Revision of the genus Endochilus Weise (Coleoptera: Coccinellidae: Chilocorini)

Abstract The members of the endemic African genus EndochilusWeise, 1898 (Coleoptera: Coccinellidae: Chilocorini) are redescribed, diagnosed, and illustrated. Lectotypes are designated for Endochilus compater Weise, Endochilus minor Weise, Endochilus plagiatus Sicard, Endochilus rubicundus Weise, and Endochilus styx Sicard. One new species is described: Endochilus abdominalissp. nov. Notes on the genus and nomenclatural history for each species are provided. A key for iden- tification of all species is presented. Adult characters concerning similarities of Endochilus to other genera of African Chilocorini are discussed.


Endochilus
(Coleoptera: Coccinellidae: Chilocorini) was established by Weise (1898) for three new species from Central Africa, Endochilus cavifrons, Endochilus minor, and Endochilus rubicundus, distinguished by dark and explanate elytral margins covered with setae. Weise placed Endochilus in the subfamily Chilocorinae, which then included hemisphaerical beetles, usually glabrous and irregularly punctate with very short antennae, with clypeus expanded laterally and dividing the eyes, and elytral epipleura more or less foveolate.
In more modern classifications, Endochilus has been placed within the tribe Chilocorini Mulsant, 1846 in the subfamily Chilocorinae (Sasaji 1968), which was often regarded as the "most primitive" lineage of Coccinellidae (Sasaji 1971;Kovář 1996). According to Ślipiński (2007), who proposed only two subfamilies for the family Coccinellidae, Microweiseinae and Coccinellinae, Endochilus belongs in the tribe Chilocorini of the subfamily Coccinellinae. This classification was subsequently supported by molecular and combined analyses by Giorgi et al. (2009) and Seago et al. (2011), and was followed and implemented by Ślipiński and Tomaszewska (2010) in a comprehensive synopsis of the family Coccinellidae.
Species belonging to Chilocorini are characterized by distinctly hemispherical body, expanded clypeus, and short appendages received in repose in various fossae on ventral surfaces of the body (Chapin 1965;Kovař 1995).
The genus Endochilus includes large or medium-sized Chilocorini possessing a labrum hidden under the clypeus and the margins of the elytra and pronotum covered with setae. Species of Endochilus are known only from the Afrotropical ecozone.
Previous works on Endochilus has been largely limited to single species descriptions, mainly by late 19th and early 20th century workers. Korschefsky's world catalogue of Coccinellidae (Korschefsky 1932) listed eight species of Endochilus. Apart from Chapin (1965), who reviewed the genera of Chilocorini based on a study mostly of single (type) species for each genus and redescribed Endochilus based on E. plagiatus Sicard, there have been no recent publications including Endochilus.
During preparation of the present review, a study of the type specimen of Endochilus meridionalis Sicard, 1929, led us to discover several features unusual for Endochilus. Three-segmented tarsi, 11-segmented antennae, and mandible bidentate apically found in E. meridionalis are unique for the tribe Chilocorini. Therefore this species was recently removed from Endochilus and a new genus of Chilocorini, Chapinaria Łączyński et Tomaszewska, 2012 was established and described (Łączyński and Tomaszewska 2012).
In the present paper, 11 species of Endochilus are recognized as valid along with E. abdominalis sp. nov., described here, all distributed along the Gulf of Guinea and throughout the Valley of Congo.
The present paper provides the first comprehensive treatment of the entire genus with a key to all species and detailed morphological characters allowing their identification.

Materials and Methods
This study was based on examination of the type and non-type specimens, borrowed from the following museums: MIZ -Muzeum i Instytut Zoologii PAN, Warszawa, Poland MNB -Museum für Naturkunde, Berlin, Germany MNHN -Museum National d'Histoire Naturelle, Paris, France NHM -The Natural History Museum, London, England RMCA -Royal Museum for Central Africa, Tervuren, Belgium ZSM -Zoologische Staatssammlung München, Germany Measurements were made using an ocular micrometer attached to an Olympus SZH 10 (www.olympus-global.com) dissecting microscope and are defined as follows: (TL) total length, from apical margin of clypeus to apex of elytra; (PL) pronotal length, from the middle of anterior margin to base of pronotum; (PW) pronotal width, at widest part; (EL) elytral length, along suture including scutellum; (EW) elytral width, across both elytra at widest part; (PSL) prosternal length, prosternum length anterior to procoxa; and (PPW) prosternal process width, at widest point of prosternal process.
Male and female genitalia were dissected, cleared in a 10% solution of KOH, and placed in glycerine on slides for further study. Structural illustrations were made from slide preparations using a camera lucida attached to a Leica dissecting microscope. SEM micrographs were made using a Hitachi S-3400N machine (www.hitachi.com), and habitus images were captured using a digital camera mounted on a Leica microscope (www.leica-microsystems.com) and subsequently enhanced using Auto-Montage software (Syncroscopy, www.syncroscopy.com) in the Electron Microscopy Laboratory of the MIZ.
The label data under material examined are given "in verbatim".

