Performance of a generalist predator, Podisus maculiventris (say) (Hemiptera:Pentatomidae) fed with adult grain moth Sitotroga cerealella (Olivier) Lepidoptera:Pyralidae) at late nymphal and adult stages

Abstract Podisus maculiventris (Say) is a generalist predator attacking many insect species from different orders. The bug injects saliva into its prey's body. The ingested hemolymph and liquefied internal tissues pass through the bug's alimentary tract. Collagenase working on peptide bonds of collagen and basement membrane proteins, leads to the disintegration of the prey's internal organs. As yet, there is an almost complete lack of knowledge on the collagenase activity in P. maculiventris. The collagenase activity of the salivary glands and midgut was optimum at pH 8.0 which was congruent with the optimal pH of the total proteolytic activity of the salivary glands. More collagenolytic activity was determined in the posterior lobe of the salivary glands and anterior midgut. Significant inhibition of collagenolytic activity by ethylenediaminetetraacetic acid (EDTA) revealed the enzyme is a metalloproteinase. The collagenase activity notably decreased when the bug went hungry. The salivary gland collagenase is a vital enzyme in extra-oral digestion and facilitates the action of other digestive enzymes. The midgut collagenase may be involved in the digestion of the ingested muscle fibers. The collagenase probably acts as an intoxicating agent in the saliva (venom) of P. maculiventris. Paralysing toxins are present in the salivary gland secretion.

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The value of three cereal aphid species as food for a generalist predator

Physiological Entomology ◽

10.1046/j.1365-3032.2001.00218.x ◽

2001 ◽

Vol 26 (1) ◽

pp. 58-68 ◽

Cited By ~ 33

Author(s):

Trine Bilde ◽

Soren Toft

Keyword(s):

Aphid Species ◽

Generalist Predator ◽

Cereal Aphid

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Small rodent cycles influence interactions among predators in a boreal forest ecosystem

Mammal Research ◽

10.1007/s13364-021-00590-7 ◽

2021 ◽

Vol 66 (4) ◽

pp. 583-593

Author(s):

Rocío Cano-Martínez ◽

David Carricondo-Sanchez ◽

Olivier Devineau ◽

Morten Odden

Keyword(s):

Structural Equation ◽

Agricultural Land ◽

Structural Equation Models ◽

Red Fox ◽

Interspecific Interactions ◽

Small Rodent ◽

Generalist Predator ◽

Pine Marten ◽

Mustela Nivalis ◽

Rodent Abundance

AbstractCyclic fluctuations of prey have profound effects on the functioning of ecosystems, for example, by changing the dynamics, behavior, and intraguild interactions of predators. The aim of this study was to assess the effect of rodent cyclic fluctuations in the interspecific interactions of a guild of small- and medium-sized predators: red fox (Vulpes vulpes), pine marten (Martes martes), and weasels (Mustela erminea and Mustela nivalis) in the boreal ecosystem. We analyzed eight years (2007–2014) of snow tracking data from southeastern Norway using structural equation models to assess hypothesized networks of causal relationships. Our results show that fluctuations in rodent abundance alter the strength of predator’s interactions, as well as the effect of determinant environmental variables. Pine marten and weasel abundances were positively associated with rodent population growth rate, but not red fox abundance. All predators were positively associated with each other; however, the association between red fox and the other predators weakened when rodents increased. Rodent fluctuations had variable effects on the habitat use of the predators. The presence of agricultural land was important for all predators, but this importance weakened for the mustelids as rodent abundance increased. We discuss the shifting role of interference and exploitative competition as possible mechanisms behind these patterns. Overall, we highlight the importance of accounting for the dynamics of prey resources when studying interspecific interactions among predators. Additionally, we demonstrate the importance of monitoring the predator populations in order to anticipate undesirable outcomes such as increased generalist predator abundances to the detriment of specialists.

