Aleurodicus talamancensis, Martin, Jon H., 2005

Martin, Jon H., 2005, Aleurodicus talamancensis, a new whitefly species damaging plantation bananas in Costa Rica, with discussion of a montane orchid­feeding population (Sternorrhyncha, Aleyrodidae), Zootaxa 843, pp. 1-10 : 3-5

Aleurodicus talamancensis sp. nov.

( Figs 1–14 )

HABITUS — In small groups, puparia often develop within the spiral of oviposition wax left by the parent female ( Fig. 13 ), each puparium with a narrow annulus peripheral wax and a thin dorsal covering of opaque white wax, often with dark wax­free spots at positions of large compound pores and thoracic cicatrices ( Figs 12­13 ). In large aggregations the amount of secreted material leads to the leaves of the host plant appearing greyish or white ( Fig. 14 ).

PUPARIUM — TYPICAL FORM, FROM BANANA. Margin. Outline broadly ovoid, 1.05–1.25 mm long, 0.75–0.91 mm wide, generally widest at abdominal segment II/ III (n=25), but one additional examined specimen only 0.98 X 0.67 mm. Margin broadly lobulate, generally 4–7 shallow lobules per 0.1 mm of abdominal margin, but rather more per 0.1 mm towards cephalic region. Margin not modified at tracheal openings. Dorsum. Cuticle brownish, distinctly paler in submedian area and inner subdorsum ( Figs 8, 10 ). Longitudinal moulting suture reaching puparial margin; transverse moulting sutures distally curving abruptly anteriad, becoming almost tangential to puparial margin and terminating opposite middle legs ( Fig. 2 ). Cuticle of submedian area somewhat corrugate, becoming subtly reticulate subdorsally and then more rugose towards submargin. Abdominal segmentation marked by folds which are suture­like submedially but still evident in subdorsum; segment VII/VIII boundary medially only marked by presence of pockets, and not by any fold ( Fig. 9 ); median lengths of segments III–V similar to each other and slightly longer than median lengths of remainder of abdominal segments. Submedian abdominal depressions narrow and elongate, little more than widenings of intersegmental divisions. Cephalothoracic segmentation only subtly marked; two pairs of thoracic cicatrices present (scars of compound pores in third­instar larva). Abdominal segments VII and VIII each bearing an ovoid raised area ( Fig. 1 ) that is lateral to vasiform orifice on segment VII and posterolateral to vasiform orifice on segment VIII; raised areas on segment VIII forming caudal furrow, within which lies excluded part of lingula. Vasiform orifice ( Figs 1 , 9 ) broadly cordate, a little wider than long, its rim smooth laterally, situated about its own length from posterior margin of puparium; operculum wider than long, laterally rounded, its anterior edge straight but posterior edge distinctly emarginate where it overlies lingula, opercular surface rather rugose, apparently without a posterior pair of setae; lingula head spinules loosely clustered, rather than covering surface evenly; lingula protruding beyond vasiform orifice, almost as wide as operculum at point of emergence from under operculum, apically rounded, laterally emarginate, its two pairs of setae situated close to apex, distal setal pair stouter and longer than proximal pair, lingular apex closely approaching puparial margin. Chaetotaxy. Anterior marginal setae not evident. Posterior marginal setae, 12 pairs of outer submarginal setae (including nominal caudal pair), and single pairs of submedian pro­, meso­ and metathoracic setae present, each long and hairlike; eighth abdominal setae present but much shorter and finer, situated anterior to vasiform orifice ( Fig. 1 ). Pores. Cephalic pair and anterior 4 pairs of abdominal compound pores (situated on segments III–VI) presenting laterally to viewer, 35 µm maximum diameter in holotype, each with an acute, dagger­shaped, axial process protruding about a porelength beyond pore rim; a pair of much smaller compound pores, about 16­20 µm in maximum diameter, present on each of abdominal segments VII & VIII, each located on outer edge of its segment’s raised area ( Fig. 1 ). Narrow submargin defined by band of crowded, wide­rimmed pores ( Figs 2–3 ) that stand proud from puparial surface, inner boundary of zone confluent with row of submarginal setal bases, pore band not interrupted at posterior extremity of puparium but often difficult to see there because of marginal down­curling; when margin completely flattened on slide, extreme outer submargin can be seen to be devoid of pores ( Fig. 3 ). Dorsal disc with scattered bright pores, most slightly larger than those of submarginal band, usually 2–3 present in vicinity of each large compound pore, and 3–6 on each raised area of abdominal segments VII & VIII ( Fig. 1 ). Ven t er. Ventral abdominal setae overlain by vasiform orifice, similar to dorsal submarginal setae. Legs typically robust and two­segmented, smooth, each with one pronounced apical claw, and with distal segment bearing one or two small lateral setae. Antennae with their bases situated anterior to fore legs, with basal one­third smooth­sided, remainder corrugate­sided, antennal apices pointed and reaching articulation of hind legs. Mouthparts typical for Aleurodicus species, rostrate, elongate­triangular and similar to lingula in dimensions. Tracheal folds absent.

