Melete lycimnia (Cramer, 1777)

Braby, Michael F. & Nishida, Kenji, 2010, The immature stages, larval food plants and biology of Neotropical mistletoe butterflies (Lepidoptera: Pieridae). II. The Catasticta group (Pierini: Aporiina), Journal of Natural History 44 (29 - 30), pp. 1831-1928 : 1842-1849

Melete lycimnia (Cramer, 1777)

This polytypic species ( Figure 4 ) occurs widely in Central and South America, and 16 subspecies are currently recognized (Lamas 2004). The subspecies M. lycimnia isandra (Boisduval, 1836) on which our observations of the life history were made occurs from central eastern Mexico ( de la Maza 1987; Dauphin et al. 2005) to Costa Rica ( DeVries 1987). It occurs predominantly in lowland areas (<500 m a.s.l.) on the Pacific slope where it inhabits dry seasonal (deciduous) tropical forest ( DeVries 1987; Dauphin et al. 2005).

The larval food plants of M. lycimnia include Struthanthus in Colombia (Constantino 2004), Struthanthus dichotrianthus Eichler (listed as “guatepajarito” or “tiña”) in Venezuela ( Alvarez and Alvarez 1984), Phoradendron in Belize ( Meerman 1999) and Phoradendron quadrangulare in Costa Rica ( Janzen and Hallwachs 2009). The immature stages of M. lycimnia were depicted by Janzen and Hallwachs (2009) and Constantino (2004), but they have not been described in detail. Alvarez and Alvarez (1984 p. 110) provided the following notes for M. lycimnia harti (Butler, 1896) from Venezuela:

Las larvas son de un color dorado amarillento. Presentan longitudinalmente tres bandas, dos laterales algo más claras y la central ligeramente más oscura. El cuerpo de la oruga está recubierto por numerosas cerdas blancas. La cabeza es pequeña, globosa, de color negro con numerosas cerdas blancas. La larva crisalida cabeza arriba. Se sujeta al tronco o ramas de los árboles por el abdomen y por la región media pas una fibra de seda alredodor de su cuerpo. Crisalidan en la parte baja del tronco de los árboles…La crisálida mide unos 2,5 centímetros de largo, es de color verdoso claro al principio, pero después ese color cambia a crema y marrón en los ƋƋ y por ocre y marrón en las ♀♀, con numerosas espinas puntiagudas en todo el cuerpo de la crisálida. Está sujeta a la corteza del árbol cabeza arriba por el abdomen y por una fibra de seda alrededor de la región torácica que la mantiene en esa posición. Presenta un a corta prolongación en la región cefálica.

[The larvae are golden-yellow. They have three longitudinal bands, two lateral which are slightly clearer and one central which is slightly darker. The body of the caterpillar is covered with numerous white hairs. The head is small, globose, black with numerous white setae. The larva pupates with head up. It is fixed to the trunk or branches of the trees by the abdomen and by the middle region where there is a silk fibre around its body. They pupate in the lower part of the tree trunk... The chrysalid has a length of 2.5 cm, the colour is whitish-green at the beginning, but later that colour changes to cream and brown in the males and ochre and brown in the females, with numerous pointed spines on the whole body of the chrysalid. It is fixed to the bark of the tree head up by the abdomen and by a silk fibre around the thoracic region that keeps it in that position. It has a short prolongation in the cephalic region.] (Our translation)

More recently, Constantino (2004 p. 107) provided the following notes for M. lycimnia reducta Constantino, 2004 from the Cauca River, Colombia:

Huevos de color amarillo intenso, alargados y puestos en grupos de 50–70 en el envés de las hojas en forma vertical. Larvas de comportamiento gregario y hábitos nocturnas, con cuerpo de color café marrón con puntos negros y blancos. Cuerpo recubierto de sedas. Las larvas se congregan en la base de los árboles, donde se protegen el día para luego ascender durante la noche por el tronco de los árboles hasta alas ramas donde de encuentran las plantas parásitas que les sirven de alimento. Las larvas deambulan en procesión y forman caminos de seda sobre el tronco de los árboles, tal vez para poder guiarse. Pupas blancas con un “cuerno” recurvado en la cabeza, cuerpo recubierto de manchas negras y cafés que simulan el excremento de un pájaro.

