458 research outputs found
Fig. 8 in Uncovering cryptic diversity in the enigmatic ant genus Overbeckia and insights into the phylogeny of Camponotini (Hymenoptera:Formicidae:Formicinae)
No full textFig. 8. Variation in Overbeckia species occurrence across four vegetation types and two seasons in the EFForTS project (dry season, bars in red; wet season, bars in blue). Values on the y-axis show the number of cases in which the species occurred at least once in a subplot. In total, 19 individuals and 14 occurrences were found across 192 subplots sampled during dry and wet seasons (0.07% occupancy). At the level of different sites (forest plots), only 9 of 32 sampled here by canopy fogging were occupied by the genus.Published as part of Klimeš, Petr, Drescher, Jochen, Buchori, Damayanti, Hidayat, Purnama, Nazarreta, Rizky, Potocký, Pavel, Rimandai, Maling, Scheu, Stefan & Matos-Maraví, Pável, 2022, Uncovering cryptic diversity in the enigmatic ant genus Overbeckia and insights into the phylogeny of Camponotini (Hymenoptera:Formicidae:Formicinae), pp. 277-288 in Invertebrate Systematics 36 (6) on page 572, DOI: 10.1071/is21067, http://zenodo.org/record/698729
Separating effects of species identity and species richness on predation, pathogen dissemination and resistance to invasive species in tropical ant communities
No full textAnts are abundant in natural and managed tropical ecosystems and can have an impact on herbivorous arthropods, as well as plant pathogens. Although it has been shown for plants that the diversity of communities can result in improved ecosystem functioning, it remains uncertain how the species richness of ants affects multiple ecosystem services and disservices. In the present study, we used experimentally enhanced natural gradients in ant species richness on 100 cacao trees in a plantation aiming to analyze the effect of ant species identity and species richness on predation pressure and the incidence of cacao pod borer (CPB), as well as the spread of black pod disease (BPD). Ant species richness did not significantly improve predation of experimentally exposed insects, and was not associated with a reduction in the incidence of CPB. However, the incidence of BPD was higher in ant species rich trees, presumably because more ant species were pathogen vectors. The identity of the dominant ant species affected the incidence of CPB and BPD, as well as predation pressure. Although both ant species richness and identity affected ecosystem services and disservices delivered by the ant community, the results of the present study suggest that the identity of dominant ants is the main driver for ecosystem services in these systems
Spider web guilds in cacao agroforestry - comparing tree, plot and landscape-scale management
No full textAim Owing to their role as insect predators, web-building spiders can be important biological control agents within agricultural systems. In complex tropical agroecosystems such as agroforests, management determines plant architecture, vegetation composition and associated ant density, but little is known on how these attributes, together with landscape context, determine spider web density. We hypothesized that all three spatial scales and the presence of Philidris ants significantly contribute to the explanation of spider web density with web types being differently affected.Location In 42 differently managed cacao agroforestry systems in Sulawesi, Indonesia.Methods We surveyed the distribution of five spider-web types on 420 cacao trees to determine how these relate to habitat variables and a numerically dominant ant species at three different spatial scales, comparing tree, plot and landscape features. We fitted linear mixed-effects model, selected the best model subset using information-theoretic criteria and calculated the model-averaged estimates. We used non-metric multidimensional scaling (NMDS) to determine and visualize guild level responses to the effects of the tree, plot and landscape-scale variables.Results The five spider guilds preferred different features of cacao tree architecture. Most frequently recorded webs belonged to the line- and orb-web type. At the tree scale, overall web density was positively related to canopy openness. At the plot scale, a higher number of shade trees was related to a higher web density. At the landscape scale, the altitude determined the distribution patterns of web-building spiders. Presence of Philidris ants was positively associated with density of orb webs, while no pattern was found for other web types.Main conclusions Results suggest spider web density could be increased by pruning of cacao trees while keeping shade trees at high density in cacao plots. The results emphasize the need to consider scale dependency of crop management and web-guild-specific responses that may be related to different functional roles of spiders as a high-density predator group in agroforestry