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Temperature and Prey Species Richness Drive the Broad-Scale Distribution of a Generalist Predator

Diversity ◽

10.3390/d13040169 ◽

2021 ◽

Vol 13 (4) ◽

pp. 169

Author(s):

Danai-Eleni Michailidou ◽

Maria Lazarina ◽

Stefanos P. Sgardelis

Keyword(s):

Species Richness ◽

Species Distribution ◽

Prey Species ◽

Abiotic Factors ◽

Biodiversity Loss ◽

Generalist Predator ◽

Distributional Patterns ◽

The Future ◽

Grass Snake ◽

Broad Scale

The ongoing climate change and the unprecedented rate of biodiversity loss render the need to accurately project future species distributional patterns more critical than ever. Mounting evidence suggests that not only abiotic factors, but also biotic interactions drive broad-scale distributional patterns. Here, we explored the effect of predator-prey interaction on the predator distribution, using as target species the widespread and generalist grass snake (Natrix natrix). We used ensemble Species Distribution Modeling (SDM) to build a model only with abiotic variables (abiotic model) and a biotic one including prey species richness. Then we projected the future grass snake distribution using a modest emission scenario assuming an unhindered and no dispersal scenario. The two models performed equally well, with temperature and prey species richness emerging as the top drivers of species distribution in the abiotic and biotic models, respectively. In the future, a severe range contraction is anticipated in the case of no dispersal, a likely possibility as reptiles are poor dispersers. If the species can disperse freely, an improbable scenario due to habitat loss and fragmentation, it will lose part of its contemporary distribution, but it will expand northwards.

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Transgenerational Effects of a Neonicotinoid and a Novel Sulfoximine Insecticide on the Harlequin Ladybird

Insects ◽

10.3390/insects12080681 ◽

2021 ◽

Vol 12 (8) ◽

pp. 681

Author(s):

Changchun Dai ◽

Michele Ricupero ◽

Zequn Wang ◽

Nicolas Desneux ◽

Antonio Biondi ◽

...

Keyword(s):

Nicotinic Acetylcholine Receptors ◽

Harmonia Axyridis ◽

Biocontrol Agent ◽

Insect Pests ◽

Negative Influence ◽

Management Approach ◽

Generalist Predator ◽

Cotton Aphid ◽

Transgenerational Effects ◽

Harlequin Ladybird

The harlequin ladybird, Harmonia axyridis Pallas (Coleoptera: Coccinellidae), is a generalist predator and an effective biocontrol agent of various insect pests that has been exploited for the control of aphid pests in the greenhouse and field. However, insecticides are widely used to control aphid pests worldwide and the potential non-target effects of sulfoxaflor and imidacloprid for controlling aphid pests towards this biocontrol agent are little known. Although both sulfoxaflor and imidacloprid act on nicotinic acetylcholine receptors of insects, sulfoxaflor has a novel chemical structure compared with neonicotinoids. We assessed the lethal, sublethal and transgenerational effects of sulfoxaflor and imidacloprid on H. axyridis simultaneously exposed via ingestion of contaminated prey and via residual contact on the host plant at LC20 and LC50 doses estimated for the cotton aphid. Imidacloprid significantly reduced the survival of H. axyridis adults compared to sulfoxaflor at the same lethal concentration against cotton aphid. Both concentrations of imidacloprid and sulfoxaflor reduced the proportion of ovipositing females, and both concentrations of imidacloprid and sulfoxaflor, except LC20 dose of sulfoxaflor, reduced the fecundity and fertility of the parental generation. In the progeny of imidacloprid- and sulfoxaflor-exposed parents, both tested LC50 concentrations significantly decreased the juvenile survival rate, and both concentrations of imidacloprid and sulfoxaflor, except LC20 dose of sulfoxaflor, prolonged the development time. Our findings provide evidence of the negative influence of imidacloprid and sulfoxaflor at low lethal concentrations on the harlequin ladybird and on the progeny of exposed individuals, i.e., transgenerational effects. Hence, these findings stress the importance of optimizing the applications of imidacloprid and sulfoxaflor for the control of aphid pests, aiming at preserving the biocontrol services provided by H. axyridis throughout the integrated pest management approach.

