Gamma-Ray Irradiation Control of Whiteflies Bemisia tabaci (Hemiptera: Aleyrodidae) and Trialeurodes vaporariorum in the Exportation of Fresh Strawberries

2019 ◽  
Vol 112 (4) ◽  
pp. 1611-1617 ◽  
Author(s):  
Sun-Ran Cho ◽  
Hyun-Na Koo ◽  
Soeun Shin ◽  
Hyun Kyung Kim ◽  
Jong-Heum Park ◽  
...  

Abstract Whitefly pests, including the sweetpotato whitefly, Bemisia tabaci (Gennadius), and the greenhouse whitefly, Trialeurodes vaporariorum (Westwood), are economically important in agriculture. With the annual growth of the domestic fresh fruit export market, various quarantine treatment methods are being used to export strawberries of better quality. The objective of the present study was to evaluate the effects of gamma rays on the development and reproductive sterility of B. tabaci and T. vaporariorum. In both species, the eggs were completely inhibited from hatching at 50 Gy, and the emergence of third-instar nymphs was completely suppressed at 150 Gy. Some adult B. tabaci and T. vaporariorum spawning occurred at 100 and 70 Gy, respectively; however, at these irradiation levels, F1 hatchability was completely inhibited. Dosimetry results showed that the penetrating power of gamma ray in the strawberry-filled box was the lowest at the mid-box position. Therefore, B. tabaci and T. vaporariorum were placed in the middle of the strawberry-filled box and irradiated. A gamma-ray irradiation of 100 Gy suppressed the development and reproduction of eggs and adults in both B. tabaci and T. vaporariorum. Our data suggest that at least 100 Gy should be used for the control of these two species of whitefly for strawberry export.

1993 ◽  
Vol 28 (1) ◽  
pp. 126-135 ◽  
Author(s):  
T. X. Liu ◽  
R. D. Oetting ◽  
G. D. Buntin

The effects of three insecticides, bifenthrin, endosulfan and aldicarb, on the within- and between-plant distributions of both greenhouse whitefly (GHWF), Trialeurodes vaporariorum (Westwood), and sweetpotato whitefly (SPWF), Bemisia tabaci (Gennadius), were examined on greenhouse-grown poinsettia using Taylor's Power Law. Insecticide applications affected the spatial distribution of GHWF and SPWF. The populations of immatures of both species surviving an insecticide application on poinsettia were less aggregated within and between plants than untreated populations. Among the three insecticides, the efficacy against the two whiteflies was not significantly different at the end of the seventh week when multiple applications were conducted. Aldicarb caused higher mortality of immature stages than bifenthrin and endosulfan after four weeks following a single application. A single application of bifenthrin and endosulfan affected the distribution of all whitefly stages in the first and second weeks after treatment, whereas aldicarb did not affect the whitefly population until the third week. Insecticidal treatments had little effect on the stratification of whitefly stages within the plant.


1994 ◽  
Vol 29 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Tong-Xian Liu ◽  
Ronald D. Oetting ◽  
G. David Buntin

Patterns of diel flight activity of the greenhouse whitefly, Trialeurodes vaporariorum (Westwood), and sweetpotato whitefly, Bemisia tabaci (Gennadius), were investigated on poinsettia, Euphorbia pulcherrima Willd., and gerbera daisy, Gerbera jamesonii H. Bolus, under greenhouse and environmentally controlled conditions. Adult flight activity was monitored at 2-h intervals (from 0700 to 2100 h EST) at various heights using yellow sticky traps. Traps placed 5 cm above the top of the plant canopy caught more adults of both species than traps placed higher. The daily patterns of catches of T. vaporariorum and B. tabaci adults in the greenhouse were similar and were unimodal with peak catches occurring between 0900–1300 h. Numbers of adults caught on the sticky traps in the greenhouse were correlated with temperature and relative humidity for T. vaporariorum, but not for B. tabaci. Few adults were caught during the dark hours (from 2100 to 0700 h). Under constant temperatures of 20°, 25°, and 30°C, the flight activity patterns of both whitefly species were unimodal, with peak catches of T. vaporariorum and B. tabaci occurring in the morning and afternoon, respectively. Differences in temperature did not significantly alter the pattern of catches of adults on sticky traps. The lowest temperature for initiation of whitefly flight was 16–17°C for T. vaporariorum, and 17–18°C for B. tabaci.


Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 111 ◽  
Author(s):  
Jin-Oh Jeong ◽  
Jong-Seok Park ◽  
Young-Ah Kim ◽  
Su-Jin Yang ◽  
Sung-In Jeong ◽  
...  

Conducting polymer (CP)-based hydrogels exhibit the behaviors of bending or contraction/relaxation due to electrical stimulation. They are similar in some ways to biological organs and have advantages regarding manipulation and miniaturization. Thus, these hydrogels have attracted considerable interest for biomedical applications. In this study, we prepared PPy/PVP hydrogel with different concentrations and content through polymerization and cross-linking induced by gamma-ray irradiation at 25 kGy to optimize the mechanical properties of the resulting PPy/PVP hydrogel. Optimization of the PPy/PVP hydrogel was confirmed by characterization using scanning electron microscopy, gel fraction, swelling ratio, and Fourier transform infrared spectroscopy. In addition, we assessed live-cell viability using live/dead assay and CCK-8 assay, and found good cell viability regardless of the concentration and content of Py/pTS. The conductivity of PPy/PVP hydrogel was at least 13 mS/cm. The mechanical properties of PPy/PVP hydrogel are important factors in their application for biomaterials. It was found that 0.15PPy/PVP20 (51.96 ± 6.12 kPa) exhibited better compressive strength than the other samples for use in CP-based hydrogels. Therefore, it was concluded that gamma rays can be used to optimize PPy/PVP hydrogel and that biomedical applications of CP-based hydrogels will be possible.


