Hologymnetis cinerea (Gory and Percheron)

Micó, Estefanía, Eugene Hall, W. & Ratcliffe, Brett C., 2001, Descriptions Of The Larvae Of Hoplopyga Singularis (Gory And Percheron) And Hologymnetis Cinerea (Gory And Percheron) With A Revised Key To The Larvae Of New World Gymnetini (Coleoptera: Scarabaeidae: Cetoniinae), The Coleopterists Bulletin 55 (2), pp. 205-217 : 213

Hologymnetis cinerea (Gory and Percheron)

Third Instar Larva ( Figs. 2 , 16–26 ). This description is based on two thirdinstar larvae associated with an adult recovered from the nest debris piles of Atta mexicana (Smith) ( Hymenoptera : Formicidae ) under hecho cactus, Pachycereus pecten ­aboriginum Britton and Rose ( Cactaceae ). Locality data: ‘‘ Mexico: Sonora, 1.0 miles by road to Microondas la Luna, NW jct with Mex. hwy 162 (Alamos Rd.), 440 m elevation, lat. 27° 04' N, long. 109° 01' W, tropical deciduous forest, X­19–1996, P. Holm’’. Specimens are deposited at the University of Nebraska State Museum (UNSM).

Description. Maximum width of head capsule 4.50 mm. Cranium ( Fig. 16 ). Color reddish brown. Frons with shallow reticulations, surface moderately punctate, with single posterior frontal seta and single anterior angle seta. Dorsoepicranium with 5–6 small setae in a line diverging from center­base of head. Clypeus. Shape subtrapezoidal with 2 posterior clypeal setae and 2 exterior clypeal setae at post clypeus on each side. Preclypeus weakly sclerotized, setae absent. Labrum trilobed, clithra present. Epipharynx ( Fig. 22 ). Plegmata absent. Corypha with 4 long, stout setae. Haptomeral region lacking process and with curved row of 10–12 heli in transverse row, 10–13 stout spine­like setae irregularly placed behind curved row. Acanthoparia with 6 short setae. Chae­ toparia with group of 57–60 setae on each side. Dexiotorma and pternotorma well developed. Laeotorma short, broad. Nesia with sensorial cone. Haptolachus with 3 sensillae below sensorial cone. Mandibles. Left mandible ( Figs. 23a, 24b ) with 1 scissorial tooth anterior to scissorial notch and 2 scissorial teeth posterior to notch. Stridulatory area elongate­oval, length over 3 times its width. Lateral edge with 2–4 setae. Dorsal surface in apical half with 1 seta. Molar area bilobed, dorsal surface with 1 dorsomolar seta. Basomedial angle with brustia possessing 7 setae. Right mandible ( Figs. 23b, 24a ) with 2 scissorial teeth, stridulatory area similar in shape to that of left mandible. Lateral edge with 2–4 setae. Dorsal surface in apical half with 1 seta. Molar area trilobed, dorsal surface with 3 dorsolmolar setae. Basomedial angle with brustia possessing 7–9 setae. Calyx present. Maxilla. Galea and lacinia fused ( Fig. 21 ), forming mala. Mala with large uncus at apex ( Fig. 26 ), 2 subterminal unci fused at base and unequal in size, dorsal surface with 2–3 indistinct rows of setae. Cardo ( Fig. 21 ) with 4–5 setae. Stridulatory area ( Fig. 25 ) possessing a row of 5 curved, blunt teeth plus a distal, truncate process. Labium. Hypopharyngeal sclerome with group of 9 setae on left side, 4 setae on right; both lateral lobes with 5–8 setae arranged in 2–3 rows. Glossa with transversal row of 11–13 setae at base, a group of 15–16 setae arranged in 2 or 3 rows, and a pair of sensilla on each side. Antennae. Surface ( Fig. 20 ) with 3 dorsal and 3 ventral sensory spots on terminal segment. Segment I of antenna equal in length to segments II and III combined. Thorax. Respiratory plate of thoracic spiracles ( Fig. 18 ) C­ shaped, 0.73 mm high and 0.50 mm wide, plate with 30 holes across diameter at middle, holes small and circular. Abdomen. Spiracles of abdominal segments I–VI similar in size, segments VII and VIII slightly larger. Scutum of abdominal segments I–VIII usually with 4–5 rows of short setae, each 3rd–4th row possessing several long setae. Segments IX and X fused, predominantly covered with short setae and fewer long setae. Spiracular area of abdominal segments I–VIII with 40–50 short and medium sized setae, pleural lobes with 25–35 setae. Raster distichous ( Fig. 17 ), possessing irregular rows of 18–20 pali. Septula elongate­oval, length nearly 4 times its width. Tegilla composed of numerous short and long setae. Lower anal lip possessing numerous short setae, fewer long setae. Legs. Tarsungulus ( Fig. 19 ) cylindrical, rounded apically, possessing 7 setae.

Figures

Fig. 2. Dorsal habitus of adult Hologymnetis cinerea (Gory and Percheron).

Figs. 16–21. Hologymnetis cinerea, third instar larva. 16) Frontal view of head; 17) Palidia; 18) Thoracic spiracle; 19) Tarsungulus of anterior leg; 20) Apical antennal segment, dorsal and ventral views; 21) Right maxilla, hypopharyngeal sclerome and labium, ventral view.

Figs. 22–26. Hologymnetis cinerea, third instar larva. 22) Epipharynx; 23) Dorsal view (a) left and (b) right mandibles; 24) Ventral view of (a) right and (b) left mandibles; 25) Stridulatory area of maxilla; 26) Apex of right mala showing unci.