scholarly journals Results of the Single Release Efficacy of the Predatory Mite Neoseiulus californicus (McGregor) against the Two-Spotted Spider Mite (Tetranychus urticae Koch) on a Hop Plantation

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.

2021 ◽  
Vol 104 (4) ◽  
pp. 218-222
Author(s):  
V. V. Moor ◽  
A. I. Anisimov ◽  
E. G. Kozlova*

The two-spotted spider mite Tetranychus urticae is a dangerous polyphagous pest of agricultural and ornamental plants. In a commercial greenhouse treated with acaricides or biological control using predatory mite Phytoseiulus persimilis individual varieties of roses differed significantly in terms of the average annual infestation by the pest mite. On the poorly populated rose varieties, the biological control agent application was more effective as compared to the acaricides. To effectively control the pest, the required predatory mite rates were 4.6–8.7 times higher on varieties with a minimal spider mite infestation (Aqua and Deep Water) as compared to the maximal pest infestation (Heaven and Brazil).


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.


2018 ◽  
Vol 23 (11) ◽  
pp. 2173
Author(s):  
Su-Qin Shang ◽  
Yao-Nian Chen ◽  
Ying-Lu Bai

The two-spotted spider mite, Tetranychus urticae, is an important mite pest worldwide. It often leads to reduced crop yields or poor marketability of the produce and has already developed resistance to many acaricides. In this study, the pathogenicity of the entomopathogenic fungus (EPF), Acremonium hansfordii, to T. urticae and its side effects on the predatory mite Neoseiulus barkeri were compared. The toxicity of A. hansfordii was evaluated on T. urticae at 1.0×104, 1.0×106, 1.0×108 conidia/mL concentrations and predatory mite N. barkeri at 1.0×108 conidia/mL under experimental conditions at 25±1°C, 75±5% RH and 16L: 8D photoperiod. The effects of EPF on the development of the F0 and F1 generation of predatory mites were also assessed at 1.0×108 conidia/mL concentration. The results showed that the corrected mortality of T. urticae at three tested concentrations were 36.67%, 53.67% and 66.33% within 11d, and the median lethal time were 14.39 d, 9.84d and 7.99d, respectively. The corrected mortality of N. barkeri was only 3.9% after 11d at 1×108 conidia/mL concentration. Some hyphae of A. hansfordii were detected on the surface of treated T. urticae but not on N. barkeri body after 7d. After N. barkeri females were treated with 1.0×108 conidia/mL, the preoviposition period of the F0 generation was prolonged 1.56 times and the other life history parameters have no significant differences; similar patterns were also shown in the F1 generation. A. hansfordii showed strong pathogenicity against T. urticae but did not significantly adversely influence N. barkeri. Therefore, the combination of A. hansfordii and N. barkeri has the potential to be used for the control of T. urticae in the future. 


Author(s):  
Sajjad Dalir ◽  
Hamidreza Hajiqanbar ◽  
Yaghoub Fathipour ◽  
Mostafa Khanamani

Abstract The age-specific functional and numerical responses of Neoseiulus cucumeris Oudemans (Mesostigmata: Phytoseiidae) on eggs of the two-spotted spider mite, Tetranychus urticae Koch (Prostigmata: Tetranychidae), were assessed in the laboratory using bean leaf discs. Densities of 2, 4, 8, 16, 32, 64, and 128 prey were provided to 4- (protonymph), 6- (deutonymph), 8-, 13-, 18-, 23-, 28-, 33-, and 40-d-old N. cucumeris individuals. The functional response of 28- and 40-d-old N. cucumeris fitted type II, whereas the other ages displayed a type III functional response. The longest handling time observed at the age of 4 d was 0.515 h, whereas the shortest handling time and highest value of maximum attack rate (T/Th) were associated with the age of the 28-d-old treatment (0.261 h and 91.95 prey/d, respectively). The numerical response of N. cucumeris showed a significant increase with increasing prey density, but its rate gradually decreased at higher densities. Therefore, the efficiency of conversion of ingested food was relatively higher at low two-spotted spider mite densities, whereas it was reduced at high two-spotted spider mite densities. The stronger functional response and predation capacity of N. cucumeris on two-spotted spider mite eggs indicated the high potential of this predatory mite as an effective biological control agent against two-spotted spider mite especially at its early and middle ages and also when higher prey densities are present.


