Ant-plant symbioses trade-offs and its role in forest restoration projects

Ant-plant symbioses are complex between-species interactions found only in the tropical environment. Typically, in such symbioses, plants provide housing structures and food to their ant symbionts. In return, the ants protect their plants' host against herbivore attack and additional nutrients to help with plants' growth. These win-win interactions range from facultative to obligate mutualism. This proposal aims to test the three main mechanisms: (1) by-product benefits, (2) partner fidelity feedback and (3) partner choice in stabilizing the ant-plant mutualism. Understanding the mechanisms are crucial as they form the foundation of the ant-plant distribution and growth, in other words - the health of the myrmecophyte (ants-loving) trees in the forest ecosystem. Hence, ant-plant symbioses are an ideal model system for investigating the effects of anthropogenic changes, such as deforestation and climate change on the outcome of ant-plant mutualistic interactions. This project attempts to identify the mechanisms regulating the mutualistic interactions and, in particular, identify the context in which such mutualistic interactions evolved and adapt to the changing environment. We hypothesise that there will be a higher diversity of obligate mutualistic ant-plant interactions in the undisturbed environment compared to degraded habitat. Furthermore, we expect there are different complexity of symbioses, involving multiple partners (ants-hemipteran insects-bacteria-fungi-plants) that deepen our understanding of how such symbioses can be stabilized. Finally, the deforestation combined with climate change in Southeast Asia will have a detrimental effect on ant-plant symbioses, causing breakdown of mutualistic partners and invasion of cheater ant species that do not confer a protective advantage to their plants' host

Biocontrol opportunities to study microevolution in invasive populations

No abstract available.http://www.cell.com/trends/ecology-evolution/homehb201

Towards a better understanding of the evolution of specialized parasites of fungus-growing ant crops

Fungus-growing ants have interacted and partly coevolved with specialised microfungal parasites of the genus Escovopsis since the origin of ant fungiculture about 50 million years ago. Here, we review the recent progress in understanding the patterns of specificity of this ant-parasite association, covering both the colony/population level and comparisons between phylogenetic clades. We use a modified version of Tinbergen's four categories of evolutionary questions to structure our review in complementary approaches addressing both proximate questions of development and mechanism, and ultimate questions of (co)adaptation and evolutionary history. Using the same scheme, we identify future research questions that are likely to be particularly illuminating for understanding the ecology and evolution of Escovopsis parasitism of the cultivar maintained by fungus-growing ants

Interaction specificity between leaf-cutting ants and vertically transmitted Pseudonocardia bacteria

BACKGROUND : The obligate mutualism between fungus-growing ants and microbial symbionts offers excellent opportunities to study the specificity and stability of multi-species interactions. In addition to cultivating fungus gardens, these ants have domesticated actinomycete bacteria to defend gardens against the fungal parasite Escovopsis and possibly other pathogens. Panamanian Acromyrmex echinatior leaf-cutting ants primarily associate with actinomycetes of the genus Pseudonocardia. Colonies are inoculated with one of two vertically transmitted phylotypes (Ps1 or Ps2), and maintain the same phylotype over their lifetime. We performed a cross-fostering experiment to test whether co-adaptations between ants and bacterial phylotypes have evolved, and how this affects bacterial growth and ant prophylactic behavior after infection with Escovopsis. RESULTS : We show that Pseudonocardia readily colonized ants irrespective of their colony of origin, but that the Ps2 phylotype, which was previously shown to be better able to maintain its monocultural integrity after workers became foragers than Ps1, reached a higher final cover when grown on its native host than on alternative hosts. The frequencies of major grooming and weeding behaviors co-varied with symbiont/host combinations, showing that ant behavior also was affected when cuticular actinomycete phylotypes were swapped. CONCLUSION : These results show that the interactions between leaf-cutting ants and Pseudonocardia bear signatures of mutual co-adaptation within a single ant population.http://www.biomedcentral.com/bmcevolbiolhb201

Disturbance gradient and mosquito diversity pattern in areas surrounding Chini Lake - the second largest freshwater lake in Peninsular Malaysia

Malaysia is a tropical country that has consistently been facing a prevalent threat of mosquito-borne diseases. Amongst the plethora of diseases, the most common mosquito borne disease in the country is dengue fever, transmitted by Aedes spp. mosquitoes. This study aims to examine the effects of human activity associated with different land use on mosquito population composition and diversity. Our study site is Chini Lake, a naturally occurring lake and the second-largest freshwater body in Malaysia. The areas surrounding the Lake have been subjected to various human activities, such as economic development and conversion into rubber plantations, while some areas remain pristine, making Chini Lake an ideal location to examine the gradient of human disturbances on mosquito composition and diversity. We sampled adult mosquitoes and larvae across a range of sites with different levels of human disturbance. As expected, in areas with high disturbance scores, the species richness of adult and larval mosquitoes were reduced while the abundance was higher. The results also revealed minimal overlap between species captured for adult and larval samplings, suggesting that land-use changes affect both life stages differently. Different resource requirements of adult and larval mosquitoes likely led to the observed diversity pattern in this small survey. We suggest future work to look into how habitat heterogeneity affects both life stages and sexes of mosquito diversity patterns and distribution

