genitalia: Genital plates and lateral plates elongated and trigonal in shape; 10th tergite narrow medially with elongated lateral arms; spermathecal capsule with only elongated oval cornu, basally broader and oval, the part between cornu and basal region narrow and constricted.
Material Comparative note: This species is similar sometimes in coloration and shape with castaneus but differs due to the presence of elytral glass shape longitudinal spot on basal half, two small circular spots on posterior half, sometimes with only posterior spots. In castaneus, spots are totally absent and also it is smaller in size than coccivora.
Head: Labrum with anterior margin slightly notched; ligula with straight margin; terminal segment of labial palp small pointed and converged.
Thorax: Anterolateral margin of pronotum bearing a group of long hairs; prosternal process with carinae strongly divergent posteriorly, anteriorly pointed; scuto-scutellar suture slightly straight, broader toward ends while narrower medially; tibia with dorsal margin distally with small hairs.
Abdomen: Second to fourth segments equal in size while last segment larger; postcoxal process slightly bifurcated; postcoxal line complete, broadly v-shaped; terminal sternite with posterior margin with hairs entire.
Male genitalia: Sipho elongated terminally with narrower and sshaped end, siphonal capsule with opposite arm short, pointed and curved while adjacent arm straight, elongated and distally rounded; basal piece triangular; median lobe longer than parameres and broadly expanded medially; trabes thick proximally and narrow and curved distally.
Comparative note: This species is similar sometimes in coloration and shape with coccivora but differs because it is larger in size, lways uniformly yellowish brown, completely devoid of markings but coccivora smaller in size and mostly markings on elytra are present.
Remarks: This species is also newly recorded from Pakistan. Scymnus (Pullus) syriacus (Marsuel 1868) (Fig. 5) Coloration: Body reddish brown, pubescent, head, mouth parts, ventral side all black, each elytron with a large longitudinal black spot attached with one small brownish patch on each side.
Head: Labrum with anterior margin slightly notched; ligula with straight margin; terminal segment of labial palp small pointed and converged.
Abdomen: Second to fourth segments equal in size except the terminal segment; postcoxal line complete, strongly v-shaped; postcoxal process with anterior margin broader, straight; terminal sternite bearing long setae medially while short setae laterally in male.
Head: Clypeus with anterior margin slightly truncate, emarginations with minute setae; antenna pseudo-11 segmented or 10 or 11 segmented, first and second segments completely tightly jointed together, basal segment moderately stout, curved, second segment separated from first by a false suture, not always visible, half as long as broad but equal in width to basal, third segment a little longer than broad, fourth, fifth, and sixth segments of same width, the fifth slightly shorter than fourth or sixth, seventh, eighth, and ninth segments progressively slightly longer and wider, 10th segment slightly longer than broad but nearly quadrate, 11th segment half as long as 10th, almost hemispherical; maxillary palpus with apical segment cylindrical, apex obliquely truncate.
Abdomen: Abdomen with six visible segments; postcoxal line incomplete.
Male genitalia: Median lobe symmetrical distinctly narrow, shorter than paramere; sipho with siphonal capsule hammer shaped but opposite arm distinctly broader; trabes slightly expanded apically.
Female genitalia: Spermatheca weakly hook shaped, deeply elongated with cornu and basal part distinctly separated with very small accessory gland with very short duct.
Coloration: Head and pronotum yellowish brown; elytra light yellowish brown, area along basal margins and suture darker, often with a distinct dark patch.
Head: Labrum large, with convex anterior margin; ligula with anterior margin slightly notched; labial palpus with terminal segment deeply pointed.
Thorax: Anterolateral margin of pronotum with minute hairs; prosternal process broader than long, without carinae and finely punctuate; tibia elongated, narrow, slightly oval with minute hairs dorsally.
Abdomen: Second to third, terminal segments large, fourth to fifth smaller; postcoxal process deeply notched; postcoxal line incomplete, parallel to posterior margin of first abdominal ventrite for up to 4/5 th of its length and then very slightly recurved; last segment with small haors throughout.
Male genitalia: Sipho thick proximally and slightly narrow distally bearing terminally a hook just like the sign of interrogation and medially passing a line from mid to end of sipho, siphonal capsule with opposite arm short, broader and tetragonal shaped while adjacent arm narrow and spoon shaped distally; tegmen with basal piece slightly tetragonal with thick margins; medial lobe shorter than parameres with right lateral margin truncate terminally (cutting); trabes narrow proximally, medially expanded and terminally upwarded and saw like.
Female genitalia: Genital plates elongated and trigonal shape; lateral plates small and also trigonal; basal portion of spermatheca elongated and oval, cornu sclerotized. Comparative note: This species resembles with tagiapatus in external appearance including the triangular brownish spot at elytral basal margins. The main difference is that in reguralis this spot is small only limited to the anterior basal part of elytra, but in tagiapatus, it is extended to the second and third parts along the medial junction as well as along lateral margins reaching to the middle of elytra.

Discussion
The study of male genitalia of the minute-sized species of the genus Scymnus was more difficult and for the first time proved to be final valid criteria for the identification at species level for any type of insect (Wilson 1927). This study helped to make the present investigation more valid by giving more focus on male genitalia of Coccinellids. Coccinellidae occurring in America north of Mexico, among which 57 genera (including six genera of the Scymnini) and 475 species (including above 90 species of Scymnini) were treated in a precise systematic way. Keys to all taxa, descriptions of the higher taxa, species diagnoses, synonymies, and host records were also included (Gordon 1985). The findings of this investigation supported this study in case of diagnostic characters, description of taxa and construction of identification keys to different groups of taxa of the family Coccinellidae. The species of the Scymnus bipunctatus group, overview of the genera and subgenera of the tribe Scymnini, and classification of the family Coccinellidae including six subfamilies with the addition of a new subfamily were given from West-Palaearctic region (Fürch 1987), which supports the classification of the Coccinellids including the tribe Scymnini of the present investigation. The annotated checklist of the Coccinellidae of the Indian Subregion covers the Coccinellids of India, Pakistan, Bhutan, Nepal, Sri Lanka, Bangladesh, and Myanmar and is considered to be more informative for the recent taxonomists of Coccinellids specially of these regions. In this checklist, a detailed geographical distributions and type depositories were mentioned. The author also recorded N. reguralis Sicard, P. murreensis Ahmad, P. simmondsi Ahmad, Scymnus (Pullus) coccivora Ayyar, S. (Neopullus) fuscatus Boheman, and S. (Scymnus) nubilus from Pakistan (Poorani 2002). This study supports all the findings, specially the identification and confirmation of Coccinellids studied in this study.
The works related to systematic, morphology, and distribution (Ahmad 1966(Ahmad , 1968Inayatullah andSiddiqui 1978, 1979;Inayatullah 1980;Hashmi and Tashfeen 1992;Irshad 2001aIrshad ,b, 2003Rafi et al. 2005;Ali 2013) from Pakistan support the identification, preys with reference to host plants, and distribution of Coccinellids including the members of the tribe Scymnini carried out in this study, but very rare systematic works of the Coccinellids were found according to the viewed and cited literatures of this study. These findings confirm the presence of Scymnus (Scymnus) nubilus Mulsant, Scymnus (Pullus) coccivora Ayyar, N. regularis (Sicard) also in the Sindh Province of Pakistan, but this investigation is unique than the other findings, because it presents few new records such as Scymnus (Pullus) syriacus Marsuel, Scymnus (Pullus) castaneus Sicard, and Scymnus (Pullus) quadrillum Motschulsky.