PUPARIUM — COLONY FROM MONTANE ORCHID. Most characters are shared with the typical, banana­feeding, specimens and only differences are described below. Margin. 1.37–1.57 mm long, 0.97–1.17 mm wide, generally widest at abdominal segment I/II (n=26). Dorsum. Raised areas on abdominal segments VII and VIII ( Fig. 4 ) broader and less well defined than in specimens from banana, with caudal furrow therefore less evident; submedian abdominal depressions more distinct, with 2–3 contiguous pits on each side of submedian area ( Fig. 6 ); cephalic pair and anterior 4 pairs of abdominal compound pores up to 65 µm maximum diameter; rim of vasiform orifice ( Fig. 4 ) a little less sharply defined; operculum with its posterior edge often not emarginate; clusters of surface spinules on lingula head more clearly defined ( Fig. 5 ); lingula apically slightly more acute, and laterally not noticeably emarginate ( Figs 4 , 11 ); largest of the dorsal disc bright simple pores apparently each with a fine transverse septum; usually more simple pores present in vicinity of each compound pore, the most numerous clusters typically on abdominal segment VII and cephalic segment, with up to 10 pores ( Figs 4, 7 ).

MATERIAL EXAMINED. Holotype puparium, COSTA RICA, on Musa cultivated variety ( Musaceae ), Limón Province, Talamanca Canton, Daytonia Farm, 2004 (D. Cubillo) ( BMNH). Paratypes: 20 puparia, 3 adult males, 4 adult females, same data as holotype ( BMNH, USNM); 5 puparia, same host, Limón Province, Talamanca Canton, Farm #97, 2004 (Cubillo) ( BMNH); 58 puparia, 3 third­instar larvae, 4 adult males, 4 adult females, same host, Limón Province, Limón Canton, Valle La Estrella, 2004 (Cubillo) ( BMNH, INBio); 2 puparia, same host, Limón Province, Matina Canton, Banasol Farm, March 2004 (D. Gerling & D. Cubillo) ( BMNH); 5 puparia, same host, Limón Province, 30 March 1999 (unknown collector) ( BMNH); numerous puparial specimens dry on leaf tissue, various data as detailed for paratypes ( BMNH, INBio).

Other material (not designated as paratypes): 50 puparia (of which 13 on leaf tissue in alcohol), 10 third­instar larvae, 1 second­instar larva, COSTA RICA, San Jose Province, Cerro Chirripó, 2600­2800 metres, on? Maxillaria sp. ( Orchidaceae ), 17 February 1983 (J H Martin #3873) ( BMNH, INBio, USNM).

ETYMOLOGY. This species is named for the Canton of Talamanca, Limón Province, Costa Rica.

COMMENTS. Many of the observed differences between the banana­feeding and orchid­feeding puparia are likely to be a result of size variation, with the size range of the orchid­feeding specimens from Cerro Chirripó not overlapping the size range of all the examined banana­feeding specimens from Limón Province. Along with larger overall puparial size, specimens from Cerro Chirripó have their large compound pores almost twice the diameter (up to 65µm) of those in puparia from the banana plantations (about 35 µm), and there are greater numbers of dorsal disc simple pores in the Cerro Chirripó sample; also, the posterior edge of the operculum and the sides of the lingula are more emarginate in banana­feeding specimens, which also have a more clearly defined caudal furrow. Although these differences are considered most likely to be artifacts of differing physical size, slight doubt does remain. Accordingly, the banana­feeding populations are regarded as the typical, name­bearing, form of this emergent pest and the montane orchidfeeding specimens from Cerro Chirripó are not designated as paratypes. This is considered to be a valid approach, despite the possibility that the hitherto usual hosts of A. talamancensis may have been orchids, and that an opportunistic move onto an alternative host, banana, may have occurred recently.

The author recently described A. niveus and A. rugioperculatus from Belize ( Martin, 2004), and these belong to the same group of Aleurodicus species, sharing the characteristically rugose operculum that occupies most of the vasiform orifice, robust and pigmented puparial cuticle, and a submarginal zone of crowded simple pores of only one type. Both species have a much wider submarginal pore band than does A. talamancensis , and neither of them possess lingular spinules arranged in clusters. A. niveus , another orchid­feeding species, is characterised by its lingular apex being developed into an acute, bifid, process, and also by the inner boundary of its very wide submarginal zone of simple pores being concentric with its puparial margin. A. rugioperculatus , from coconut palms and an unidentified broad­leaved host, has its entire lingula head acute­triangular, and the inner boundary of its submarginal band of simple pores lobe­like.

Figures

FIGURE 14. Mature banana leaf completely covered by immature stages of Aleurodicus talamancensis.

FIGURES 1 – 7. Dorsal puparial details of Aleurodicus talamancensis: 1 – 3, paratypes from banana. 1, posterior detail; 2, submarginal detail and apex of transverse moulting suture; 3, fully­flattened margin at confluence with longitudinal moulting suture; 4 – 7, specimens from montane orchid. 4, posterior detail (to same scale as Fig. 1); 5, surface detail of lingula; 6, abdominal segment IV with intersegmental divisions and submedian depressions; 7, cephalic compound pore and adjacent wide­rimmed simple pores, with inset detail of submarginal pore band.

FIGURES 8 – 11. Photomicrographs of slide­mounted puparia of Aleurodicus talamancensis. 8 – 9, puparium and posterior detail from banana; 10 – 11, puparium and posterior detail from montane orchid.

FIGURE 12 – 13. Habitus photographs of puparia of Aleurodicus talamancensis. 12, on leaf of plantation banana, Limón Province; 13, on leaf of? Maxillaria sp. (Orchidaceae), Cerro Chirripó.