An elevational survey of honeybee species in Marai Parai, Mount Kinabalu

The honeybees (Apis spp.) constitute a monophyletic genus with ten recognised species exhibiting notable geographic variations. Sabah hosts five honeybee species, spanning the Micrapis, Megapis, and Apis clades. This study aims to establish the baseline data on the altitudinal distribution of honeybee species in Marai Parai, the northwestern side of Kinabalu Park. Samples were collected over a five-day period using opportunistic netting techniques. Species were identified based on morphological characters using published identification keys. The honeybees were collected on three elevations, including Nunuk Subcamp (1177m a.s.l), Nabalu Sambau (1400m a.s.l.) and Marai Parai Subcamp (1696 m a.s.l.) consisting of three different forest types of lowland dipterocarp forest, oak-chestnut montane forest and ultramafic forest respectively. The majority of the collection was carried out at 1177m a.s.l. (58.73%), followed by 1696m a.s.l. (34.92%) and 1400m a.s.l. (6.35%), reflecting the variability in sampling effort. Four out of five honeybee species known in Sabah were collected: dwarf honeybee A. andreniformis, giant honeybee A. dorsata, and two cavity-nesting honeybees A. cerana and A. nuluensis. Six different foraging sites were recorded in this study, including cut banana trees, herbaceous plants, wet ultramafic rocks, wet cut wood logs, food waste, and cut wood logs. More research should be conducted on honeybee species, diversity, and elevational distribution in Kinabalu Park to gain a deeper understanding of their foraging behaviour and ecological roles

Obligate Ant-Associated Macaranga bancana is Better Protected from Herbivory Than Facultative Ant-Associated Macaranga tanarius

Protective mutualism between ant and Macaranga plants are complex between species interactions found only in the tropical environment. In such interactions, plants provide housing structures (in the form of domatia) and food (in the form of food bodies) to their ant symbionts. In return, the ants protect their Macaranga plant hosts against herbivore attacks. Macaranga ant protective mutualism is manifested in a wide range of interactions, from facultative to obligate. In facultative interactions, Macaranga plants attract predatory ants to the plant via food rewards. In return, foraging ants may opportunistically provide protection from insect herbivores. In obligate interactions, plants provide shelter and food rewards to permanent ant partners. We hypothesize that in obligate Macaranga, the host is better protected because of the permanent presence of its resident ant partners, whereas in facultative Macaranga, the defense against insect herbivores may be less efficient depending on the attractiveness of the food rewards and the aggressiveness of the ant species in the plant’s vicinity. In this study, we compare herbivory damage and phytophagous insect herbivore types between a facultative ant-plant M. tanarius and an obligate anti-plant M. bancana. This study further highlights that co-evolved ant partners are more efficient in defending their host plants against phytophagous insect herbivores than facultative ant-plant interactions

The effects of anthropogenic disturbance and seasonality on the ant communities of Lang Tengah Island

Anthropogenic disturbances and seasonal changes significantly impact diversity and community composition of ants, but their effects are often intertwined. We investigated these drivers on Lang Tengah Island, a location with a pronounced monsoon season and three resorts that close during this period. We surveyed four sites, two disturbed and two undisturbed, before and after the monsoon season, using pitfall traps to sample epigaeic ant communities. Undisturbed habitats had higher species diversity, but both habitats (undisturbed and disturbed sites) have a high proportion of ants with characteristics of being encroached by generalist and invasive/tramp ant species. Post-monsoon sampling yielded an increase in species richness and diversity. Seasonal changes, such as monsoonal rains, can temporarily alter ant interactions and resource distribution, potentially maintaining diversity. Future studies should validate these findings for ant communities under similar pressures, using ant composition and functional roles for conservation and management purposes

Limited Effect of Ground Floor Fogging on Mosquito Distribution in High-Rise Condominia

Fogging with insecticides is one of the main control measures for adult mosquito populations employed in countries that are affected by dengue. In many such countries, urban communities are increasingly characterised by high-density residence in high-rise condominia. Although fogging is typically applied at the ground level, its efficacy in three-dimensional urban environments is poorly understood. Here, we investigated the effect of fogging on vector mosquito distribution and abundance in high-rise condominia by conducting a before-after fogging survey. We showed that although mosquitoes were significantly concentrated at the lower levels in high-rise condominia, they were found throughout the three-dimensional environments. Fogging did not significantly alter this distribution or abundance pattern across any floor level. Thus, any fogging effect was short-lived as mosquito populations recovered within a few days before the subsequent scheduled treatment. In addition, increasing fogging frequency within practicable limits did not prolong the intended control effect. As urban mosquitoes are increasingly insusceptible to fogging due to insecticide resistance and vertical avoidance, this study demonstrates the need to implement other mosquito control strategies for high-rise condominia to manage mosquito populations

Ground Dwelling Ants as Surrogates for Establishing Conservation Priorities in the Australian Wet Tropics

This study aims to identify a set of areas with high biodiversity value over a small spatial scale within the Australian Wet Tropics. We identified sites of high biodiversity value across an altitudinal gradient of ground dwelling ant communities using three measures of biodiversity. The three measures considered were estimated species richness, complementarity between sites and evolutionary history. The latter measure was derived using the systematic nomenclature of the ants to infer a surrogate phylogeny. The goal of conservation assessments could then be achieved by choosing the most diverse site combinations. This approach was found to be valuable for identifying the most diverse site combinations across an altitudinal gradient that could ensure the preservation of terrestrial ground dwelling invertebrates in the Australian Wet Tropics