18-0 18-1

16—Rostrum, dorsal surface

(0) plane or medially sulcate, not carinate

(1) medially carinate

17—Rostrum, dorso-lateral angle

(0) smoothly curved, any angulation weak

(1) conspicuously angulate

18—Rostrum, medio-longitudinal sulcus

(0) absent

(1) present

21—Rostrum, dorsolateral fovea

(0) absent

(1) present

28—Rostrum, occipital suture

(0) short, not reaching eye

(1) reaching middle of eye ventrally

16-0 16-1

17-1 17-0

21-0 21-1

45—Pronotum, surface

(0) smooth or finely rugose

(1) irregularly excavate

29—Rostrum, ventral surface

(0) medially flat, not impressed

(1) medially with triangular impression

79—Elytral vestiture, curled serrate setae

(0) absent

(1) present 79-1

80—Elytral vestiture, series of stripes

(0) absent

(1) present 80-1

60—Metatibial apex, vestiture

(0) ventrally lacking linear, suberect setae

(1) ventrally with sparse, suberect setae

116—Aedeagus, endophallus, sclerites (0) separate or contiguous, lacking bridge

(1) connected through arched bridge 116-1

119—Aedeagus, endophallus, posterior sclerite (0) width constant, basally not enlarged

(1) basally enlarged, arched 119-1

48—Pronotum, postocular vibrissae

(0) absent

(1) present 48-1

67—Elytra, apex

(0) not projected, may be acute

(1) distinctly projected

60-1

110—Aedeagus, endophallus, tubular sclerite (0) absent

(1) present

111—Aedeagus, endophallus, tubular sclerite (0) not divided into two regions

(1) divided into anterior/posterior region 111-1

24—Rostrum, hypostomal-labial suture

(0) reduced, short, or foveate

(1) long, linear, reaching prementum

29-1 29-0

24-0 24-1

Figure 5. Core morphological characters (orange color in Fig. 2).

45-1 45-0

41—Pronotum, disc

(0) convex

(1) flattened 41-1 41-0

110-1

28-1 28-0

144—Vestiture, circular glossy metallic scales (0) absent; if metallic, not circular or glossy

(1) present; often arranged as fasciae or stripes 144-1 144-1

67-0 67-1

The New World tribe Eustylini Lacordaire, 1863, pertains to the broad-nosed weevils

(Entiminae) and currently comprises 23 genera. Members of Eustylini include

agriculturally important species, e.g., Diaprepes abbreviatus (Linnaeus, 1758), an

introduced citrus pest in the continental U.S. Franz (2012) published the first phylogeny

of Eustylini based on morphological characters. Eustylini were recovered as polyphyletic

and re-circumscribed to include several genera previously placed in other tribes. As a

result, all but two of the sampled eustyline genera formed a monophyletic clade. The

Exophthalmus genus complex is positioned within that clade and contains eight

sampled genera, the largest (with 95 species) being Exophthalmus Schoenherr, 1823.

The 2012 analysis uncovered systematic problems that motivate the current study.

Exophthalmus remains polyphyletic, with its species separated into at least three

clades. Thus Exophthalmus needs to be redelimited and its current members reassigned

to phylogenetically appropriate generic membership. The clade of continentals species

also contains Rhinospathe Chevrolat, 1878, and Chauliopleurus Champion, 1911,

warranting generic synonymy. Tropirhinus Schoenherr, 1823, Tetrabothynus Labram &

Imhoff, 1852, Compsoricus Franz, 2012, and part of Exophthalmus exhibit ambiguous

boundaries. These groups need to be either re-circumscribed or synonymized.

Systematics of the Exophthalmus genus complex – current status

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1. Test and delimit generic boundaries within the Exophthalmus genus complex based on both

morphological and molecular phylogenetic inferences.

2. Revise generic classification within the Exophthalmus genus complex.

3. Redefine the limit of Exophthalmus and reclassify its current constituent species.

Research objectives

Morphological phylogeny. Character matrix (144 characters, examples in Figs 4 & 5) was extracted

and modified from Franz (2012). Thirty-eight species of eight genera in the Exophthalmus genus

complex were sampled, along with 52 species of other eustylines or from other tribes. Phylogenetic

trees were inferred with NONA and character optimizations with WinClada under parsimony.

Molecular phylogeny. Seventy ingroup terminals were included, representing > 65 species and

seven genera. The outgroup contained 105 terminals. Six gene fragments (COI, COII, Ef1-α, Arginine

kinase, 12S, 28S) were sequenced, aligned, and concatenated to generate a 4787 bp data set.

Phylogenetic reconstructions were performed using parsimony in TNT.

Materials & methods

(1) Pachnaeus Schoenherr, 1826 Synapomorphies: Hypostomal-labial suture

long, reaching prementum (24-1, Figs. 2 &

5); postocular vibrissae present (48-1);

anterior endophallic sclerite membranous,

posteriorly tubular (113-1).

Distribution: Cuba & Jamaica.

(2) Tropirhinus Schoenherr, 1823 Taxonomic amendments: Tetrabothynus

Labram & Imhoff, 1852, and Compsoricus

Franz, 2012, placed as junior synonyms.

