scholarly journals Assessment of the impacts of microbial plant protection products containing Bacillus thuringiensis on the survival of adults and larvae of the honeybee (Apis mellifera)

Author(s):  
Charlotte Steinigeweg ◽  
Abdulrahim T. Alkassab ◽  
Hannes Beims ◽  
Jakob H. Eckert ◽  
Dania Richter ◽  
...  

AbstractThis study was aimed at evaluating the effect of a microbial pest-controlling product (MPCP) with the active substance Bacillus thuringiensis ssp. aizawai (strain: ABTS-1857) on adults and larvae of honeybees. To determine the contamination levels of Bt spores in different matrices, a colony-feeding study under semi-field conditions was performed. Furthermore, two chronic adult trials and a chronic larval study were conducted under laboratory conditions to test the effects of different concentrations of the plant protection product (PPP) on the development and mortality. Possible modifications of the chronic oral toxicity test were assessed by additional pollen feeding. Our results showed that Bt spores were detected in all matrices over the entire test duration in different concentrations, decreasing over time. The survival of adult bees and larvae was negatively affected in laboratory conditions after a chronic exposure to the MPCP depending on the tested concentrations. Moreover, the earliest sign of bee mortality, resulting from exposure to ABTS-1857, was recorded only after 96 h at the highest tested concentration. Pollen feeding to adults significantly increased the survival of the treated bees. In conclusion, the PPP with the Bt strain ABTS-1857 showed an effect on the mortality of adults and larvae under laboratory conditions. Further studies with Bt-based PPPs under realistic field conditions are necessary to evaluate the potential risk of those MPCPs on honeybees.

2017 ◽  
Vol 18 ◽  
pp. 62 ◽  
Author(s):  
Z.D. Zartaloudis ◽  
M.D. Kalapanida ◽  
E.I. Navrozidis

In this study some selected insecticides were evaluated for their effect on gypsy moth Lymantria dispar L., (Lepidoptera: Lymantriidae) under laboratory conditions. Diflubenzuron, methoxyfenozide, triflumuron, fenoxycarb, fenoxycarb + lufenuron, Bacillus thuringiensis 50% subsp. kurstaki + Bacillus thuringiensis 50% subsp. aizawai, Bacillus thuringiensis subsp. aizawai and spinosad were used in the recommended concentration, against the 1st, 2nd, 3rd and 4th larval instars of L. dispar. The effectiveness of the above insecticides as well as the speed of action (LTime50 and LTime90) expressed in days, were examined in detail. Spinosad and methoxyfenozide presents a relatively higher speed of action in relation to the other insecticides. LTime50 of spinosad and methoxyfenozide did not differ significantly among the first three larval instars and ranged from 0 to 0.61 and 1.13 to 1.74 days, respectively. Regarding IGRs, the mixture (fenoxycarb + lufenuron) and triflumuron were the most effective in relation to the other IGRs tested. Moreover, Bacillus thuringiensis toxins were effective only against the first two larval instars.


Author(s):  
Marco Grella ◽  
Fabrizio Gioelli ◽  
Paolo Marucco ◽  
Ingrid Zwertvaegher ◽  
Eric Mozzanini ◽  
...  