[Eggs bright yellow, elongated and laid in 50–70 on underside of leaves in vertical form. Larvae exhibit gregarious behaviour, active at night. Body brown chestnut colour with black and white spots. Body covered by setae. The larvae group together at the base of trees where protected during the day, and go up during the night via trunk to the branches where the parasitic host plants are found. The larvae move in procession and form silk trail on the trunks, probably to guide themselves. Pupae are white with curved horn on the head, body covered with black and brown spots simulating a bird dropping.] (Our translation)

The following observations on the life history of M. lycimnia isandra were based on material reared from Costa Rica at the field station headquarters of Sector Santa Rosa of Área de Conservación Guanacaste, Guanacaste Province (c. 300 m a.s.l.), during the wet season of 2001. Additional observations were made near Monteverde (700 m a.s.l.) on the Pacific slope of Cordillera de Tilarán (W. Haber, personal communication 2001). We also provide descriptions and comments on the morphology and variation of the adult stage because of problems in the past of accurately diagnosing this taxon .

Immature stages

Egg

See Figures 45–47 ; 0.9 mm high, 0.55 mm wide; yellow; barrel-shaped, with base flattened and narrower in width (0.3 mm) than middle; chorion with numerous (approx. 30) fine longitudinal ribs, and a series of finer transverse lines between longitudinal ribs; apical rim with seven to eight prominent paler protuberances or nodules.

First-instar larva

See Figures 48–50 ; 3.0 mm long, head capsule 0.4 mm wide (n = 1); head black; body yellow after eclosion, changing to lime-yellow and then green after consuming food, reddish-brown at anterior and posterior ends, with numerous long, fine colourless primary setae; paired dorsal setae with club at apex; prothorax with a subdorsal plate bearing three setae, two dorsolateral setae and a lateral seta; mesothorax to abdominal segment 9 each with four setae (one subdorsal, two dorsolateral, one lateral); abdominal segment 10 with a dorsal plate bearing six setae.

Second-instar larva

See Figure 51 ; 6 mm long, head capsule 0.7 mm wide (n = 7); similar to first-instar larva, but primary setae white and arising from cream protuberances or panicula; each segment with a few additional white setae and several short brown secondary setae; paired dorsal primary setae with club at apex; prothorax with a broad dorsal plate bearing six long white setae (in two groups, three on either side of middorsal line); abdominal segment 10 with a dorsal plate bearing several long white setae.

Third-instar larva

See Figure 52 ; 10 mm long, head capsule 1.1 mm wide (n = 11); similar to final instar, except body green, with brown on anterior and posterior segments.

Fourth-instar larva

See Figure 53 ; 19 mm long, head capsule 1.9 mm wide (n = 7); similar to final instar, except body greenish-brown.

Fifth-instar larva

See Figures 54–58 ; 28 mm long, head capsule 3.2 mm wide (n = 23); head dark brown-black, with numerous cream panicula from which arise long white setae; body brown, with a broad darker brown middorsal line, paler grey-brown in intersegmental areas which form a series of transverse bands; surface densely covered with numerous cream panicula from which arise long white setae (up to 1.2 mm long), and numerous short brown secondary setae; prothorax and abdominal segment 10 each with a darker brown dorsal plate bearing numerous long white setae; spiracles black. The numerous white setae give the larval body a greyish appearance.

