Epilachna vigintioctopunctata (Fabricius)

Casari, Sonia A. & Teixeira, Edson P., 2015, Immatures of Epilachna Chevrolat (Coleoptera, Coccinellidae, Epilachninae), Revista Brasileira de Entomologia 59 (2), pp. 113-120 : 114-116

Epilachna vigintioctopunctata (Fabricius) ( Figs. 1–23 )

Redescription of fourth instar larva

The fourth instar larvae have a length of 6–8 mm. After fixation, cream coloration in general with brown scoli and brownish or cream strumae, lateral scoli clearer than dorsal can be noted. Scoli brown, clearer at base, with cream-colored basal and brownish distal ramifications; apical spine of each ramification brown and a few whitish; as well as two last lateral pairs of scoli on abdomen smaller and clearer too can be noticed. Dorsal scoli along with at least twelve branches arising from a rounded brown area; branches moderately long, except for a few shorter ones situated near base; each branch bearing, in addition to the apical spine, and two or three short and very thin setae are some of the features. Head remains partially yellowish or brownish except in lateral areas; besides a band on frontal sutures, cream; frontal area with several brown patches; dorsal area outside frontal sutures brownish; dorsal region with brownish irregular spots near base; stemmata black, located on a brownish small area; antennae brownish except at antennifer; labrum with brownish narrow band lateral and anterior; mandibles brown with black apex; maxilla and labium partially brownishcream with palpi slightly darker, brownish; legs brownish, darker in direction of apex; and distal region of tibiae and claws brown ( Figs. 1–3 ) too can be noticed.

Head ( Figs. 2 , 9–11 ) is not visible dorsally, but is rounded with several long setae; epicranial suture marked by wide cream band; frontal arms V-shaped; coronal suture long; frontoclypeal suture complete; frons with seven pairs of setae: an inclined row of five on each side near frontoclypeal suture, and two pairs near middle, one near anterior margin and one near base; four setae inside or near cream band of each frontal arm; each epicranial half with two setae near stemmata, two setae laterally below stemmata (one basal shorter) and an inclined row of four short setae on each side near base of epicranial suture are some of the features. Ventrally, two setae near each antenna, two laterally bellow anterior and three setae on each side, near gular area can be found. Occipital foramen remains large and sub-rounded. Stemmata ( Figs. 9 and 11 ) is very prominent and black, with three on each side on a brownish patch. Antennae ( Figs. 9, 14–16 ) are long; antennifer may be membranous and with three antennomeres: antennomeres I and II elongate; I shorter than II, almost as long as wide, with two campaniform sensilla dorsally near base; II is slightly narrower, which is almost twice as long as wide, with one long lateroexternal seta near apex, and at apex antennomere III, one long spine-like ventral seta and one laterointernal microseta; antennomere III remains ( Figs. 15 and 16 ) very short, band-like, with six short setae (two longer) at apex. Clypeus ( Fig. 12 ) is transverse, trapezoidal and translucent with two setae and one campaniform sensilla on each side, forming an inclined row, and anterior seta shorter. Labrum ( Fig. 12 ) is transverse, with fore angles rounded, almost twice as long as wide, sclerotized in a narrow basal band, six pairs of setae and two of campaniform sensilla (three pairs longer). Epipharynx is membranous with narrow band of fine setae near anterior margin. Mandible ( Fig.13 ) remains symmetrical, much narrowed near apex, with five apical teeth [plant feeders]; mola and penicillus absent; and with one lateral long seta. Maxilla ( Figs. 17 and 18 ) with mala transverse, wider than stipes, with anterior margin rounded; six ventral setae near middle; curved, longer, stout setae internally at apex; dorsally with setae, longer, denser and stouter near apex and microspines near middle; cardo is fused to stipes; stipes elongate, membranous laterally, with two long lateral setae, one at middle and one near anterior margin; palpifer lays transverse with one seta ventral; palpi remains with three palpomeres. Its basal palpomere is short, wider than long, with a campaniform ventral sensilla; palpomeres 2 and 3 elongate, 3 longer than 2; palpomere 2 with two long setae near apex, one dorsal and one ventral, and one campaniform ventral sensillum, near middle; distal palpomere narrowed apicad, with two ventral setae and one peg-like dorsal in groove, and several microsensilla at apex. Labium ( Fig. 17 ) is fused to gula, almost totally translucent, formed by a unique piece with two setae at middle, near anterior margin, and another ten setae: a row of four near anterior margin, four near middle and two near base; palpi with two palpomeres elongate: basal palpomere with one ventral laterointernal campaniform sensillum near apex; distal palpomere narrower with one large dorsal campaniform sensillum near apex; microsensilla at apex can be noted. Hypopharynx is ( Fig. 18 ) densely setose laterally and microspined at middle; lateral setae longer.

Prothorax ( Figs. 1 and 2 ) appears dorsally with two well-developed sclerotized plates, almost covering whole pronotum; each plate with one pair of scoli and three or four short chalazae near base, and one very long chalaza near anterior margin; laterally with one clear brownish well-developed struma near procoxa; ventrally with one cream struma between procoxae. Meso- and metathorax have with two dorsally sclerotized plates, smaller than those of pronotum; each plate with one pair of scoli; laterally, each side with one scolus and one sclerotized struma near each coxa; ventrally, each with two cream strumae between coxae. One pair of rounded latero-anterior spiracles on mesothorax is there. Legs ( Figs. 3 and 4 ) are setose; setae brownish; distal setae of tibiae clubbed; coxae elongate, inserted distant from middle line of thorax; trochanter triangular; femur and tibia elongate; tibia narrower and brown near apex, with longitudinal narrow sclerotized band near margin of internal face, and densely setose laterally on distal third of posterior face; dark-brown claws inserted on anterior face of tibia, with one seta at base of anterior face.

Its abdomen shall be described as: for segments I–VII, each bearing dorsally two median scoli inserted in one sclerotized plate and one scolus on each side of plate (dorsolateral); laterally, each segment with one scolus on each side; scoli decreasing slightly in size in direction of apex; ventrally with 6–7 strumae on each segment; strumae more sclerotized and larger in direction of apex. This is for segments I–VIII, each with one rounded spiracle anterolaterally on each dorsolateral scolus. Segment VIII type has with four short dorsal scoli, one large sclerotized lateral verruca, and six ventral smaller sclerotized chalazae. Segment IX is narrower with one sclerotized dorsal plate, having several setae and six small ventral verrucae, each with one seta. Segment X tubular, sucker-like protuberance.

Figures

Figs. 1–8. Epilachna vigintioctopunctata (Fabricius).Larva: 1, 2, habitus (dorsal, lateral); 3, 4, leg (external, internal view). Pupa: 5, head and pronotum; 6–8, habitus (dorsal, ventral, lateral). Bars= 1 mm.

Figs. 9–18. Epilachna vigintioctopunctata (Fabricius).Larva:9–11, head (dorsal; ventral,mandibles removed; laterodorsal,mouthparts removed); 12, clypeus and labrum; 13, mandible (dorsal); 14–16, antenna (ventral, apex dorsolateral, dorsal); 17, labium and maxila; 18, apex of maxila and hypopharynx. Bars= 1 mm, except Figs. 9–11 =2 mm; Figs.14–16= 0.5mm.

Figs. 19–26. Epilachna vigintioctopunctata (Fabricius). 19–20, larvae (first and fourth instars); 21, pupa (dorsal); 22, larval and pupal exuviae; 23, adult. Figs. 24–26. Pupae: 24, Epilachina clandestina (Mulsant); 25, E. paenulata (Germar); 26, E. spreta (Mulsant).