scholarly journals Effects of Lecanicillium lecanii strain JMC-01 on the physiology, biochemistry, and mortality of Bemisia tabaci Q-biotype nymphs

PeerJ ◽  
2019 ◽  
Vol 7 ◽  
pp. e7690 ◽  
Author(s):  
Ting Xie ◽  
Ling Jiang ◽  
Jianshe Li ◽  
Bo Hong ◽  
Xinpu Wang ◽  
...  

Background Lecanicillium lecanii is an entomopathogenic fungi, which was isolated from insects suffering from disease. Now, it is an effective bio-control resource that can control agricultural pests such as whitefly and aphids. There are many studies on the control of various agricultural pests by L. lecanii, but no report on its control of Bemisia tabaci biotype-Q exists. In this work, we studied the susceptibility of B. tabaci Q-biotype (from Ningxia, China) to L. lecanii JMC-01 in terms of nymph mortality and the changes in detoxifying protective enzymes activities. Methods B. tabaci nymphs were exposed to L. lecanii JMC-01 conidia by immersion with the host culture. Mortality was assessed daily for all nymph stages. The detoxifying and protective enzyme activity changes, weight changes, and fat, and water contents of the nymphs were determined spectrophotometrically. Results All instars of B. tabaci died after being infested with 1 × 108 conidia/mL. The 2nd-instar nymphs were the most susceptible, followed by the 3rd-instar nymphs. The corrected cumulative mortality of the 2nd- and 3rd-instar nymphs was 82.22% and 75.55%, respectively. The levels of detoxifying and protective enzymes initially increased and then decreased. The highest activities of carboxylesterase, acetylcholinesterase, peroxidase, and catalase occurred on the 3rd day, reaching 10.5, 0.32, 20, and 6.3 U/mg prot, respectively. These levels were 2.2-, 4.3-, 2.4-, and 1.4-fold the control levels, respectively. The highest activities of glutathione-S transferase and superoxide dismutase on the 2nd day were, respectively, 64 and 43.5 U/mg prot. These levels were, respectively, 2.7 and 1.1-fold that of the control level. The water and fat content in the infected B. tabaci nymphs decreased and differed significantly from the control levels. The weight increased continuously in the first 24 h, decreasing thereafter. At 72 h, the infestation level was about 0.78-fold that of the control level. Conclusions The studied L. lecanii JMC-01 strain is pathogenic to the B. tabaci Q-biotype. This strain interferes with the normal functioning of detoxifying and protective enzymes, and is also involved in the disruption of normal physiological metabolism in B. tabaci.

2019 ◽  
Author(s):  
Ting Xie ◽  
Ling Jiang ◽  
Jianshe Li ◽  
Bo Hong ◽  
Xinpu Wang ◽  
...  

Background. Lecanicillium lecanii is an entomopathogenic fungi, which was isolated from insect suffer from a disaster. Now, it is an effective bio-control resource that can control agricultural pests such as whitefly and aphids. There are many studies on the control of various agricultural pests by L. lecanii, but no report on its control of Bemisia tabaci biotype-Q exists. In this work we studied the susceptibility of B. tabaci Q-biotype (from Ningxia, China) to L. lecanii JMC-01 in terms of nymph mortality and the changes in detoxifying protective enzymes activities. Methods. Bemisia tabaci nymphs were exposed to L. lecanii JMC-01 conidia by immersion with the host culture. Mortality was assessed daily for all nymph stages. The detoxifying and protective enzyme activity changes, weight changes, and fat, and water contents of the nymphs were determined spectrophotometrically. Results. All instars of B. tabaci died after being infested with 1×108 conidia/mL. The 2nd-instar nymphs were the most susceptible, followed by the 3rd-instar nymphs. The corrected cumulative mortality of the 2nd- and 3rd-instar nymphs was 82.22% and 75.55%, respectively. The levels of detoxifying and protective enzymes initially increased and then decreased. The highest activities of carboxylesterase (CarE), acetylcholinesterase (AchE), peroxidase (POD), and catalase (CAT) occurred on the 3rd day, reaching 10.5 U/mg prot, 0.32 U/mg prot, 20 U/mg prot, and 6.3 U/mg prot, respectively. These levels were 2.2-fold, 4.3-fold, 2.4-fold, and 1.4-fold the control levels, respectively. The highest activities of glutathione-S transferase (GSTs) and superoxide dismutase (SOD) on the 2nd day were, respectively, 64 U/mg prot and 43.5 U/mg prot. These levels were, respectively, 2.7-fold and 1.1-fold that of the control level. The water and fat content in the infected B. tabaci nymphs decreased and differed significantly from the control levels. The weight increased continuously in the first 24 h, decreasing thereafter. At 72 h, the infestation level was about 0.78-fold that of the control level. Conclusions. The studied L. lecanii JMC-01 strain is pathogenic to the B. tabaci Q-biotype. This strain interferes with the normal functioning of detoxifying and protective enzymes, and is also involved in the disruption of normal physiological metabolism in B. tabaci.


