scholarly journals Parental RNAi Silencing of the transformer-2 Gene in a Species of the Anastrepha fraterculus Complex of Cryptic Species (Diptera, Tephritidae)

2021 ◽  
Vol 13 (10) ◽  
pp. 70
Author(s):  
Pietro E. Vicari ◽  
Esther S. Chang ◽  
André L. P. Perondini ◽  
Denise Selivon

In genera Anastrepha, Bactrocera and Ceratitis of the tephritid fruit flies the auto-regulatory function of gene transformer is assumed to be activated by maternal derived mRNA or the proteins of the gene transformer (tra-2 mat) and transformer-2 (tra-2mat). However, this maternal effect was not yet been demonstrated. The objective of the present study was to test the effect of absence of tra-2mat in the eggs on the sex determination of A. sp.1 affinis fraterculus. This was achieved by silencing gene tra-2 in the parental females via the pRNA interference. The data showed that tra-2 was transiently silenced in the female for three weeks period. The progenies sex ratio produced by these females during the silencing of tra-2 depart from 1:1 in favor of males. The excess of males was due to the transformation of a fraction of genotypical female XX embryos into XX males, the so-called pseudomales, Individual F1 males from the offspring of treated females crossed to females from the stock, revealed that majority of them showed regular mating behavior and were fertile. However, no offspring was produced in the crosses by a fraction of males that have produced sperms, showed regular mating behavior but did not transfer sperms to the females. The data allow the conclusion that the absence of tra-2mat in the eggs had impaired the self-regulation of the embryonic gene tra resulting in the transformation of XX embryos into pseudomales and also that these pseudomales are sterile. This effect may be useful improve more sustainable technologies for fruit fly control such as SIT.

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Michael D. Ormsby

AbstractTephritid fruit flies (Diptera; Tephritidae) represent a group of insects that include some of the most economically important pests in horticulture. Because of their economic importance, the financial impacts of an incursion of tephritid fruit flies into a new area can often result in restrictions to trade. The economic impacts of any trade restrictions imposed by importing countries are confounded by the current absence of consistent and accepted criteria for the strength and extent of any trade restrictions and declaring the end of an incursion. The author has developed models that can be used to establish criteria for the management of tephritid fruit fly outbreaks as outlined in international standards. A model enables criteria on when to recognise an incursion has occurred and establish export restrictions. Another model determines what area or radius an export restriction zone (ERZ) should cover. And a third model establishes criteria for the conditions required to enable an ERZ to be rescinded and the area’s pest free status reinstated. The models rely primarily on fruit fly biology and the effectiveness of surveillance trapping systems. The adoption of these proposed criteria internationally for establishing a control system and responding to fruit fly outbreaks would provide considerable economic benefits to international trade. Additionally, these criteria would enable countries to make more informed cost–benefit decisions on the level of investment in fruit fly control systems that better reflects the economic risks fruit flies represent to their economy.


2000 ◽  
Vol 83 (3) ◽  
pp. 563-568
Author(s):  
Jocelyn P Alcantara-Licudine ◽  
Ngoc Lan Bui ◽  
Qing X Li ◽  
Grant T McQuate ◽  
Steven L Peck

Abstract Xanthene dyes, i.e., phloxine B and uranine or phloxine B alone, are phototoxic to tephritid fruit flies infesting guava fruits. An analytical method was developed for determination of residues of these dyes used in bait solutions for suppression of the tephritid fruit fly population in guava fruits. The procedure involved solvent extraction, anionexchange cleanup, and determination by liquid chromatography or capillary zone electrophoresis. The dyes were extracted from 50 g guava fruit at 45°C with 400 mL methanol–acetonitrile (1 + 1) and 5 g magnesium oxide added as an alkaline and clarifying agent. The guava extract was adjusted to pH 8.5 and subjected to an amino column cleanup. Average recoveries of xanthene dyes added to guava purees ranged from 77 to 99% for phloxine B and from 79 to 102% for uranine at spiking levels of 0.05–1.00 μg/g. The method was applied to the determination of phloxine B residues in guava fruits collected from a dye-sprayed orchard. After phloxine B was applied at a rate of 62.5 g/ha for 14 weekly sprayings, it was found on guava fruits at an average concentration of 111 ± 18 ng/g 4 h after the 11th spraying. The concentration of phloxine B was 426 ± 94 ng/g in selected fruits with high deposits of the dye 4 h after spraying. Average concentrations of phloxine B 5 days after the 7th and 14th sprayings were 29 ± 7 and 19 ± 8 ng/g, respectively.


