Search results for "natural enemies"
showing 10 items of 22 documents
Innate antipredator behavior can promote infection in fish even in the absence of predators
2019
Natural enemies—predators and parasites—largely shape the dynamics of ecosystems. It is known that antipredator and antiparasite defense can be mutually conflicting, however consequences of this trade-off for the regulation of infection burden in animals are still poorly understood. We hypothesize that even in the absence of cues from predators, innate antipredator behavior (“ghost of predation past”) interferes with defense against parasites and can enhance the infection risk. As a case study, we explore interactions between a commercial species, the rainbow trout Oncorhynchus mykiss, and its parasite, the trematode eye-fluke Diplostomum pseudospathaceum. Fish–parasite interactions were te…
Foraging behavior of two egg parasitoids exploiting chemical cues from the stink bug Piezodorus guildinii (Hemiptera: Pentatomidae).
2019
Several parasitoids attacking the same host may lead to competition. Adult parasitoids' abilities to find, parasitize and defend hosts determine resource's retention potential. In soybean, two egg parasitoid species, Telenomus podisi and Trissolcus urichi (Hymenoptera: Platygastridae), compete on the egg masses of Piezodorus guildinii (Hemiptera: Pentatomidae) one of the major pest of this crop. We evaluated parasitoid's abilities to exploit hosts' footprints; and parasitoid's behavior when competing for the same host. Both arena residence time and retention time were similar for T. podisi and T. urichi on male or female host footprints. In its turn, T. urichi reentered the area contaminate…
New Mediterranean records of Trabutina mannipara (Hemprich & Ehrenberg 1829) (Hemiptera: Coccomorpha: Pseudococcidae)
2018
The occurrence of Trabutina mannipara (Hemprich & Ehrenberg, 1829) (Hemiptera: Coccomorpha) is reported for the first time at Linosa (Pelagian Islands, Sicily Channel, Italy) and Libya. T. mannipara was approved by USA authorities for release as biocontrol agents against invasive saltcedars. The potential impact of this species, that in the Mediterranean area showed to be occasionally invasive, is discussed.
The response of an egg parasitoid to substrate-borne semiochemicals is affected by previous experience
2016
AbstractAnimals can adjust their behaviour according to previous experience gained during foraging. In parasitoids, experience plays a key role in host location, a hierarchical process in which air-borne and substrate-borne semiochemicals are used to find hosts. In nature, chemical traces deposited by herbivore hosts when walking on the plant are adsorbed by leaf surfaces and perceived as substrate-borne semiochemicals by parasitoids. Chemical traces left on cabbage leaves by adults of the harlequin bug (Murgantia histrionica) induce an innate arrestment response in the egg parasitoid Trissolcus brochymenae characterized by an intense searching behaviour on host-contaminated areas. Here we …
ICTV Virus Taxonomy Profile: Dicistroviridae
2017
Dicistroviridae is a family of small non-enveloped viruses with monopartite, linear, positive-sense RNA genomes of approximately 8–10 kb. Viruses of all classified species infect arthropod hosts, with some having devastating economic consequences, such as acute bee paralysis virus in domesticated honeybees and taura syndrome virus in shrimp farming. Conversely, the host specificity and other desirable traits exhibited by several members of this group make them potential natural enemies for intentional use against arthropod pests, such as triatoma virus against triatomine bugs that vector Chagas disease. This is a summary of the International Committee on Taxonomy of Viruses (ICTV) Report on…
Enhancement of the Diversity of Pollinators and Beneficial Insects in Intensively Managed Vineyards
2021
Simple Summary The continuous intensification of agricultural production has resulted in higher yields and more yield security. However, these achievements went along with the substitution of heterogeneous agricultural landscapes by homogeneous ones with poor crop diversity, short crop rotations, and thanks to the high efficacy of modern herbicides and also to minimum in-crop diversity. A severe increase in plot size led to the elimination of ecologically valuable structural elements that had provided floral resources and nesting sites. Over the few last decades, several studies have been conducted to try to find solutions against insect decline and to preserve biodiversity. In the present …
Eradicating Mosquitoes using Translocations: a First Field Experiment
1972
THEORETICAL considerations have led to the assumption that chromosomal translocations with ensuing semisterility could be used to control pests1–3. Inversions could have the same effect in animals and plants in which crossing over occurs in both sexes4. Many translocations of different type and with various degrees of sterility have been produced in the mosquito Culex pipiens5–8. Preliminary laboratory experiments with these translocations have shown that a cage population can be diminished and finally exterminated after a few generations by the release of translocation heterozygotes into the population9.
Effects of isolation, area and predators on invasion: A field experiment with artificial islands
2007
Abstract The three most important ecological factors affecting the success of island invasions are the area of the island, isolation of the island and occurrence of predators on the island. Traditionally, invasion success has been studied on natural islands, which partly explains the rarity of controlled and replicated experiments. Here we report results from a field experiment investigating the influence of the above three factors in artificial islands. As an experimental system, we used predatory mites and a nematode community occurring naturally in boreal coniferous forests. We found that all three factors had an effect on invasion success, but surprisingly, that there were no interactio…
Challenging fear: chemical alarm signals are not causing morphology changes in crucian carp (Carassius carassius)
2010
Published version of an article in the journal: Environmental Biology of Fishes. Also available at SpringerLink: http://dx.doi.org/10.1007/s10641-010-9707-9 Crucian carp develops a deep body in the presence of chemical cues from predators, which makes the fish less vulnerable to gape-limited predators. The active components originate in conspecifics eaten by predators, and are found in the filtrate of homogenised conspecific skin. Chemical alarm signals, causing fright reactions, have been the suspected inducers of such morphological changes. We improved the extraction procedure of alarm signals by collecting the supernatant after centrifugation of skin homogenates. This removes the minute …
The microbiology of Lascaux Cave.
2010
Lascaux Cave (Montignac, France) contains paintings from the Upper Paleolithic period. Shortly after its discovery in 1940, the cave was seriously disturbed by major destructive interventions. In 1963, the cave was closed due to algal growth on the walls. In 2001, the ceiling, walls and sediments were colonized by the fungus Fusarium solani. Later, black stains, probably of fungal origin, appeared on the walls. Biocide treatments, including quaternary ammonium derivatives, were extensively applied for a few years, and have been in use again since January 2008. The microbial communities in Lascaux Cave were shown to be composed of human-pathogenic bacteria and entomopathogenic fungi, the for…