2019 ◽  
Vol 24 (7) ◽  
pp. 1225-1235
Author(s):  
Rui Zhu ◽  
Jian-Jun Guo ◽  
Tian-Ci Yi ◽  
Rong Xiao ◽  
Dao-Chao Jin

The predatory mite, Neoseiulus californicus (McGregor), is an important biological control agent of Tetranychus urticae Koch in greenhouse crops. Oulenziella bakeri is an important alternative prey for the commercial production of N. californicus. To confirm that the predatory relationship between N. californicus and O. bakeri is beneficial to the reproduction of N. californicus, the functional and numerical responses of N. californicus to O. bakeri and T. urticae were compared when exposed to six prey densities (2, 4, 8, 16, 32 and 64 individuals) under laboratory conditions. An analysis of the logistic regression showed that the adult female N. californicus displayed a type II functional response when fed on O. bakeri and T. urticae eggs and nymphs. The proportion of the consumed prey by N. californicus to the total supplied prey declined, even though the absolute number of predation events increased as the prey density increased. The Holling disc equation revealed that N. californicus had greater attack rates on the eggs (0.86-1.03) and nymphs (0.73-0.93) of T. urticae than those of O. bakeri, which were (0.55–0.73) and (0.71–0.96), respectively. N. californicus had longer handling times for the eggs (0.05–0.09) and nymphs (0.07–0.12) of O. bakeri compared with those of T. urticae, which were (0.03–0.05) and (0.04–0.07), respectively. The numbers of eggs laid by N. californicus feeding on eggs and nymphs of T. urticae were greater than those feeding on O. bakeri; but as the density increased, the difference in the oviposition rates between the predators feeding on two mites decreased. The comparison of the functional and numerical responses of the predator to O. bakeri and T. urticae revealed that the former is a good alternative food in the commercial production of N. californicus.


2020 ◽  
Vol 25 (8) ◽  
pp. 1359-1372
Author(s):  
Matheus S. Rocha ◽  
Lívia A. Celada ◽  
Everton N. L. Rodrigues ◽  
Luiz E. Costa-schmidt

The emergence of anti-predatory strategies for prey survival are ruled by the minimization of the encounters/interactions with potential predators, but at the same time by maximizing the access to limiting resources such as food or mating partners. Cues indicating predatory activity influence decision-making activities in the two-spotted spider mite Tetranychus urticae, such as dispersion, foraging activities, and reproductive effort.  However, anti-predatory strategies studied in spider mites generally considers mainly the female perspective (e.g. oviposition), leaving a gap in how T. urticae couples deal with predatory risk. Here, through laboratory experiments, we observed that matured spider mite couples were only affected by predation risk during the pre-copulatory stages of the mating process, especially when deciding to proceed in a mating opportunity. The mating performance of individuals was independent of their exposure to predation risk, suggesting that couples would adopt full investment behavior after opting to proceed in a mating attempt. Though our working hypothesis predicted predation risk interference throughout the entire mating process, we conclude that decision-making activities by spider mite during pre-copulatory stages act independently from copulatory stages associated to insemination.


2011 ◽  
Vol 48 (2) ◽  
pp. 193-205 ◽  
Author(s):  
Anna Tomczyk ◽  
Magdalena Suszko

The role of phenols in the influence of herbal extracts fromSalvia officinalisL. andMatricaria chamomillaL. on two-spotted spider miteTetranychus urticaeKochExtracts prepared from 2 medicinal herbs (common sageSalvia officinalisL. and German chamomileMatricaria chamomillaL.) were used in this study for biological control of spider mites. Their effect on mortality, fecundity, and development ofTetranychus urticaeKoch on English ivy (Hedera helixL.) was studied under laboratory and greenhouse conditions. The extracts were prepared by soaking freshSalvialeaves or dryMatricariaflowers in ethanol for 24 h, followed by evaporation, and finally suspension of the pellets in water. Full extracts and extracts without phenols were tested. TheSalviaextracts had a higher acaricidal activity thanMatricariaextracts, but the toxicity of both extracts to spider mite eggs was low. The toxic effect of fullSalviaextracts on larval stages and females ofT. urticaewas evident. More than 50% of larvae and females were killed by this treatment in 4 days. Besides, total fecundity of survived females was evidently lower. Mortality and low fecundity after fullSalviaextract application decreased the spider mite population by 76%. The toxicity ofSalviaextracts after removal of phenols strongly declined, so the negative effect of the fullSalviaextract on spider mites was connected with a high concentration of phenolic compounds. The toxic effect ofMatricariaextracts in all tests was much lower and no evident role of phenolic compounds in its extracts was observed.


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