Pupa

See Figures 59–63 , 218, 219 ; 22 mm long, 6 mm wide (n = 28); head with a prominent anterior projection, and a subdorsal protuberance posteriorly; anterior projection stout, upturned and broadened apically so that apex appears T-shaped; prothorax with a pronounced longitudinal dorsal ridge; mesothorax with a pronounced longitudinal dorsal ridge, a rounded lateral protuberance at base of fore wing, and a broad lateral ridge posterior to lateral protuberance; metathorax with a shallow longitudinal dorsal ridge; abdominal segment 1 with a small dorsolateral protuberance; abdominal segments 2 and 3 each with a white dorsolateral conical projection anteriorly, followed by a shallow dorsolateral ridge posteriorly; abdominal segment 4 with a prominent black dorsolateral conical projection; abdominal segment 2 with a small white middorsal protuberance; abdominal segments 3–8 each with a prominent black middorsal bifurcated (i.e. Y-shaped) projection anteriorly, forks of each projection oriented transversely. Colour pattern variable: either uniformly white, with reduced pale brown markings on head and thorax, and a few small black spots on abdomen; or white, with extensive dark brown markings, particularly on mesothorax, including wing cases, abdominal segment 4, and lateral areas of abdominal segments 5–10.

Adult stage

Male

Upperside white; fore wing with apex dark brown extending narrowly along costa and more broadly along termen to vein CuA 1, brown cell on underside sometimes visible; hind wing with yellow suffusion in tornal region, sometimes extending narrowly along termen or more broadly along dorsum, a very narrow brown terminal line. Underside ground colour yellow; fore wing with a prominent pale brown bar at end of cell, anterior half of cell variably suffused with yellow, apex pale brown extending narrowly along costa and more broadly along termen to about vein CuA 1, posterior portion below vein M 3 and cell uniformly white; hind wing with a very narrow brown terminal line.

Female

See Figure 4 ; upperside yellow; fore wing with a prominent brown bar at end of cell, apex dark brown extending narrowly along costa and more broadly along termen to vein CuA 1, usually broader than in male; hind wing with a narrow brown terminal line but usually more conspicuous than in male. Underside similar to upperside but brown markings paler; fore wing with ground colour yellow becoming paler and whitish in posterior half towards dorsum; hind wing with a narrow brown terminal line.

Variation

In both sexes, the extent (width) of the brown markings varies, particularly the apical patch on the upper- and underside of the fore wing, the cell bar on the fore wing, and the terminal line on the hind wing. In both sexes, the apex on the underside of the forewing may be broadly yellow with the brown patch absent and only a narrow brown terminal line present. In the female, the upper- and underside ground colour varies from pale yellow through yellow to rich dark yellow.

Comments

There has been confusion over the identity of M. lycimnia isandra owing to variation in the adult and lack of reared material, particularly with M. polyhymnia florinda (Butler, 1875) to which it closely resembles. DeVries (1987 p. 89) illustrated the upper- and underside of the male and stated that adults have “Two morphs, either white or yellow”. However, from material (n = 40) reared from the immature stages collected from Sector Santa Rosa of Área de Conservación Guanacaste, Costa Rica, together with a series (15 ƋƋ, 17 ♀♀) reared from the same area in 1993 by D.H. Janzen and his co-workers, it was evident that the species is sexually dimorphic – males are white and females yellow, as described above. Females apparently have two colour morphs ( Dauphin et al. 2005), but in Costa Rica only the yellow morph was detected in our reared specimens. The taxon M. polyhymnia florinda , which also occurs in Costa Rica, can be distinguished from M. lycimnia isandra by several features. In both sexes of M. polyhymnia florinda , the brown terminal line on both wings is more prominent and broader, especially in the female, and the brown apical patch on the fore wing encloses a series of faint yellow spots (particularly evident in the female), a feature not present in M. lycimnia isandra . In M. polyhymnia florinda males, the upperside is uniform lemon-yellow, rather than white. In M. polyhymnia florinda females, the underside ground colour is yellow in the fore wing but orange in the hind wing, whereas in M. lycimnia isandra the differences between the wings are less pronounced. In M. polyhymnia florinda , like M. lycimnia isandra , the sexes can be readily distinguished by the presence of a prominent brown bar at the end of the cell on the upperside of the fore wing in the female, this bar being present only on the underside in the male.