Exophthalmus species in clade 2 transferred

to Tropirhinus.

Synapomorphies: Pronotal disc flattened or

impressed (41-1); elytral apex projected (67-

1); circular metallic scales forming fasciae

(144-1).

Distribution: Cuba, Hispaniola & Puerto Rico.

(3) Rhinospathe Chevrolat, 1878 Taxonomic amendments: Chauliopleurus

Champion, 1911, placed as junior synonym.

Continental Exophthalmus spp. transferred to

Rhinospathe.

Diagnosis: Rostrum with dorsolateral fovea

(21-1); rostrum ventrally with a short, deep,

triangular impression (29-1).

Distribution: Southern Mexico, Central

America & northern South America.

(4) Diaprepes Schoenherr, 1823 Synapomorphies: Rostrum dorsolaterally

carinate (17-1); occipital suture extends to

middle part of eye (28-1); pronotum

irregularly excavate (45-1).

Distribution: Lesser Antilles & Puerto Rico.

(5) Exophthalmus Schoenherr, 1823 Taxonomic amendments: Exophthalmus re-

circumscribed to refer to a clade containing

its type species E. quadrivittatus (Olivier,

1807). More than 50 species transferred to

other genera.

Synapomorphies: Rostrum dorsally plane,

lacking carina or groove (15-1, 16-0);

Pronotum and elytra with curled, serrate

scales (79-1), arranged into stripes or patches

(80-1).

Distribution: Cuba, Jamaica & Hispaniola.

Figure 1 (left). Proposed new generic classification within the Exophthalmus genus complex, and habitus images of select species. Five genera are recognized (Figs. 2 & 3). Three are placed in synonymy. Exophthalmus is redefined. Habitus image (current, unchanged names): (1-3) Pachnaeus spp., Cuba (4) Pachnaeus marmoratus (5) Pachnaeus sp., Jamaica (6) Compsoricus maricao (7) Exophthalmus humeridens (8) E. regalis (9) E. roseipes (10) E. quindecimpunctatus (11) Tetrabothynus spectabilis (12) Tropirhinus elegans (13) Tropirhinus nr. lepidus (14) Tropirhinus Cuba GZ48 (15) T. lepidus (16) E. agrestis (17) E. impositus (18) E. jekelianus (19) E. lunaris (20) Exophthalmus Mexico (21) Exophthalmus nr. annulonotatus (22) E. opulentus (23) Exophthalmus PA[Panama].GZ65 (24) Exophthalmus CR[Costa Rica].GZ147 (25) Exophthalmus CR.GZ163 (26) E. triangulifer (27) E. verecundus (28) Exophthalmus nr. vermiculatus (29) E. sulcicrus (30) Rhinospathe v-album (31) Diaprepes abbreviatus (32) D. boxi (33) D. doublierii (34) D. maugei (35) D. rohrii (36) E. cinerascens (37) E. hieroglyphicus (38) E. pictus (39) E. similis (40) E. scalaris (41) E. quadrivittatus (42) Exophthalmus DR[Dominican Republic] sp. nov. (43) Exophthalmus DR6 (44) Exophthalmus nr. sulphuratus (45) E. vittatus.

Both morphological and molecular phylogenies recover the monophyly of the Exophthalmus genus

complex and the polyphyly of Exophthalmus. They are broadly congruent in five clades, although

the relationships among the clades differ between the two analyses. Five genera can be delimited

within these clades (Fig. 1). Two (Clades 1 & 4 in Figs. 2 & 3) correspond to Pachnaeus and

Diaprepes. Clade 2 contains Tetrabothynus, Tropirhinus, Compsoricus, and Exophthalmus spp.

Tropirhinus is considered the valid name for this clade, hence the other two genera are

synonymized. A large continental clade (3) is obtained, now referred to as Rhinospathe. The genus

Exophthalmus is narrowed to include only West Indian species with a "stripy look" (Figs. 1 & 5).

Future work will focus on increasing species sampling, expanding the character range, combining

morphological and molecular data in phylogeny reconstructions, and describing new species.

Results, taxonomic proposals & conclusions

Figure 2 (above). Morphological phylogeny of the Exophthalmus genus complex, with character optimizations.

Figure 3 (above). Molecular phylogeny reconstructed using parsimony.

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Franz N.M. 2012. Phylogenetic reassessment of the Exophthalmus genus complex

(Curculionidae: Entiminae: Eustylini, Geonemini). Zoological Journal of the

Linnean Society 164: 510–557.

This work is supported by the National Science Foundation (DEB-1155984) and the

United States Department of Agriculture (USDA) (Agreement No. 58-1275-1-335).

Dr. Charles W. O'Brien assisted with species identifications. Lin Pan, Will Sides,

Julian Jones, and Joseph Hunter captured habitus or head images.

Reference & acknowledgements

Figure 4 (left).

Morphological diversity of

the rostrum (dorsal view).

Orange numbers denote "core

characters" (see Fig. 5).

Numbers

shown above

branches are

jackknifing

resampling

values.

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