Nomenclature
This publication and the nomenclature it contains have been registered in Zoobank. The LSID number is: urn:lsid:zoobank.org:pub:F3B4BD0D-65AB-449F-AAD0-1DE76354F74F It can be found online by inserting the LSID number after www.zoobank.org/

Genus and species descriptions
Genus Endochilus Weise, 1898 Endochilus Weise, 1898: 119. Type species, by subsequent designation of Korschefsky, 1932: Endochilus cavifrons Weise, 1898 Diagnosis. Within the tribe Chilocorini, Endochilus can be easily distinguished from other taxa by the following combination of characters: labrum hidden under clypeus; clypeus expanded laterally deeply into eyes and almost dividing each eye into two parts; antennae 8-segmented, short; distinct and deep antennal grooves for reception of 3 rd and 4 th antennomeres; pronotum wholly or partly covered with setae; margins of elytra broadly explanate, but not abruptly reflexed, and covered with setae.
Description. Length 2.89-6.10 mm. Body rounded and convex; pronotal margin moderately to very broad; elytral margins moderately to widely explanate; both entirely visible from above. Pronotum black, blackish, bright red to dark red; elytra black, bright red to dark red. Punctures on pronotum and elytra about as large as eye facets; these on pronotum moderately deep, on elytra shallower; surfaces between elytral and pronotal punctures polished and shiny; dorsum apparently glabrous except pronotal and elytral margins, which are covered with setae (in some taxa entire pronotum setose). Ventral surface reddish, dark reddish to brown or black.
Abdomen with 5 or 6 ventrites in male, 5 in female; intercoxal process smooth or distinctly punctate, punctures about as large as eye facets; postcoxal lines usually separated medially, curved posteriorly, closely paralleling posterior margin, incomplete laterally; ventrite 1 along midline between 1.85-2.90 times longer than ventrite 2; ventrite 5 with posterior margin truncate or emarginate in male, rounded in female. Abdominal segment VIII with posterior margin of sternite deeply emarginate medially in male, rounded or somewhat narrowly truncate or sometimes weakly emarginate in female. Male genital segment usually with long apophysis, at base distinctly or weakly swollen, narrow and simple at apex.

Distribution.
Endochilus is entirely comprised of African species, with its greatest diversity in the West and Central Africa.
Head flat medially, punctate, covered with rather dense and moderately long setae. Clypeus ( Figure 106) length anterior to eyes about 0.23 times head width, weakly arcuate anteriorly, weakly reflexed in the middle of anterior margin. Eyes large; interocular distance nearly 0.45 times head width; medial margins of eyes slightly rounded, divergent anteriorly. Maxillary terminal palpomere (Figure 107) about 1.5 times longer than wide, lateral margin about 3.75 times as long as medial, subparallel along basal 1/4 of its length, strongly tapering apically. Antenna as in Figure 107  Etymology. The name of this species refers to the shape of the abdominal postcoxal lines, which are narrowly separated on intercoxal process, differently than in other Endochilus species.

Endochilus brunneocinctus
Head flat medially, punctate, covered with rather dense and moderately long setae. Clypeus ( Figure 113) length anterior to eyes about 0.18 times head width, with straight anterior margin. Eyes large; interocular distance nearly 0.42 times head width; medial margins of eyes slightly rounded, divergent anteriorly. Maxillary terminal palpomere ( Figure 112) about 1.8 times longer than wide, lateral margin about 3 times as long as medial, subparallel along basal 1/3 of its length, tapering apically. Antenna as in Figure 112, with penultimate antennomere about 1.2 times as long as terminal antennomere.
Head flat medially, punctate, covered with dense and long setae. Clypeus (Figures 121,123) length anterior to eyes about 0.25 times head width, weakly arcuate anteriorly. Eyes large; interocular distance nearly 0.45 times head width; medial margins of eyes slightly rounded, almost parallel. Maxillary terminal palpomere (Figures 117, 119) about 1.45 times longer than wide, lateral margin about 2.8 times as long as medial, subparallel along basal 1/3 of its length, moderately tapering apically. Antenna ( Figure 119) with penultimate antennomere about 2 times as long as terminal antennomere.

Endochilus compater
Head flat medially, punctate, covered with dense and long setae. Clypeus ( Figure 124) length anterior to eyes about 0.25 times head width, weakly arcuate anteriorly. Eyes large; interocular distance nearly 0.4 times head width; medial margins of eyes slightly rounded, almost parallel. Maxillary terminal palpomere (Figure 125) about 1.6 times longer than wide, lateral margin about 2.7 times as long as medial, subparallel along basal 1/3 of its length, moderately tapering apically. Antenna as in Figure 119 with penultimate antennomere about 2.4 times as long as terminal.

