scholarly journals Benefit-cost Trade-offs of Early Learning in Foraging Predatory Mites Amblyseius Swirskii

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Inga C. Christiansen ◽  
Sandra Szin ◽  
Peter Schausberger

Abstract Learning is changed behavior following experience, and ubiquitous in animals including plant-inhabiting predatory mites (Phytoseiidae). Learning has many benefits but also incurs costs, which are only poorly understood. Here, we addressed learning, especially its costs, in the generalist predatory mite Amblyseius swirskii, a biocontrol agent of several herbivores, which can also survive on pollen. The goals of our research were (1) to scrutinize if A. swirskii is able to learn during early life in foraging contexts and, if so, (2) to determine the costs of early learning. In the experiments, we used one difficult-to-grasp prey, i.e., thrips, and one easy-to-grasp prey, i.e., spider mites. Our experiments show that A. swirskii is able to learn during early life. Adult predators attacked prey experienced early in life (i.e., matching prey) more quickly than they attacked unknown (i.e., non-matching) prey. Furthermore, we observed both fitness benefits and operating (physiological) costs of early learning. Predators receiving the matching prey produced the most eggs, whereas predators receiving the non-matching prey produced the least. Thrips-experienced predators needed the longest for juvenile development. Our findings may be used to enhance A. swirskii’s efficacy in biological control, by priming young predators on a specific prey early in life.

2015 ◽  
Vol 68 ◽  
pp. 446-446
Author(s):  
D.J. Wilson ◽  
P.J. Gerard

Spiny snout mite (Neomolgus capillatus) is a potential biocontrol agent for clover flea (Sminthurus viridis) a white clover pest on dairy farms in warmer and wetter parts of New Zealand In the 1990s this mite was introduced from Brittany France into Tasmania for clover flea control Results during the release programme were highly promising and subsequent anecdotal farmer reports indicate widespread decreases in damage As N capillatus is a predatory mite and already known to attack nontarget organisms habitat specificity will determine whether it could be introduced into New Zealand without risk to native insects To assess this pastures on nine of the original Tasmanian release farms and adjacent nontarget habitats ranging from bush wetlands eucalypt stands to sand dune country were sampled in April 2014 Litter samples were collected heat extracted and mite species identified Neomolgus capillatus was found at effective densities in pastures that had good clover cover Where present it displaced Bdellodes spp mites that are ineffective against clover flea No N capillatus were found in the nontarget habitats all of which lacked clover and contained other predatory mites including Bdellodes spp Therefore the preference by N capillatus for lush pastures makes it an excellent prospect for introduction as a biocontrol agent into clover flea prone regions of New Zealand


2014 ◽  
Vol 65 (4) ◽  
pp. 419-433 ◽  
Author(s):  
F. Javier Calvo ◽  
Markus Knapp ◽  
Yvonne M. van Houten ◽  
Hans Hoogerbrugge ◽  
José E. Belda

2021 ◽  
Author(s):  
Somayyeh Ghasemzadeh ◽  
Gerben J. Messelink ◽  
Gonzalo A. Avila ◽  
Yongjun Zhang

Abstract The predatory mite Amblyseius swirskii is widely used natural enemy of phytophagous pests. Due to negative effects of conventional pesticides on non-target organism, the development of selective natural and eco-friendly pesticides such as essential plant oils are a useful pest control tool to use in synergy with biological control agents. Essential oils of Nepeta crispa, Satureja hortensis and Anethum graveolens showed promising results to control Tetranychus urticae. Hence an experiment was carried out to evaluate the effects of these essential oils on biochemical and demographic parameters of A. swirskii. Significant reduction of carbohydrate, lipid and protein contents of oil-treated predatory mites was observed. However oils of S. hortensis and A. graveolens had no negative impact on lipid reserve. Glutathione-S-transferase activity of A. swirskii was influenced by A. graveolens. In addition, the enzyme activity of the α-esterases was elevated by all treatments. The essential oils showed no effect on β-esterases activity compared to the control treatment. None of the concentrations of the different tested oils affected the population growth parameters of A. swirskii. However, a significant reduction was observed in oviposition time and total fecundity of predatory mites. Our observations show that the tested essential plant oils need some caution when applied as alternatives to synthetic pesticides in combination with A. swirskii and may have critical implications for Integrated Pest Management (IPM) programs. However, semi-field and field studies are required to evaluate the effects of these products on T. urticae and A. swirskii for developing IPM strategies.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Gongyu Lin ◽  
Claude Guertin ◽  
Sean-Anthony Di Paolo ◽  
Silvia Todorova ◽  
Jacques Brodeur

