Search results for "oratory"
showing 10 items of 1379 documents
Next-generation biological control
2020
Biological control is widely successful at controlling pests, but effective biocontrol agents are now more difficult to import from countries of origin due to more restrictive international trade laws (the Nagoya Protocol). Coupled with increasing demand, the efficacy of existing and new biocontrol agents needs to be improved with genetic and genomic approaches. Although they have been underutilised in the past, application of genetic and genomic techniques is becoming more feasible from both technological and economic perspectives. We review current methods and provide a framework for using them. First, it is necessary to identify which biocontrol trait to select and in what direction. Nex…
Plant-phenotypic changes induced by parasitoid ichnoviruses enhance the performance of both unparasitized and parasitized caterpillars
2021
Early Access; International audience; There is increasing awareness that interactions between plants and insects can be mediated by microbial symbionts. Nonetheless, evidence showing that symbionts associated with organisms beyond the second trophic level affect plant-insect interactions are restricted to a few cases belonging to parasitoid-associated bracoviruses. Insect parasitoids harbor a wide array of symbionts which, like bracoviruses, can be injected into their herbivorous hosts to manipulate their physiology and behavior. Yet, the function of these symbionts in plant-based trophic webs remains largely overlooked. Here we provide the first evidence of a parasitoid-associated symbiont…
Distribution of sea urchins living near shallow water CO2 vents is dependent upon species acid-base and ion-regulatory abilities.
2013
To reduce the negative effect of climate change on Biodiversity, the use of geological CO2 sequestration has been proposed; however leakage from underwater storages may represent a risk to marine life. As extracellular homeostasis is important in determining species' ability to cope with elevated CO2, we investigated the acid-base and ion regulatory responses, as well as the density, of sea urchins living around CO2 vents at Vulcano, Italy. We conducted in situ transplantation and field-based laboratory exposures to different pCO2/pH regimes. Our results confirm that sea urchins have some ability to regulate their extracellular fluid under elevated pCO2. Furthermore, we show that even in cl…
Effects of starvation on survival, cannibalism, body mass, and intestinal protozoan profile in the subterranean termite Reticulitermes lucifugus
2019
Scarcity or inadequate nutrition can affect biological and behavioural aspects of subterranean termites and their intestinal protozoan profile. The aim of this study was to investigate changes in survival, cannibalism, body mass, and protist community structure of Reticulitermes lucifugus Rossi subspecies “Sicily” following starvation to provide basic knowledge for the development of more specific studies on a possible survival strategy under stressful conditions. In nature, this termite consumes many food sources and its feeding activity is continuous during the year. In a 35-day laboratory experiment, groups of 50 termites (worker/soldier ratio 49:1) were subjected to two diets, starvatio…
The effect of maze complexity on maze-solving time in a desert ant
2019
One neglected aspect of research on foraging behavior is that of the effect of obstacles that increase habitat complexity on foraging efficiency. Here, we explored how long it takes individually foraging desert ant workers (Cataglyphis niger) to reach a food reward in a maze, and examined whether maze complexity affects maze-solving time (the time elapsed till the first worker reached the food reward). The test mazes differed in their complexity level, or the relative number of correct paths leading to the food reward, vs. wrong paths leading to dead-ends. Maze-solving time steeply increased with maze complexity, but was unaffected by colony size, despite the positive correlation between co…
Testing the habituation assumption underlying models of parasitoid foraging behavior
2016
BackgroundHabituation, a form of non-associative learning, has several well-defined characteristics that apply to a wide range of physiological and behavioral responses in many organisms. In classic patch time allocation models, habituation is considered to be a major mechanistic component of parasitoid behavioral strategies. However, parasitoid behavioral responses to host cues have not previously been tested for the known, specific characteristics of habituation.MethodsIn the laboratory, we tested whether the foraging behavior of the egg parasitoidTrissolcus basalisshows specific characteristics of habituation in response to consecutive encounters with patches of host (Nezara viridula) ch…
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 …
An Insight in the Reproductive Biology of Therophilus javanus (Hymenoptera, Braconidae, and Agathidinae), a Potential Biological Control Agent agains…
2017
Therophilus javanus is a koinobiont, solitary larval endoparasitoid currently being considered as a biological control agent against the pod borer Maruca vitrata, a devastating cowpea pest causing 20–80% crop losses in West Africa. We investigated ovary morphology and anatomy, oogenesis, potential fecundity, and egg load in T. javanus, as well as the effect of factors such as age of the female and parasitoid/host size at oviposition on egg load. The number of ovarioles was found to be variable and significantly influenced by the age/size of the M. vitrata caterpillar when parasitized. Egg load also was strongly influenced by both the instar of M. vitrata caterpillar at the moment of parasit…
Prospects of herbivore egg-killing plant defenses for sustainable crop protection
2016
Abstract Due to a growing demand of food production worldwide, new strategies are suggested to allow for sustainable production of food with minimal effects on natural resources. A promising alternative to the application of chemical pesticides is the implementation of crops resistant to insect pests. Plants produce compounds that are harmful to a wide range of attackers, including insect pests; thus, exploitation of their natural defense system can be the key for the development of pest‐resistant crops. Interestingly, some plants possess a unique first line of defense that eliminates the enemy before it becomes destructive: egg‐killing. Insect eggs can trigger (1) direct defenses, mostly i…
Influence of Distance from the Host on Parasitisation by Psyttalia concolor (Szépligeti) (Hymenoptera: Braconidae)
2019
The olive fruit fly, Bactrocera oleae, is considered the main olive pest worldwide, and has been the target of biological control programmes through the release of the braconid parasitoid Psyttalia concolor. Laboratory tests were performed to evaluate the influence of distance from the host on parasitisation, placing larvae of the substitute host Ceratitis capitata at seven distances (0, 0.5, 1, 1.5, 2, 2.5, 3 mm) and four different time periods (7, 15, 30, 60 min). Moreover, field collected olives of Ogliarola Barese cultivar infested by B. oleae were exposed to P. concolor females to confirm its ability to parasitise B. oleae in small olives. Psyttalia concolor oviposition was inhibited a…