1970 ◽  
pp. 01-04
Author(s):  
Esameldin B. M. Kabbashi, Ghada H. Abdelrahman and Nawal A. Abdlerahman

Guava (Psidium guajava L.) is a lovely tropical and subtropical fruit that originates in Mexico, Central America, and then taken to other distant and near parts around the world. In Sudan this popular fruit is produced in orchards and household and is so profitable but yet attacked by a lot of fruit fly species of the Genera Ceratitis and Bactrocera and the result is a loss of more than 70%. This research aimed at evaluating the effect of Gum Arabic coating (GAC) in extending the shelf life of guava fruit and disinfesting it from these notorious pests. Guava fruits from Kadaro orchards, Khartoum North, were tested using seven concentrations of Gum Arabic solutions. The results reflect that 1: 4 (25%) and 1: 8 (12.5%) (GA: water) concentrations attained 56 and 40% disinfestation, respectively whereas the other lower concentrations effected corresponding results in a range from 20 – 08%. The reduction in maggots per test fruit reached upto 188% as compared to the control.  The highest concentrations (1: 4 & 1: 8) effected a sustainability of 52% in fruit firmness (FF) with an average of medium (3) FF compared to soft FF (4) in the control. The corresponding results in other lower concentrations (1: 16; 1: 32; 1: 64; 1: 72 & 1: 96) were 36, 24, 24, 20 and 16%, respectively. In addition to an average FF of 4 (soft) for all these concentrations and 5 (very soft) for all the corresponding controls. Nevertheless, the sustainability of fruit color (FC) effected by the test concentrations was 52, 44, 24, 22, 24, 20, and 24%, respectively. Regarding these results, the two highest test concentrations effected a sizeable disinfestation and control of fruit flies and a good extension of shelf life of guava in Khartoum State. These findings support using this treatment as an effective IPM tool to extend guava fruit shelf life and upgrading its postharvest quality.


Author(s):  
Peter A Follett ◽  
Fay E M Haynes ◽  
Bernard C Dominiak

Abstract Tephritid fruit flies are major economic pests for fruit production and are an impediment to international trade. Different host fruits are known to vary in their suitability for fruit flies to complete their life cycle. Currently, international regulatory standards that define the likely legal host status for tephritid fruit flies categorize fruits as a natural host, a conditional host, or a nonhost. For those fruits that are natural or conditional hosts, infestation rate can vary as a spectrum ranging from highly attractive fruits supporting large numbers of fruit flies to very poor hosts supporting low numbers. Here, we propose a Host Suitability Index (HSI), which divides the host status of natural and conditional hosts into five categories based on the log infestation rate (number of flies per kilogram of fruit) ranging from very poor (<0.1), poor (0.1–1.0), moderately good (1.0–10.0), good (10–100), and very good (>100). Infestation rates may be determined by field sampling or cage infestation studies. We illustrate the concept of this index using 21 papers that examine the host status of fruits in five species of polyphagous fruit flies in the Pacific region: Bactrocera tryoni Froggatt, Bactrocera dorsalis (Hendel), Bactrocera latifrons (Hendel), Zeugodacus cucurbitae (Coquillett), and Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). This general-purpose index may be useful in developing systems approaches that rely on poor host status, for determining surveillance and detection protocols for potential incursions, and to guide the appropriate regulatory response during fruit fly outbreaks.


