scholarly journals Environmental RNAi-based reverse genetics in the predatory mite Neoseiulus californicus: towards improved methods of biological control

2021 ◽  
Author(s):  
Noureldin Abuelfadl Ghazy ◽  
Takeshi Suzuki

The predatory mite Neoseiulus californicus (McGregor) (Mesostigmata: Phytoseiidae) has been commercialized by manufacturers in the pest control industry and is used worldwide as a natural enemy of spider mites. However, because its genome has not been sequenced, reverse genetics techniques that could be used to analyze gene function have not been established. Here we partially sequenced the gene that encodes the vacuolar-type H+-ATPase (V-ATPase), an ATP-dependent proton pump, in N. californicus (NcVATPase) and then conducted a functional analysis using environmental RNA interference (eRNAi) by orally administering sequence-specific exogenous dsRNA (dsRNA-NcVATPase) to larvae and adult females. The larvae treated with dsRNA-NcVATPase took longer to develop and had lower survivorship, fecundity, and offspring viability at the adult stage than those treated with a control dsRNA. Adult females treated with dsRNA-NcVATPase showed significant reductions in survival, fecundity, and prey consumption, and their endogenous gene expression level of NcVATPase was reduced by approximately 65% compared with the control. Our findings suggest that the NcVATPase gene, silencing of which inhibits feeding and reproduction, is an excellent biomarker for investigating the eRNAi mechanism in N. californicus. The highly efficient experimental system of eRNAi established in this study paves the way for applied research using eRNAi to enhance the predatory ability of N. californicus.

2020 ◽  
Vol 25 (1) ◽  
pp. 51-62
Author(s):  
Mariana Soledad Pascua ◽  
Margarita Rocca ◽  
Nancy Greco ◽  
Patrick De Clercq

Neoseiulus californicus (McGregor) (Mesostigmata: Phytoseiidae) is considered a specialized predator of spider mites and has mainly been used to control Tetranychus urticae Koch (Acari: Tetranychidae). However, this phytoseiid is also able to feed and reproduce on certain pollens. In the present laboratory study, survival, development time, and reproduction of N. californicus were determined when reared on T. urticae, Typha angustifolia pollen, or on a combined diet of both foods. The immature stages of N. californicus developed faster when T. urticae was present in the diet. The total developmental time of females was longer when offered T. angustifolia pollen only (6.6 days), than when fed on T. urticae (4.5 days) or T. urticae + pollen (4.5 days). The oviposition rate of N. californicus was higher on the two diets containing T. urticae (3.1-3.3 eggs/female/day) than on T. angustifolia pollen alone (0.9 eggs/female/day). The intrinsic rates of natural increase (rm) were estimated to be 0.273, 0.268 and 0.149 females/female/day on T. urticae, T. urticae + T. angustifolia and T. angustifolia, respectively. Our results indicate that supplementing a T. urticae diet with T. angustifolia pollen would not improve population parameters. However, in the absence of spider mites, providing commercial pollen might help sustain populations of the phytoseiid in the field.


2016 ◽  
Vol 21 (10) ◽  
pp. 1662
Author(s):  
Maicon Toldi ◽  
Marliza Beatris Reichert ◽  
Priscila De Andrade Rode ◽  
Liana Johann ◽  
Noeli Juarez Ferla

Mites and insects cause damage to soybean crops (Glycine max (L.): Fabaceae). Mononychellus planki McGregor, Tetranychus ludeni Zacher (Acari: Tetranychidae) and Caliothrips phaseoli Hood (Insecta: Thripidae) have been mentioned as pests of soybean crops in Brazil, while Neoseiulus californicus McGregor (Acari: Phytoseiidae) is considered a generalist predatory mite. This work aimed to determine the biological parameters of N. californicus feeding on T. ludeni, M. planki and C. phaseoli on transgenic soybean leaves. Thirty N. californicus eggs were individually placed in arenas with T. ludeni, M. planki and C. phaseoli. Egg-to-adult duration (in days) was longest when fed T. ludeni (5.52±0.06) and shortest when fed C. phaseoli (4.89±0.06). Mean fertility was approximately 32 eggs/female and did not differ significantly when N. californicus fed on T. ludeni or M. planki. During the adult stage, N. californicus did not lay eggs when feeding on C. phaseoli and survived for only a few days. The net reproductive rate (Ro) of N. californicus was larger when fed T. ludeni (20.30±0.68) than M. planki (14.66±0.29). Both M. planki and T. ludeni were suitable prey for N. californicus, while C. phaseoli was not. 


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.


