Prenolepis dugasi Forel, 1911

Williams, Jason L. & Lapolla, John S., 2018, Two new Prenolepis species (Hymenoptera: Formicidae) from Indomalaya and Australasia, with a redescription of P. dugasi from Vietnam, Zootaxa 4441 (1), pp. 171-180 : 175-176

Prenolepis dugasi Forel, 1911 , comb. rev.

Figs. 7–9 (worker)

Prenolepis (Nylanderia) dugasi Forel, 1911: 227 (w.). Lectotype worker (designated here), VIETNAM: Cochinchine Française, Region de Moïs; A. Forel (ANTWEB CASENT0911004) (MHNG). 4 paralectotype workers (designated here), same locality as lectotype (MHNG). Combination in Paratrechina (Nylanderia) : Emery, 1925: 220; in Nylanderia: LaPolla, Brady & Shattuck 2010a: 127 .

Worker diagnosis: A clypeal tooth with a single seta extending from its point found medially on the anterior border of the clypeus ( Fig 1 ). This species also has three small ocelli on the head.

Compare with: P. melanogaster .

WORKER. Measurements (n=5): CMC: 12–17; EL: 0.16–0.18; HL: 0.67–0.72; HW: 0.61–0.70; MMC: 2–3; PMC: 4–5; PrMC: 2–3; SL: 0.64–0.70; TL: 2.53–2.80; WL: 0.80–0.91; CI: 91–96; REL: 23–25; REL2: 24–26; SI: 99–105.

Light to medium brown, with gaster (and sometimes head) darker than mesosoma; overall cuticle smooth and shiny; decumbent setae on head; long, erect macrosetae on head, mesosoma, and gaster; abundant suberect setae on scapes and legs; head about as long as broad and subtriangular in shape with indistinct posterolateral corners and a straight posterior margin; three small ocelli present; compound eyes moderately large and convex, but do not surpass lateral margins of head in full-face view; torulae do not touch posterior border of clypeus; anterior border of clypeus without prominent anterolateral lobes ( Fig 1 ); single clypeal tooth with an erect seta projecting from its point, located medially on anterior border of clypeus; mandibles with 5 teeth on masticatory margin; ectal surface of mandibles smooth and shiny; in profile view, pronotum is rounded and continuous with mesonotum, which flatly declines posteriorly at a shallow angle before abruptly deepening at mesosomal constriction; propodeum is obtusely angled with flat dorsal and posterior faces; dorsal apex of petiole scale is sharply angled and forwardinclined ( Fig 4 ).

Notes: Although this species most closely resembles P. melanogaster , the latter is still quite distinct and confusion between the two is very unlikely. Prenolepis dugasi is much smaller in comparison, does not have the distinct body color pattern seen in P. melanogaster (yellow-brown head and mesosoma with dark brown to black gaster), has suberect rather than erect setae on the scapes, and fewer erect macrosetae overall across the head, mesosoma, and gaster. Additionally, P. melanogaster has a head that is broader than long, with scapes that are about a third longer than the head width. Prenolepis dugasi has a head that is about as long as it is broad, and the scapes are about as long as the head is wide. Prenolepis dugasi also has three small ocelli, while P. melanogaster does not have any ocelli at all.

Figures

FIGURES 7–9. Prenolepis dugasi lectotype worker ANTWEB CASENT0911004. Lateral, full-face, and dorsal view of the body. Images were downloaded from www.AntWeb.org and were taken by Will Ericson.

FIGURES 1–3. Illustrations of head shapes in full-face view for all three species. 1, P. dugasi; 2, P. lakekamu; 3, P. nepalensis.

FIGURES 4–6. Illustrations of mesosoma shapes in profile view for all three species. 4, P. dugasi; 5, P. lakekamu; 6, P. nepalensis.