Can the evolution of insects be influenced by agriculture

Agriculture has evolved independently in three insect orders: once in ants, once in termites, and seven times in ambrosia beetles. Although these insect farmers are in some ways quite different from each other, in many more ways they are remarkably similar, suggesting convergent evolution.


How many times has abstract agriculture evolved in insects?

▪ Abstract Agriculture has evolved independently in three insect orders: once in ants, once in termites, and seven times in ambrosia beetles. Although these insect farmers are in some ways quite different from each other, in many more ways they are remarkably similar, suggesting convergent evolution.

How does intensive agriculture affect insects?

The last line of attack on insects by intensive agriculture is intensification of pasture. Traditionally grass pastures were managed with little chemical fertilisation, a low density of grazing animals, and long periods of rest between grazing. They used to be an important habitat for plant and insect biodiversity.

Is agribusiness causing a global decline in insect populations?

Intensive agribusiness is causing a global decline in insect populations with serious consequences for humans and the rest of nature. As the son of an agricultural worker in NE Scotland in the 1970s and 80s I recall the amazing abundance and diversity of insects and other types of nature in agricultural areas.

What is the relationship between agriculture and entomology?

Entomologists (insect scientists) have a well-concealed but cosy relationship with agriculture and the agrochemical industry. If entomologists are speaking out you can bet they are really worried. Agriculture impacts nature so profoundly by virtue of its scale.

How does agriculture affect evolution?

One of the most important drivers of rapid evolution in wild species is the homogenization of agricultural habitats and the high density of domesticated species in order to maximize production [13,22]. As mentioned above, wild species often evolve in response to host traits.

How do insects affect agriculture?

They have a direct impact on agricultural food production by chewing the leaves of crop plants, sucking out plant juices, boring within the roots, stems or leaves, and spreading plant pathogens. They feed on natural fibers, destroy wooden building materials, ruin stored grain, and accelerate the process of decay.

What causes insects to evolve rapidly?

Insect evolution is characterized by rapid adaptation due to selective pressures exerted by the environment and furthered by high fecundity. It appears that rapid radiations and the appearance of new species, a process that continues to this day, result in insects filling all available environmental niches.

How evolution is applied in the agriculture?

The use of evolutionary principles is not new in agriculture (e.g. crop breeding, domestication of animals, management of selection for pest resistance), but given land-use trends and other transformative processes in production landscapes, ecological and evolutionary research in agro-ecosystems must consider such …

Why did the farmers use insects on their farms?

Insects are primary decomposers of organic material, provide essential pollination services for natural landscapes and crop production, and add ecosystem balance to complex food webs.

What are pests agriculture?

Pests can include weeds, plant pathogens (certain fungi, bacteria, and viruses), rodents, and nematodes in addition to the plant-feeding insects and mites described in the preceding text, and are estimated to destroy as much as one-third of all agricultural yield.

What are the main reasons for the success of insects?

It is believed that insects are so successful because they have a protective shell or exoskeleton, they are small, and they can fly. Their small size and ability to fly permits escape from enemies and dispersal to new environments.

Why insects are dominant all over the world?

To escape from enemies and unfavourable conditions. iv. To migrate (i.e. for long distance travel e.g. Locusts) 2. Adaptability or Universality: Insects are the earliest groups to make their life on the earth and to occupy vast habitats of soil and water.

How did insects evolve flight?

Insects first flew in the Carboniferous, some 350 to 400 million years ago, making them the first animals to evolve flight. Wings may have evolved from appendages on the sides of existing limbs, which already had nerves, joints, and muscles used for other purposes.

Why is understanding evolution important to agriculture?

Understanding evolution helps us solve biological problems that impact our lives. There are excellent examples of this in agriculture. We’ve seen how knowledge of genetic variation and evolutionary relationships helps farmers improve the ability of crops to resist disease.

What were some adaptations that made a significant impact on agriculture?

A number of adaptation strategies, such as crop and livestock mix shifts, altered planting/harvesting dates, altered livestock stocking rates, and increased pesticide use, have been observed mostly implemented by farmers acting in their own best interests [10, 11, 12, 13, 14].

Is agriculture a co evolutionary development?

