Plant host shift: The viability and persistence of a polyphagous non-native insect

Drosophila suzukii (Diptera: Drosophilidae) has become a pervasive pest in several countries around the world. Many studies have investigated the preference and attractiveness of potential hosts on this invasive, polyphagous drosophilid. Thus far, no studies have investigated whether a shift of fruit host could affect its ecological viability or spatiotemporal persistence. In this study, we analysed the fecundity and oviposition period jointly with the survival time of D. suzukii subject to a shift in host fruit, using a joint modelling method for longitudinal outcomes and time-until-event outcomes. The number of eggs laid by females was higher in raspberry than in strawberry and when setting adults of F1 generation underwent a first host shift. The joint modelling also suggested that insects reared on raspberry survived longer. We then combined experimental results with a two-patch dispersal model to investigate how host shift in a species that exhibits both passive and density-dependent dispersal may affect its asymptotic dynamics. In line with empirical evidence, we found that a shift in host choice can significantly affect the growth potential and fecundity of a species such as D. suzukii, which ultimately could aid such invasive populations in their ability to persist within a changing environment.

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Predation on Drosophila suzukii within Hedges in the Agricultural Landscape

Insects ◽

10.3390/insects12040305 ◽

2021 ◽

Vol 12 (4) ◽

pp. 305

Author(s):

Alexandra Siffert ◽

Fabian Cahenzli ◽

Patrik Kehrli ◽

Claudia Daniel ◽

Virginie Dekumbis ◽

...

Keyword(s):

Agricultural Landscape ◽

Vital Role ◽

Agricultural Landscapes ◽

Gut Content ◽

Drosophila Suzukii ◽

Natural Habitats ◽

Host Fruit ◽

Molecular Gut Content Analysis ◽

Wild Fruits ◽

Diverse Community

The invasive Drosophila suzukii feeds and reproduces on various cultivated and wild fruits and moves between agricultural and semi-natural habitats. Hedges in agricultural landscapes play a vital role in the population development of D. suzukii, but also harbor a diverse community of natural enemies. We investigated predation by repeatedly exposing cohorts of D. suzukii pupae between June and October in dry and humid hedges at five different locations in Switzerland. We sampled predator communities and analyzed their gut content for the presence of D. suzukii DNA based on the COI marker. On average, 44% of the exposed pupae were predated. Predation was higher in dry than humid hedges, but did not differ significantly between pupae exposed on the ground or on branches and among sampling periods. Earwigs, spiders, and ants were the dominant predators. Predator communities did not vary significantly between hedge types or sampling periods. DNA of D. suzukii was detected in 3.4% of the earwigs, 1.8% of the spiders, and in one predatory bug (1.6%). While the molecular gut content analysis detected only a small proportion of predators that had fed on D. suzukii, overall predation seemed sufficient to reduce D. suzukii populations, in particular in hedges that provide few host fruit resources.

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Joint modelling of time-to-event and multivariate longitudinal outcomes: recent developments and issues

BMC Medical Research Methodology ◽

10.1186/s12874-016-0212-5 ◽

2016 ◽

Vol 16 (1) ◽

Cited By ~ 45

Author(s):

Graeme L. Hickey ◽

Pete Philipson ◽

Andrea Jorgensen ◽

Ruwanthi Kolamunnage-Dona

Keyword(s):

Time To Event ◽

Joint Modelling ◽

Longitudinal Outcomes ◽

Recent Developments ◽

Multivariate Longitudinal Outcomes

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Joint modelling of multivariate longitudinal outcomes and a time-to-event: A nonlinear latent class approach

Computational Statistics & Data Analysis ◽

10.1016/j.csda.2008.10.017 ◽

2009 ◽

Vol 53 (4) ◽

pp. 1142-1154 ◽

Cited By ~ 52

Author(s):

Cécile Proust-Lima ◽

Pierre Joly ◽

Jean-François Dartigues ◽

Hélène Jacqmin-Gadda

Keyword(s):

Latent Class ◽

Time To Event ◽

Joint Modelling ◽

Longitudinal Outcomes ◽

Multivariate Longitudinal Outcomes

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Effect of Drosophila suzukii on blueberry VOCs: chemical cues for a pupal parasitoid, Trichopria anastrephae

10.21203/rs.3.rs-320923/v1 ◽

2021 ◽

Author(s):

Gerardo de la Vega ◽

Federico Triñanes ◽

Andres González

Keyword(s):