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Cold storage and gamma irradiation of Sitotroga cerealella Olivier eggs (Lepidoptera: Gelechiidae) in relation to the success of parasitism by Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae)

Egyptian Journal of Biological Pest Control ◽

10.1186/s41938-019-0189-6 ◽

2019 ◽

Vol 29 (1) ◽

Author(s):

Naglaa F. Abdel-Hameid ◽

I. R. M. Elzoghby ◽

A. L. Mehany ◽

W. A. A. Sayed

Keyword(s):

Gamma Irradiation ◽

Cold Storage ◽

Mass Rearing ◽

Egg Parasitoid ◽

Sitotroga Cerealella ◽

Trichogramma Evanescens ◽

Control Programs ◽

Angoumois Grain Moth ◽

Rearing Techniques ◽

The Times

AbstractThe performance of parasitism by the egg parasitoid, Trichogramma evanescens Westwood (Hymenoptera: Trichogrammatidae) on eggs of Angoumois grain moth, Sitotroga cerealella Olivier (Lepidoptera: Gelechiidae) was investigated under cold storage and gamma irradiation treatments of the host eggs. Cold storage treatment could improve the parasitoid mass rearing techniques and reduced the costs of biological control programs, while gamma irradiation might be used as a supplementary support at the times of high demand. The suitability of the S. cerealella eggs, stored at – 20 °C for 0.5, 1, or 2 h. as a host for T. evanescens was evaluated. The sensitivity of S. cerealella eggs to gamma irradiation treatments and the acceptability of irradiated eggs for parasitism by T. evanescens females for the parental P and F1 generations were examined. The results revealed that parasitism was drastically reduced more than adult’s emergence and sex-ratio (% of females) after cold storage periods of S. cerealella eggs. Moreover, the parasitism percentages were relatively reduced to (97.1, 96.1, 93.03, and 92.7 %) after irradiating the S. cerealella eggs at 40, 60, 80, and 100 Gy, respectively than the control (97.3% emergence). The percentages of emergence and females’ percent were slightly decreased by gamma irradiation doses, while, equal preferred by the F1 generation of parasitoid that produced from irradiated S. cerealella eggs.

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Influence of prey size and environmental factors on predation by Podisus maculiventris (Hemiptera: Pentatomidae) on viburnum leaf beetle (Coleoptera: Chrysomelidae)

The Canadian Entomologist ◽

10.4039/n07-021 ◽

2008 ◽

Vol 140 (2) ◽

pp. 192-202 ◽

Cited By ~ 7

Author(s):

Gaylord A. Desurmont ◽

Paul A. Weston

Keyword(s):

Host Plant ◽

Plant Species ◽

Biological Control Agent ◽

Handling Time ◽

Leaf Beetle ◽

Podisus Maculiventris ◽

Viburnum Opulus ◽

Host Plant Species ◽

Search Area ◽

Rate Of Increase

AbstractExperiments were conducted under laboratory conditions to determine the influence of the relative sizes of predator and prey, temperature, presence of refugia, size of the search area, and host-plant species on the predation performance of Podisus maculiventris (Say) nymphs against viburnum leaf beetle, Pyrrhalta viburni (Paykull), a new landscape pest in North America that feeds on the foliage of species of Viburnum L. (Caprifoliaceae). Predator handling time was positively correlated with body mass of the prey for all instars of P. maculiventris, but the rate of increase of handling time relative to prey mass decreased as predator age increased. Temperature was positively correlated with predation rates, but the presence of refugia did not have an impact on predation. The influence of host-plant species and size of the search area was tested on southern arrowwood (Viburnum dentatum L.) and American cranberrybush (Viburnum opulus L. var. americanum Aiton). There was a significant interaction between plant species and size of the search area, the species effect becoming significant as leaf surface area increased. In the case of southern arrowwood a negative correlation between size of the search area and predation rate was also detected. The identification of these factors adds valuable knowledge for using P. maculiventris as a biological-control agent against P. viburni.

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