Larval food plants

In Costa Rica, eight cohorts of the immature stages were recorded on clumps of Phoradendron quadrangulare ( Figures 43, 44 ) parasitizing two host tree species, usually Guazuma ulmifolia Lam. (Sterculiaceae) but also Bauhinia ungulata L. ( Fabaceae ), growing in Pacific lowland deciduous forest at Sector Santa Rosa of Área de Conservación Guanacaste ( Appendix 1). Additional observations made near Monteverde by W. Haber (personal communication 2001) indicated an association with the same mistletoe species ( Appendix 1). The population at Santa Rosa was highly localized: of several hundred mistletoe clumps examined throughout Park, the immature stages were found only on six clumps growing 3–6 m above ground level in a small circumscribed area at the field station headquarters ( Figure 42 ). No adults were sighted in the breeding area, but a male was collected several miles away near the beach on 7 October 2001, and a female was observed flying around clumps of P. quadrangulare parasitizing roadside trees of Guazuma ulmifolia growing outside the Park (c. 20 km north-west of Liberia) on 9 October 2001 at 11:30 h.

Biology

Eggs were laid in large compact clusters in the central portion of new soft leaves of the larval food plant. Clutch sizes varied from 25 to 70 eggs per cohort (x - = 50.2; n = 5 cohorts). Janzen and Hallwachs (2009) recorded a slightly larger clutch size (79 eggs) for a cohort at Sector Santa Rosa of Área de Conservación Guanacaste, Costa Rica. On hatching, the first-instar larva ate a small hole from the upper longitudinal side of the chorion just below the apex; once emerged it then proceeded to devour part or all of the chorion, often just leaving the circular base of the egg adhered to the leaf. The first-instar larvae then commenced to feed gregariously, usually starting at the apex of the leaf where they nibbled the margin or “skeletonized” the leaf by grazing the surface. Once they reached the second instar they usually consumed the entire leaf, working from the apex back towards the petiole. In the early instars (I–III), the larvae fed and moulted gregariously and remained on the foliage of the larval food plant during both day and night. They did not spin silk over the leaf to facilitate mobility; however, prior to moulting they spun a platform of silk over the substrate (i.e. surface of leaf or branch) to which they attached themselves; they also strengthened the base of the leaf petiole, at its point of attachment to the stem, with silk before moulting. When molested they wriggled violently and thrashed their heads back and regurgitated green fluid. In captivity, the late instars (IV, V) also fed gregariously, but spun considerable amounts of silk over the branches and leaves before proceeding to crawl or feed on the leaves, especially in the final instar. When molested they also regurgitated green fluid from the mouth. Instars I and II possessed paired dorsal setae which contained fluid droplets at their tips ( Figure 49 ), while instars III and IV possessed short subdorsal spines also tipped with fluid droplets. We did not observe late-instar larvae and pupae in the field, but observations made at Belize (J. Meerman, personal communication 2000), Costa Rica (W. Haber, personal communication 2001), Panama (A. Aiello, personal communication 2008) and Colombia ( Schultze-Rhonhof 1933; Constantino 2004) indicate that the larvae, from about third instar onwards, switch their habits and feed only at night, resting by day in tight aggregations near the base of the trunk of the host tree. These aggregations may comprise up to 500 individual larvae, and such numbers may defoliate the mistletoe food plants. At Sector Santa Rosa of Área de Conservación Guanacaste, Costa Rica, Janzen and Hallwachs (2009) found a single pupa under the eaves of a house and another on the larval food plant, indicating capacity for the larvae to disperse from the food plant. However, Alvarez and Alvarez (1984) noted in Venezuela that the larvae of M. lycimnia usually pupate in the lower part of the trunk of the host tree, which suggests the larvae pupate in similar sites in which they shelter during the day. In captivity, larvae pupated singly, secured by the cremaster and a silken central girdle, which passed over abdominal segment 1. Although the extent of brown markings of the pupa was variable, the ground colour was predominantly white, the overall effect of which was that the pupa resembled a bird dropping. Adults of a given cohort emerged synchronously and, following emergence, they spread and dried their wings within 1 h but were not able to fly normally until about 4–7 h later.

