Efficacy of Entomopathogenic Nematode Steinernema feltiae (Rhabditida: Steinernematidae) as Influenced by Frankliniella occidentalis (Thysanoptera: Thripidae) Developmental Stage and Host Plant Stage

2005 ◽  
Vol 98 (5) ◽  
pp. 1480-1485 ◽  
Author(s):  
R. Buitenhuis ◽  
J. L. Shipp
Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer

Understanding the mechanisms involved in host plant resistance opens the way for improved resistance breeding programs by using the traits involved as markers. Pest management is a major problem in cultivation of ornamentals. Gladiolus (Gladiolus hybridus L.) is an economically important ornamental in the Netherlands. Gladiolus is especially sensitive to attack by western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera:Thripidae)). The objective of this study was, therefore, to investigate morphological and chemical markers for resistance breeding to western flower thrips in Gladiolus varieties. We measured thrips damage of 14 Gladiolus varieties in a whole-plant thrips bioassay and related this to morphological traits with a focus on papillae density. Moreover, we studied chemical host plant resistance to using an eco-metabolomic approach comparing the 1H NMR profiles of thrips resistant and susceptible varieties representing a broad range of papillae densities. Thrips damage varied strongly among varieties: the most susceptible variety showed 130 times more damage than the most resistant one. Varieties with low thrips damage had shorter mesophylls and epidermal cells, as well as a higher density of epicuticular papillae. All three traits related to thrips damage were highly correlated with each other. We observed a number of metabolites related to resistance against thrips: two unidentified triterpenoid saponins and the amino acids alanine and threonine. All these compounds were highly correlated amongst each other as well as to the density of papillae. These correlations suggest that papillae are involved in resistance to thrips by producing and/or storing compounds causing thrips resistance. Although it is not possible to distinguish the individual effects of morphological and chemical traits statistically, our results show that papillae density is an easy marker in Gladiolus-breeding programs targeted at increased resistance to thrips.


Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 847-852 ◽  
Author(s):  
D. G. Riley ◽  
H. R. Pappu

Two studies were conducted in Georgia during the spring of 1997 and 1998 to evaluate various management practices for reducing thrips and thrips-vectored Tomato spotted wilt virus (TSWV) in tomato. Populations of the two species of thrips responsible for transmitting TSWV in tomato fields, Frankliniella occidentalis and F. fusca, were determined using blossom and sticky trap samples. Management practices evaluated were host plant resistance, insecticide treatments, planting date, and light-reflective mulch. In both years, intensive insecticide treatment had the largest effect in reducing thrips and spotted wilt and increasing marketable yield, compared with host plant resistance and reflective mulch. The effect of planting date was consistent in that the later planting date resulted in higher incidence of TSWV, lower thrips numbers, and lower tomato yields, both in fruit quality and dollar value. Host plant resistance and reflective mulch significantly reduced thrips and TSWV. In both years, early planting on black plastic with an intensive insecticide treatment resulted in the highest yield.


Nematology ◽  
2003 ◽  
Vol 5 (4) ◽  
pp. 539-547 ◽  
Author(s):  
Dammini Premachandra ◽  
Christian Borgemeister ◽  
Oliver Berndt ◽  
Ralf-Udo Ehlers ◽  
Hans-Michael Poehling

Abstract The efficacy of entomopathogenic nematodes (EPN) was evaluated in a laboratory trial against soil-dwelling stages, late second instar larvae and pupal stages of western flower thrips (WFT), Frankliniella occidentalis Pergande. Among the six EPN strains assessed for the first time, Steinernema feltiae (Nemaplus®) and Heterorhabditis bacteriophora (HD01) caused 65 and 59% mortality, respectively. Steinernema carpocapsae (Agriotos) and S. arenarium (Anomali) caused moderate mortality (40-45%) while Steinernema spp. (Morocco) and H. bacteriophora (Nematop®) had little effect. In a dose response study with concentrations of 100, 400 and 800 infective juveniles (IJ) per cm2 soil of H. bacteriophora (HK3), S. feltiae (Nemaplus®) and H. bacteriophora (HD01), mortality increased only up to 400 IJ cm-2. The rate of infectivity of H. bacteriophora (HK3) and S. feltiae (Nemaplus®) indicated that both strains could survive at least 6 days in the soil and infect WFT immature stages.


1997 ◽  
Vol 71 (3) ◽  
pp. 197-202 ◽  
Author(s):  
D.A. Bohan ◽  
W.M. Hominick

AbstractAn infection experiment was conducted to assess the change in the proportions of Steinernema feltiae Filipjev (Site 76 strain) infective juveniles becoming male or female on exposure to the test host Galleria mellonella L. Using a mathematical model for the infection interaction, the per capita probability of penetration per unit time (transmission coefficient), for those juveniles becoming male or female, and the magnitude of the male and female classes in the infective juvenile pool were estimated. The results show that S. feltiae infective juveniles which subsequently become female have a greater probability of invasion into test hosts than their male counterparts, which leads to markedly female biased sex ratios during the initial stages of the infection interaction. As the infection progresses, however, it was found that the sex ratio became balanced. This was because the underlying sex ratio in the infective stage pool was balanced. The implications of this dynamism in the sex ratio of the entomopathogenic nematodes are discussed with respect to the infection interaction, transmission and the likely environment in which the infective juveniles reside.


2017 ◽  
Vol 49 (1) ◽  
pp. 229-234 ◽  
Author(s):  
Ali Murad Rahoo ◽  
Tariq Mukhtar ◽  
Simon R. Gowen ◽  
Rehana Kanwal Rahoo ◽  
Shaukat Ibrahim Abro

Nematology ◽  
2009 ◽  
Vol 11 (3) ◽  
pp. 439-451 ◽  
Author(s):  
Martin Downes ◽  
Conor Meade ◽  
Stephen Boyle ◽  
Alec Rolston ◽  
Thomae Kakouli-Duarte

AbstractThe application of large numbers of entomopathogenic nematodes (EPN) to control insect pests of agriculture is likely to have an impact on the local EPN fauna, yet little is known about the intraspecific relationships between EPN populations, particularly with regard to phylogeny and outbreeding. Here we assess the fitness, with regards to fecundity, host insect mortality and time taken to produce progeny, of isolates of Steinernema feltiae from Bull Island, Ireland. Exon-primed, intron-crossing (EPIC) PCR was used to examine intraspecific phylogenies between S. feltiae isolates, and identified up to three possible colonisation events of Bull Island. EPIC-PCR grouped two isolates, 33.D.(2) and 59.F.(2), separately from the remaining ten S. feltiae isolates These same two isolates consistently performed poorly in all fitness assessments. Following the crossbreeding of all isolates in Galleria mellonella, the number of host cadavers exhibiting emerging infective juveniles was significantly fewer than expected and there were significant differences between isolates in the number of days until progeny were observed. Host insect mortality varied between 40 and 87%. Such intraspecific variation may be a result of adaptation to different microhabitats of Bull Island, which in turn may be accentuated by laboratory culture practices.


2007 ◽  
Vol 44 (4) ◽  
pp. 226-229 ◽  
Author(s):  
V. Valadas ◽  
S. Boyle ◽  
P. Vieira ◽  
T. Kakouli-Duarte ◽  
M. Mota

AbstractIn continental Portugal no information is available concerning the occurrence of entomopathogenic nematodes. During a survey in several different habitats from the southern regions of the country, several isolates where identified as Steinernema feltiae. This represents the first report of an entomopathogenic nematode genus for continental Portugal.


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