scholarly journals Factors affecting the biology of Pachycrepoideus vindemmiae (Hymenoptera: Pteromalidae) on spotted-wing drosophila (Drosophila suzukii)

2019 ◽  
Author(s):  
Cherre S. Bezerra Da Silva ◽  
Briana E. Price ◽  
Alexander Soohoo-Hui ◽  
Vaughn M. Walton
Keyword(s):  
Sex Ratio ◽  
Spotted Wing Drosophila ◽  
Host Feeding ◽  
Drosophila Suzukii ◽  
Factors Affecting ◽  
Intrinsic Factors ◽  
Young Females ◽  
Biocontrol Potential ◽  
Host Killing ◽  
The Impact

AbstractPachycrepoideus vindemmiae is a parasitoid of the invasive spotted-wing drosophila (SWD, Drosophila suzukii) in the U.S. Few studies have addressed interactions between these two species and little is known about the potential of this parasitoid as a biocontrol agent of SWD. Here, we investigated the impact of extrinsic and intrinsic factors on life-history traits of P. vindemmiae. Both constant (entire adulthood) and limited (30 minutes) supply of water + honey, honey, or host increased parasitoid survival compared to controls (water or fasting). Water + honey caused the highest parasitoid survivals (35-60 days), independent of supply period, sex, and host availability. Females were intrinsically more resistant to water and honey scarcity than males, and host-feeding elevated such resistance even higher. Constant supply of honey supported the highest host-killing capacity (ca. 600 SWD pupae/wasp). However, in young females (4-9 days old), such honey effect was insignificant while water deprivation (either with or without honey) resulted in the highest host-killing potential. This indicate that although sugar becomes a critical nutritional resource as females age, young females depend more on water than sugar. No effect of water nor honey was observed on the sex ratio of young females, but when we considered the entire adulthood honey supply produced the lowest proportion of females (0.50), independent of water availability. Such reduction derived from sperm depletion, likely caused by both lack of re-mating and higher fecundity in honey-fed wasps. Neither water nor honey affected parasitoid emergence rate (0.97), independent of female age. Based on survival and host-killing capacity, we conclude that P. vindemmiae has a tremendous biocontrol potential against SWD. Both limited and constant supply of water, sugar, and host increase parasitoid survival, while constant supply of water and/or honey enhance its host-killing potential and decrease sex ratio depending on mother age.

Oviposition Preference and Larval Performance of Drosophila suzukii (Diptera: Drosophilidae), Spotted-Wing Drosophila: Effects of Fruit Identity and Composition

2019 ◽  
Vol 48 (4) ◽  
pp. 867-881 ◽  
Author(s):  
Laure Olazcuaga ◽  
Nicolas O Rode ◽  
Julien Foucaud ◽  
Benoit Facon ◽  
Virginie Ravigné ◽  
...  
Keyword(s):  
Emerging Adults ◽  
Oviposition Behavior ◽  
Oviposition Preference ◽  
Adult Emergence ◽  
Spotted Wing Drosophila ◽  
Larval Performance ◽  
Drosophila Suzukii ◽  
Management Tools ◽  
Factors Affecting ◽  
And Performance

Abstract A better understanding of the factors affecting host plant use by spotted-wing drosophila (Drosophila suzukii) could aid in the development of efficient management tools and practices to control this pest. Here, proxies of both preference (maternal oviposition behavior) and performance (adult emergence) were evaluated for 12 different fruits in the form of purees. The effect of the chemical composition of the fruits on preference and performance traits was then estimated. We synthesized the literature to interpret our findings in the light of previous studies that measured oviposition preference and larval performance of D. suzukii. We show that fruit identity influences different parts of the life cycle, including oviposition preference under both choice and no-choice conditions, emergence rate, development time, and number of emerging adults. Blackcurrant was always among the most preferred fruit we used, while grape and tomato were the least preferred fruits. Larvae performed better in cranberry, raspberry, strawberry, and cherry than in the other fruits tested. We found that fruit chemical compounds can explain part of the effect of fruit on D. suzukii traits. In particular, oviposition preference under choice conditions was strongly influenced by fruit phosphorus content. In general, the consensus across studies is that raspberry, blackberry, and strawberry are among the best hosts while blackcurrant, grape and rose hips are poor hosts. Our results generally confirm this view but also suggest that oviposition preferences do not necessarily match larval performances. We discuss opportunities to use our results to develop new approaches for pest management.

scholarly journals Evaluation of Exclusion Netting for Spotted-Wing Drosophila (Diptera: Drosophilidae) Management in Minnesota Wine Grapes

