REVIEW | doi:10.20944/preprints202002.0119.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: predator-prey; insects; arthropods; entomology; herpetology; species interactions; predation
Online: 10 February 2020 (05:29:27 CET)
Arthropod predators preying on vertebrates is generally overlooked in ecological studies, as it is not typically observed in nature and generally considered a rare event. This is likely due to the cryptic nature of these predatory events, the relatively small size of arthropods, and the difficulty in collating published data which is scattered throughout the literature. Although arthropods are known to readily hunt and consume vertebrates, very little is known about these predatory events. In this study, a systematic literature review was conducted to provide a conceptual framework, identify global patterns, and create a searchable database of arthropod preying on vertebrates. This study represents the largest global assessment of arthropod predators and vertebrate prey with over a thousand recorded observations collated from over 80 countries across every continent except Antarctica, where no arthropod predator exists. Arthropod predators were represented by six classes (insects, arachnids, centipedes, and crustaceans: Malacostraca, Ostracoda, Hexanauplia) and over 80 families. Vertebrate prey were represented by five classes (birds, mammals, reptiles, amphibians, fish) and 160 families. The most common prey were frogs consisting of over a third of all observations. The most commonly preyed reptiles were nearly all lizards, half of mammal prey were bats, nearly a third of fish were Cypriniformes, and half of bird prey were passerines. Spiders represented over half of all predatory events found and were the main predator for all vertebrates except birds, which were preyed mostly upon praying mantises. However, prey varied between spider families. For insects, true bugs (Hemiptera) and beetles preyed mostly on amphibians while the aquatic Odonata larvae preyed on amphibians and fish. Decapod predators were observed preying equally between reptiles, birds, and amphibians; with centipedes preying mainly on reptiles and mammals. Predation was mostly recorded from the Americas and Australia, with countries and regions varying between predator and prey groups. This study demonstrates that arthropods are indeed an overlooked predator of vertebrates. Recognizing and quantifying these predator-prey interactions is vital for identifying patterns and the potential impact of these relationships on shaping vertebrate populations and communities. Understanding the possible threat of arthropod predators may be especially important to improve the success of conservation efforts by accounting for predators which may currently be overlooked.
ARTICLE | doi:10.20944/preprints201903.0213.v4
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: compensatory habitat, frog, invertebrate, predation, reintroduction, tadpoles
Online: 2 April 2019 (15:25:57 CEST)
The role of invertebrate predation in shaping vertebrate communities is often underestimated or overlooked, which has resulted in the lack of their recognition in conservation planning. This is evident with predaceous diving beetles (Coleoptera: Dytiscidae) which are often the top predator in many aquatic freshwater habitats. During weekly monitoring of a compensatory habitat reintroduction for an endangered frog species, a group of a dozen adult diving beetles were encountered attacking and quickly dismembering and consuming a tadpole. A single adult diving beetle was also discovered burrowing its head deep inside and consuming a tadpole approximately three to four times its size. Although Dytiscidae are known to occasionally consume vertebrates such as tadpoles, adults are typically considered scavengers, and this communal predatory behavior and feeding method have not been previously documented. Besides these interesting novel behaviors, these observations may have implications for amphibian conservation since management efforts are not typically concerned with naturally occurring ubiquitous threats such as those from small invertebrate predators, as it is rarely been observed in nature. However, this may be perhaps due to their ability to consume prey rapidly, especially if predating in groups. Although amphibian conservation plans expect some losses from natural predation, diving beetles may affect conservation efforts such as captive breeding and reintroductions with populations already on the threshold of extinction and where every individual critical to success.
ARTICLE | doi:10.20944/preprints201903.0234.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Batrachochytrium dendrobatidis; Chytridiomycosis; Amphibian pathogen; Amphibian disease; Culex quinquefasciatus, vector-borne disease
Online: 26 March 2019 (10:01:02 CET)
The amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), is an infectious disease responsible for the worldwide decline of amphibian species. To mitigate these declines, it is necessary to identify the various vectors by which the fungus can be transmitted between individuals and populations. The objective of this study was to determine whether adult female mosquitoes can carry and transfer Bd fungal cells. Mosquitoes were exposed to net soaked in a live Bd zoospore suspension to determine whether they are able to externally acquire the fungus. Another group was placed into containers with a sterile and Bd-inoculated agar plate to determine whether mosquitoes could transfer Bd between these surfaces. Bd DNA was found to be present on mosquito legs exposed to inoculated netting and agar plates suggesting that Bd can be transmitted by the mosquito over short distances This is the first study to demonstrate that an insect host may be a mechanical vector of Bd and suggests that we should begin to consider the role of mosquitoes in the dissemination and control of the fungus.