scholarly journals Performance of Trichopria drosophilae (Hymenoptera: Diapriidae), a Generalist Parasitoid of Drosophila suzukii (Diptera: Drosophilidae), at Low Temperature

2020 ◽  
Vol 20 (3) ◽  
Author(s):  
Fernanda Colombari ◽  
Lorenzo Tonina ◽  
Andrea Battisti ◽  
Nicola Mori

Abstract Survival and parasitism activity of Trichopria drosophilae Perkins adults, a cosmopolitan parasitoid of Drosophila spp., were studied under laboratory conditions using five constant temperatures at the lower range known for this enemy, from 4 to 20°C in 4°C increments. Drosophila suzukii Matsumura, an invasive pest of small fruits, was used as a host. Commercially available adult parasitoids were provided with 1) food and D. suzukii pupae; 2) food and no D. suzukii pupae; 3) no food and no pupae. The results show that adult females of T. drosophilae lived longer than males, and both generally benefitted from food supply. The highest level of survival was observed between 8 and 12°C for fed insects, irrespective of whether they were offered host pupae or not. The absence of food led to the highest mortality, but the parasitoid demonstrated considerably resistance to prolonged starvation. Successful parasitism increased steadily with temperature and reached the highest value at 20°C. Conversely, D. suzukii emergence rate was high after exposure of pupae to parasitoids at 4°C, while pupal mortality increased strongly with temperature until 12°C. The findings indicate that T. drosophilae is well adapted to the relatively cold conditions experienced in early spring and in autumn or at high elevations, when the host pupae could be largely available. The long lifespan of the adults and the ability to parasitize the host at low temperature make T. drosophilae potentially useful for the biocontrol of D. suzukii.

2016 ◽  
Vol 109 (3) ◽  
pp. 1071-1078 ◽  
Author(s):  
J Cossentine ◽  
M Robertson ◽  
D Xu

Abstract Whole-culture extracts of Bacillus thuringiensis Berliner strains were assayed against larval and adult Drosophila suzukii (Matsumura), an important invasive pest of many thin-skinned soft fruit crops in North America. Of the 22 serovars tested versus larval D. suzukii , strains of Bacillus thuringiensis var. thuringiensis , kurstaki , thompsoni , bolivia , and pakistani caused high (75 to 100%) first-instar mortalities. Pupal mortality, measured as a failure of adults to emerge, varied with serovar. The first D. suzukii instar was the most susceptible of the three larval instars to B. thuringiensis var. kurstaki HD-1. Larval D. suzukii are shielded from crop treatments, as they develop under the skin of infested fruit, and adults would be a more vulnerable target for an efficacious strain of B. thuringiensis . Only one of the 21 B. thuringiensis serovars, var. thuringiensis , prepared as oral suspensions in sucrose for adult D. suzukii ingestion resulted in significant, albeit low mortality within 7 d. It is not a candidate for use in pest management, as it produces β -exotoxin that is toxic to vertebrates.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Sarah Biganski ◽  
Sabrina Fückel ◽  
Johannes A. Jehle ◽  
Regina G. Kleespies

AbstractMicrosporidian infections of insects are important natural constraints of population growth, often reducing lifespan, fecundity and fertility of the infected host. The recently discovered Tubulinosema suzukii infects Drosophila suzukii (spotted wing drosophila, SWD), an invasive pest of many fruit crops in North America and Europe. In laboratory tests, fitness effects on larval and adult stages were explored. High level infection after larval treatment caused up to 70% pupal mortality, a decreased lifespan and a 70% reduced oviposition of emerging adults in biparental infection clusters. A shift to higher proportion of female offspring compared to controls suggested a potential parthenogenetic effect after microsporidian infection. A clear sex-linkage of effects was noted; females were specifically impaired, as concluded from fecundity tests with only infected female parents. Additive effects were noted when both parental sexes were infected, whereas least effects were found with only infected male parents, though survival of males was most negatively affected if they were fed with T. suzukii spores in the adult stage. Although most negative effects on fitness parameters were revealed after larval treatment, infection of offspring was never higher than 4%, suggesting limited vertical transmission. For that reason, a self-reliant spread in natural SWD populations would probably only occur by spore release from cadavers or frass.


Insects ◽  
2019 ◽  
Vol 10 (12) ◽  
pp. 448 ◽  
Author(s):  
Fabiana Sassù ◽  
Katerina Nikolouli ◽  
Silvana Caravantes ◽  
Gustavo Taret ◽  
Rui Pereira ◽  
...  

Drosophila suzukii (Diptera: Drosophilidae) is an invasive pest of a wide range of commercial soft-skinned fruits. To date, most management tactics are based on spraying of conventional and/or organic insecticides, baited traps, and netting exclusion. Interest has been expressed in using the sterile insect technique (SIT) as part of area-wide integrated pest management (AW-IPM) programs to control D. suzukii infestations. Mass-rearing protocols are one of the prerequisites for successful implementation of the SIT. To establish mass-rearing methods for this species, two different egg-collection systems were developed and compared with respect to the number of eggs produced, egg viability, pupa and adult recovery, adult emergence rate, and flight ability. Female flies kept in cages equipped with a wax panel produced significantly more eggs with higher viability and adult emergence rate, as compared to the netted oviposition system. The wax panel system was also more practical and less laborious regarding the collection of eggs. Furthermore, the wax panel oviposition system can be adapted to any size or design of an adult cage. In conclusion, this system bears great promise as an effective system for the mass production of D. suzukii for SIT.


Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 145 ◽  
Author(s):  
Aurore Panel ◽  
Laura Zeeman ◽  
Bart Van der Sluis ◽  
Peter Van Elk ◽  
Bart Pannebakker ◽  
...  

The mechanisms allowing the widespread invasive pest Drosophila suzukii to survive from early spring until the availability of the first fruit crops are still unclear. Seasonal biology and population dynamics of D. suzukii were investigated in order to better understand the contribution of the early spring hosts to the infestation of the first fruit crops of the season. We identified hosts available to D. suzukii in early spring and assessed their suitability for the pest oviposition and reproductive success under field and laboratory conditions. The natural infestation rate of one of these hosts, Aucuba japonica, was assessed over springtime and the morphology of the flies that emerged from infested A. japonica fruits was characterized under field conditions. Then, these findings were correlated with long-term monitoring data on seasonal reproductive biology and morphology of the pest, using a cumulative degree-days (DD) analysis. Field sampling revealed that overwintered D. suzukii females were physiologically able to lay eggs at 87 DD which coincided with the detection of the first infested early spring hosts. The latter were continuously and increasingly infested by D. suzukii eggs in nature from early spring until the end of May, in particular Aucuba japonica. Individuals emerged from most of these hosts were characterized by a poor fitness and a rather low success of emergence. In the field, only few summer morphs emerged from naturally infested A. japonica fruits around the end of May-beginning of June. However, field monitoring in orchards revealed that D. suzukii individuals consisted solely of winter morphs until mid-June. These observations indicate that overwintered D. suzukii females are the predominant source for the infestations in the first available fruit crops of the season. We discuss these findings in the context of possible pest control strategies.


2021 ◽  
Vol 485 ◽  
pp. 118942
Author(s):  
Alberto Maceda-Veiga ◽  
Sergio Albacete ◽  
Miguel Carles-Tolrá ◽  
Juli Pujade-Villar ◽  
Jan Máca ◽  
...  

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Michelle T. Fountain ◽  
Amir Badiee ◽  
Sebastian Hemer ◽  
Alvaro Delgado ◽  
Michael Mangan ◽  
...  

Abstract Spotted wing drosophila, Drosophila suzukii, is a serious invasive pest impacting the production of multiple fruit crops, including soft and stone fruits such as strawberries, raspberries and cherries. Effective control is challenging and reliant on integrated pest management which includes the use of an ever decreasing number of approved insecticides. New means to reduce the impact of this pest that can be integrated into control strategies are urgently required. In many production regions, including the UK, soft fruit are typically grown inside tunnels clad with polyethylene based materials. These can be modified to filter specific wavebands of light. We investigated whether targeted spectral modifications to cladding materials that disrupt insect vision could reduce the incidence of D. suzukii. We present a novel approach that starts from a neuroscientific investigation of insect sensory systems and ends with infield testing of new cladding materials inspired by the biological data. We show D. suzukii are predominantly sensitive to wavelengths below 405 nm (ultraviolet) and above 565 nm (orange & red) and that targeted blocking of lower wavebands (up to 430 nm) using light restricting materials reduces pest populations up to 73% in field trials.


2021 ◽  
Author(s):  
Nikolay P. Kandul ◽  
Esther J. Belikoff ◽  
Junru Liu ◽  
Anna Buchman ◽  
Fang Li ◽  
...  

AbstractOriginally from Asia,Drosophila suzukii(Matsumura, 1931, Diptera:Drosophilidae) is presently a global pest of economically important soft-skinned fruits. Also commonly known as spotted wingDrosophila(SWD), it is largely controlled through repeated applications of broad-spectrum insecticides. There is a pressing need for a better understanding of SWD biology and for developing alternative environmentally-friendly methods of control. The RNA-guided Cas9 nuclease has revolutionized functional genomics and is an integral component of several recently developed genetic strategies for population control of insects. Here we have developed transgenic strains that encode three different terminators and four different promoters to express Cas9 in both the soma and/or germline of SWD. The Cas9 lines were evaluated through genetic crossing to transgenic lines that encode single guide RNAs targeting the conserved X-linkedyellowbody andwhiteeye genes. We find that several Cas9/gRNA lines display very high editing capacity. Going forward, these tools will be instrumental for evaluating gene function in SWD and may provide tools useful for the development of new genetic strategies for control of this invasive species.


2009 ◽  
Vol 19 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Filip Vandelook ◽  
Nele Bolle ◽  
Jozef A. Van Assche

AbstractA low-temperature requirement for dormancy break has been observed frequently in temperate-climate Apiaceae species, resulting in spring emergence of seedlings. A series of experiments was performed to identify dormancy-breaking requirements of Aegopodium podagraria, a nitrophilous perennial growing mainly in mildly shaded places. In natural conditions, the embryos in seeds of A. podagraria grow in early winter. Seedlings were first observed in early spring and seedling emergence peaked in March and April. Experiments using temperature-controlled incubators revealed that embryos in seeds of A. podagraria grow only at low temperatures (5°C), irrespective of a pretreatment at higher temperatures. Seeds did not germinate immediately after embryo growth was completed, instead an additional cold stratification period was required to break dormancy completely. Once dormancy was broken, seeds germinated at a range of temperatures. Addition of gibberellic acid (GA3) had a positive effect on embryo growth in seeds incubated at 10°C and at 23°C, but it did not promote germination. Since seeds of A. podagraria have a low-temperature requirement for embryo growth and require an additional chilling period after completion of embryo growth, they exhibit characteristics of deep complex morphophysiological dormancy.


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