2019 ◽  
Vol 112 (5) ◽  
pp. 2287-2294 ◽  
Author(s):  
Dominique N Ebbenga ◽  
Eric C Burkness ◽  
William D Hutchison
Keyword(s):  
The United States ◽  
Field Trials ◽  
Spotted Wing Drosophila ◽  
Wine Grape ◽  
Fruit Crops ◽  
Drosophila Suzukii ◽  
Wine Grapes ◽  
High Fecundity ◽  
Untreated Check ◽  
The Impact

Abstract Spotted-wing drosophila, Drosophila suzukii (Matsumura), an economically damaging invasive species of numerous fruit crops, was first detected in Minnesota in 2012. High fecundity, and short generation times facilitated a rapid rise in the global pest status of D. suzukii, particularly in North America and Europe. To date, the majority of crop injury research has focused on fruit crops such as blueberries, raspberries, and cherries. However, little is known regarding the impact of D. suzukii on the wine grape industry in the upper Midwest region of the United States. Field trials were conducted in Minnesota during the summers of 2017–2018 to examine season-long phenology of D. suzukii in wine grape vineyards and wineries, and to assess the efficacy of exclusion netting for control of D. suzukii. Four treatments were evaluated, 1) open plot check (control), 2) open plot treated with an insecticide, 3) exclusion netting, and 4) exclusion netting, with artificial infestations of D. suzukii adults. Exclusion netting was applied at véraison and removed at harvest. On each sample date, 20 berries (10 intact and 10 injured) were collected from each plot for dissection. The number of larvae and adults were recorded for each berry to determine infestation levels. As shown by mean larval infestations and injured berries across treatments, exclusion netting provided a significant reduction in the level of D. suzukii infested berries when compared with the untreated check. These results indicate that exclusion netting could provide an effective alternative management strategy for D. suzukii in wine grapes.

scholarly journals Factors affecting the biology of Pachycrepoideus vindemmiae (Hymenoptera: Pteromalidae), a parasitoid of spotted-wing drosophila (Drosophila suzukii)

PLoS ONE ◽  
2019 ◽  
Vol 14 (7) ◽  
pp. e0218301 ◽  
Author(s):  
Cherre S. Bezerra Da Silva ◽  
Briana E. Price ◽  
Alexander Soohoo-Hui ◽  
Vaughn M. Walton
Keyword(s):  
Spotted Wing Drosophila ◽  
Drosophila Suzukii ◽  
Factors Affecting

The dichotomy of customer relationship management and variety-seeking behaviour in the hotel sector

2018 ◽  
Vol 25 (4) ◽  
pp. 444-461 ◽  
Author(s):  
Maduka Udunuwara ◽  
Dale Sanders ◽  
Hugh Wilkins
Keyword(s):  
Customer Relationship Management ◽  
Word Of Mouth ◽  
Relationship Management ◽  
Customer Relationship ◽  
Variety Seeking ◽  
Factors Affecting ◽  
Intrinsic Factors ◽  
Positive Word Of Mouth ◽  
The Impact ◽  
The Relationship

Customer relationship management (CRM) and variety-seeking behaviour (VSB) are paradoxical constructs due to their contradictory intentions. CRM is implemented by organizations to retain customers and generate loyalty while VSB by customers can result in switching. This study addresses the question ‘what is the impact of VSB on the relationship between CRM and its outcomes: repeat visitation and positive word of mouth?’ Following analysis of 400 questionnaire responses from Australian leisure travellers who have visited the same international destination two or more times, the findings indicate that CRM leads to word-of-mouth recommendations, but not repeat visitation. Through multi-group moderation analysis, it was further identified that the outcomes of CRM do not vary based on the degree of VSB of travellers, and CRM leading to repeat visitation is fully mediated by the intrinsic factors affecting VSB, while CRM does have a significant influence on VSB.

scholarly journals Phenotypic Plasticity Promotes Overwintering Survival in A Globally Invasive Crop Pest, Drosophila suzukii

Insects ◽  
2018 ◽  
Vol 9 (3) ◽  
pp. 105 ◽  
Author(s):  
Dara Stockton ◽  
Anna Wallingford ◽  
Gregory Loeb
Keyword(s):  
Phenotypic Plasticity ◽  
Thermal Environment ◽  
Population Monitoring ◽  
Cold Hardening ◽  
Drosophila Suzukii ◽  
Factors Affecting ◽  
Lethal Limit ◽  
Major Pest ◽  
Overwintering Survival ◽  
The Impact

