Review of the tribe Chilocorini Mulsant from Iran (Coleoptera, Coccinellidae)

Abstract The Iranian checklist of the tribe Chilocorini Mulsant, 1846 (Coleoptera: Coccinellidae) is updated. In total, 13 species belonging to four genera (Brumoides Chapin, 1965, Chilocorus Leach, 1815, Exochomus Redtenbacher, 1843, and Parexochomus Barovsky, 1922) are listed from Iran. An identification key to all genera and species currently known from Iran is presented along with illustrations of adult specimens and male genitalia.

Although most members of Chilocorini are coccidophagous (Giorgi et al. 2009, Escalona et al. 2017, aphidophagy is also present in some species (Ślipiński and Giorgi 2006); so, the members of this tribe have the potential to be effective biological control agents of coccids and aphids (Drea andGordon 1990, Ponsonby andCopland 1997).
In the last classification of the former subfamily Chilocorinae by Kovář (2007), the species of the genus Brumus Mulsant, 1850 were transferred to Exochomus Redtenbacher and the subgenus Parexochomus of Exochomus was considered as a valid genus, under the name of Parexochomus Barovsky, 1922. This classification was followed by Nedvěd and Kovář (2012). Moreover, according to Ślipiński (2007), the subfamily Chilocorinae Mulsant was dissolved and all tribes were lumped into the subfamily Coccinellinae. This classification was confirmed by subsequent morphological and molecular studies (Seago et al. 2011, Robertson et al. 2015. The number of genera and species of this tribe is continuously increasing (Ślipiński and Giorgi 2006, Łączyński and Tomaszewska 2009, Wang and Ren 2010, Łączyński and Tomaszewska 2012, Li et al. 2015 and it is expected that this trend will be continuing. Although a large number of species of this tribe have hitherto been reported from Iran (Duverger 1983, Kovář 2007, Moddarres-Awal 2012, there is no complete and comprehensive information on the Iranian Chilocorini. The checklist by Abdolahi Mesbah et al. (2016) differs from our view and does not include identification key, diagnosis, and synonymy. Our paper corrects the previous studies on the species of this tribe in Iran, in order to update the information about Iranian Chilocorini.

Materials and methods
This study was mainly based on review of the literature along with the samples collected by the first author. The samples were collected by hand, aspirator, or sweep net in the fields, orchards, and pastures of various provinces of Iran. The specimens were examined under Olympus stereomicroscope (SZ-ST). The specimens were first boiled in 10% KOH for a maximum of 20 min depending on the darkness of the body color/ sclerotization in order to dissect the genitalia. The dissected genitalia were then transferred into distilled water for a maximum of 10 min to rinse off the KOH. Finally, the slides were prepared using Canada balsam. The slides were examined under a microscope (Olympus CX21) and images were taken using a digital camera and edited in Photoshop software (Adobe Photoshop CS5.1). The specimens were identified to species using available keys and resources (Mader 1955, Fürsch 1961, Bielawski 1984, Kovář 1995, Raimundo and van Harten 2000, Raimundo et al. 2008. Although the higher classification of Seago et al. (2011) was followed in this study, taxonomy at the species level is based on Kovář (2007). Morphological terminology follows that of Ślipiński (2007). All of the specimens collected and examined during this study are deposited in Plant Protection Department, Lorestan University, Agricultural Faculty, Khorramabad, Iran.

Results and discussion
The Iranian coccinellid species list of the tribe Chilocorini is updated, which includes 13 species belonging to four genera (Brumoides, Chilocorus, Exochomus, and Parexochomus).
Although there are some records of Exochomus flavipes Thunberg, 1781 from Iran (Ansari pour and Shakarami 2011, Tavakol et al. 2014), re-examination of the voucher specimens of this species showed that these reports are misidentifications and these samples are actually Parexochomus nigromaculatus (Goeze, 1777). Parexochomus flavipes is morphologically similar to P. nigromaculatus but is distinguished from it by the male genitalia, and P. flavipes has not hitherto been reported from Palaearctic region (Kovář 2007). It is distributed in the northern states of USA (Gordon 1985) and south and west of Africa (Fürsch 1961). Mahghari and Ostovan (2006) reported two ladybird species, Brumus undecempunctata L. and Chilocorus stigma (Say, 1835), from the northern provinces of Iran (Gilan and Mazandaran province) as natural enemies of whiteflies. In coccinellid taxonomy, there is no known species under the name of Brumus undecempunctata, while Chilocorus stigma has not been reported so far from Palaearctic region (Kovář 2007). According to our knowledge, the presence of these species in Iran is doubtful and not confirmed. Barovsky (1922) reported Exochomus kiritshenkoi Barovsky, 1922 from Iran (Shahrood, H. Christoph leg.). There are also specimens in Zoologichesky Institut (Akademii Nauk SSSR) in St. Petersburg, labeled as E. kiritshenkoi which had been collected from Iran (Shahrood, H. Christoph leg). Kovář (1995) however identified these specimens as E. gebleri Weise.
Data on the presence of E. bifasciatus in Iran are based on Kovář (2007). Since we do not have any information (particularly morphological) about this species, it is excluded from the identification key of Iranian species of Chilocorini.

Subfamily Coccinellinae Latreille, 1807
Tribe Chilocorini Mulsant, 1846 Diagnosis. Body size small to medium (2.0-8.0 mm), with downward directed head inserted into prothorax to some extent; dorsum usually without obvious pubescence. Head wider than long, flattened ventrally; clypeus variously expanded laterally and wholly concealing antennal insertions. Mandibles triangular, strong with an apical tooth and heavily developed molar teeth; maxillary palps relatively long, terminal palpomere parallel sided to weakly enlarged apically; labial palp clearly separated basally, inserted on ventral side of prementum. Antenna composed of 7-10 antennomeres, markedly short with a fusiform club composed of three terminal antennomeres. Prosternum fairly elongate in front of coxae; prosternal process narrow, parallel sided without carinae. Hind wings with large anal lobe. Elytra irregularly punctate, with epipleuron wide and complete to apex, frequently with foveae for receiving apices of femora. Abdomen with five or six ventrites; postcoxal lines at abdominal ventrite 1 variable, without associated pits and pores. Male genitalia with symmetrical tegmen, penis guide sometimes asymmetrical; parameres well developed, apically setose; penis a simple, single sclerite with sizeable basal capsule. Coxites triangular and faintly sclerotized, usually without styli; bursa copulatrix with infundibulum or fleshy lobe, with sperm duct composed of two parts of different diameter; spermatheca bean-shaped, sclerotised without well differentiated nodulus or ramus, with large accessory gland (after Ślipiński 2007).