2018 ◽  
Vol 53 ◽  
pp. 01007
Author(s):  
Yinghong Zuo ◽  
Maoyu Zhang ◽  
Guoxin Cheng ◽  
Shengli Niu

To obtain the transient current response law of the metal component irradiated by pulsed gamma rays, the pulsed gamma ray irradiation experiment of the iron plate was carried out on “Qiangguang-I” accelerator. The transient current of iron plate generated by pulsed gamma rays was measured and analysed, and the relationship between the amplitude of pulse current and the dose rate of gamma rays was obtained. The results show that the current response sensitivity of the iron plate is about 5.7×10-7(A/m2)/(Gy/s) when the gamma rays with the energy of 0.8 MeV irradiate the iron plate. The charge deposition rate in the iron plate can be obtained by Monte Carlo simulation, and then it can be converted to gamma ray induced current of the metal component irradiated by gamma rays.


2008 ◽  
Vol 600-603 ◽  
pp. 707-710
Author(s):  
Shigeomi Hishiki ◽  
Naoya Iwamoto ◽  
Takeshi Ohshima ◽  
Hisayoshi Itoh ◽  
Kazu Kojima ◽  
...  

The effect of the fabrication process of n-channel 6H-SiC MOSFETs on their radiation resistance is investigated. MOSFETs that post implantation annealing for source and drain was carried out with carbon coating on the sample surface are compared to MOSFETs that post implantation annealing was carried out without carbon coating. The radiation resistance (gamma-rays) of the carbon-coated MOSFETs is higher than that of non-coated ones. The channel mobility for MOSFETs whose gate oxide was formed using pyrogenic or dry oxidation process dose not change by gamma-ray irradiation below 1x105 Gy. The value of channel mobility slightly increases with increasing dose above 1x105 Gy. No significant increase in irradiation induced interface traps is observed.


2011 ◽  
Vol 679-680 ◽  
pp. 362-365 ◽  
Author(s):  
Takeshi Ohshima ◽  
Naoya Iwamoto ◽  
Shinobu Onoda ◽  
Takahiro Makino ◽  
Shinji Nozaki ◽  
...  

Charge induced in 6H-SiC nMOS capacitors by 15 MeV oxygen ion microbeams was measured using Transient Ion Beam Induced Current (TIBIC) before and after gamma-ray irradiations. The peak amplitude of TIBIC signals decreases and the fall time increases with increasing number of incident ions. The decrease in the TIBIC peak eventually saturated. The TIBIC signal can be refreshed to its original shape by applying a positive bias of + 1V to gate oxide. Small decrease in both the peak amplitude of TIBIC signal and collected charge was observed due to gamma-ray irradiation.


1993 ◽  
Vol 28 (1) ◽  
pp. 102-112 ◽  
Author(s):  
Tong-Xian Liu ◽  
Ronald D. Oetting ◽  
G. David Buntin

The within-plant and between-plant distributions of all stages of both greenhouse whitefly (GHWF), Trialeurodes vaporariorum (Westwood) on poinsettia, chrysanthemum and gerbera daisy, and sweetpotato whitefly (SPWF), Bemisia tabaci (Gennadius) on poinsettia, were examined using Taylor's power law (s2 = amb) and Iwao's patchiness () methods. We found that all developmental stages of the two whitefly species on all plants examined were aggregated within and between plants. The vertical distribution of whitefly stages is stratified among leaves within the plant with respect to leaf age rather than relative height of the leaves on the plants. Most of the adults, eggs and the first-instar nymphs occurred on young leaves. The second- and third-instar nymphs occurred on middle-aged leaves, and most of the pupae and empty pupal cases occurred on middle-aged and older leaves. Comparison of whitefly counts from the different combinations of top, middle, and bottom leaves with the whole-plant counts on poinsettia was correlated and these leaves can be sampled as an indication of population levels within a greenhouse population.


Pastura ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 1
Author(s):  
Prihantoro, I. ◽  
Anandia, A. ◽  
Aryanto, A. T. ◽  
Setiana, M. A. ◽  
Karti, P. D. M. H.

Alfalfa (Medicago sativa L.) a high nutritious and palatability legume for ruminant. Constrain of alfalfa availability in Indonesia are due to the plant adaptability in tropical environment. Aim of the study was to measure the adaptation level of alfalfa that irradiated with gamma rays on a field scale. The study consisted of four types of plant sources, mutation plants with different gamma ray levels (0Gy, 200Gy, 300Gy and 400Gy). Plant tillers was analyzed with a complete randomized design with 3 replications, 20 plants per replication. Growth capability, leaf color, flowering time and pest attack level were analyzed descriptively. The results showed that alfalfa irradiated with 300 Gy significantly (p<0.05) produced highest tillers. Irradiated 300 Gy plant gave better result on growth capability, flowering capability, and number of not attack plant from pests. The higher level of gamma ray irradiation showed the changed in leaf color levels from dark green to light green. Keywords: alfalfa (Medicago sativa L.), mutation, gamma ray irradiation, field scale


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