Effect of temperature and host plant on the efficacy of different entomopathogenic fungi from Thailand against Frankliniella occidentalis (Pergande) and Thrips tabaci Lindeman (Thysanoptera: Thripidae) in the laboratory

2006 ◽  
Vol 113 (4) ◽  
pp. 181-187 ◽  
Author(s):  
M. Thungrabeab ◽  
P. Blaeser ◽  
C. Sengonca
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.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Belén Cotes ◽  
Gunda Thöming ◽  
Carol V. Amaya-Gómez ◽  
Ondřej Novák ◽  
Christian Nansen

AbstractRoot-associated entomopathogenic fungi (R-AEF) indirectly influence herbivorous insect performance. However, host plant-R-AEF interactions and R-AEF as biological control agents have been studied independently and without much attention to the potential synergy between these functional traits. In this study, we evaluated behavioral responses of cabbage root flies [Delia radicum L. (Diptera: Anthomyiidae)] to a host plant (white cabbage cabbage Brassica oleracea var. capitata f. alba cv. Castello L.) with and without the R-AEF Metarhizium brunneum (Petch). We performed experiments on leaf reflectance, phytohormonal composition and host plant location behavior (behavioral processes that contribute to locating and selecting an adequate host plant in the environment). Compared to control host plants, R-AEF inoculation caused, on one hand, a decrease in reflectance of host plant leaves in the near-infrared portion of the radiometric spectrum and, on the other, an increase in the production of jasmonic, (+)-7-iso-jasmonoyl-l-isoleucine and salicylic acid in certain parts of the host plant. Under both greenhouse and field settings, landing and oviposition by cabbage root fly females were positively affected by R-AEF inoculation of host plants. The fungal-induced change in leaf reflectance may have altered visual cues used by the cabbage root flies in their host plant selection. This is the first study providing evidence for the hypothesis that R-AEF manipulate the suitability of their host plant to attract herbivorous insects.


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.


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