Behavioral Response ◽

Chemical Cues ◽

Chemical Characterization ◽

Trophic Levels ◽

Parasitic Wasps ◽

Drosophila Suzukii ◽

Control Programs ◽

Host Fruit ◽

Volatile Organic ◽

Volatile Cues

Abstract Biocontrol agents such as parasitic wasps use long-range volatiles and host-associated cues from lower trophic levels to find their hosts. Although, this chemical landscape may be altered by the invasion of exotic insect species. The spotted-wing drosophila (SWD), Drosophila suzukii (Diptera: Drosophilidae), is a highly polyphagous fruit pest native to eastern Asia and recently arrived in South America. The aim of our study was to characterize the effect of SWD attack on the volatile organic compounds (VOCs) of blueberries, a common host fruit, and to correlate these odor changes with the olfactory-mediated behavioral response of resident populations of Trichopria anastrephae parasitoids. Using fruit VOC chemical characterization followed by multivariate analyses of the odor blends of SWD-attacked blueberries, we showed that the development of SWD immature stages inside the fruit generates a different odor profile than control fruits (physically damaged and free of damage). These differences can be explained by the diversity, frequency and amounts of fruit VOCs. The behavioral response of female parasitic wasps showed that T. anastrephae has an innate attraction to volatile cues from infested host fruits, which may lead to successful location of their insect host. Since resident parasitoids are able locate this novel potential host, biological control programs using local populations may be plausible as a SWD control strategy.

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Electrophysiological and Behavioral Responses of Drosophila suzukii (Diptera: Drosophilidae) Towards the Leaf Volatile β-cyclocitral and Selected Fruit-Ripening Volatiles

Environmental Entomology ◽

10.1093/ee/nvz092 ◽

2019 ◽

Vol 48 (5) ◽

pp. 1049-1055 ◽

Cited By ~ 3

Author(s):

L Grant Bolton ◽

Jaime C Piñero ◽

Bruce A Barrett

Keyword(s):

Fruit Ripening ◽

Behavioral Responses ◽

Drosophila Suzukii ◽

Male And Female ◽

Host Fruit ◽

Small Fruit ◽

Electrophysiological Responses ◽

The Mean ◽

Species Specific ◽

Female Responses

Abstract The spotted-wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), is attracted to numerous volatile organic compounds (VOCs) emitted from several ripening, small fruit crops. However, the strawberry leaf terpenoid, β-cyclocitral, is reportedly very attractive to D. suzukii (but not to all Drosophila spp.). This suggests that leaf and fruit VOCs may be critical sources needed to further develop a more species-specific D. suzukii monitoring lure, or semiochemically based attract-and-kill systems. This study investigated the electrophysiological responses of male and female D. suzukii towards selected host fruit-ripening VOCs and β-cyclocitral, along with behavioral responses toward combined fruit VOCs with β-cyclocitral. Electroantennogram (EAG) results revealed a positive dose–response, for both sexes, as concentrations increased for all VOCs tested. For β-cyclocitral, hexyl acetate and methyl butyrate, the mean male EAG responses were significantly greater than the female responses at lower doses. In caged behavioral bioassays, only in the β-cyclocitral treatments were the mean number of flies captured (sexes combined) significantly greater than that captured in solvent (mineral oil) controls. Our study has demonstrated that while single fruit-based VOCs alone are not enough to cause a strong behavioral attraction by both male and female D. suzukii, the addition of β-cyclocitral did produce a significant attraction response from both sexes. In both bioassays, males had higher responses to β-cyclocitral than females, which suggest a greater sensitivity to this compound. Further studies are needed to ascertain the role β-cyclocitral may play in the development of a more species-specific D. suzukii monitoring lure.

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Biological annuloplasty rings with growth potential for mitral valve surgery

The Thoracic and Cardiovascular Surgeon ◽

10.1055/s-2008-1037881 ◽

2008 ◽

Vol 56 (S 1) ◽

Author(s):

A Lichtenberg ◽

P Minol ◽

H Baraki ◽

E Bagaev ◽

M Suprunov ◽

...

Keyword(s):

Mitral Valve ◽

Mitral Valve Surgery ◽

Valve Surgery ◽

Growth Potential

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Opportunities for accelerating labor productivity growth: The role of small and medium enterprises

Voprosy Ekonomiki ◽

10.32609/0042-8736-2020-3-98-114 ◽

2020 ◽

pp. 98-114

Author(s):

Evguenia V. Bessonova ◽

Alexander G. Morozov ◽

Natalia A. Turdyeva ◽

Anna N. Tsvetkova

Keyword(s):

Labor Productivity ◽

Productivity Growth ◽

Small And Medium Enterprises ◽

Growth Potential ◽

Business Climate ◽

Labor Productivity Growth ◽

Positive Effects ◽

Low Efficiency ◽

Medium Enterprises ◽

Medium Firms

The paper considers necessary conditions for acceleration of labor productivity growth in Russia. Based on micro data, as well as aggregate data, the paper quantifies the contribution of small and medium firms to labor productivity growth. It shows that mere increase of the number of small and medium enterprises is not as important for positive effects of these programs, as qualitative improvements: development of favorable environment for growth, which is largely determined by business climate. Accelerating productivity growth involves redistribution of labor and capital from inefficient to efficient enterprises. In particular, it is necessary to create conditions, which allow a firm to grow after it enters the market instead of stagnating as a small firm with low efficiency. At the same time, it is necessary for ineffective firms, which exhausted their growth potential, to have an opportunity to exit the market easily leaving resources including labor to fast-growing companies.

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