AbstractRecent studies have shown that predatory mites used as biocontrol agents can be loaded with entomopathogenic fungal conidia to increase infection rates in pest populations. Under laboratory conditions, we determined the capacity of two phytoseiid mites, Amblyseius swirskii and Neoseiulus cucumeris to deliver the entomopathogenic fungus Beauveria bassiana to their prey, Frankliniella occidentalis. Predatory mites were loaded with conidia and released on plants that had been previously infested with first instar prey clustered on a bean leaf. We examined each plant section to characterize the spatial distribution of each interacting organism. Our results showed that A. swirskii delivered high numbers of conidia to thrips infested leaves, thereby increasing the proportion of thrips that came into contact with the fungus. The effect was larger when thrips infestation occurred on young leaves than on old leaves. Neoseiulus cucumeris delivered less conidia to the thrips infested leaves. These patterns result from differences in foraging activity between predatory mite species. Amblyseius swirskii stayed longer on plants, especially within thrips colonies, and had a stronger suppressing effect on thrips than N. cucumeris. Our study suggests that loading certain predatory mite species with fungal conidia can increase their capacity to suppress thrips populations by combining predation and dispersing pathogens.


2014 ◽  
Vol 54 (4) ◽  
pp. 349-353 ◽  
Author(s):  
Żaneta Fiedler ◽  
Danuta Sosnowska

Abstract Experiments were carried out on the toxicity of selected insecticides and fungicides to the predatory mites species: Amblyseius swirskii, A. andersoni, and Phytoseiulus persimilis. Among the tested active substances: abamectin, hexytiazox, and spinosad were safe to the predators. The mortality level of the tested predator was comparable to the control treatment, seven days after application. The percentage values of these predatory mites’ mortality caused by these insecticides, applied at one and a half of the recommended dose did not exceed a low toxicity – 25% (referring to International Organisation for Biological and Integrated Control (IOBC) classification on the toxicity to beneficial organisms). The results of the tests revealed that imidaclopryd, lambda-cyhalothrin, and fenpyroksymat were highly toxic to the predatory mites. It was found that toxicity of fungicides to the tested predatory mite species depended on the date of the chemical treatment and the date the predators were introduced. The fungicide Topsin M 500 SC – thiophanate-methyl, appeared to be selective to the species A. swirskii and it could be used in the Integrated Pest Management (IPM) programs for greenhouse grown crops.


2019 ◽  
Vol 26 (01) ◽  
pp. 125-134
Author(s):  
Altantsesteg Z ◽  
Oyungerel J ◽  
Undarmaa D