AbstractThe pulse width modulation (PWM) spray system is the most advanced technology to obtain variable rate spray application without varying the operative sprayer parameters (e.g. spray pressure, nozzle size). According to the precision agriculture principles, PWM is the prime technology that allows to spray the required amount where needed without varying the droplet size spectra which benefits both the uniformity of spray quality and the spray drift reduction. However, some concerns related to the effect of on–off solenoid valves and the alternating on/off action of adjacent nozzles on final uneven spray coverage (SC) have arisen. Further evaluations of PWM systems used for spraying 3D crops under field conditions are welcomed. A tower-shaped airblast sprayer equipped with a PWM was tested in a vineyard. Twelve configurations, combining duty cycles (DC: 30, 50, 70, 100%) and forward speeds (FS: 4, 6, 8 km h−1), were tested. Two methodologies, namely field-standardized and real field conditions, were adopted to evaluate the effect of DC and FS on (1) SC variability (CV%) along both the sprayer travel direction and the vertical spray profile using long water sensitive papers (WSP), and (2) SC uniformity (IU, index value) within the canopy at different depths and heights, respectively. Furthermore, the SC (%) and deposit density (Nst, no stains cm−2), determined using short WSP, were used to evaluate the spray application performances taking into account the spray volumes applied. Under field-controlled conditions, the pulsing of the PWM system affects both the SC variability measured along the sprayer travel direction and along the vertical spray profile. In contrast, under real field conditions, the PWM system does not affect the uniformity of SC measured within the canopy. The relationship between SC and Nst allowed identification of the ranges of 200–250 and 300–370 l ha−1 as the most suitable spray volumes to be applied for insecticide and fungicide plant protection products, respectively.


2009 ◽  
Vol 49 (3) ◽  
pp. 290-296 ◽  
Author(s):  
Gnanadhas Preetha ◽  
Johnson Stanley ◽  
Thiagarajan Chandrasekaran ◽  
Sasthakutty Kuttalam

Toxicity of Imidacloprid and Diafenthiuron toChrysoperla Carnea(Stephens) (Neuroptera: Chrysopidae) in the Laboratory ConditionsInsecticides are unavoidable in pest management programs especially when the pest crosses Econimic Threshold Level (ETL). Nevertheless, often the plant protection products kill the natural enemy population making the pest to resurge and thus demanding more sprays. Therefore, insecticides used in IPM programs should be selective enough to spare the beneficials. Laboratory studies were conducted to find out the toxicity of imidacloprid and diafenthiuron to the eggs, larvae and adults ofChrysoperla carnea.Imidacloprid at the recommended dose of 0.28 ml/l caused 15.38% egg mortality, 26.67 and 33.33% larval mortality by ingestion and contact, respectively and 50.00% adult mortality. The egg mortality was about 15.38% and larval mortality of 23.33% and adult mortality of 26.67% was caused by diafenthiuron. Based on the classification given by IOBC/WPRS working group on Pesticides and non-target invertebrates, both the insecticides were classified as harmless toC. carnea, since the recommended dose caused less than 50% mortality in the laboratory conditions.


2018 ◽  
Vol 85 (0) ◽  
Author(s):  
Samara dos Santos ◽  
Valdemir Albuquerque da Silva Júnior ◽  
Sonia Maria Forti Broglio ◽  
Aldomario Santo Negrisoli Junior ◽  
Elio Cesar Guzzo

ABSTRACT: With the aim of developing tools for simultaneously managing Rhynchophorus palmarum and the coconut stem bleeding disease, we evaluated the effects of the insecticide thiamethoxam and the fungicide cyproconazole on R. palmarum larvae under laboratory conditions. Early-instar and intermediate-instar larvae were fed on an artificial diet containing 0.1% concentration of insecticide, fungicide or a mixture of both. Larval mortality was assessed daily during the 48 hours after the application of the treatments. Mean mortality values were subjected to analysis of variance and compared by Tukey’s test (p ≤ 0.05). Thiamethoxam caused mortality of 100% of early-instar and 90% of intermediate-instar larvae. In contrast, mortality was significantly lower in the cyproconazole treatment (60% for early-instar and 0% for intermediate-instar larvae) and the control (0% mortality for both treatments). The insecticide/fungicide mixture was equally effective (100% for early-instar and 86.67% for intermediate-instar larvae) to the insecticide only treatment. Differences in mortality between early-instar and intermediate-instar larvae were significant only for the thiamethoxam and cyproconazole treatments. These results indicate that, for the doses used here, thiamethoxam is toxic to both early-instar and intermediate-instar larvae, while cyproconazole is toxic just to early-instar larvae. Moreover, cyproconazole does not increase the toxicity of thiamethoxam. Early-instar larvae are more sensitive to thiamethoxam and cyproconazole than intermediate-instar larvae. We conclude that thiamethoxam + cyproconazole mixture may be effective for managing R. palmarum and associated fungal diseases on coconut palms.


