White-nose syndrome (WNS) and the increased development of wind-power facilities are threatening populations of insectivorous bats in North America. Bats are voracious predators of nocturnal insects, including many crop and forest pests. We present here analyses suggesting that loss of bats in North America could lead to agricultural losses estimated at more than $3.7 billion/year. Urgent efforts are needed to educate the public and policy-makers about the ecological and economic importance of insectivorous bats and to provide practical conservation solutions.

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Economic Importance of Bats in Agriculture

Bats are an ecologically and taxonomically diverse group accounting for roughly a fifth of mammalian diversity worldwide. Many of the threats bats face (e.g., habitat loss, bushmeat hunting, and climate change) reflect the conservation challenges of our era. However, compared to other mammals and birds, we know significantly less about the population status of most bat species, which makes prioritizing and planning conservation actions challenging. Over a third of bat species assessed by the International Union for Conservation of Nature (IUCN) are considered threatened or data deficient, and well over half of the species have unknown or decreasing population trends. That equals 988 species, or 80% of bats assessed by IUCN, needing conservation or research attention. Delivering conservation to bat species will require sustained efforts to assess population status and trends and address data deficiencies. Successful bat conservation must integrate research and conservation to identify stressors and their solutions and to test the efficacy of actions to stabilize or increase populations. Global and regional networks that connect researchers, conservation practitioners, and local stakeholders to share knowledge, build capacity, and prioritize and coordinate research and conservation efforts, are vital to ensuring sustainable bat populations worldwide.

A review of the major threats and challenges to global bat conservation

Understanding distribution patterns and multitrophic interactions is critical for managing bat- and bird-mediated ecosystem services such as the suppression of pest and non-pest arthropods Despite the ecological and economic importance of bats and birds in tropical forests, agroforestry systems, and agricultural systems mixed with natural forest, a systematic review of their impact is still missing A growing number of bird and bat exclosure experiments has improved our knowledge allowing new conclusions regarding their roles in food webs and associated ecosystem services Here, we review the distribution patterns of insectivorous birds and bats, their local and landscape drivers, and their effects on trophic cascades in tropical ecosystems We report that for birds but not bats community composition and relative importance of functional groups changes conspicuously from forests to habitats including both agricultural areas and forests, here termed 'forest-agri' habitats, with reduced representation of insectivores in the latter In contrast to previous theory regarding trophic cascade strength, we find that birds and bats reduce the density and biomass of arthropods in the tropics with effect sizes similar to those in temperate and boreal communities The relative importance of birds versus bats in regulating pest abundances varies with season, geography and management Birds and bats may even suppress tropical arthropod outbreaks, although positive effects on plant growth are not always reported As both bats and birds are major agents of pest suppression, a better understanding of the local and landscape factors driving the variability of their impact is needed

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Bird and bat predation services in tropical forests and agroforestry landscapes

Pattern analysis in agricultural science

Durian (Durio zibethinus) is a Southeast Asian tropical plant known for its hefty, spine-covered fruit and sulfury and onion-like odor. Here we present a draft genome assembly of D. zibethinus, representing the third plant genus in the Malvales order and first in the Helicteroideae subfamily to be sequenced. Single-molecule sequencing and chromosome contact maps enabled assembly of the highly heterozygous durian genome at chromosome-scale resolution. Transcriptomic analysis showed upregulation of sulfur-, ethylene-, and lipid-related pathways in durian fruits. We observed paleopolyploidization events shared by durian and cotton and durian-specific gene expansions in MGL (methionine γ-lyase), associated with production of volatile sulfur compounds (VSCs). MGL and the ethylene-related gene ACS (aminocyclopropane-1-carboxylic acid synthase) were upregulated in fruits concomitantly with their downstream metabolites (VSCs and ethylene), suggesting a potential association between ethylene biosynthesis and methionine regeneration via the Yang cycle. The durian genome provides a resource for tropical fruit biology and agronomy.

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The draft genome of tropical fruit durian ( Durio zibethinus )

The floral biology and pollination ecology of durian, Durio zibethinus, were determined in eight semi-wild trees in mixed-fruit orchards in southern Thailand during April-May 2003 and 2005. Flowers open fully at 16h00–16h30 and most androecia drop around 01h00. Anthers dehisce at 19h30–20h00 when the stigmata are already receptive. In a series of pollination experiments, fruit was set in all treatments within 10 d. The greatest pollination success occurred after hand-crossed (76.6%), open (54.4%) and emasculation pollination (53.3%). Consistently, hand-crossed (12.2%), emasculation (8.7%) and open pollination (5.1%) yielded a substantial fruit set 2 mo after the pollination experiments. Very low pollination success in facilitated autogamy suggests that most durian trees are highly self incompatible. No mature fruit was found after insect pollination and automatic autogamy. Fruit bats, especially Eonycteris spelaea, are the major pollinators of this durian although the giant honey bee (Apis dorsata) was the most frequent visitor to the flowers. Bats visited durian flowers at the rate of 26.1 (SD = 20.7) visits per inflorescence per night. Since this semi-wild durian depends on fruit bats as its pollinator, protecting fruit bat populations and their roosts is vital for the production of the durian fruit crop.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0266467408005531