We point out that changes in agricultural knowledge and practices are a prime example of cumulative cultural evolution (CCE) and gene-culture co-evolution (GCC), and that agriculture is associated with extensive cultural niche construction (CNC), in part due to the fact that agricultural practices transform the …

How have insect farmers evolved?

All propagate their cultivars as clonal monocultures within their nests and, in most cases, clonally across many farmer generations as well. Long-term clonal monoculture presents special problems for disease control, but insect farmers have evolved a combination of strategies to man-age crop diseases: They (a) sequester their gardens from the environment; (b) monitor gardens intensively, controlling pathogens early in disease outbreaks; (c) occasion-ally access population-level reservoirs of genetically variable cultivars, even while propagating clonal monocultures across many farmer generations; and (d) manage, in addition to the primary cultivars, an array of “auxiliary” microbes providing disease suppression and other services. Rather than growing a single cultivar solely for nutri-tion, insect farmers appear to cultivate, and possibly “artificially select” for, integrated crop-microbe consortia. Indeed, crop domestication in the context of coevolving and codomesticated microbial consortia may explain the 50-million year old agricultural success of insect farmers.

Why are leaf cutting ants considered an epizootic organism?

Leaf-cutting ants of the genera Atta and Acromyrmex are at constant risk of epizootics due to their dense living conditions and frequent social interactions between genetically related individuals. To help mitigate the risk of epizootics, these ants display individual and collective immune responses, including associations with symbiotic bacteria that can enhance their resistance to pathogenic infections. For example, Acromyrmex spp. harbor actinobacteria that control infection by Escovopsis in their fungal gardens. Although Atta spp. do not maintain symbiosis with protective actinobacteria, the evidence suggests that these insects are colonized by bacterial microbiota that may play a role in their defense against pathogens. The potential role of the bacterial microbiome of Atta workers in enhancing host immunity remains unexplored. We evaluated multiple parameters of the individual immunity of Atta cephalotes (Linnaeus, 1758) workers, including hemocyte count, encapsulation response, and the antimicrobial activity of the hemolymph in the presence or absence of bacterial microbiota. Experiments were performed on ants reared under standard conditions as well as on ants previously exposed to the entomopathogenic fungus Metharrizium anisopliae . Furthermore, the effects of the presence/absence of bacteria on the survival of workers exposed to M . anisopliae were evaluated. The bacterial microbiota associated with A . cephalotes workers does not modulate the number of hemocytes under control conditions or under conditions of exposure to the fungal pathogen. In addition, infection by M . anisopliae , but not microbiota, increases the encapsulation response. Similarly, the exposure of workers to this fungus led to increased hemolymph antimicrobial activity. Conversely, the removal of bacterial microbiota did not have a significant impact on the survival of workers with M . anisopliae . Our results suggest that the bacterial microbiota associated with the cuticle of A . cephalotes workers does not play a role as a modulator of innate immunity, either at baseline or after exposure to the entomopathogen M . anisopliae . Further, upon infection, workers rely on mechanisms of humoral immunity to respond to this threat. Overall, our findings indicate that the bacterial microbiota associated with A . cephalotes workers does not play a defensive role.

What is the microbiome of plants?

The plant microbiome encompasses several microorganisms residing on the various tissues of the plant body imparting beneficial aspects to the plant and the soil in total. The plant microbiome comprises miscellaneous groups of microbial populations colonizing the inner and outer tissues of the plants, all tissue layers reachable by the microbes and complementing various plant functions that promote the growth of healthy plants. The region of soil present immediately around the seeds where the soil particles, microbioflora, and the germinating seeds interact with each other is termed the spermosphere. Synthetic microbiomes are the culture of microbes used as inoculants to create an artificial microbiome inside the seed or plants. Microbiome engineering using artificial selection of microbes results in increased growth, plant health, plant performance in terms of better yield, which may contain “biologically, medically, or economically important” characteristics.

What are bark beetles? What are their functions?

