N;Ilustration;Description 1;;"Postpetiole swollen relative to petiole. Postpetiole with a posterodorsal bulge (a) and anteroventral bulge (b) (major and minor worker). Diagnostic character of P. megacephala among introduced Pheidole" 2;;"Postpetiole forming a high dorsally bulging dome that is tallest at midpoint (a); ventral margin flat to very weakly convex (b) (major and minor worker). Diagnostic character of P. noda among introduced Pheidole" 3;;"Postpetiole not swollen relative to petiole (major and minor worker). Separates all introduced Pheidole species from P. megacephala and P. noda" 4;;"Promesonotum in profile forming a single dome, lacking a distinct mound or prominence on the posterior slope (major worker)" 5;;"Promesonotum in profile with two convexities, the large anterior dome in addition to a distinct mound or prominence on the posterior slope (major worker)" 6;;"Head heart-shaped (major worker). Diagnostic character of P. megacephala among introduced Pheidole" 7;;"Head subquadrate (major worker)" 8;;"Cephalic dorsum with strong rugoreticulate sculpture, at least on posterolateral lobes (major worker)" 9;;"Posterolateral lobes lacking sculpture (including foveolate ground sculpture, carinae and rugae) posterior to maximum extent of antennal scapes in repose (major worker)" 10;;"Posterolateral lobes rugose or rugulose (major worker)" 11;;"Posterolateral lobes punctate or foveolate (major worker)" 12;;"Head almost entirely covered by network of intersecting rugae (a), lacking long, well-organized and parallel longitudinal rugae on the frons (b). Frontal carinae indistinct, quickly becoming integrated into dense rugoreticulum that covers the entire face. Antennal scrobes entirely lacking. Antennal insertions surrounded by deeply excavated pits (c). Diagnostic characters of P. obscurithorax major workers among introduced Pheidole" 13;;"Head rugoreticulate on posterolateral lobes and laterad of frontal carinae (a), but frons dominated by long, well-organized and parallel longitudinal rugae (b). Antennal scrobes indistinct to moderately impressed, but frontal carinae always forming a border capable of accepting the antennal scape (c). Antennal insertions not surrounded by deeply excavated pits. Illustration applies to P. indica and P. fervens" 14;;"Frontal carinae relatively longer, extend 4/5 distance of head before terminating (major worker). Diagnostic character separating P. fervens from P. indica" 15;;"Frontal carinae relatively shorter, extend 3/4 distance of head before terminating (major worker). Diagnostic character separating P. indica from P. fervens" 16;;"Petiolar node strongly punctate and metapleuron with moderate rugulae and some weak punctation (major worker). Diagnostic character separating P. proxima from P. vigilans" 17;;"Petiolar node mostly glossy, metapleuron almost completely glossy with strongly reduced carinulae and lacking punctation (major worker). Diagnostic character separating P. vigilans from P. proxima" 18;;"Hypostomal bridge with a small median tooth in addition to a pair of larger inner teeth (major worker). Diagnostic character separating P. proxima from P. vigilans" 19;;"Hypostomal bridge with two well-developed inner teeth but lacking a median tooth (major worker) Diagnostic character separating P. vigilans from P. proxima" 20;;"Promesonotal dorsum glossy with thin but distinct subparallel striae running oblique to the longitudinal midline (major worker). Diagnostic character separating P. rugosula from other introduced Pheidole" 21;;"Promesonotal dorsum with distinct transverse striae (major worker). Character present among some species of the P. flavens complex, including P. navigans" 22;;"Promesonotal dorsum rugoreticulate with distinct long longitudinal striae in addition to shorter sections of transverse and intersecting striae (major worker). Illustration refers to P. parva" 23;;"Promesonotal dorsum glossy, lacking foveolate ground sculpture or striae (major worker). Character useful for separating P. vigilans and P. proxima from P. rugosula." 