2012 ◽  
Vol 51 (No. 4) ◽  
pp. 125-133
Author(s):  
P. Harašta

Verification of the possibilities of a droplet spectrum regulation due to the change of working pressure, as well as the change of the size of the discharge orifice of a nozzle, was undertaken in laboratory conditions by measurement of the size of a droplet spectrum of the applied liquid. Selected types of low drift nozzles &ndash; Albuz AVI 025, Lechler ID 120, Lechler IDK 120-05, Lechler IDN 120-025, TurboDrop 03, Hardi INJET 02, Hardi B JET 02, Hardi LD 02<br />and a flat fan nozzle Hardi ISO F 02-110 &ndash; underwent the measurement. The measurement of droplet spectrum was carried out at the nozzle&rsquo;s working height of 500 mm, and at working pressures of 0.1, 0.2, 0.3, 0.5 and 0.7 MPa. A laser measure equipment was used to measure the droplet spectrum of liquid.


2016 ◽  
Vol 48 (3) ◽  
pp. 355
Author(s):  
K. Saeidi ◽  
E. Saeidi

The citrus leaf miner, <em>Phyllocnistis citrella</em> Stainton (Lep., Gracillariidae), is one of the most destructive pest of citrus and related Rutaceae and ornamental plants in Iran. Larvae damage leaves by creating serpentine feeding mines, which have been lead to reduce yield. Resistance and toxicity problems derived from synthetic insecticides have made it necessary to find more effective and healthier alternatives; therefore, bio-insecticides (<em>i.e</em>., <em>Bacillus thuringiensis</em>) are becoming an important component in plant protection. The aim of the present study was to evaluate the efficiency of <em>B. thuringiensis</em> against <em>P. citrella</em>. Eight <em>B. thuringiensis</em> concentrations were used against <em>P. citrella</em> L3 on orange and mortality was recorded at 1, 4, 7 and 10 days after spraying. The results showed that <em>B. thuringiensis</em> significantly affected mortality of <em>P. citrella</em>. After 1, 4, 7 and 10 days of spraying 108 concentration of <em>B. thuringiensis</em> had significantly caused the highest mortality to the pest with 59.8, 68.4, 73.6 and 77.0%, respectively. Then the mortality percent decreased until it reached 6.5, 9.5, 39.3 and 46.7% at 101 concentration, respectively. In conclusion, the study indicated that <em>B. thuringiensis</em> is effective in controlling <em>P. citrella</em> under laboratory conditions.


2017 ◽  
Vol 4 ◽  
pp. 31 ◽  
Author(s):  
Ν.Ε. Roditakis

The effectiveness of Bacillus thuringiensis Berliner var. kurstaki (Dipel Abbot Lab.) against the grape berry moth (Lobesia botrana Den. & Shiff.) was evaluated under laboratory and field conditions. Under laboratory conditions (24±0.5°C, 55±5% r.h., 2,000 Lux, and 16 hours light daily) B. thuringiensis was compared to triflumuron and methomyl on egg hatching and shallow entries per grape berry. B. thuringiensis had no effect on egg hatching while methomyl and triflumuron had ovicidal action. Shallow entries per grape berry were 0.9-1, 0, 0 and 4.55 for B. thuringiensis, triflumuron, methomyl and control, respectively. Under field conditions, using as criteria for the timing of sprays: a. pheromone and food trap catches and b. visual counting of egg laying and a threshold of 20-30 eggs/100 grapes, two applications of B. thuringiensis at Kastelli Pediados in 1981 and four at Peza in 1982 were made both at the 2nd and 3rd flights. Its effectiveness was 96-100% and 92% at Kastelli Pediados and 73-75% at Peza.


