scholarly journals Long-Term Suppressive Effect of Buprofezin on Population Growth of the Greenhouse Whitefly, Trialeurodes vaporariorum(WESTWOOD)(Homoptera:Aleyrodidae)

1991 ◽  
Vol 26 (2) ◽  
pp. 271-274 ◽  
Author(s):  
Michihiro YASUI ◽  
Tetsuyosi NISHIMATU ◽  
Minoru FUKADA ◽  
Sadafumi MAEKAWA
2013 ◽  
Vol 28 (4) ◽  
pp. 239-245 ◽  
Author(s):  
Mirjana Prijovic ◽  
Dejan Marcic ◽  
Tanja Drobnjakovic ◽  
Irena Medjo ◽  
Pantelija Peric

The effects of five tomato genotypes (cv. Narvik and hybrids NS-6, Tamaris, Alliance and Marko) on the survival, reproduction, development and population growth of the greenhouse whitefly Trialeurodes vaporariorum were examined. A laboratory population of T. vaporariorum had been reared on tobacco plants for three years before the study. Females that laid eggs on the genotype Marko lived significantly longer and their offspring needed significantly shorter periods to develop than females on the genotype Narvik. The highest gross and net fecundity rates were found in females on the genotype Marko (36.74 eggs/ female and 27.93 eggs/female, respectively) and they differed significantly from the corresponding rates of females living on the genotype NS-6 (18.55 eggs/female and 15.33 eggs/ female), who had the lowest fecundity rates. The highest gross and net fertility rates were also found in females on the genotype Marko (31.24 adults/female and 23.73 adults/female), and they were significantly higher than those of females living on NS-6 (14.85 adults/female and 12.53 adults/female). Besides, net fertility rate of the females living on the genotype Narvik (13.80 adults/female) was also significantly lower than the rate of females on Marko. The instantaneous rates of increase showed no significant difference over a 10-day interval following the start of oviposition, while the increase rate was significantly higher on the genotype Marko after 12, 14 and 16 days, compared to the genotype NS-6. Eighteen, 20 and 22 days after the beginning of oviposition, the instantaneous rate of increase on the genotype Marko was significantly higher than it was on NS-6 and Narvik. Our data provide a basis for further research aiming to improve programs of integrated management of greenhouse whitefly.


Euphytica ◽  
2021 ◽  
Vol 217 (3) ◽  
Author(s):  
Joris Santegoets ◽  
Marcella Bovio ◽  
Wendy van’t Westende ◽  
Roeland E. Voorrips ◽  
Ben Vosman

AbstractThe greenhouse whitefly Trialeurodes vaporariorum is a major threat in tomato cultivation. In greenhouse grown tomatoes non-trichome based whitefly resistance may be better suited than glandular trichome based resistance as glandular trichomes may interfere with biocontrol, which is widely used. Analysis of a collection of recombinant inbred lines derived from a cross between Solanum lycopersicum and Solanum galapagense showed resistance to the whitefly T. vaporariorum on plants without glandular trichomes type IV. The resistance affected whitefly adult survival (AS), but not oviposition rate. This indicates that S. galapagense, in addition to trichome based resistance, also carries non-trichome based resistance components. The effectiveness of the non-trichome based resistance appeared to depend on the season in which the plants were grown. The resistance also had a small but significant effect on the whitefly Bemisia tabaci, but not on the thrips Frankliniella occidentalis. A segregating F2 population was created to map the non-trichome based resistance. Two Quantitative trait loci (QTLs) for reduced AS of T. vaporariorum were mapped on chromosomes 12 and 7 (explaining 13.9% and 6.0% of the variance respectively). The QTL on chromosome 12 was validated in F3 lines.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Valeria Fattoruso ◽  
Gianfranco Anfora ◽  
Valerio Mazzoni

AbstractThe greenhouse whitefly (GW), Trialeurodes vaporariorum is considered one of the most harmful insect pests in greenhouses worldwide. The GW mating behavior has been partially investigated and its vibrational communication is only in part known. A deeper knowledge of its intraspecific communication is required to evaluate the applicability of control methods based on techniques of behavioral manipulation. In this study, for the first time, we provided a detailed ethogram of the GW mating behavior and we characterized the vibrational signals emitted during the process of pair formation. We characterized two types of male vibrational emissions (“chirp” and “pulses”), differently arranged according to the behavioral stage to form stage-specific signals, and a previously undescribed Male Rivalry Signal. We recorded and characterized two new female signals: The Female Responding Signal and the Female Rejective Signal. The mating behavior of GW can be divided into six different stages that we named “call”, “alternated duet”, “courtship”, “overlapped duet”, “mating”, “failed mating attempt”. The analysis performed with the Markovian behavioral transition matrix showed that the “courtship” is the key stage in which male exhibits its quality and can lead to the “overlapped duet” stage. The latter is strictly associated to the female acceptance and therefore it plays a crucial role to achieve mating success. Based on our findings, we consider the use of vibrational playbacks interfering with GW mating communication a promising option for pest control in greenhouses. We discuss the possibility to start a research program of behavioral manipulation to control the populations of GW.