The pollination ecology of durian (Durio zibethinus, Bombacaceae) in southern Thailand

Although the floral traits of Parkia conform to the bat-pollination syndrome, many visitors other than bats have been observed at their flowers. Some chiropterophilous plants are also pollinated by other animals; the syndrome is therefore best regarded as a hypothesis for which field observations and pollination experiments are required. The present study aimed, for the first time, to determine the breeding system of the economically important canopy trees, Parkia speciosa and P. timoriana, and to identify their pollinators. Pollination experiments carried out in Trang and Songkhla Provinces, in 28 trees of P. speciosa and four P. timoriana indicated that they are self incompatible. Open pollination resulted in the highest fruit set (average 60–67% of inflorescences per tree) although this was not significantly different from hand-crossed pollination (48–60%). Insect pollination resulted in fruit set in only 12% of P. speciosa inflorescences. Fruit bats, mainly Eonycteris spelaea, visit flowering plants continuously from dusk till after midnight. Nocturnal and diurnal insects (moths and stingless bees respectively) visit capitula, mostly at the nectar zone. Nectarivorous bats are the most effective pollinator for P. speciosa and P. timoriana. The fact that populations of E. spelaea appear to be declining throughout their distribution is therefore a matter of increasing concern.

The pollination ecology of two species of Parkia (Mimosaceae) in southern Thailand

Summary
Economically feasible strategies to cope with invasive species are urgently needed. Plant density can be increased to reduce competitive effects on target plants. This study indicates that increasing native plant density can be used to reduce the effect of invasive Ageratina adenophora. Seedlings of an indigenous tree species, Schima wallichii, were grown in pots containing uninvaded or invaded soil, with or without A. adenophora leaf litter on the soil surface. Schima wallichii seedlings were also grown at four densities under four levels of A. adenophora leaf litter. Root and shoot biomass and length were measured as response parameters in both bioassays. Schima wallichii growth was inhibited by A. adenophora leaf litter and invaded soil. High litter levels reduced S. wallichii root length and dry weight at low plant densities. The inhibition disappeared at high S. wallichii plant densities. As A. adenophora did not inhibit S. wallichii growth at high plant densities, adjustments of seedling density should be studied as a possible management strategy for invasion by A. adenophora and potentially by other exotic plant species. As density-dependent growth inhibition is the key characteristic of chemical interference, we propose that phytotoxins contribute to A. adenophora invasion particularly at low densities of native seedlings.

Plant invasiveness and target plant density: high densities of native Schima wallichii seedlings reduce negative effects of invasive Ageratina adenophora

Argostemma Wall. (Rubiaceae). a disjunct genus (A frica: 2 spp.: SE Asia: > 95 spty .). has 31 taxa in Thailand of which 17 are endemic. Their distributions within the Thai noristic regions are: Northern (N) - II spp. (of which six arc endemic to the region); North-eastern (NE): I sp.;Eastern (E): 3 spp.; South-western (SW): 4 spp. ; Central (C): 3 spp.; South-eastern (SE): 5 spp. (of which one is endemic to the region): Peninsular (PEN): 18 taxa (of which seven are endemic to the region). Some species are endemic to Thailand but have wider distributions 'within the country e.g. A. concinnum (N+E+SE). A. monophyllun  (NE+E+C+SE). and A. parvum (E+SE). The 14 non-endemic taxa fall into three categories: (I) "northern" species. also occurring in Myanmar, and India and/or China (Yunnan): (2) "southern" species. also in the Malay Peninsula [and/or S. Myanmar (Tenassermin in). or also on Sumatra or the Andaman Is.]; (3) widespread species (A. neurocalyx only), distributed rrom Borneo. Sumatra, and the Malay Peninsula to Indochina (and also widespread in Thailand: N+C+SE+PEN). An attempt is made to correlate distribution patterns with morphological "species groups" distinguishable within the genus.

Kitichate Sridith

Papers

The pollination ecology of durian (Durio zibethinus, Bombacaceae) in southern Thailand

The pollination ecology of two species of Parkia (Mimosaceae) in southern Thailand

Plant invasiveness and target plant density: high densities of native Schima wallichii seedlings reduce negative effects of invasive Ageratina adenophora

Distribution of Argostemma Wall. (Rubiaceae), with special reference to Thailand and surrounding areas

“Soaked in rainwater” effect of Ageratina adenophora on seedling growth and development of native tree species in Nepal