2019 ◽  
Author(s):  
Ting Xie ◽  
Ling Jiang ◽  
Jianshe Li ◽  
Bo Hong ◽  
Xinpu Wang ◽  
...  

Background. Lecanicillium lecanii is an entomopathogenic fungi, which was isolated from insect suffer from a disaster. Now, it is an effective bio-control resource that can control agricultural pests such as whitefly and aphids. There are many studies on the control of various agricultural pests by L. lecanii, but no report on its control of Bemisia tabaci biotype-Q exists. In this work we studied the susceptibility of B. tabaci Q-biotype (from Ningxia, China) to L. lecanii JMC-01 in terms of nymph mortality and the changes in detoxifying protective enzymes activities. Methods. Bemisia tabaci nymphs were exposed to L. lecanii JMC-01 conidia by immersion with the host culture. Mortality was assessed daily for all nymph stages. The detoxifying and protective enzyme activity changes, weight changes, and fat, and water contents of the nymphs were determined spectrophotometrically. Results. All instars of B. tabaci died after being infested with 1×108 conidia/mL. The 2nd-instar nymphs were the most susceptible, followed by the 3rd-instar nymphs. The corrected cumulative mortality of the 2nd- and 3rd-instar nymphs was 82.22% and 75.55%, respectively. The levels of detoxifying and protective enzymes initially increased and then decreased. The highest activities of carboxylesterase (CarE), acetylcholinesterase (AchE), peroxidase (POD), and catalase (CAT) occurred on the 3rd day, reaching 10.5 U/mg prot, 0.32 U/mg prot, 20 U/mg prot, and 6.3 U/mg prot, respectively. These levels were 2.2-fold, 4.3-fold, 2.4-fold, and 1.4-fold the control levels, respectively. The highest activities of glutathione-S transferase (GSTs) and superoxide dismutase (SOD) on the 2nd day were, respectively, 64 U/mg prot and 43.5 U/mg prot. These levels were, respectively, 2.7-fold and 1.1-fold that of the control level. The water and fat content in the infected B. tabaci nymphs decreased and differed significantly from the control levels. The weight increased continuously in the first 24 h, decreasing thereafter. At 72 h, the infestation level was about 0.78-fold that of the control level. Conclusions. The studied L. lecanii JMC-01 strain is pathogenic to the B. tabaci Q-biotype. This strain interferes with the normal functioning of detoxifying and protective enzymes, and is also involved in the disruption of normal physiological metabolism in B. tabaci.


2020 ◽  
Vol 110 (4) ◽  
pp. 487-496 ◽  
Author(s):  
Vinicius Henrique Bello ◽  
Luís Fernando Maranho Watanabe ◽  
Lucas Machado Fusco ◽  
Bruno Rossitto De Marchi ◽  
Felipe Barreto da Silva ◽  
...  

