Worldwide decline of the entomofauna: A review of its drivers

Statistics and Data Analysis in Geology

Since their discovery in the late 1980s, neonicotinoid pesticides have become the most widely used class of insecticides worldwide, with large-scale applications ranging from plant protection (crops, vegetables, fruits), veterinary products, and biocides to invertebrate pest control in fish farming. In this review, we address the phenyl-pyrazole fipronil together with neonicotinoids because of similarities in their toxicity, physicochemical profiles, and presence in the environment. Neonicotinoids and fipronil currently account for approximately one third of the world insecticide market; the annual world production of the archetype neonicotinoid, imidacloprid, was estimated to be ca. 20,000 tonnes active substance in 2010. There were several reasons for the initial success of neonicotinoids and fipronil: (1) there was no known pesticide resistance in target pests, mainly because of their recent development, (2) their physicochemical properties included many advantages over previous generations of insecticides (i.e., organophosphates, carbamates, pyrethroids, etc.), and (3) they shared an assumed reduced operator and consumer risk. Due to their systemic nature, they are taken up by the roots or leaves and translocated to all parts of the plant, which, in turn, makes them effectively toxic to herbivorous insects. The toxicity persists for a variable period of time—depending on the plant, its growth stage, and the amount of pesticide applied. A wide variety of applications are available, including the most common prophylactic non-Good Agricultural Practices (GAP) application by seed coating. As a result of their extensive use and physicochemical properties, these substances can be found in all environmental compartments including soil, water, and air. Neonicotinoids and fipronil operate by disrupting neural transmission in the central nervous system of invertebrates. Neonicotinoids mimic the action of neurotransmitters, while fipronil inhibits neuronal receptors. In doing so, they continuously stimulate neurons leading ultimately to death of target invertebrates. Like virtually all insecticides, they can also have lethal and sublethal impacts on non-target organisms, including insect predators and vertebrates. Furthermore, a range of synergistic effects with other stressors have been documented. Here, we review extensively their metabolic pathways, showing how they form both compound-specific and common metabolites which can themselves be toxic. These may result in prolonged toxicity. Considering their wide commercial expansion, mode of action, the systemic properties in plants, persistence and environmental fate, coupled with limited information about the toxicity profiles of these compounds and their metabolites, neonicotinoids and fipronil may entail significant risks to the environment. A global evaluation of the potential collateral effects of their use is therefore timely. The present paper and subsequent chapters in this review of the global literature explore these risks and show a growing body of evidence that persistent, low concentrations of these insecticides pose serious risks of undesirable environmental impacts.

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Systemic insecticides (neonicotinoids and fipronil): trends, uses, mode of action and metabolites

https://www.boerenlandvogels.nl/sites/default/files/Morrissey%20et%20al_2015_Neonicotinoid%20contamination%20of%20global%20surface%20water%20%20%20.pdf

Neonicotinoid contamination of global surface waters and associated risk to aquatic invertebrates: A review

We assessed the state of knowledge regarding the effects of large-scale pollution with neonicotinoid insecticides and fipronil on non-target invertebrate species of terrestrial, freshwater and marine environments. A large section of the assessment is dedicated to the state of knowledge on sublethal effects on honeybees (Apis mellifera) because this important pollinator is the most studied non-target invertebrate species. Lepidoptera (butterflies and moths), Lumbricidae (earthworms), Apoidae sensu lato (bumblebees, solitary bees) and the section “other invertebrates” review available studies on the other terrestrial species. The sections on freshwater and marine species are rather short as little is known so far about the impact of neonicotinoid insecticides and fipronil on the diverse invertebrate fauna of these widely exposed habitats. For terrestrial and aquatic invertebrate species, the known effects of neonicotinoid pesticides and fipronil are described ranging from organismal toxicology and behavioural effects to population-level effects. For earthworms, freshwater and marine species, the relation of findings to regulatory risk assessment is described. Neonicotinoid insecticides exhibit very high toxicity to a wide range of invertebrates, particularly insects, and field-realistic exposure is likely to result in both lethal and a broad range of important sublethal impacts. There is a major knowledge gap regarding impacts on the grand majority of invertebrates, many of which perform essential roles enabling healthy ecosystem functioning. The data on the few non-target species on which field tests have been performed are limited by major flaws in the outdated test protocols. Despite large knowledge gaps and uncertainties, enough knowledge exists to conclude that existing levels of pollution with neonicotinoids and fipronil resulting from presently authorized uses frequently exceed the lowest observed adverse effect concentrations and are thus likely to have large-scale and wide ranging negative biological and ecological impacts on a wide range of non-target invertebrates in terrestrial, aquatic, marine and benthic habitats.

