scholarly journals Modelling Drosophila suzukii Adult Male Populations: A Physiologically Based Approach with Validation

Insects ◽  
2020 ◽  
Vol 11 (11) ◽  
pp. 751
Author(s):  
Luca Rossini ◽  
Mario Contarini ◽  
Federica Giarruzzo ◽  
Matteo Assennato ◽  
Stefano Speranza

The Spotted Wing Drosophila (SWD), Drosophila suzukii (Matsumura), is a harmful insect pest for soft fruit cultivations. Even though its main hosts belong to the genera Prunus and Rubus, its high polyphagy and adaptability to new environments makes it a serious problem for farmers worldwide, who have reported several economic losses because of this pest. A wide series of proposals to control SWD are available and operate in line with the mechanisms of integrated pest management, demonstrating their high efficiency when applied at the opportune moment. This work aims to apply and validate a physiologically based model which summarises all the available information about D. suzukii biology, such as the relationship between environmental temperature and its development, fertility and mortality rates. The model provided, as a result, a description of a population of SWD females taking into consideration the multiple generations that occurred during the year. Simulations were then compared with field data collected in a three-year survey in two experimental fields located in the Sabina Romana area (Lazio, Italy). More specifically, D. suzukii males were monitored with traps in fields cultivated with mixed varieties of cherries and they were selected because of their clearer identification in comparison to females. Results showed a high level of reliability of simulations in representing the field data, highlighting at the same time that there is no discrepancy in simulating D. suzukii females in order to represent male populations.

2020 ◽  
Vol 113 (3) ◽  
pp. 1097-1104 ◽  
Author(s):  
Marysol Aceituno-Medina ◽  
Alicia Ordoñez ◽  
Morfa Carrasco ◽  
Pablo Montoya ◽  
Emilio Hernández

Abstract The spotted wing drosophila, Drosophila suzukii Matsumura, has emerged as a major invasive insect pest of small and stone fruits in both the Americas and Europe in the last decade. Females oviposit in ripening fruit, and significant economic losses can occur. Control measures are mainly associated with the use of pesticides, but the sterile insect technique (SIT), an ecologically friendly pest-specific method, could be used against this species. The objective of this study was to estimate the mass rearing, quality control parameters, and bioconversion using four artificial larval diets and their economic aspects oriented to the SIT application. Diets were based on the combination of coconut fiber, corncob powder, Brewer’s and Torula yeast and were used as oviposition substrate and larval development. We found that a life cycle is completed in 10.19 ± 0.35 d and that adults live an average of 33.67 ± 0.76 d. The highest number of pupae per gram of diet and the maximum bioconversion (6%) were associated with flies developed in the coconut fiber + Brewer’s yeast diet. Under our conditions, the establishment of D. suzukii required at least four generations. The use of 30 × 40 × 30 cm Plexiglas cages, each loaded with 5,000 adults and stocked with 500 g of coconut fiber and Brewer’s yeast diet distributed in 15 × 5 × 10 cm plastic trays with a diet layer 3-cm thick, allows a minimum production of 84,000 pupae of D. suzukii per day.


2020 ◽  
Vol 13 ◽  
pp. e898
Author(s):  
Léo Rodrigo Ferreira Louzeiro ◽  
Miguel Francisco Souza-Filho ◽  
Adalton Raga ◽  
Carla A. Bulgarelli ◽  
Louis Bernard Klaczko

Females of Drosophila suzukii Matsumura (Diptera: Drosophilidae) have a serrated ovipositor that causes severe physical damage to soft fruit. This behaviour results in the early ripening and accelerated rotting of infested fruit. In addition, feeding by larvae softens of the fruit peel, causing in a depreciation in commercial value. In this study, results of infestation indices, pupal viability, egg-adult period, degradation time of infested fruit, and description of physical injuries caused by oviposition and larval feeding of D. suzukii in Barbados cherries (Malpighia emarginata DC., Malpighiaceae) are described. Overall, our results and discussion contribute to the understanding of the status of D. suzukii as an insect pest of the Barbados cherry.


Agronomy ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 937
Author(s):  
Francisco Javier López-Moreno ◽  
Santiago Atero-Calvo ◽  
Eloy Navarro-León ◽  
Begoña Blasco ◽  
Teresa Soriano ◽  
...  

Green asparagus (Asparagus officinalis L.) is a widely grown and consumed crop which provides high-level nutritional interest. In recent years, the decline syndrome in asparagus plantations has been rapidly augmenting. This syndrome causes the early death of whole plants, also negatively affecting the new replanting. Decline causes notable economic losses in the sector. The objective of this work was to verify the effect of different treatments against asparagus decline syndrome on the physiological parameters and nutritional quality of the spears. To meet the objective, four different treatments were applied to asparagus plots strongly affected by decline syndrome: (T1) untreated control soil, (T2) biofumigation with Brassica pellets, (T3) biofumigation with chicken manure pellets, and (T4) disinfestation of the soil with Dazomet. The cumulative yield and physiological and quality parameters of green asparagus spears were studied. Thus, malondialdehyde (MDA), photosynthetic pigments, glutathione (GSH), ascorbate (AsA), total phenols, flavonoids, anthocyanin, antioxidant test, mineral nutrients, and the amino acid profile were measured on asparagus spears. The results showed that the Brassica pellets and Dazomet treatments were the most effective against the damage caused by the decline syndrome. However, it would be necessary to monitor the evolution in the following years.