Endochilus epipleuralis
Head flat medially, punctate, covered with rather dense and moderately long setae. Clypeus ( Figure 133) length anterior to eyes almost 0.2 times head width, with deep emargination in the middle of anterior margin, weakly reflexed along anterior margin. Eyes large; interocular distance about 0.38 times head width; medial margins of eyes slightly rounded, almost parallel. Maxillary terminal palpomere (Figure 130) about 1.5 times longer than wide, lateral margin about 2.15 times as long as medial, subparallel along basal 1/2 of its length, moderately tapering apically. Antenna as in Figure 130 with penultimate antennomere about 1.52 times as long as terminal antennomere.
Head flat medially, punctate, covered with rather dense and moderately long setae. Clypeus ( Figure 136) length anterior to eyes about 0.2 times head width, with almost straight anterior margin. Eyes large; interocular distance nearly 0.42 times head width; medial margins of eyes slightly rounded, divergent anteriorly.
Maxillary terminal palpomere (Figure 137) about 1.4 times longer than wide, lateral margin about 2 times as long as medial, subparallel along basal 1/2 of its length, moderately tapering apically. Antenna ( Figure  138) with penultimate antennomere about 1.42 times as long as terminal segment.
Head flat medially, punctate, covered with rather dense and moderately long setae. Clypeus ( Figure 142) length anterior to eyes about 0.17 times head width, with almost straight anterior margin, weakly reflexed along anterior margin. Eyes large; interocular distance nearly 0.5 times head width; medial margins of eyes slightly rounded, divergent anteriorly. Maxillary terminal palpomere (Figures 141,  142) about 1.8 times longer than wide, lateral margin about 1.65 times as long as medial, subparallel along basal about 2/3 of its length, moderately tapering apically. Antenna with penultimate antennomere about 1.5 times as long as terminal antennomere.

Endochilus plagiatus
Head flat medially, punctate, covered with dense and long setae. Clypeus (Figure 145) length anterior to eyes about 0.22 times head width, weakly arcuate anteriorly, weakly reflexed along anterior margin. Eyes large; interocular distance nearly 0.41 times head width; medial margins of eyes slightly rounded, divergent anteriorly. Maxillary terminal palpomere (Figure 146) about 1.7 times longer than wide, lateral margin about 2 times as long as medial, subparallel along basal 1/2 of its length, moderately tapering apically. Antenna as in Figure 146 with penultimate antennomere about 1.42 times as long as terminal segment.

Endochilus weisei
Head flat medially, punctate, covered with dense and long setae. Clypeus (Figure 161) length anterior to eyes about 0.21 times head width, weakly arcuate anteriorly. Eyes large; interocular distance nearly 0.43 times head width; medial margins of eyes slightly rounded, almost parallel. Maxillary terminal palpomere (Figure 162) about 1.42 times longer than wide, lateral margin about 2.6 times as long as medial, subparallel along basal 1/3 of its length, moderately tapering apically. Antenna as in Figure 162 with penultimate antennomere about 2 times as long as terminal segment.
Male genitalia as in Figures 100, 104, 105. Penis guide as long as parameres; penis with row of teeth placed on outer and inner margin before apex; apex of penis ( Figure 105) stout bottle-opener-shaped.

Discussion
Endochilus is a homogenous and not speciose group. There are few differences between species of this genus, based mainly on shapes of penis apex, sizes of body, shades of coloration, arrangement of postcoxal lines on abdominal process, or presence of foveolation on hypomera and epipelura.
Endochilus shares various characters with other five Afrotropical genera of Chilocorini. It shares 8-segmented antennae with Brumoides Chapin; arrangement of metaventral and abdominal postcoxal lines resemble those in Chilocorus Leach; moderately stout tibia and simple tarsal claws are similar to Brumus Mulsant and Brumoides; spermatheca simple without membranous beak resembles that in Exochomus Redtenbacher. In particular Endochilus shares numerous features with Chapinaria Łączyński et Tomaszewska, such as characters of maxillae, labium, foveolate hypomera and elytral epipleura, shape of meso-metaventrite junc-tion, arrangement of metaventral postcoxal lines, and pattern of dorsal coloration.
Endochilus, however, differs from all other Chilocorini genera in having labrum entirely hidden under clypeus, lateral margins of pronotum and elytra setose, antennal grooves on a head deep but short, clypeus long in front of eyes and expanded laterally into eyes almost dividing each eye in two parts, prosternal and mesoventral processes very broad, elytral epipleura very broad, and sperm duct short and only slightly longer or as long as spermatheca.