AbstractThe whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae), is one of the most important agricultural pests and virus vectors worldwide. Bemisia tabaci is considered a complex of cryptic species with at least 44 species. Among them, the species Middle East-Asia Minor 1 (MEAM1, formerly B biotype) and Mediterranean (MED, formerly Q biotype) are the most important, and they have attained global status. In Brazil, MEAM1 was first reported in the 1990s and is currently the predominant species in the country, meanwhile, MED was recently reported in the South and Southeast regions and was found to be mainly associated with ornamental plants. Currently, an increasing problem in the management of whitefly infestations in greenhouses associated with bell pepper was observed in São Paulo State, Brazil. The whiteflies were collected and identified based on a microsatellite locus (primer pair BEM23F and BEM23R) and the mitochondrial cytochrome oxidase I gene followed by restriction fragment length polymorphism analysis and sequencing. We observed that MED was the predominant species collected on bell pepper, but it was also found on tomato, cucumber, eggplant, and weeds grown in greenhouses. In open field, we found MED on tomatoes, bell peppers, and eggplants. In addition, MED was identified in Goiás State in association with ornamental plants. The begomovirus Tomato severe rugose virus and the crinivirus Tomato chlorosis virus was detected on bell pepper and tomato, respectively. Only MED specimens were found associated with the virus-infected plants. Moreover, we also investigated the endosymbionts present in the MED whiteflies. The collected populations of B. tabaci MED harbored a diversity of secondary endosymbionts, with Hamiltonella (H) found predominantly in 89 specimens of the 129 tested. These results represent a new concern for Brazilian agriculture, especially for the management of the newly introduced whitefly MED species, which must be implemented to limit the spreading and establishment of this pest in different crops in this country.


2005 ◽  
Vol 95 (1) ◽  
pp. 29-35 ◽  
Author(s):  
H. Delatte ◽  
B. Reynaud ◽  
M. Granier ◽  
L. Thornary ◽  
J.M. Lett ◽  
...  

AbstractFollowing the first detection of tomato yellow leaf curl virus (TYLCV) from R=union (700 km east of Madagascar) in 1997 and the upsurge of Bemisia tabaci (Gennadius) on vegetable crops, two genetic types of B. tabaci were distinguished using RAPD–PCR and cytochrome oxidase I (COI) gene sequence comparisons. One type was assigned to biotype B and the other was genetically dissimilar to the populations described elsewhere and was named Ms, after the Mascarenes Archipelago. This new genetic type forms a distinct group that is sister to two other groups, one to which the B biotype is a member and one to which the Q biotype belongs. The Ms biotype is thought to be indigenous to the region as it was also detected in Mauritius, the Seychelles and Madagascar. Both B and Ms populations of B. tabaci induced silverleaf symptoms on Cucurbita sp., and were able to acquire and transmit TYLCV. Taken together these results indicate that the Ms genetic type should be considered a new biotype of B. tabaci.


2009 ◽  
Vol 51 ◽  
pp. 75-77 ◽  
Author(s):  
Hiroyuki Iida ◽  
Toshio Kitamura ◽  
Ken-ichiro Honda ◽  
Yasuhiro Mizusawa ◽  
Shigeru Kamata ◽  
...  
Keyword(s):  

Insects ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 115 ◽  
Author(s):  
Nicholas Johnston ◽  
Xavier Martini

The silverleaf whitefly, Bemisia tabaci, is one of the most destructive agricultural pests in the world, vectoring a large number of devastating viruses, including Tomato Yellow Leaf Curl Virus (TYLCV). When selecting a host, B. tabaci is primarily influenced by a range of visual and olfactory cues. Therefore, elucidating how such cues become modified in the presence of whitefly-vectored begomoviruses is critical to better understanding the epidemiology of many economically important diseases. The goal of this study was to determine how both visual and odor cues interact in the presence of TYLCV. In Y-tube olfactometer assays, whiteflies were submitted to a range of isolated visual and olfactory cues to determine behavioral changes. B. tabaci choices were then compared to both stimuli combined in the presence or absence of TYLCV. Under visual stimuli only, B. tabaci exhibited a visual attraction to the color yellow, TYLCV-infected tomato leaves, and TYLCV-infected tomato volatiles. Attraction was the strongest overall when both visual and olfactory cues from TYLCV-symptomatic tomato plants were combined, as opposed to a single isolated cue. These results highlight the importance of both sensory stimuli during B. tabaci host selection in the presence of an associated begomovirus.


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