Dissimilarity of Ant Communities Increases with Precipitation, but not Reduced Land-Use Intensity, in Indonesian Cacao Agroforestry
No full textLand-use degradation and climate change are well-known drivers of biodiversity loss, but little information is available about their potential interaction. Here, we focus on the effects of land-use and precipitation on ant diversity in cacao agroforestry. In Central Sulawesi, Indonesia, we selected 16 cacao agroforestry plots with a shaded vs. unshaded plot in each of eight villages differing in precipitation (1032–2051 mm annual rainfall). On each plot, 10 cacao trees with similar size and age (7–10 years) were selected for hand collection of ants on each cacao tree and the soil surface. In total, we found 80 ant species belonging to five subfamilies. Land-use intensification (removal of shade trees) and precipitation had no effect on species richness of ants per cacao tree (alpha diversity) and, in an additive partitioning approach, within-plot beta diversity. However, higher precipitation (but not shade) significantly increased ant species dissimilarity across cacao trees within a plot, with ant species showing contrasting responses to precipitation. Reduced precipitation causing drought stress appeared to contribute to convergence of ant community structure, presumably via reduced heterogeneity in cacao tree growth. In conclusion, reduced precipitation greatly influenced ant community dissimilarity and appeared to be more important for ant community structure than land-use intensification
Effects of Land‐Use Intensity in Tropical Agroforestry Systems on Coffee Flower‐Visiting and Trap‐Nesting Bees and Wasps
No full textSpatiotemporal density patterns of the pest predator Rhynchium haemorrhoidale (F.) along a land-use gradient in cacao agroforestry systems
No full textEleven new species of jumping spiders (Araneae, Salticidae) from Sumatra
No full textEleven new species of jumping spiders (Araneae: Salticidae) from Jambi Province, Sumatra, Indonesia, are described: Chalcovietnamicus tikus Dhiya’ulhaq sp. nov. (♂♀), Dendroicius garigi Dhiya’ulhaq sp. nov. (♂), Epeus kepayang Dhiya’ulhaq sp. nov. (♂♀), Indomarengo likaliku Dhiya’ulhaq sp. nov. (♂♀), Pengmarengo gepeng Dhiya’ulhaq sp. nov. (♂♀), Phintella candramawa Dhiya’ulhaq sp. nov. (♂♀), Phintella castor Dhiya’ulhaq sp. nov. (♂♀), Phintella siginjai Dhiya’ulhaq sp. nov. (♂), Poecilorchestes keciknyo Dhiya’ulhaq sp. nov. (♂♀), Psenuc lalawa Dhiya’ulhaq sp. nov. (♂♀) and Stertinius senja Dhiya’ulhaq sp. nov. (♂♀). Additionally, new species records of Epeus albus (Prószyński, 1992) (♂♀) and Simaetha cheni (Wang & Li, 2021) (♂♀) for Sumatra are provided, as well as high-resolution images of Epeus sumatranus (Prószyński & Deeleman-Reinhold, 2012) (♂♀). Spider specimens were collected by canopy fogging in four land-use systems: (1) lowland rainforest, (2) smallholder plantations of ‘jungle rubber’ (low impact rubber agroforestry, Hevea brasiliensis), (3) smallholder monoculture rubber and (4) smallholder monoculture oil palm (Elaeis guineensis). Of the eleven new salticid spider species, seven were exclusively found in the rather natural systems of lowland rainforest and jungle rubber, while two were found in jungle rubber and rubber, and the remaining two were found in rubber or oil palm monocultures. No species encountered in oil palm was also encountered in forest or vice versa. This applies also to the extant species, which were either found in monocultures of oil palm and rubber, or in lowland rainforest or jungle rubber. This observation offers the first glimpse into the ecology of the eleven newly described salticids and adds to existing knowledge on the other three
Critical factors limiting pollination success in oil palm: A systematic review