2021 ◽  
Vol 22 (9) ◽  
pp. 5027
Author(s):  
Changwei Gong ◽  
Xinge Yao ◽  
Qunfang Yang ◽  
Xuegui Wang ◽  
Yuming Zhang ◽  
...  

Spodopteraexigua, a multifeeding insect pest, has developed a high level of resistance to chlorantraniliprole, which is a benzoylurea insecticide that targets the ryanodine receptors (RyRs). Herein, the resistant strain (SE-Sel) and sensitive strain (SE-Sus) were obtained by bidirectional screening for six generations. The potential oviposited eggs and oviposition rate of the SE-Sel strain were dramatically lower than those of the SE-Sus strain; on the contrary, the weights of prepupae and preadult were significantly increased. As a post-mating response, the higher number of non-oviposited eggs in the SE-Sel strain was caused by a lower mating rate. In addition, the expression levels of vitellogenin (SeVg) and its receptor (SeVgR) in the SE-Sel strain were consistently lower than those in the SE-Sus strain. An RyRI4743M mutation, contributing to the resistance to chlorantraniliprole, was located in the S3 transmembrane segments and might have affected the release of calcium ions; it led to the upregulated expression of the neuropeptide SeNPF and its receptor SeNPFR, and the mating and oviposition rate were significantly recovered when the SeNPF was knocked down though RNA interference (RNAi) in the male adult of the SE-Sel strain. Moreover, the expression of the juvenile hormone-binding proteins SeJHBWDS3 and SeJHBAN in the male adult of the SE-Sel strain was significantly decreased, which proved the existence of a fitness cost from another angle. Therefore, these results indicate that the fitness cost accompanied by chlorantraniliprole resistance in S. exigua may be related to the decrease in mating desire due to SeNPF overexpression.


2021 ◽  
Vol 11 (15) ◽  
pp. 6831
Author(s):  
Yue Chen ◽  
Jian Lu

With the rapid development of road traffic, real-time vehicle counting is very important in the construction of intelligent transportation systems (ITSs). Compared with traditional technologies, the video-based method for vehicle counting shows great importance and huge advantages in its low cost, high efficiency, and flexibility. However, many methods find difficulty in balancing the accuracy and complexity of the algorithm. For example, compared with traditional and simple methods, deep learning methods may achieve higher precision, but they also greatly increase the complexity of the algorithm. In addition to that, most of the methods only work under one mode of color, which is a waste of available information. Considering the above, a multi-loop vehicle-counting method under gray mode and RGB mode was proposed in this paper. Under gray and RGB modes, the moving vehicle can be detected more completely; with the help of multiple loops, vehicle counting could better deal with different influencing factors, such as driving behavior, traffic environment, shooting angle, etc. The experimental results show that the proposed method is able to count vehicles with more than 98.5% accuracy while dealing with different road scenes.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
R. Jones ◽  
M. T. Fountain ◽  
C. S. Günther ◽  
P. E. Eady ◽  
M. R. Goddard

AbstractDrosophila suzukii flies cause economic losses to fruit crops globally. Previous work shows various Drosophila species are attracted to volatile metabolites produced by individual fruit associated yeast isolates, but fruits naturally harbour a rich diversity of yeast species. Here, we report the relative attractiveness of D. suzukii to yeasts presented individually or in combinations using laboratory preference tests and field trapping data. Laboratory trials revealed four of 12 single yeast isolates were attractive to D. suzukii, of which Metschnikowia pulcherrima and Hanseniaspora uvarum were also attractive in field trials. Four out of 10 yeast combinations involving Candida zemplinina, Pichia pijperi, M. pulcherrima and H. uvarum were attractive in the laboratory. Whilst a combination of M. pulcherrima + H. uvarum trapped the greatest number of D. suzukii in the field, the efficacy of the M. pulcherrima + H. uvarum combination to trap D. suzukii was not significantly greater than traps primed with volatiles from only H. uvarum. While volatiles from isolates of M. pulcherrima and H. uvarum show promise as baits for D. suzukii, further research is needed to ascertain how and why flies are attracted to certain baits to optimise control efficacy.