2021 ◽  
pp. 002200272110411
Author(s):  
Vincent Bauer ◽  
Michael Reese ◽  
Keven Ruby

Scholars of civil wars have long argued that non-state actors can use selective punishment to reduce collaboration with state adversaries. However, there is little systematic evidence confirming this claim, nor investigation into the mechanisms at play. In this paper, we provide such evidence from the drone war in Pakistan. Militants in Pakistan’s tribal areas engaged in a brutal counterespionage campaign with the aim of reducing collaboration with the United States. Our analysis combines a novel dataset of collaborator killings with data on drone strike outcomes. We find that strikes killed half as many militant leaders and fighters following collaborator killings and that this suppressive effect likely works by deterring spying in the future. Beyond providing an empirical confirmation of the selective punishment hypothesis, our paper suggests an unacknowledged vulnerability of the drone program to reprisals against local allies and collaborators that limits its effectiveness as a long-term tool of counterterrorism.


2015 ◽  
Vol 42 (2) ◽  
pp. 185 ◽  
Author(s):  
Lise Ruffino ◽  
Diane Zarzoso-Lacoste ◽  
Eric Vidal

Bird conservation is nowadays a strong driving force for prioritising rodent eradications, but robust quantitative estimates of impacts are needed to ensure cost-effectiveness of management operations. Here, we review the published literature to investigate on what methodological basis rodent effects on island bird communities have been evaluated for the past six decades. We then discuss the advantages and limitations of each category of methods for the detection and quantification of impacts, and end with some recommendations on how to strengthen current approaches and extend our knowledge on the mechanisms of impacts. Impact studies (152 studies considered) emphasised seabirds (67%), black rats (63%) and the Pacific Ocean (57%). Among the most commonly used methods to study rodent impacts on birds were the observation of dead eggs or empty nests while monitoring bird breeding success, and the analyses of rodent diets, which can both lead to misleading conclusions if the data are not supported by direct field evidence of rodent predation. Direct observations of rodent–bird interactions (19% of studies) are still poorly considered despite their potential to reveal cryptic behaviours and shed light on the mechanisms of impacts. Rodent effects on birds were most often measured as a change or difference in bird breeding parameters (74% of studies), while estimates of bird population growth rates (4%) are lacking. Based on the outcomes of this literature review, we highlight the need for collecting unbiased population-level estimates of rodent impacts, which are essential prerequisites for predicting bird population growth scenarios and prioritising their conservation needs. This could be achieved by a more systematic integration of long-term monitoring of bird populations into rodent management operations and modelling bird population dynamics. We also strongly recommend including various complementary methods in impact assessment strategies to unravel complex interactions between rodents and birds and avoid faulty evidence. Finally, more research should be devoted to a better understanding of the cases of non-impacts (i.e. long-term coexistence) and those impacts mediated by mechanisms other than predation and ecosystem-level processes.


2000 ◽  
Vol 84 (3) ◽  
pp. 1279-1288 ◽  
Author(s):  
Kuei-Sen Hsu ◽  
Wen-Chia Ho ◽  
Chiung-Chun Huang ◽  
Jing-Jane Tsai

Previous work has shown that seizure-like activity can disrupt the induction of long-term potentiation (LTP). However, how seizure-like event disrupts the LTP induction remains unknown. To understand the cellular and molecular mechanisms underlying this process better, a set of studies was implemented in area CA1 of rat hippocampal slices using extracellular recording methods. We showed here that prior transient seizure-like activity generated by perfused slices with Mg2+-free artificial cerebrospinal fluid (ACSF) exhibited a persistent suppression of LTP induction. This effect lasted between 2 and 3 h after normal ACSF replacement and was specifically inhibited by N-methyl-d-aspartate (NMDA) receptor antagonistd-2-amino-5-phosphovaleric acid (d-APV) and L-type voltage-operated Ca2+ channel (VOCC) blocker nimodipine, but not by non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX). In addition, this suppressive effect was specifically blocked by the selective protein kinase C (PKC) inhibitor NPC-15437. However, neither Ca2+/calmodulin-dependent protein kinase II inhibitor KN-62 nor cAMP-dependent protein kinase inhibitor Rp-adenosine 3′,5′-cyclic monophosphothioate (Rp-cAMPS) affected this suppressive effect. This persistent suppression of LTP was not secondary to the long-lasting changes in NMDA receptor activation, because the isolated NMDA receptor–mediated responses did not show a long-term enhancement in response to a 30-min Mg2+-free ACSF application. Additionally, in prior Mg2+-free ACSF–treated slices, the entire frequency-response curve of LTP and long-term depression (LTD) is shifted systematically to favor LTD. These results suggest that the increase of Ca2+ influx through NMDA channels and L-type VOCCs in turn triggering a PKC-dependent signaling cascade is a possible cellular basis underlying this seizure-like activity-induced inhibition of LTP.


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