No full textOil palm (Elaeis guineensis Jacq) is an economically important crop, yet it plays a major role in tropical deforestation and has significant negative impacts on biodiversity. The ecological drivers of oil palm pollination are still poorly understood, despite pollination being a key ecosystem service for the yield of this multi-billion-dollar industry, with potential links to biodiversity conservation. Here we review biotic and abiotic drivers of pollination and known oil palm pollinators, including local insect species endemic to specific growing regions, and an important, globally-introduced West African weevil (Elaeidobius kamerunicus) whose fluctuating populations have led to concerns about yield and resilience. Future research should clarify pollinator community dynamics to facilitate pollination complementarity, which may strengthen pollination services in regions beyond the oil palm and weevil’s native West African ecosystem. In addition, other interactions such as mutualism, predation, and parasitism are not yet well understood, but could provide further insight into population drivers. Future management research should explore manipulating male palm inflorescence density, a key resource for pollinators, as well as investigate spatial and landscape effects on pollinator populations. Critically, no studies have investigated the effects of climate change on pollination, despite the impacts of rain and temperature on pollination efficiency. A greater understanding of the role of pollinator species and their nonlinear relationships to yield, as well as the complexity of biotic, management, and climate drivers of successful pollination can contribute to a more sustainable oil palm production system that values ecosystem services gained from biodiversity, while also improving producer livelihoods
Temperature and a dominant dolichoderine ant species affect ant diversity in Indonesian cacao plantations
No full textAgricultural land conversion and climate change play a major role in shaping tropical landscapes, but thedirect and indirect links to biodiversity and species community composition remain little understood.We tested how landscape and environmental factors and management techniques, affect the diversity ofground and tree living ants in cacao plantations in Sulawesi (Indonesia). In addition, we investigated theoccurrence of an aggressive, numerically dominant dolichoderine ant species (genusPhilidris). Half of the43 study plots, which differed in canopy cover, shade tree diversity, cacao tree age and their distance tothe nearest rainforest, were weeded manually every 3 month, the others biannually. Each plot wasdivided into two subplots, one was fertilized twice a year whereas the other remained unfertilized. Usingprotein and sugar-solution baits, we examined species richness, abundances and interspecificinteractions of ants on the ground and in cacao trees. In total we collected 160 ant morphospecies.Reduced ant species richness on the ground and in the trees was significantly correlated with highermean temperatures while the other factors, including number of shade trees did not have any significantinfluence. The abundant and aggressivePhilidrisspecies, reduced arboreal ant species richness. Itoccurred more frequently in warmer, less shaded plots and on older cacao trees, which offer morenesting sites. In our study we show, that micro-climatic conditions and the occurrence of singleecologically dominant species are the major factors predicting species diversity in tropical agriculturalecosystems
Habitat transformation and sustainable landscape: a preliminary study of the diversity of cross habitat pollinators
No full textSustainable landscape consist of the healthy provision of ecological services and the improvement of local human well-being. However, habitat transformation often affects pollinators. There is still a lack of research about how far does pollinators presence is being changed by habitat types. The aim of this research is to investigate the consequence of habitat transformation to pollinator diversity among habitat types. This research was conducted in the Harapan Forest, Jambi on three types of habitat from April to September 2017. Pollinators were collected using insect net and traps in and around the flowering plants in the plots. All pollinators were brought to the laboratory for identification. The highest abundance and species richness of pollinators were found in rubber and oil palm plantation, while the lowest were found in secondary forest. These results seem to be related to the presence of flowering plants that were more abundant in rubber and oil palm plantation compared to secondary forest. Different species of pollinators has different responses to the habitat transformation. For instance, the genus Tetragonula spp. (Hymenoptera: Apidae) were found to be highly abundant in secondary forest, whereas Ceratina spp. (Hymenoptera: Apidae) were highly abundant in rubber and oil palm plantation
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