2002 ◽  
Vol 70 (9) ◽  
pp. 4880-4891 ◽  
Author(s):  
Julia Eitel ◽  
Petra Dersch

ABSTRACT The YadA protein is a major adhesin of Yersinia pseudotuberculosis that promotes tight adhesion to mammalian cells by binding to extracellular matrix proteins. In this study, we first addressed the possibility of competitive interference of YadA and the major invasive factor invasin and found that expression of YadA in the presence of invasin affected neither the export nor the function of invasin in the outer membrane. Furthermore, expression of YadA promoted both bacterial adhesion and high-efficiency invasion entirely independently of invasin. Antibodies against fibronectin and β1 integrins blocked invasion, indicating that invasion occurs via extracellular-matrix-dependent bridging between YadA and the host cell β1 integrin receptors. Inhibitor studies also demonstrated that tyrosine and Ser/Thr kinases, as well as phosphatidylinositol 3-kinase, are involved in the uptake process. Further expression studies revealed that yadA is regulated in response to several environmental parameters, including temperature, ion and nutrient concentrations, and the bacterial growth phase. In complex medium, YadA production was generally repressed but could be induced by addition of Mg2+. Maximal expression of yadA was obtained in exponential-phase cells grown in minimal medium at 37°C, conditions under which the invasin gene is repressed. These results suggest that YadA of Y. pseudotuberculosis constitutes another independent high-level uptake pathway that might complement other cell entry mechanisms (e.g., invasin) at certain sites or stages during the infection process.


Vaccines ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 86
Author(s):  
Weiwei Zeng ◽  
Yingying Wang ◽  
Huzi Hu ◽  
Qing Wang ◽  
Sven M. Bergmann ◽  
...  

Tilapia lake virus (TiLV) is a newly emerging pathogen responsible for high mortality and economic losses in the global tilapia industry. Currently, no antiviral therapy or vaccines are available for the control of this disease. The goal of the present study was to evaluate the immunological effects and protective efficacy of formaldehyde- and β-propiolactone-inactivated vaccines against TiLV in the presence and absence of the Montanide IMS 1312 VG adjuvant in tilapia. We found that β-propiolactone inactivation of viral particles generated a vaccine with a higher protection efficacy against virus challenge than did formaldehyde. The relative percent survivals of vaccinated fish at doses of 108, 107, and 106 50% tissue culture infectious dose (TCID50)/mL were 42.9%, 28.5%, and 14.3% in the absence of the adjuvant and 85.7%, 64.3%, and 32.1% in its presence, respectively. The vaccine generated specific IgM and neutralizing antibodies against TiLV at 3 weeks following immunization that were significantly increased after a second booster immunization. The steady state mRNA levels of the genes tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interferon γ (IFN-γ), cluster of differentiation 4 (CD4), major histocompatibility complex (MHC)-Ia, and MHC-II were all increased and indicated successful immune stimulation against TiLV. The vaccine also significantly lowered the viral loads and resulted in significant increases in survival, indicating that the vaccine may also inhibit viral proliferation as well as stimulate a protective antibody response. The β-propiolactone-inactivated TiLV vaccine coupled with the adjuvant Montanide IMS 1312 VG and booster immunizations can provide a high level of protection from virus challenge in tilapia.


2020 ◽  
Vol 152 (4) ◽  
pp. 415-431
Author(s):  
Susanna Acheampong ◽  
Etienne Lord ◽  
D. Thomas Lowery

AbstractSpotted-wing drosophila, Drosophila suzukii, (Matsumura) (Diptera: Drosophilidae), has become a serious pest of soft fruit in the Okanagan Valley of British Columbia, Canada since its detection in 2009. The study was conducted to determine the distribution of D. suzukii and damage levels in grapes. Apple cider vinegar-baited traps placed in table and wine grape (Vitis vinifera Linnaeus; Vitaceae) vineyards during 2011–2013 demonstrated that D. suzukii was numerous in all sites, with earliest emergence and highest numbers recorded in 2013. Drosophila suzukii were reared from intact and damaged table grapes and damaged wine grapes collected from the field, but not from intact wine grapes. Drosophila suzukii were reared in low numbers in 2011 from intact fruit of 11 wine grape cultivars exposed artificially in the laboratory. Susceptibility of intact wine grapes under laboratory conditions in 2011 when sour rot was widespread might relate in part to undetected infections of berries due to weather conditions. Identification of Drosophila Fallén species revealed that D. suzukii comprised a small portion of the total. Our results demonstrate that healthy wine grapes in the Okanagan Valley of British Columbia are largely undamaged by D. suzukii, while certain table grape cultivars should be protected from attack.


Author(s):  
L. S. Pioro ◽  
I. L. Pioro

It is well known that high-level radioactive wastes (HLRAW) are usually vitrified inside electric furnaces. Disadvantages of electric furnaces are their low melting capacity and restrictions on charge preparation. Therefore, a new concept for a high efficiency combined aggregate – submerged combustion melter (SCM)–electric furnace was developed for vitrification of HLRAW. The main idea of this concept is to use the SCM as the primary high-capacity melting unit with direct melt drainage into an electric furnace. The SCM employs a single-stage method for vitrification of HLRAW. The method includes concentration (evaporation), calcination, and vitrification of HLRAW in a single-stage process inside a melting chamber of the SCM. Specific to the melting process is the use of a gas-air or gas-oxygen-air mixture with direct combustion inside a melt. Located inside the melt are high-temperature zones with increased reactivity of the gas phase, the existence of a developed interface surface, and intensive mixing, leading to intensification of the charge melting and vitrification process. The electric furnace clarifies molten glass, thus preparing the high-quality melt for subsequent melt pouring into containers for final storage.


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