/pdf/effects-of-neonicotinoids-and-fipronil-on-non-target-4tz7hct25w.pdf

Effects of neonicotinoids and fipronil on non-target invertebrates

Alien species in the family Poaceae play an important role as cover plants for erosion control on slopes, particularly in Japan. However, concerns have arisen regarding the adverse effects of these species on the local ecosystem and biodiversity. This study therefore examined the succession and seed propagation of alien Poaceae that are used for erosion control on the cut slopes of Sakurajima volcano in southwesternJapan. The results were as follows: Although the alien species used as cover plants were dominant for the first couple of years following their introduction to the slopes, they were displaced entirely by native species after the sixth year, which is considerably faster than ordinary succession. In addition, heading (flowering) of alien species was also rarely observed in this period. It is considered that the observed results were caused by the oligotrophic conditions of the slopes on Sakurajima volcano.

Evaluating the dynamics of alien species (poaceae) used for erosion control on sakurajima volcano

Strategic responses to invasive Latrodectus widow spiders are a global challenge due to the risks they pose to health and ecosystems. Chemical strategies involving the use of pyrethroids are effective against adult spiders, but as their populations rebound, chemical control becomes costly and unsustainable for eradication. A major obstacle is the inefficacy of insecticides against eggs, which are covered by a protective silk egg sac. Eradication of invasive spiders must focus on destroying progeny. Here, the responses of eggs in egg sacs of two invasive Latrodectus spiders in Japan (Latrodectus hasseltii (Thorell) and Latrodectus geometricus (C.L. Koch)) to short-term dry-heat exposure were examined. To test whether the dry-heat tolerance of the egg sacs of both spider species differed, lethal temperature (LT) was determined based on the hatching rate of eggs from egg sacs subjected to a range of temperatures. Hatching in both species failed completely when the egg sacs were exposed to temperatures of 55°C and above for 10 min, but the LT to reduce hatching by 90% (LT90) differed significantly between L. hasseltii (50. 9°C) and L. geometricus (52. 8°C). Our study highlights the efficacy of dry heat in suppressing hatching and thus shows the possibility for effective extermination of these noxious invasive pests. Further exploration and investigation of the effects of humidity and heat exposure time on egg sacs under field conditions are needed to guide Latrodectus spider control strategies.

http://academic.oup.com/jee/advance-article-pdf/doi/10.1093/jee/toab189/40530618/toab189.pdf

Dry-Heat Tolerance of Egg Sacs of Invasive Latrodectus Spiders (Araneae: Theridiidae) in Japan: Implications for Efficient Control/Extermination.

Effect of pavement and streetlight on the abundance of the redback spider inhabiting on guardrails and guard-pipes

今後の海岸管理・海浜植物群落保全に対する基礎資料を作成する事を目的とし，人為的活動，開発圧の強い湘南海岸に現存する植物群落(海浜・非海浜植物群落を含む)の成立に及ぼす影響について検討した。現地植生調査資料を相互に比較，整理した結果，現在，湘南海岸には，4 クラス，9 群集，6 群落(上級単位不明の2 群落を含む) が成立していた。土壌窒素含量，土質，1m2 あたりの平均海水浴客数および清掃頻度を用いて主成分分析を行った結果，オカヒジキクラス，ハマボウフウクラスおよびハマゴウクラスは，人為的影響が弱い貧栄養地に，オオバコクラスおよび上級単位不明の群落は，細礫率が高く土壌窒素分の高い立地に成立傾向にあり，クラス間で明確な立地環境の違いが認められた。非海浜植物群落であるギョウギシバ群落およびコマツヨイグサ群落は湘南海岸全域で広く見られたが，コマツヨイグサ群落は攪乱強度の低い海岸前面の裸地に，ギョウギシバ群落は人為的攪乱により形成された裸地に侵入するというように，定着場所に明確な違いが認められた。これら群落の分布拡大は神奈川県内だけにとどまらず，人為的影響の強い様々な海岸で生じている。人間の利用地域と海浜植物群落の保護地域との明確な境界を引き，内陸生雑草の侵入経路である植被の隙間(植生の面的拡がりが，人為的撹乱によってパッチ状になること)を作らない事が有効であると考えられる。湘南海岸で見られる全植生単位が，平塚市および大磯町で網羅される事から，今後は，これら2 市町を要保全地域として管理していく必要がある。

Human activities and environmental factors determining vegetation composition on the dry coastal sand dunes along the Shonan Coast, Kanagawa Prefecture

Daisuke Hayasaka

Papers

Evaluating the dynamics of alien species (poaceae) used for erosion control on sakurajima volcano

Dry-Heat Tolerance of Egg Sacs of Invasive Latrodectus Spiders (Araneae: Theridiidae) in Japan: Implications for Efficient Control/Extermination.

Effect of pavement and streetlight on the abundance of the redback spider inhabiting on guardrails and guard-pipes

Human activities and environmental factors determining vegetation composition on the dry coastal sand dunes along the Shonan Coast, Kanagawa Prefecture