2021 ◽  
Vol 13 (29) ◽  
pp. 31-38
Author(s):  
Vinelina Yankova ◽  
◽  
Dima Markova ◽  
Slavka Kalapchieva ◽  
◽  
...  

Pea (Pisum sativum L.) is a valuable grain legume crop, the seeds of which are used for human food and fodder. The seeds are consumed in a mature or green state. The priorities of the peas as a crop are the following: it is a legume, which enriches the soil with nitrogen; peas are the best possible precursor - clears the areas early; non-particular to soil and growing conditions; high protein content crop. However, the growing process of this crop could be worse by various pests that lead to product quality decay or they could even destroy the pea production. Economically important pests in field cultivation of peas are: pea aphid (Acyrthosyphon pisum Harris), pea weevil (Bruchus pisi L.) and pea moths (Laspeyresia nigricana Step. and Laspeyresia dorsana L.). Field experiments on pea variety Paldin were conducted at the Maritsa Vegetable Crops Research Institute, Plovdiv to determine the effectiveness of different plant protection products against a natural background of pest infestation. The biological activity of the insecticides Deca EC 50 ml/da (a. i. deltamethrin), Oasis 5 EC 25 ml/da (a. i. esfenvalerate), Piretro Natura 75 ml/da (a. i. pyrethrins), Neem Azal T/C 0.3% (a. i. azadirachtin), Naturalis 100 ml/da (a. i. Beauveria bassiana), Dipel 2 X 100 g/da (a. i. Bacillus thuringiensis var. kurstaki strain ABTS) and Rapax 100 ml/da (a. i. Bacillus thuringiensis subsp. kurstaki, strain EG 2348) against the main pests of peas in conventional and biological production systems was established.


1963 ◽  
Vol 95 (2) ◽  
pp. 127-133 ◽  
Author(s):  
W. A. Smirnoff

The susceptibility of the spruce budworm, Choristoneura fmiferana (Clemens), under laboratory conditions, to commercial preparations of Bacillus thuringiensis var. thuringiensis Berliner was reported by Angus et al. in 1961. This bacterium was recently tested, under field conditions, both as dusts and sprays. The results of ehese tests are presented here with comments on the effect of the environment and other factors.


2021 ◽  
Vol 51 (1) ◽  
pp. 67-73
Author(s):  
T. K. Kovalenko ◽  
A. S. Pronyushkina

The results of the application of environmentally friendly methods of potato pest control are presented. Comparative field trials of insectoacaricides and microbiological preparations were carried out on potatoes of the recognized variety Yantar in the Primorsky Territory in 2018 and 2019. The object of research was the larvae and beetles of the potato ladybird Henosepilachna vigintioctomaculata. The tubers were planted at the optimal time for the region, late April – early May. The study used Fitoverm preparations based on aversectin C (50 g/l), Akarin based on avertin N (2 g/l), Batsikol based on the strain of Bacillus thuringiensis var. darmstadiensis (BtH10), Bitoxybacillin based on the strain of Bacillus thuringiensis var. thuringiensis (BtH1). The preparations were studied independently and with Corado insecticide. Potato plants were sprayed with the preparations once. Pest counts were carried out before treatment and after treatment on the 5th, 10th, 15th day on 10 potato plants in three replications in accordance with the approved methods. Bioinsecticide Fitoverm showed a high efficiency of 90.5–94.0% at the application rate of 0.16 l/ha. A single application of bioinsecticides for 15 days restrained the intensity of the pest development below the threshold level. The combined use of bioinsecticides and an insecticide against the potato ladybird provided a decrease in the phytophage population by 90.8–99.8% compared to the control variant (without the use of plant protection products). The inclusion of preparations of biological origin Fitoverm, Akarin, Batsikol, Bitoxybacillin in potato cultivation technology will allow to limit the number of potato ladybird and solve the problem of plant protection in an environmentallyfriendly way in the south of the Far East.


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