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a n n e Da mon 1, *, Fa Biol a h e r ná n De Z-r a m í r e Z 2 , l au r a r ig gi 3 , ru Di v e r spo or 3 , v i nce nZ o Be rtol i n i 1 , m e l is sa l e n na rtZWa l k e r 3 , a n Dr eW W i l e s 3 , a nd a i l sa Bu r ns 3 1 el colegio de la Frontera sur, apdo. posta 36, carretera antiguo aeropuerto km 2.5, tapachula, chiapas, c.p. 30700.tel.: +52 (962) 628 9800 ext. 5300; Fax: +52 (962) 628 9806 2 Faculty of agricultural sciences, autonomous university of chiapas (unach), huehuetán, chiapas 3 university of edinburgh, old college, south Bridge, edinburgh, scotland, uk. eh8 9yl * corresponding author: adamon@ecosur.mx AbstrAct to determine the reproductive status of the native orchids of the biodiversity "hotspot", Biological corridor tacaná-Boquerón, in the region of soconusco, southeast Mexico, which are suffering the effects of habitat degradation, unsustainable exploitation and potentially, climate change, we analysed the species richness, abundance, habitat and abiotic preferences, pollinaria transport and relation to orchid populations, of male euglossine bees (Hymenoptera: apidea: euglossini) in agroecosystems and forest fragments within the region. using volatile baits we trapped 2,480 bees, consisting of 14 species, during a total of 256 hours, of which 284 individuals (11.5%) had pollinaria of 18 orchid species adhered to their bodies. three species of Eufriesia (E. caerulescens, E. mexicana, E. rugosa) and one species of euglossa (E. villosa) were recorded for the first time. We report Eulaema meriana as the pollinator of the recently rediscovered Plectrophora alata. We did not detect habitat preferences for the species of euglossini captured, and they were frequent, or even more frequent, in intensive coffee plantations, as are many of the orchid species, which can be classified as a disturbed habitat. Bees tended to be more abundant with increasing light intensity and decreasing humidity at each site. there was little indication of pollinator specificity and the position of the pollinaria of each orchid species on the bodies of the bees was also variable. We did not recover any pollinaria from various euglossinophylic, epiphytic orchid species present in the region and three bee species showed signs of population decline. However, our results indicate that many species of orchids with this pollination syndrome are receiving pollination service within an increasingly fragmented and disturbed environment, suggesting that both the orchids and the bees are adapting to the changes.

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Orchids coexist with a diversity of endophytic fungi within their roots and other parts of the plant. These are presumed to contribute to nutrition, and may protect the plants against pathogens and herbivores; however, some may be latent pathogens and/or bring no benefit to the plant. Guarianthe skinneri is an epiphytic Central American threatened orchid used as an ornamental plant and in the rituals and celebrations of many communities. However, in the Soconusco region (Chiapas, Mexico), the pseudobulbs of mature plants are affected by the Lasiodiplodia theobromae fungus, causing the disease “black blotch”. We evaluated and compared the diversity of the endophytic fungal community within the leaves, pseudobulbs and roots of mature plants in two conditions, asymptomatic and symptomatic. Thirty samples from each condition and tissue were amplified with ITS and sequenced by Illumina MiSeq. Sequences were obtained and analyzed to determine taxonomic assignment and functionality with FUNGuild, obtaining 1857 amplicon sequence variants (ASVs). Alpha diversity was similar between plant conditions. In symptomatic plants, significant differences were found between the three types of tissue. According to the FUNGuild functionality analysis, 368 ASVs were determined to be endophytic fungi. The tissues of G. skinneri plants are reservoirs of fungal endophytes that should be considered for further exploration for research and conservation purposes.