Few observations were made in the field on behaviour of the adult stage ( Figure 4 ). Adults have been reported to have a slow fluttery flight, and frequently puddle from edges of moist sand along creeks and river banks during the morning (Constantino 2004). DeVries (1987) noted that males patrol a defined area along the forest edge, flying 2–8 m above the ground during the morning under sunny conditions. Such patrolling behaviour suggests they establish mating territories, similar to that observed in Pereute and Leodonta , although this remains to be confirmed. In Costa Rica, they have been recorded visiting flowers of Oyedaea verbesinoides DC. (Asteraceae) in transitional forest during August–October at El Rodeo west of San José ( Vega and Gloor 2001).

The life cycle of M. lycimnia , from egg to adult, when reared at room temperature (c. 21–22°C) was completed in approximately 4–5 weeks (egg ≥ 4 d; larva 21 d; pupa 7 d). The rearing conditions were slightly cooler than that experienced in the lowland areas of Sector Santa Rosa of Área de Conservación Guanacaste at the same time of year (October), implying that the developmental time may be faster than one month in the field. Melete lycimnia appears to be very seasonal in occurrence in Central America. In Mexico, adults have been recorded from January to October ( de la Maza 1987). In Belize, Meerman (1999; personal communication 2000) noted that the species is usually uncommon and localized in occurrence, but it is sporadic and may have sudden population explosions in April. In Costa Rica, DeVries (1987) also noted that in certain years the species has large population explosions lasting only a few weeks early in the wet season at Área de Conservación Guanacaste. D. Janzen (personal communication 2001) has noted that at Sector Santa Rosa of Área de Conservación Guanacaste the immature stages have been recorded only from August to November, which coincides with the late wet season. Moreover, the species is not present every season, but in some years they are common (D. Janzen, personal communication 2001). In Colombia, Constantino (2004) made general reference to the species’ phenology and suggested that seasonal peaks in abundance early in the wet season were because of the synchronous emergence of adults, presumably from many cohorts at once. Our observations on the phenology of the immature stages in Costa Rica suggested that females were ovipositing in the area no earlier than late September 2001, and that the synchronous emergence of these cohorts potentially could have contributed to a seasonal peak in abundance approximately a month later.

It is not clear what the species does during the non-breeding season. The short seasonality, together with the rapid rate of development and high abundance in some years, suggest that M. lycimnia is present only temporarily in the lowland deciduous forests of Costa Rica, dispersing to breed elsewhere during the dry season (December– April). Evidence for dispersal capacity is provided by Dauphin et al. (2005), who recently recorded the species outside the breeding range in southern Texas, USA, and postulated that the four individuals encountered were migrants from Mexico.

Figures

Figures 4–13. Adults of the Catasticta group. (4) Melete lycimnia isandra freshly emerged female, Costa Rica; (5) M. leucanthe male puddling, Peru; (6) Pereute callinice male puddling, Peru; (7) P. callinira male puddling, Peru; (8) P. cheops female freshly emerged, Costa Rica; (9) P. charops mass emergence, Costa Rica; (10) Leodonta tellane chiriquensis freshly emerged, Costa Rica; (11) Catasticta sisamnus sisamnus female freshly emerged, Costa Rica; (12) Archonias brassolis approximata male perching, Costa Rica; (13) A. brassolis negrina male basking (note beak mark on both wings), Peru. Note: Figure 9 photo, W. Haber.

Figures 45–63. Melete lycimnia immature stages on Phoradendron quadrangulare, Sector Santa Rosa of Área de Conservación Guanacaste (300 m), Guanacaste Province, Costa Rica. (45–47) Eggs, showing cohort (45), dorsolateral view (46) and lateral view (47); (48–50) larval instar I, showing newly emerged (48), setae with terminal fluid droplets (49), and after feeding (50); (51) larval instar II, cohort moulting; (52) larval instar III, cohort; (53) larva instar IV, lateral view; (54–57) larva instar V, showing lateral view (54), dorsal view (55), anterior view of head capsule (56), and posterolateral view (57); (58) prepupa, lateral view; (59–63) pupa, showing lateral view of pale form (59), lateral view of dark form (60), dorsal view of dark form (61), anterolateral view of projection of head (62), and posterior view of last abdominal segments (63).