Spotted wing drosophila, Drosophila suzukii Matsumura, is a major pest of small fruit worldwide in temperate and subtropical growing regions. In Northern climates, D. suzukii likely overwinters locally under leaf litter and snow pack, but our understanding of the factors affecting thermal susceptibility is limited. While previous investigations of thermal susceptibility in this species have employed conventional static acclimation protocols, we aimed to determine whether gradual cooling, or dynamic acclimation, may extend the limits of known thermal tolerance by more closely approximating naturally occurring shifts in temperature. First, we assessed survival among adult and pupal D. suzukii using static acclimation. Then, we re-assessed survival using a novel dynamic acclimation method. We found that while static acclimation was sufficient to induce cold tolerance, dynamic acclimation significantly improved survival at temperatures as low as −7.5 °C. Following static acclimation, the lower lethal limit of adult D. suzukii was −1.1 °C in winter morphotype (WM) adults compared to 1.7 °C in non-acclimated summer morphotype (SM) adults. Dynamic acclimation reduced the lower limit to −5 °C in SM flies. At the end of our study 50% of WM flies survived 72 h at −7.5 °C. Below 0 °C pupal survival declined significantly regardless of acclimation procedure. However, pupal acclimation improved survival outcomes significantly compared to non-acclimated pupae, suggesting that while juvenile diapause is unlikely, cold hardening likely benefits those flies which may develop into the overwintering WM population. These data suggest that the degree of cold hardening is proportional to the thermal environment, a finding previously unrecognized in this species. Given the economic impact of this pest, these data may have important implications for offseason population monitoring and management. We discuss how phenotypic plasticity may drive geographical range expansion, and the impact of climate change on the spread of this species.

The Impact of the Tobacco Market Opening on Smoking Status in Taiwan: Findings from a Secular Smoking Rates Analysis

2005 ◽  
Vol 25 (3) ◽  
pp. 271-281 ◽  
Author(s):  
Chih-Cheng Hsu ◽  
Asta Y. Z. Lord ◽  
Tung-Sung Tseng ◽  
Ted Chen
Keyword(s):  
Smoking Status ◽  
Steady Increase ◽  
Smoking Rate ◽  
Factors Affecting ◽  
Young Females ◽  
Market Opening ◽  
Directorate General ◽  
Per Capita ◽  
Major Factors ◽  
The Impact

The forced opening of Taiwan's tobacco market in 1987 has changed the smoking environment. This study analyzes the effects this market opening had on Taiwan's secular smoking rates over 15 years. The data sources used were consumer surveys conducted by the Taiwan Tobacco & Wine Monopoly Bureau 1964–1996, the 2001 National Health Interview Survey, and a series of annual per capita gross national product (GNP) data reported by the Directorate-General of Budget, Accounting & Statistics. After Taiwan's tobacco market was forced open in 1987 by the U.S. government in trade negotiations, smoking rates rose (7%-10% for males and 39%-75% for females) for the first three years. After the initial 3-year surge, smoking rates gradually declined to 1986 baseline rates or even lower for all groups except females aged 30 and younger, who have shown a small but steady increase in cigarette consumption. Results of multiple regression analysis showed per capita GNP and age to be the two major factors affecting smoking rate change after the Taiwan market opening. National tobacco control policies and campaigns seem to have an impact on tempering the effect of foreign tobacco imports in all groups, except young females, whose rise in smoking rate is significant and alarming.

scholarly journals Impact of a nonnative parasitoid species on intraspecific interference and offspring sex ratio

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yao Zhuo Zhang ◽  
Zhengya Jin ◽  
James Rudolph Miksanek ◽  
Midori Tuda
Keyword(s):  
Sex Ratio ◽  
Community Dynamics ◽  
Interspecific Interactions ◽  
Host Density ◽  
Type I ◽  
Host Feeding ◽  
Offspring Sex Ratio ◽  
Anisopteromalus Calandrae ◽  
Offspring Sex ◽  
The Impact

AbstractIn an assemblage of multiple predators sharing a single prey species, the combined effects of the component species may scale unpredictably because of emergent interspecific interactions. Prior studies suggest that chaotic but persistent community dynamics are induced by intra-/interspecific interactions between native and nonnative parasitoids competing over a shared host. Here, we test the impact of the nonnative parasitoid Heterospilus prosopidis (Hymenoptera: Braconidae) on the intraspecific interference and offspring sex ratio of the native parasitoid Anisopteromalus calandrae (Hymenoptera: Pteromalidae). We found that the nonnative parasitoid reduced intraspecific interference among native parasitoids and decreased the proportion of female offspring produced by the native parasitoid (predicted under conditions of reduced host availability). At higher host densities, the nonnative parasitoid contributed less to the total proportion of hosts parasitized, as its innate saturating Type II response changed to a dome-shaped Type IV response with increasing density of the native parasitoid, while the native parasitoid retained its increasing Type I response. This inverse host-density-dependent response between the two parasitoids and associated competitive superiority can explain the observed changes in parasitism; at high host densities, the searching efficiency of the native parasitoid increases via host feeding while the nonnative parasitoid experiences egg limitation. These results highlight the importance of the complementary top-down effects of multiple consumers on a single resource.

