scholarly journals The predatory mite Neoseiulus californicus (Acari: Phytoseiidae) does not respond for volatiles of maize infested by Tetranychus urticae (Acari: Tetranychidae)

2022 ◽  
Vol 82 ◽  
Author(s):  
M. S. Rocha ◽  
P. T. Nascimento ◽  
B. L. F. Santos ◽  
M. A. M. Fadini

Abstract Among the plants defense mechanisms, the induction and emission of volatile organic compounds, which can be used to attract natural enemies, such predators insects. Although well studied, the induction of plant volatiles that attract natural enemies can vary according to intensity of infestation of herbivores and the species of host plant. We investigated the olfactory behavioral responses of the predatory mite Neoseiulus californicus (McGregor) (Acari: Phytoseiidae) to the volatiles of infested maize (Zea mays) plants by the two-spotted spider mite Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) in early and advanced infestations. The Bt (Viptera) maize cultivar Impact® was used for tests the behavior of N. californicus. After initial and advanced infestations, the phytophagous mites T. urticae were removed, and the plants were tested using a “Y” olfactometer. The following treatments were evaluated: air vs. air, uninfested plants vs. air, uninfested plants vs. plants infested with 10 females of T. urticae, uninfested plants vs. plants infested with 100 females of T. urticae, uninfested plants vs. plants infested with 200 females of T. urticae and plants infested with 10 vs. plants infested with 200 females of T. urticae. The predatory mite N. californicus did not show preference to the treatments tested, suggesting that maize plants infested by T. urticae do not induce volatiles capable of attracting the predatory mite N. californicus. We concluded that N. californicus is not attracted by maize plants infested by T. urticae.

2017 ◽  
Vol 78 (1) ◽  
pp. 13-17 ◽  
Author(s):  
P. D. Paulo ◽  
C. G. Lima ◽  
A. B. Dominiquini ◽  
M. A. M. Fadini ◽  
S. M. Mendes ◽  
...  

Abstract Plants can be attacked by a wide variety of herbivores. Thus, developing protective mechanisms for resistance against these agents is an advantage for survival and reproduction. Over the course of evolution, many resistance mechanisms against herbivory have been developed by the plants. Induced direct and indirect resistance mechanisms can manifest in plants after herbivore attack. The two-spotted spider mite Tetranychus urticae is not a pest of maize crops (Zea mays), despite being reported infesting plants that may have resistances against this herbivore. We tested the hypothesis that maize plants would be able to induce direct resistance against T. urticae after, evaluating the effect of T. urticae infestation in maize plants on the development and reproduction of conspecifics. We tested induced direct resistance performing infestation and measuring biological parameters upon a second infestation. Maize plants, 40 days after sowing, were divided into two groups: 30 not infested by T. urticae (clean plants clean) and, 30 infested by the spider mite. Infestation of maize plants by T. urticae reduced the conspecific female adult survival. However, no change in the survival of immature or reproduction was observed. These results suggest the induction of induced direct resistances in maize by T. urticae. This is first report of direct resistance induction in Z. mays by the two-spotted spider mite T. urticae.


2020 ◽  
Vol 11 (1) ◽  
pp. 118
Author(s):  
Matej Vidrih ◽  
Anja Turnšek ◽  
Magda Rak Cizej ◽  
Tanja Bohinc ◽  
Stanislav Trdan

In 2015, we studied the efficiency of the predatory mite Neoseiulus californicus (McGregor) for suppression of the two-spotted spider mite Tetranychus urticae in a field experiment at a hop plantation. We randomly arranged four treatments in a three-block experiment. Fungicides were used in all treatments; insecticides were used in all treatments except the predatory mite treatment and acaricides were used in only two treatments. A single inundative release of the mite N. californicus was carried out on 4 July. On four different dates (10 June, 17 July, 29 July and 9 August), we counted the eggs and the mobile stages (larvae, nymphs and adults) of the two-spotted spider mite in all four treatments. In the treatment with the predatory mite, we established the fewest eggs and mobile stages of T. urticae 14 days after the release of the predator. The selected acaricides in our research acted in a primarily ovicidal manner, but we did not detect satisfactory effects on the mobile stages of the two-spotted spider mite. This result suggests the emergence of resistance of two-spotted spider mites to the acaricides hexythiazox and abamectin. Our research established comparable effects of the predatory mite N. californicus and acaricides, and further improvement of the efficiency would require release of the natural enemy into a hop plantation in mid-June, followed by a second release three weeks later. The costs of acaricide use in our experiment were from 12.7-fold (two sprayings of hexythiazox, and a single spraying with abamectin) to 17.8-fold (single treatments of hexythiazox and abamectin) lower than those of a single release of the biological control agent in question. The results of our study represent a starting point for future research, which could achieve satisfactory results in suppressing two-spotted spider mites on a hop plantation by repeated use of the predatory mite N. californicus.


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