Insects: biodiversity, threat status and conservation approaches

Insect Conservation and Diversity

1. There is mounting concern over the conservation status and long-term trends in insect populations. Many insect populations have been reported to be falling and many species are threatened with extinction. While this is true, the evidence does not support unqualified statements of 'global insect decline'. Global environmental change does not affect all species equally, and there are clear winners as well as losers from anthropogenic impacts. 2. In this special issue of Insect Conservation and Diversity, we draw together articles that (i) identify key challenges in robust inference about insect population trends, (ii) present new empirical evidence for declines (and increases) in insect populations, spanning whole communities down to single species, in both aquatic and terrestrial ecosystems, and (iii) address the interacting drivers of population change, from empirical studies of environmental correlates, to experimental manipulation of driving mechanisms. 3. We argue that the way forward for insect conservation includes more nuanced language and approaches when communicating ecological evidence to peer and public audiences, beyond just a simplistic focus on the insect decline narrative. This will require an expanded portfolio of approaches to promote the value of insects to society, which in turn, should reinforce the social licence to prioritise insect conservation research. This should help us to deliver the rigorous science necessary to document ongoing trends and understand the drivers and mechanisms of population change. Only then will we be able to mitigate or reverse declining populations.

Global Decline of Insects, IntechOpen, 2022

Insects play a very vital role in divergent ecosystems and have gained great economic and medical importance as pollinators, pests, predators, parasitoids, decomposers and vectors. With the large-scale practice of synthetic pesticides, the diminishing rate of beneficial and pollinator insects is increasing rapidly. Environmental pollution, climate change, global warming, urbanization, industrialization and some natural calamities like wildfires add more fuel to the acceleration of insect decline all over the world. Alternative steps should be employed to replace the toxic pesticides and implementation of integrated pest management (IPM) should be put forward to reduce the overuse of synthetic pesticides and fertilizers, which have a great impact on beneficial insects as well as birds, aquatic organisms, and also on human health. The present study aims to create awareness among the researchers and general public by providing a brief review of insect importance, decline and conservation strategies.

2011

In this thesis I investigated various factors that might affect species diversity and the relations between predator/parasitoid and host, using mainly insects as a model group. These factors were agricultural practices, landscape composition, climate change and invasive species.

Insect Conservation and Diversity, 2008

Comptes Rendus. Biologies

Insects appeared more than 400 million years ago and they represent the richest and most diverse taxonomic group with several million species. Yet, under the combined effect of the loss of natural habitats, the intensification of agriculture with massive use of pesticides, global warming and biological invasions, insects show alarming signs of decline. Although difficult to quantify, species extinction and population reductions are confirmed for many ecosystems. This results in a loss of services such as the pollination of plants, including food crops, the recycling of organic matter, the supply of goods such as honey and the stability of food webs. It is therefore urgent to halt the decline of Insects. We recommend implementing long-term monitoring of populations, tackling the * Corresponding author.

Biological Conservation, 2009

The status and trends of global biodiversity are often measured with a bias towards datasets limited to terrestrial vertebrates. The first global assessment of an insect order (Odonata) provides new context to the ongoing discussion of current biodiversity loss. A randomly selected sample of 1500 (26.4%) of the 5680 described dragonflies and damselflies was assessed using IUCN's Red List criteria. Distribution maps for each species were created and species were assigned to habitat types. These data were analysed in respect to threat level for regions and habitat types. We have found that one in 10 species of dragonflies and damselflies is threatened with extinction. This threat level is among the lowest of groups that have been assessed to date, suggesting that previous estimates of extinction risk for insects might be misleading. However, Odonata only comprise a small invertebrate order, with above-average dispersal ability and relatively wide distribution ranges. For conservation science and policy to be truly representative of global biodiversity a representative cross-section of invertebrates needs to be included.

Insect Conservation and Diversity, 2010

Agricultural Reviews, 2021

The diversity and abundance of insect is facing serious challenges globally in the current era. Although the loss of biodiversity other than invertebrates has been a burning issue from a long ago, some recent reports on insect decline and its impact on agriculture have given it a crucial dimension. Studies related to insect decline revealed that 40% of insect taxa are going through the risk of decline. The current situation is the resultant of several human-influenced factors, most prominently the intensification of agriculture. Insect is one of the most diverse groups having immense effects on ecosystem as an integral part of food web which ultimately has direct effect on other organisms of environment. The most conspicuous contribution of insect is its pollination services to 80% of the flowering plants worldwide which have direct effect on human food security. Decline of pollinator insects and natural enemies of insect pests can impair the crop production due to insufficient pollination and underutilization of the insect control potential of predator insects. To resist the vulnerability of nature and to ensure food security, insect decline should be cut down by controlling anthropogenic stressors through the conservation of natural habitats, eliminating deleterious agricultural practices, implementing insect friendly policies, etc. Immediate action is necessary to alter the nature exploiting agricultural practices causing insect decline to ensure the normal functioning and integrity of entire ecosystem and for human welfare.

Biological Conservation, 2020

The fate of humans and insects intertwine, especially through the medium of plants. Global environmental change, including land transformation and contamination, is causing concerning insect diversity loss, articulated in the companion review Scientists' warning to humanity on insect extinctions. Yet, despite a sound philosophical foundation, recognized ethical values, and scientific evidence, globally we are performing poorly at instigating effective insect conservation. As insects are a major component of the tapestry of life, insect conservation would do well to integrate better with overall biodiversity conservation and climate change mitigation. This also in- volves popularizing insects, especially through use of iconic species, through more media coverage, and more inclusive education. Insect conservationists need to liaise better with decision makers, stakeholders, and land managers, especially at the conceptually familiar scale of the landscape. Enough evidence is now available, and synthesized here, which illustrates that multiple strategies work at local levels towards saving insects. We now need to expand these locally-crafted strategies globally. Tangible actions include ensuring maintenance of biotic complexity, especially through improving temporal and spatial heterogeneity, functional connectivity, and metapopulation dynamics, while maintaining unique habitats, across landscape mosaics, as well as instigating better communication. Key is to have more expansive sustainable agriculture and forestry, improved regulation and prevention of environmental risks, and greater recognition of protected areas alongside agro-ecology in novel landscapes. Future-proofing insect diversity is now critical, with the benefits far reaching, including continued provision of valuable ecosystem services and the conservation of a rich and impressive component of Earth's biodiversity.