24;;"Head with distinct parallel rugae extend from frontal lobes posterior to apices of frontal carinae. Shorter lengths of rugae present across entire posterior region of head and extending to posterior margin in full-face view (major worker). Diagnostic character useful for separating P. rugosula from other introduced Pheidole, especially those introduced in New Zealand" 25;;"Posterolateral lobes variously sculptured, but posterior head margin always free of distinct rugae or rugoreticulum (major worker). Illustration refers to P. flavens, P. navigans and other members of the P. flavens complex" 26;;"Posterolateral lobes, including posterior head margin, strongly rugoreticulate (major worker). Illustration refers to P. parva and character is useful for separating that species from those of the P. flavens complex and the P. punctatissima clade" 27;;"Posterolateral lobes variously sculptured, but posterior head margin always free of rugoreticulum (major worker)" 28;;"Promesonotum in dorsal view strongly transverse with strongly projecting shoulders (major worker). Illustration refers to P. parva and character is useful for separating that species from those of the P. flavens complex and the P. punctatissima clade" 29;;"Promesonotum in dorsal view less transverse with weakly projecting shoulders in dorsal view (major worker)" 30;;"Postpetiole relatively narrow, distinctly less than 2× petiolar width in dorsal view (major worker). Character useful for separating members of the P. flavens complex, including P. flavens and P. navigans, from those of the P. punctatissima clade" 31;;"Postpetiole relatively broad, distinctly more than 2× petiolar width in dorsal view (major worker). Character useful for separating members of the P. punctatissima clade from those of the P. flavens complex, including P. flavens and P. navigans" 32;;"Gaster with entire first tergite glossy (major and minor worker). Character useful for separating members of the P. flavens complex, including P. flavens and P. navigans, from those of the P. punctatissima clade" 33;;"Gaster with at least anterior 1/3 of first tergite matte (major and minor worker). Character useful for separating members of the P. punctatissima clade from those of the P. flavens complex, including P. flavens and P. navigans" 34;;"Head bicolored with the yellowish posterior two-thirds contrasting with the darker brown anterior third and rest of body (major worker). Diagnostic character for separating P. punctatissima from all other introduced Pheidole" 35;;"Head uniform in color (major worker). Character used to separate P. anastasii and P. bilimeki from P. punctatissima" 36;;"Head predominantly glossy, lacking punctation and or rugae above eye level (minor worker). Character used to separate P. indica, P. fervens, P. obscurithorax, P. proxima and P. vigilans from all other introduced Pheidole." 37;;"Head, including the area mesad of the frontal carinae, entirely covered by reticulated network of punctures, giving it a dull appearance; if rugae are present they are generally short segments and mostly restricted to posterior portion of head (minor worker). Character used to separate P. anastasii, P. bilimeki, P. flavens, P. navigans and P. parva from all other introduced Pheidole" 38;;"Head with well-defined, long segments of rugae running longitudinally from below the eyes to the posterior head margin. Frontal carinae distinct and reaching towards the posterior head margin, although they may occasionally be interrupted. Punctate ground sculpture present on lateral surfaces of head and just mesad of the frontal carinae, but median portion of head with a large glossy section. Diagnostic characters separating P. rugosula from all other introduced Pheidole" 39;;"Antennal scapes extremely long, surpassing posterior head margin by more than 2× eye length (minor worker). Diagnostic character separating P. obscurithorax from P. fervens and P. indica" 40;;"Antennal scapes surpass posterior head margin by approximately same length as eye (minor worker)" 41;;"Antennal scapes relatively short, either failing to surpass posterior head margin, or surpassing it by less than the distance of eye length (minor worker)" 42;;"Promesonotum in profile forming a single dome, lacking a distinct mound or prominence on the posterior slope (minor worker)" 43;;"Promesonotum in profile with two convexities, the large anterior dome (a) in addition to a distinct prominence on the posterior slope (b) (minor worker)" 44;;"Posterior margin strongly convex in full-face view such that the head outline forms a single unbroken curve from eye to eye (minor worker). Diagnostic character for separating P. obscurithorax from P. fervens and P. indica" 45;;"Posterior head margin weakly convex to flat in full-face view (minor worker). Diagnostic character for separating P. fervens and P. indica from P. obscurithorax" 46;;"Posterior head margin weakly concave in full-face view (minor worker)" 47;;"Petiole and postpetiole strongly sculptured laterally. Diagnostic character for separating P. obscurithorax from P. fervens and P. indica" 48;;"Petiole and postpetiole glossy to very weakly sculptured laterally (minor worker). Diagnostic character for separating P. fervens and P. indica from P. obscurithorax" 