Monza cretacea Snellen, 1872

Cock, Matthew J. W. & Congdon, T. Colin E., 2014, Observations on the biology of Afrotropical Hesperiidae (Lepidoptera). Part 7. Hesperiinae incertae sedis: grass and bamboo feeders, Zootaxa 3872 (4), pp. 301-354 : 343-346

Monza cretacea Snellen, 1872

This species occurs from Guinea to Uganda and Angola, with a possible record from south-western Kenya (South Kavirondo, after a van Someren manuscript stating that the abdomen was white) ( Larsen 1991). The type locality ‘Neder-Guinea’ is given as a false locality in Ackery et al. (1995) but Snellen (1872) is referring to the region where van Woerden collected in Lower Guinea, at the mouth of the Congo River of Zaire, at around 6 degrees south latitude (de landstreek waar var Woerden verzamelde, ligt in Neder-Guinea aan den mond der rivier Congo of Zaire, op ongeveer 6 graden Zuiderbreedte). Evans (1937) and Lindsey & Miller (1965) point out that although the uncus and right clasper are constant, the left clasper is individually highly variable and no alignment with adult markings or geographic distribution has been made. Although Evans (1937, 1956) treated M. punctata as a subspecies of M. cretacea, Carcasson (1981) and Ackery et al. (1995) accept that it is a valid species (see below). Nevertheless, Larsen (2005) suggests there may be 3–4 species in the M. cretacea - punctata complex. We have single observations from Côte d’Ivoire and Nigeria, but unfortunately both reared specimens are female.

Food plants

In Côte d’Ivoire, Vuattoux (1999) reared this species three times from Setaria megaphylla and once from sugarcane, Saccharum officinarum , which is an introduced species. MJWC found a pupa on Megathrysus maximus (= Panicum maximum ) in Nigeria (94/108) and a caterpillar in Côte d’Ivoire on what was probably M. maximum (89/ 205).

Leaf shelters

A penultimate instar caterpillar (89/205A) was found in a shelter about 60mm long, made by rolling the distal part of a leaf downwards, the apex of the leaf being about 20mm beyond the end of the shelter; feeding was basal to the shelter; the distal end of the shelter was blocked with frass and an early instar head capsule (?n-3). The pupal shelter found in the field (94/108) was made from the distal 150mm of a leaf rolled downwards and sealed at each end; lined with silk, but no wax; basal to shelter, feeding left the midrib bare for about 50mm, so that the shelter was pendulous. In contrast, the shelter of 89/205A was lightly dusted with white waxy powder at each end, and more sparsely ventral to the pupa ( Figure 45 ).

Caterpillar

The following is based on MJWC’s observations in Côte d'Ivoire (89/205A). An early instar head capsule found in the leaf shelter was black, the surface finely striated, 1.1 x 1.2mm wide x high.

In the penultimate instar, the head measured 2.5 x 2.6mm wide x high, rounded, rugose; matt black, the frons, clypeus and around the mouthparts brown; pronotum narrow, black; body dull green, similar in tone to food plant, with yellowish bands of folded cuticle at intersegmental region; spiracles brown, those of T1 and A8 quite conspicuous; anal plate with a pair of longitudinally elongate conspicuous black spots.

The final instar caterpillar grew to 40mm ( Figure 44 ) and is quite similar to that of the dark form of M. alberti . Head large, 3.0 x 3.8mm wide x high; shiny rugose; dark except for a pale brown stripe each side of epicranial suture in upper half of face, the corresponding adjacent sutures brown; upper adfrontals pale brown against adfrontal suture, making an inverted V in lower part of face; pale brown frons. Pronotum a narrow black plate on posterior margin of T1, not extending as far as the spiracle. Body whitish green, tinged yellow on posterior margin of A1–A4; inter-segmental area corrugated with about seven folds; darker dorsal line; subdorsal black dot in smooth area of A1–A8; spiracles brown, those of T1 and A8 conspicuous. Wax glands not noted. The head capsule of the cast final caterpillar skin of the collection from Nigeria (94/108B) was similar, 2.9 x 3.4mm wide x high; rather than black, the head is brown, paler posterior to the stemmata.

Pupa

The pupa of 89/205A from Côte d’Ivoire was 23mm long, while that of 94/108B from Nigeria was 22mm; both were female. Pupa 89/205A: cylindrical; thorax bulges above head; rather truncate at posterior end, with downturned cremaster; proboscis sheath extends to end of cremaster; light brown, matt surface; front of head brown, shiny; similar texture in three spots on anterior dorsal thorax, the central one anterior to the other two which lie between the T1 spiracles (all of which are missing on pupa 94/108B); erect brown setae on anterior part of thorax from wing base to wing base, and on posterior margin of thorax, ventrally on head and on anterior and posterior parts of the eye. T1 spiracle brown; raised, semicircular; brown; comprising four (89/205A) or six (94/108B) raised portions, separated by longitudinal grooves.

Figures

FIGURE 44. Final instar caterpillar of Monza cretacea collected on probably Megathrysus maximus, 28 May 1989, Adiopodoumé, Côte d’Ivoire; moulted to final instar c. 4 Jun; photographed 14 Jun; pupal shelter 18 Jun; 40 mm; 90 / 205. 1, detail of head, dorsolateral view; 2, dorsal view.

FIGURE 45. Pupa of Monza cretacea collected on probably Megathrysus maximus, 28 May 1989, Adiopodoumé, Côte d’Ivoire; pupal shelter 18 Jun; photographed 23 Jun; adult 9 Jul; 23 mm; 90 / 205 A. 1, dorsal view; 2, lateral view.