2015 ◽  
Vol 147 (6) ◽  
pp. 776-786 ◽  
Author(s):  
W.L. Yee

AbstractUnderstanding factors that influence attraction of tephritid fruit flies (Diptera: Tephritidae) to objects can lead to development of more sensitive traps for fly detection. Here, the objective was to determine if differences in attractiveness between two sticky yellow rectangle traps to western cherry fruit fly,Rhagoletis indifferensCurran, depend on ambient light intensity and direction. The translucent plastic Yellow Sticky Strip (YSS) was compared with the less translucent yellow cardboard Alpha Scents (AS). Flies were released inside a box or cage opposite a trap or traps illuminated from outside at different intensities to generate variable light passage. Regardless of type, the trap with greatest light passage was most attractive. When the same light intensity was shone on both traps, the YSS, which allowed greater light passage, was more attractive than the AS. When the light was inside a cage and shone onto the two traps in the same direction as approaching flies, the AS reflected more light and was more attractive. A field experiment generally supported light passage effects seen in the laboratory. Results suggest trap placement with respect to sunlight intensity and direction affects light passage and the attractiveness of yellow traps toR. indifferens.


2020 ◽  
Vol 73 (4) ◽  
pp. 737-742
Author(s):  
Valentina P. Trufanova ◽  
Olha V. Sheshukova ◽  
Natalia A. Lyakhova ◽  
Tetiana V. Polishchuk ◽  
Sofia S. Bauman ◽  
...  

The aim: To determine the structure of acute injuries of temporary and permanent frontal teeth in children, to analyze the applied diagnostic and treatment measures for acute tooth trauma and to investigate their effectiveness. Materials and methods: The subject of the study were 31 children aged 2-12 years with acute temporary and permanent tooth trauma. Methods: clinical (radiological, thermodiagnosis), medical and statistical. Results: The number of injured permanent teeth was greater than the number of injured temporary teeth. The pattern of temporary and permanent tooth injuries differed, so in temporary teeth dislocations were observed, and in permanent teeth fractures prevailed over dislocations. In our opinion, this is due to the peculiarities of the anatomy of the temporary teeth. Usually, the therapeutic tactics of acute temporary teeth injuries is to remove them, despite their important role in the growth and development of jaws, physiological formation and eruption of permanent teeth. The therapeutic tactics of dynamic observation in the case of intrusive dislocation of the temporary tooth were selected in the clinic of the Department of Pediatric Dentistry. In some cases, with a slight change in the position of the temporary tooth, self-regulation of its position was observed, in other cases the tooth remained dystopic, but its viability remained in 50% of cases. Therapeutic tactics of acute injuries of permanent teeth were selected according to the type of trauma. In the case of permanent tooth dislocation, with a slight change in its position, tooth immobilization was carried out by splinting with fiberglass tape and photopolymer composite material. Conclusions: Our observations have shown that the complex of modern specialized medical care for the affected children with acute traumatic injuries of the teeth should be guided by their preservation, which ensures the subsequent normal formation of the dental-jaw apparatus. To ensure these conditions, a long, reliable immobilization of the damaged tooth is required as soon as possible after injury.


Inclusion ◽  
2014 ◽  
Vol 2 (3) ◽  
pp. 175-194 ◽  
Author(s):  
Jean Ann Summers ◽  
Mary Jane Brotherson ◽  
Elizabeth J. Erwin ◽  
Susan P. Maude ◽  
Susan B. Palmer ◽  
...  

Abstract This study investigated families' perspectives about and strategies used to develop foundational skills (i.e., choice-making, self-regulation, and engagement) leading to the development of the self-determination of their young children with disabilities. Two research questions guided the study: (1) What do families believe is important when working with practitioners in partnership to build foundational skills leading to self-determination at home and school? (2) What do families think about providing opportunities for developing these skills, and how do they provide such opportunities? Qualitative data were collected through in-depth interviews and an open-ended online survey. Families reported a variety of strategies used to develop choice-making, self-regulation, and engagement skills. Results can assist early education service providers to better understand how families conceptualize choice-making, self-regulation, and engagement for their children to successfully build partnerships and engage families.


Author(s):  
Laura Corbin Frazier ◽  
Barbara Martin Palmer

This chapter provides a description of five models for professional development (PD) for online instruction and analyzes each model according to domains of effective online instruction (i.e., faculty stance, student self-regulation, faculty support, authentic practice, engagement, community development, and cognitive demand). Additionally, a decision model is provided for K-12 and university administrators, teacher educators, and policymakers to guide strategic decision making in the determination of a model for PD best suited to the needs and resources of their institution.


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