2018 ◽  
Vol 6 (1) ◽  
pp. 01-06
Author(s):  
Maryam Rezaie ◽  
Fatomhe Montazerie

Neoseiulus californicus (Acari: Phytoseiidae) is an effective predator in greenhouses which feeds on plant injurious mites. Searching capacity is one of importance in the effectiveness of this predatory mite. In this research, the population fed with corn pollen, walnut and date pollen and the spider mite (four strains) were investigated. The prey-stage preference of N. californicus was studied on different developmental stages of Tetranychus urticae. The predation rate of rearing population of N. californicus was determined; it was used eggs of T. urticae. Experiments were carried out on strawberry disc in Petri dish (6 cm diameter) under laboratory conditions (27±1ºC temperature, 70±5% RH and 16L: 8D photoperiod). After 24 hours, the total numbers of prey consumed were counted. The predatory mites reared on different pollens prefer eggs or nymphs to adults and the Preference Index of different strains was not different. Result of consumed of spider mites by female predatory mites indicated the predation rate of the predatory mites fed with corn pollen (9±1.46), walnut pollen (8.19±0.99) and Date pollen (8.28±0.80) did not any significant difference, however when spider mites and the mentioned pollens were used, the predation rate of predatory mites when fed with T.  urticae (14.74±0.94), Walnut (15.24±1.05) and date pollen (14.17±1.04) show significant difference with the population of corn pollen (10.0±0.95). The predation rate of four strains decreased at present of plant pollens. Use of the predatory mite fed with the different developmental stage of two-spotted spider mite and pollen in the biological control of the pests is useful.


EDIS ◽  
1969 ◽  
Vol 2005 (2) ◽  
Author(s):  
Silvia I. Rondon ◽  
James F. Price ◽  
Oscar E. Liburd ◽  
Roger Francis ◽  
Daniel J. Cantliffe

Neoseiulus californicus McGregor (Acari: Phytoseiidae) is an oblong, tiny, mobile, predatory mite that feeds on a variety of prey (Fig. 1). It belongs to the suborder Acariforme in the Acari order. The division includes more than 30,000 described species included in the ancient group of Arachnida (Krantz, 1978). This document is HS1001, one of a series of the Horticultural Sciences Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Publication date: November 2004.  


2021 ◽  
Vol 26 (4) ◽  
pp. 713-723
Author(s):  
Wei Zhen Li ◽  
Hao Long Li ◽  
Zi Kun Guo ◽  
Su Qin Shang

The predatory mite Neoseiulus barkeri (Acari: Phytoseiidae), which is one of the best natural enemies, has been used as a biological control agent against multiple insect pests, such as spider mite, Tetranychus urticae and thrips. Its growth and development were affected by the environmental temperature changes. This study was conducted to evaluate the hatching rate of the eggs and the immature developmental times of N. barkeri after incubation of the eggs under heat stress at 38, 40 and 42℃, 85% ± 5% RH and a 16h:8h light: dark (L:D) photoperiod for 2, 4 and 6h. After adult females emerged, they were treated under the same conditions again, and the parameters such as oviposition period, fecundity and female longevity were observed. The results showed that with the increase of the temperature and the extension of the duration of the heat stress, the hatching rate was lower. The eggs treated at 42℃ for 2h or more could not hatch, and the developmental duration of each immature stage showed a trend of decreasing at first and then increasing. The fastest development was observed after incubation of eggs at 40℃ for 2h, and the shortest developmental duration was 4.60d. Under the condition of 38℃, the oviposition period and life span of adult females were shortened with the extension of treatment time, and the fecundity decreased at first and then increased. At 40℃, the fecundity, oviposition period and longevity of adult females showed a trend of gradual increase with the extension of treatment time. The shortest oviposition period, the lowest fecundity and the shortest life span of adult females were 12.14d, 18.92 eggs and 16.65d, respectively after incubation of eggs at 40℃, for 2h. Therefore, the short-term heat stress had a significant effect on the hatching rate and the duration of the immature stage, and also had a negative effect on the fecundity, oviposition period and longevity of adult females. In rearing and field release, heat stress should be avoided as much as possible to achieve the best predation and control effect of N. barkeri.


2014 ◽  
Vol 74 (3) ◽  
pp. 691-697 ◽  
Author(s):  
PP Marafeli ◽  
PR Reis ◽  
EC. da Silveira ◽  
GC Souza-Pimentel ◽  
MA. de Toledo

The predatory mite, Neoseiulus californicus(McGregor, 1954) (Acari: Phytoseiidae) is one of the principal natural enemies of tetranychid mites in several countries, promoting efficient control of those mites in several food and ornamental crops. Pest attacks such as that of the spider mite, Tetranychus urticaeKoch, 1836 (Acari: Tetranychidae), is one of the problems faced by farmers, especially in the greenhouse, due to the difficulty of its control with the use of chemicals because of the development of fast resistance making it hard to control it. The objective of this work was to study the life history of the predatory mite N. californicus as a contribution to its mass laboratory rearing, having castor bean plant [Ricinus communis L. (Euphorbiaceae)] pollen as food, for its subsequent use as a natural enemy of T. urticae on a cultivation of greenhouse rosebushes. The studies were carried out in the laboratory, at 25 ± 2°C of temperature, 70 ± 10% RH and a 14 hour photophase. The biological aspects and the fertility life table were appraised. Longevity of 32.9 days was verified for adult females and 40.4 days for males. The intrinsic rate of increase (rm) was 0.2 and the mean generation time (T) was 17.2 days. The population doubled every 4.1 days. The results obtained were similar to those in which the predatory mite N. californicus fed on T. urticae.


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