Bark beetles (sensu lato) colonize woody tissues like phloem or xylem and are associated with a broad range of microorganisms. Specific fungi in the ascomycete orders Hypocreales, Microascales and Ophistomatales as well as the basidiomycete Russulales have been found to be of high importance for successful tree colonization and reproduction in many species. While fungal mutualisms are facultative for most phloem-colonizing bark beetles (sensu stricto), xylem-colonizing ambrosia beetles are long known to obligatorily depend on mutualistic fungi for nutrition of adults and larvae. Recently, a defensive role of fungal mutualists for their ambrosia beetle hosts was revealed: Few tested mutualists outcompeted other beetle-antagonistic fungi by their ability to produce, detoxify and metabolize ethanol, which is naturally occurring in stressed and/or dying trees that many ambrosia beetle species preferentially colonize. Here, we aim to test (i) how widespread beneficial effects of ethanol are among the independently evolved lineages of ambrosia beetle fungal mutualists and (ii) whether it is also present in common fungal symbionts of two bark beetle species (Ips typographus, Dendroctonus ponderosae) and some general fungal antagonists of bark and ambrosia beetle species. The majority of mutualistic ambrosia beetle fungi tested benefited (or at least were not harmed) by the presence of ethanol in terms of growth parameters (e.g., biomass), whereas fungal antagonists were inhibited. This confirms the competitive advantage of nutritional mutualists in the beetle’s preferred, ethanol-containing host material. Even though most bark beetle fungi are found in the same phylogenetic lineages and ancestral to the ambrosia beetle (sensu stricto) fungi, most of them were highly negatively affected by ethanol and only a nutritional mutualist of Dendroctonus ponderosae benefited, however. This suggests that ethanol tolerance is a derived trait in nutritional fungal mutualists, particularly in ambrosia beetles that show cooperative farming of their fungi.

What is agriculture in biology?

Agriculture – cultivation of plants, algae, fungi and animal herding – is found in numerous taxa such as humans, but also ants, beetles, fishes and even bacteria. Such niche construction behaviours have evolved independently from hunter/predation behaviours, though many species remain primarily predators. We here investigate when such a transition from predation/hunter behaviour to agriculture is favoured. In these systems where a consumer has a positive effect on its resource, we can expect an allocative cost of agriculture for the farmer, hence modifying the selective pressures acting upon it. The management of the resource may have a negative effect on its consumption: for instance, when the consumer defends the resource against other predators (exploitation cost). In other situations, the cost may occur on the foraging of alternative resources, for instance if the consumer spends more time nearby the farmed resource (opportunity cost). Here, we develop a simple three-species model constituted by a farmer species that consumes two resource species, one of them receiving an additional positive effect from the consumer. We consider two trade-off scenarios based on how the cost of agriculture is implemented, either as an exploitation cost or as an opportunity cost. We use an adaptive dynamics approach to study the conditions for the evolution of the investment into agriculture and specialization on the two resources, and consequences on the ecological dynamics of the community. Eco-evolutionary dynamics generate a feedback between the evolution of agriculture and specialization on the helped resource, that can lead to varying selected intensity of agriculture, from generalist strategies with no agriculture, to farmer phenotypes that are entirely specialized on the farmed resource, with possible coexistence between those two extreme strategies.

What are some examples of nutritional symbiosis?

Insects that farm monocultures of fungi are canonical examples of nutritional symbiosis as well as independent evolution of agriculture in non-human animals. But just like in human agriculture, these fungal crops face constant threat of invasion by weeds which, if unchecked, takes over the crop fungus. In fungus-growing termites, the crop fungus (Termitomyces) faces such challenges from the parasitic fungus Pseudoxylaria. The mechanism by which Pseudoxylaria is suppressed is not known. However, evidence suggests that some bacterial secondary symbionts can serve as defensive mutualists by preventing the growth of Pseudoxylaria. However, such secondary symbionts must possess the dual, yet contrasting, capabilities of suppressing the weedy fungus while keeping the growth of the crop fungus unaffected. This study describes the isolation, identification and culture-dependent estimation of the roles of several such putative defensive mutualists from the colonies of the wide-spread fungus-growing termite from India, Odontotermes obesus. From the 38 bacterial cultures tested, a strain of Pseudomonas showed significantly greater suppression of the weedy fungus than the crop fungus. Moreover, a 16S rRNA pan-microbiome survey, using the Nanopore platform, revealed Pseudomonas to be a part of the core microbiota of Odontotermes obesus. A meta-analysis of microbiota composition across different species of Odontotermes also confirms the wide-spread prevalence of Pseudomonas within this termite. These evidence indicate that Pseudomonas could be playing the role of defensive mutualist within Odontotermes.

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