Figures 14–23. Adults of the Catasticta group. (14) Catasticta reducta boliviana male puddling, Peru; (15) C. prioneris male puddling, dorsal view showing red patches at base of each hind wing being “displayed”, Peru; (16) C. eurigania straminea male puddling, Peru; (17) C. hegemon hegemon male perching at encounter site, Costa Rica; (18) C. teutila flavomaculata male basking on rock between drinking bouts along creek edge, Costa Rica; (19) C. teutila flavomaculata female feeding from flowers of Ageratina ixiocladon, Costa Rica; (20) C. teutila flavomaculata male freshly emerged, Costa Rica; (21) C. theresa male puddling, Costa Rica; (22) C. cerberus male freshly emerged, Costa Rica; (23) puddling aggregation of Catasticta, Archonias and Pereute amongst other diurnal Lepidoptera, Peru.

Figures 24–33. Habitats and larval food plants of the Catasticta group. (24–25) Pereute callinira habitat, San Ramón (1400 m), Chanchamayo district, Peru; (26) P. cheops breeding habitat, showing larval food plant Phoradendron tonduzii parasitizing host tree Croton, Copey (1850 m), San José Province, Costa Rica; (27) P. cheops larval silken trail on trunk of mistletoe host tree Croton, Copey (1850 m), Costa Rica; (28–29) P. charops breeding habitat, Orosi Valley (1100–1200 m), Cartago Province, Costa Rica; arrows show cohort of pupal exuviae on trunk of mistletoe host tree (28) and location of cohort of larvae on trunk of mistletoe host tree Psidium guajava (29); (30) Phoradendron undulatum, a larval food plant of P. charops, Orosi Valley (1100m), Costa Rica; (31) Phoradendron chrysocladon, a larval food plant of Leodonta tellane, Monteverde (1500 m), Puntarenas Province, Costa Rica; (32–33) Leodonta tellane breeding habitat, Monteverde (1500 m), Costa Rica; arrows show location of cohort of larvae on trunk of mistletoe host tree Psidium guajava (32) and location of cohort of pupae on leaves of Clusia stenophylla growing adjacent to mistletoe host tree Conostegia oerstediana (33).

Figures 218–235. Pupae of the Catasticta group, showing dorsal and lateral views. (218–219) Melete isandra; (220–221) Pereute charops; (222–223) P. cheops; (224–225) Leodonta tellane; (226–227) Catasticta cerberus; (228–229) C. teutila; (230–231) C. sisamnus; (232–233) C. flisa; (234–235) C. ctemene. Note: Cuticle of L. tellane is clothed with numerous setae, which are not shown.

Figures 34–44. Habitats and larval food plants of the Catasticta group, Costa Rica. (34) Pereute charops, Leodonta tellane, Archonias brassolis, Catasticta teutila and C. ctemene habitat, Río Grande Orosi, Parque Nacional Tapantí (1200 m), Cartago Province; (35) C. theresa and C. teutila male puddling habitat, Copey (2200 m), San José Province; (36) C. cerberus breeding habitat, Cerro de la Muerte (3100 m), San José Province; (37) C. teutila breeding habitat, arrow shows location of larval food plant Dendrophthora costaricensis growing on mistletoe host tree, Villa Mills-Siberia Convenio Catie Field Station (2800 m), San José Province; (38) Dendrophthora costaricensis, a larval food plant of C. teutila, arrow shows cohort of larval instar I, Vara Blanca (2000 m), Heredia Province; (39–41) Antidaphne viscoidea, a larval food plant of Catasticta spp., Monteverde (1400–1500 m), Puntarenas Province; arrow shows cohort of larval instar II of C. ctemene, note larval feeding damage to terminal leaves (41); (42) Melete lycimnia breeding habitat, Sector Santa Rosa of Área de Conservación Guanacaste (300 m), Guanacaste Province; (43– 44) Phoradendron quadrangulare, a larval food plant of Melete lycimnia, parasitizing Guazuma ulmifolia, Sector Santa Rosa of Área de Conservación Guanacaste (300 m).