scholarly journals Biological Control of Spotted-Wing Drosophila (Diptera: Drosophilidae)—Current and Pending Tactics

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Jana C Lee ◽  
Xingeng Wang ◽  
Kent M Daane ◽  
Kim A Hoelmer ◽  
Rufus Isaacs ◽  
...  
Keyword(s):  
Biological Control ◽  
Natural Enemy ◽  
Life Stage ◽  
Residual Activity ◽  
Field Trials ◽  
Spotted Wing Drosophila ◽  
Drosophila Suzukii ◽  
The Impact ◽  
Near Future ◽  
Dose Dependent

Abstract Spotted-wing drosophila, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae) is originally from Asia, and in the last decade it has become a global economic pest of small fruits and cherries. Growers have expressed strong interest in biological control and other sustainable tactics to reduce reliance on insecticides. Biological control of spotted-wing drosophila has been studied intensively, with over 75 research publications. Here, we are reporting current information on predators, parasitoids, pathogens (fungi, nematodes, bacteria, endosymbiotic bacteria, and viruses), and competitors of spotted-wing drosophila. When relevant for the natural enemy group, the discussion focuses on the impact each natural enemy has been observed to have in the field, how to optimize control, the efficacy of commercial products available, and options that may be available in the near future. Studies are summarized in tables that can be sorted by species, spotted-wing drosophila life stage targeted, outcomes, lab/field trials, and studies that examined residual activity, dose-dependent responses, or other effects.

On the occurrence of Corynosoma spp. (Acanthocephala) in ringed seals (Pusa hispida) in the Bothnian Bay, Finland

1980 ◽  
Vol 58 (2) ◽  
pp. 298-303 ◽  
Author(s):  
Eero Helle ◽  
E. Tellervo Valtonen
Keyword(s):  
Small Intestine ◽  
Sex Ratio ◽  
Anterior Part ◽  
Intensity Of Infection ◽  
Factors Affecting ◽  
Young Females ◽  
Ringed Seals ◽  
Pusa Hispida ◽  
Gravid Females ◽  
Bothnian Bay

The occurrence, location, sex ratio, growth, and development of Corynosoma strumosum and Corynosoma semerme were studied in 29 Baltic ringed seals, Pusa hispida botnica, in October–November 1977. The prevalence of infection was 96.5% for both species, the intensity of infection being 68(1 to 324) per infected seal in C. strumosum and 140 (1 to 1230) in C. semerme. Of the C. strumosum, 99% were in the small intestine; the remainder, together with 97% of the C. semerme, were distributed from the caecum to the rectum. The numbers of C. strumosum increased along the small intestine, and although the sex ratio remained constant, young females were more numerous in the anterior part of the intestine and gravid females more numerous distally. Factors affecting the numbers and proportions of the Corynosoma species are discussed with reference to their development and the progress of infection in the intestine of the ringed seal.

scholarly journals Responses of the pest Drosophila suzukii population to environmental variables in southern Spain (Granada, Andalusia) – results of a pilot study

2021 ◽  
Vol 70 (1) ◽  
pp. 65-74
Author(s):  
Peter Manko ◽  
J. Manuel Tierno de Figueroa ◽  
Jozef Oboňa
Keyword(s):  
Sex Ratio ◽  
Environmental Variables ◽  
Heavy Rainfall ◽  
Spotted Wing Drosophila ◽  
Southern Spain ◽  
Invasive Pest ◽  
Effect Of Temperature ◽  
Flight Period ◽  
Drosophila Suzukii ◽  
Two Peaks

Abstract In this study conducted in Granada province in southern Spain, we analysed the flying activity and sex-ratio variability of the invasive pest Drosophila suzukii (the spotted wing drosophila) in the context of environmental factors and compared it with co-occurring Drosophilidae in a village garden. The studied D. suzukii population showed overwintering capabilities and successful maintenance in village garden with non-crop plants. Its flight period showed two peaks: female-biased, in November, and male-biased, in May. The sex ratio varied throughout the year and was mostly female-biased. We observed the effect of temperature on Drosophilidae and rainfall and temperature on the D. suzukii. Catches of the studied species were minimal at the minimal temperatures below 0 °C, and absent or near absent when the maximal temperature exceeded 30 °C. Moreover, we did not observe D. suzukii in samples when the minimum temperature below 0 °C was combined with heavy rainfall. The spotted wing drosophila seems to be more sensitive to precipitation than native Drosophilidae, as its proportion in the samples decreased with increasing rainfall. This pest also shows more pronounced short peaks in which it makes an important proportion of the biocoenosis of in comparison with other Drosophilidae.

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