49;;"Promesonotal prominence relatively flat (a); metanotal depression relatively deep (b) (minor worker). Diagnostic character for separating P. fervens from P. indica" 50;;"Promesonotal prominence relatively convex (a); metanotal depression relatively shallow (minor worker). Diagnostic character for separating P. indica from P. fervens" 51;;"Mesopleuron entirely glossy (a); propodeal spines weakly produced and dentiform (b) (minor worker). Diagnostic character for separating P. vigilans from P. proxima" 52;;"Mesopleuron entirely punctate (a); propodeal spines moderately produced and spiniform (b) (minor worker). Diagnostic character for separating P. proxima from P. vigilans" 53;;"Hairs on mesosoma stout, stiff, of equal length and arranged in pairs (minor worker). Diagnostic character for separating P. anastasii, P. bilimeki and P. punctatissima from P. flavens, P. navigans and P. parva" 54;;"Hairs on mesosoma fine, flexuous, of unequal length and not arranged in pairs (minor worker). Diagnostic character for separating P. flavens, P. navigans and P. parva from P. anastasii, P. bilimeki and P. punctatissima" 55;;"Antennal scapes lack standing hairs (minor worker). Diagnostic character for separating P. anastasii, P. bilimeki and P. punctatissima from P. flavens, P. navigans and P. parva" 56;;"Antennal scapes with erect to suberect hairs (minor worker). Diagnostic character for separating P. flavens, P. navigans and P. parva from P. anastasii, P. bilimeki and P. punctatissima" 57;;"Posterior head margin relatively broad (minor worker). Diagnostic character for separating P. bilimeki from P. anastasii and P. punctatissima" 58;;"Posterior head margin more narrow (minor worker). Diagnostic character for separating P. anastasii and P. punctatissima from P. bilimeki" 59;;"Posterior portion of head with many short to medium length segments of striae distinctly interlaced among punctate ground sculpture (minor worker). Diagnostic character for separating P. parva from P. flavens and P. navigans" 60;;"Posterior portion of head lacking many short to medium length segments of striae distinctly interlaced among punctate ground sculpture (minor worker). Diagnostic character for separating P. flavens and P. navigans from P. parva" 61;;"Postpetiole narrow in dorsal view, only slightly broader than petiole (minor worker). Diagnostic character for separating P. flavens and P. navigans and from P. anastasii, P. bilimeki and P. punctatissima" 62;;"Postpetiole broad in dorsal view, distinctly broader than petiole (minor worker). Diagnostic character for separating P. anastasii, P. bilimeki and P. punctatissima from P. flavens and P. navigans" 63;;"Promesonotal prominence relatively flat (a); propodeal spine relatively weak, narrow at base, weakly downcurved at apex (b) (major worker). Diagnostic character for separating P. fervens from P. indica" 64;;"Promesonotal prominence convex and pronounced (a); propodeal spine relatively stout, broad at base, straight (b) (major worker). Diagnostic character for separating P. indica from P. fervens" 65;;"Eye relatively small, eye length distinctly less than length of antennal segment 10 (minor worker). Diagnostic character for separating P. fervens from P. indica" 66;;"Eye relatively large, eye length subequal to length of antennal segment 10 (minor worker). Diagnostic character for separating P. indica from P. fervens" 67;;"The carinae between eye and mandible are branching and reticulated (major worker). Diagnostic character for separating P. fervens from P. oceanica" 68;;"The carinae between eye and mandible are parallel and not reticulated (major worker). Diagnostic character for separating P. oceanica from P. fervens" 69;;"The length of propodeal spine equal to or less than the diameter of propodeal spiracle (minor worker). Diagnostic character for separating P. fervens from P. oceanica" 70;;"The length of propodeal spine greater than the diameter of propodeal spiracle (minor worker). Diagnostic character for separating P. oceanica from P. fervens" 71;;"Antennal scrobe distinct and narrow, shallow but capable of receiving the entire antennal scape in repose (a); bordered by strong, unbroken frontal carina mesially (b); depression marked by a continuous smooth surface entirely (or nearly entirely) uninterrupted by rugulae (major worker). Diagnostic character for separating P. navigans from P. flavens" 72;;"Antennal scrobe broad, ill-defined, incapable of receiving the entire antennal scape in repose (a); bordered by relatively weak and interrupted frontal carina mesially (b); depression opaque and strongly punctate. Diagnostic character for separating P. flavens from P. navigans"