Epidromia zetophora (Noctuidae) visiting Aspidosperma macrocarpon. Note the minute aperture of the corolla tube 

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... Cerrado community in the study area included 120 species of shrubs and trees of which 20 species were observed to be visited by moths ( Table 1). However, only 13 of these species were effectively moth pollinated and had correlated floral features (see below). Other species were occasionally visited by moths in the Cerrado areas studied, but they were effectively pollinated by other groups of visitors: for instance, Caryocar brasiliense is pollinated mainly by bats although sphingids are occa- sional visitors and may be secondary pollinators (Gribel and Hay 1993); Couepia grandiflora was cited as moth pollinated by Silberbauer-Gottsberger and Gottsberger (1975) at a Cerrado area at Botucatu in Sa ̃ o Paulo state, but in our study area the species presented diurnal anthesis and was visited mainly by large bees; Hymenaea stigonocarpa is a bat pollinated species with sphingids as visitors which rarely touch the stigma or anthers (Gibbs et al. 1999); Lafoensia pacari is another bat pollinated species for which sphingid moth visitors may be secondary pollinators (Sazima and Sazima 1975); Pseudobombax longiflorum and P. tomentosum have very large nocturnal flowers which are polli- nated by bats or non-flying mammals (Gribel 1988) although again occasionally visited by sphingids; Vochysia species have diurnal, large- bee pollinated flowers which are occasionally visited by some diurnal sphingids (Oliveira and Gibbs 1994). The effectively moth pollinated plants had mostly tubular flowers (or spurred flowers as in the Vochysiaceae) with the exception of Roupala montana (see below). They were easily separated (Fig. 1A) as relatively large sphingophilous flowers (tube 40 to 100 mm) versus smaller phalenophilous flowers (tube less than 15 mm). Flowering phenology of the 13 moth- pollinated species was concentrated at the end of the dry season (Aug.–Oct.) but moths were observed on flowers of different species all year round. (Table l). Moth visitors were rare during the study periods and difficult to collect. The few identified species are presented in Table 2 but they probably represent only a fraction of the taxa which may be involved in the pollination of these Cerrado species. rocarpon (Apocynaceae) is a tree up to 10 m, which produces dense, globular inflorescences each with hundreds of flowers. Flowering occurs at the end of the dry season when the trees are virtually leafless. Flowers open late in the afternoon and produce an unpleasant, sweaty odour. Petals are cream-coloured and fleshy, fused in a short (ca. 15 mm) tube which opens by a narrow mouth of 1 mm or so. The staminal filaments are epipetalous, with the anthers disposed so as largely to restrict direct access to the lower portion of the flower (Fig. 1B). The anthers are introrse and release their pollen prior to anthesis, and it loosely accumulates in the cone formed by the anthers. No secondary pollen presentation ( sensu Yeo 1993), as in other Apocynaceae, occurs in this case, since the mass of pollen is retained by the anthers. The style is short and the stigma is placed below the level of the anthers. The whole surface of stigmatic head is wet and receptive from the onset of anthesis. Nectar is produced in very small amounts which could not be quantified in our study. Flowers probably remain functional for more than a week, i.e. until the waxy perianth drops. Several flowers open each night per inflorescence and due to their longevity the floral display increased over about a week to a peak of flowering, when most of the flowers in an inflorescence were open. Visitors were exclusively small moths, mainly Noctuidae but also Geometridae. These moths landed on the inflorescence and walk from flower to flower probing for nectar with their probosces (Fig. 2). Visits were pro- tracted, sometimes more than 10 minutes, and in late stage inflorescences many flowers were visited, presumably promoting geitonogamous pollination. Access to the lower nectar chamber is effected by inserting the proboscis via minute slits between the anthers, and if the moth arrives bearing pollen, contact with the stigma may occur on withdrawal, although no scraping surface characteristic of the stigmas of other apocynaceous species is present. Subsequently, the proboscis, covered with sticky stigmatic secretion, collects a new charge of pollen from the pollen cluster lying on top of the stigmatic head. Hand-pollinations were performed in flowers during the first three days of anthesis by removing the corolla and placing pollen all over the stigmatic surface. Very few fruits were initiated, but all were from cross-pollinations, which indicates a xenogamous breeding system (Table 3). Flowers left open for natural pollination (control) lost their perianth after the first week, but fruits initially developed very slowly so that at three weeks after pollination no perceptible growth could be observed. No marked abscission of hand self-pollinated flowers was observed during this period, whereas unpollinated flowers abscised irregularly during the first week. Cross-pollinated fruits start to grow after a month or so, by which time all selfed flowers had abscised, and fruits developed slowly to maturation almost one year later, towards the end of the following dry season. Fruits are large (ca. 15 Â 9 cm), schizocarpic follicles (follicarium sensu Spjut 1994) which open to release circular, flat, winged seeds. Studies of pollen tube growth in fixed pistils under fluorescence microscopy were only partially successful. Very few showed pollen germination, but some, including both self- and cross-pollinated pistils, had profuse pollen germination on the stigma and pollen tube growth down to the ovary with evident ovule penetration. Thus, as reported in other Apocynaceae (Lipow and Wyatt 1998, 1999, 2000), A. macrocarpon shows a late-acting self- incompatibility (LSI) mechanism (Seavey and Bawa 1986, Sage et al. 1994). Aspidosperma tomentosum (Apocynaceae) is a treelet up to 6m with inflorescences bearing far fewer flowers than in A. macrocarpon. Flowers open in the evening, and floral structure was similar to that of the congeneric species, although the flowers of A. tomentosum are smaller, with ca. 6 mm tube length, and narrower petals (Fig. 1C). Visitors were set- tling moths which were only very rarely observed and not collected. However, some visitor overlap with A. macrocarpon was observed and the spectrum of visitors may be similar. Fruit-set was always low and restricted to some individuals. Fruit development, observed during subsequent reproductive seasons, also takes almost one year as in A. macrocarpon , although mature fruits are much smaller in this species. Roupala montana (Proteaceae) is a shrub or small tree up to 6 m. This species produces long racemes of variable size bearing a series of two-flowered cymes. Inflorescences mature from the base to the apex and all flowers in a particular inflorescence open over two or three consecutive nights. Flowers open at dusk. Pistils are enclosed by four sepals with sessile episepalous anthers which open prior to the onset of anthesis. During the opening, the sepals curl back bringing the anthers with them (Fig. 1E), whilst the pollen remains deposited on the upper portion of the style (secondary pollen presentation [2PP] of the pseudostamen type sensu Yeo 1993). At this stage, the apex of the style was completely covered by pollen, including the stigmatic surface, which was still dry. Nectar is produced from the onset of anthesis by four nectaries alternate with the sepals at the base of the ovary. Without disturbance, the nectar forms four droplets which are held at the base of the sepals. Such exposed droplets usually have highly concentrated sugar content ( > 60%) but this is probably due to evaporation, since recently opened flowers have nectar droplets with a much lower sucrose concentration (ca. 15%). Flowers were markedly protandrous and the stigmas, at the very tip of the style, were not receptive until the third night (i.e. 48 hours later), when the surface became wet, and by which time most of the pollen had been removed by nocturnal or diurnal visitors. Nectar and a very pleasant odour are produced each night throughout the 3-night longevity of the flower, and flowers with pollen only, and others in the receptive stigma stage, may be displayed during the same night in different portions of some inflorescences. After the third night flowers withered slowly, nectar and scent production ceased, and the sepals dropped. Successfully pollinated pistils started to develop fruits but the growth was very irregular, with fruits initiated at the same time presenting different sizes during development. Fruits are mature two months ...