We conducted this study on the “Black Beauty” variety from Russia, which was planted in a 120 sqrm greenhouse in the Agropark Center of the Mongolian University of Life Sciences in 2017. During vegetation period of egg plant were occurred the polyphagous insect pests such as two spotted spider mite (Tetranychus urticae), тrips (Thripidaes.sp), peach aphid (Myzodes persicae) and caused a injury at 1-2 rate.  For controlling these arthropod pests, we have used 4 different  treatments as А-(predatory mites- Phytoseilus persimilis, Amblyseius swirskii) ), B- (Neem oil), C- (Predators+Nеем oil), D-BEB (LC) 2% as comparing to control plot. In calculating the effectiveness of treatments, А-(predatory mites- Phytoseilus persimilis, Amblyseius swirskii) -79.1%, B- (Neem oil)-73.7%, C- (Predators+Nеем oil)-85.5%, D-BEB (LC) 2% -83.1% as comparing to control plot were killed respectively. We have tested 4 different treatment including the predacious mite (Phytoseiulus persimilis) to control  a two spotted spider mite (TSSM)-Tetranychus urticae) and A.swirskii against trips on the eggplant field . The treatments have been included A (predatory mite alone at 1:5 ratio), B (P+N (predatory mite at 1:5 ratio+Neem oil), C-neem oil alone), LC+BEB 2% and control plots with 4 replications. We have assessed the efficacy of each control treatment, and the B ( predatory mite+neem oil) treatment has reduced TSSM densities at most. These treatments for controlling the pests was  increased the eggplant yield 3.8-36.4% per sqm  area comparing to control plots. There was observed a differences between yield of  control and treatment plots and observed as A plots  (t=2.19, d.f.=174, p≥0,29), B plots  (t=0.88, d.f.=174, p≥0,37),C  plots  (t=8.8, d.f.=174, p≥3.78) as shown on the result of T-test analysis of SPSS.   Цэсийн (solanum melongеna) талбайд тархсан үе хөлтөн хөнөөлт организм (шавж, хачиг), тэдгээртэй тэмцэх биологийн аргын үр нөлөөг судалсан дүн Хураангуй: Бид энэхүү судалгааны ажлыг 2017 онд ХААИС-ийн Агропарк Сургалт, судалгааны төв дэх  120 мкв нийлэг хальсан хүлэмжинд тариалсан цэсийн ОХУ-ын “Чёрная красавица” сорт дээр  гүйцэтгэв. Ургамал ургалтын хугацаанд цэсийн талбайд хоёр толбот шүлхий  хачиг(Tetranychus urticae), трипс (Thripidaes.sp), Тоорийн бөөс (Myzodes persicae) зэрэг үе  хөлтний хүрээний хөнөөлтэй, элдэв идэшт зүйлүүд давхцан гарч бүлгээр хөнөөл учруулж  байсан бөгөөд эдгээрийн эсрэг тэмцэх аргын А-(Ангуучин хачгууд- Phytoseilus persimilis,  Amblyseius swirskii) ), B - (неем тос), C- (Ангуучин+Nеем тос), D-BEB (LC) 2% зэрэг  хувилбаруудыг хяналттай (E) харьцуулан туршиж, үр дүнг тогтоолоо. Эдгээрээс тархалт,  хөнөөлийн хувьд трипс, хоёр толбот шүлхий хачиг нь зонхилон тархаж, цэсийн навчийг 1-2  баллаар гэмтээж байв. Туршилтанд хэрэглэсэн хувилбаруудаас А. Ангуучин фитосейлюс хачиг  \1:5\ хувилбар 79.1%, B. Neem тос /0.01% уусмал + Фитосейулус хачиг /1:5/ -85.5% буюу  хамгийн өндөр , C. Neem тос /0.01% уусмал/-73.7%, D. BEB (LC) 2% уусмал /Дархлааны  бэлдмэл/ 83.1% -иар хөнөөлт организмыг үхүүлсэн техник үр дүнг үзүүлэв.Тэмцэх аргын  хувилбаруудын ургац хяналтын дэвсгээс давсан бөгөөд A,B,C,D хувилбаруудын ургац 23.69-  29.66 kг-аар хяналтын(E)-аас илүү байгааг SPSS, T-test-ийн аргаар шинжилэхэд A хувилбар  (t=2.19, d.f.=174, p≥0,29), B хувилбар (t=0.88, d.f.=174, p≥0,37),C хувилбар (t=8.8, d.f.=174,  p≥3.78) байгаа нь хувилбаруудын ургац хяналтын хувилбараас бодит зөрүүтэйг харуулж  байна. Түлхүүр үг: Хүлэмж, шүлхий хачиг, ангуучин хачиг, биологийн хамгаалал


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