ABSTRACT
The present study is carried out to evaluate the toxic efficiency and delayed effects of five botanical oils on the greasy cut worm Agrotis ipsilon (Lepidoptera: Noctuidae), as a trial for the attainment of a possible use of an alternative safe and effective phytochemicals against the insect-pest. So as to minimize or prevent the repeated usage of conventional insecticides, then reduce the environmental pollution as well as the occurring hazards to man and domestic animal due to the use of the pesticides alone. Four tested concentrations (0.5, 1.0, 1.5 and 2.5% v/v) from each of camphor, red basil, menthol, rose and anise oils, were bioassayed by treating the offered castor oil bean leaves, to the 4th instar larvae along 48h, under the laboratory higrothermic conditions of 25±2 °C and 65±5% R.H. The obtained results showed that the five tested oils were found to have more or less toxic activity and drastic effects on the inspected parameters of fitness components of the treated parent generation of the insect, in particular, pupae, emerged adult moths and laid eggs/female. In this respect camphor and red basil oils were highly effective, followed by menthol oil, anise oil and the least effective one was rose oil. Moreover, the assessed unprofitable delayed effects on the going on of the biological performance within the treated insects showed the adverse effects on the fitness components of the consequent generations (fs) post (p) one treatment with each of the bioassyed oils. The prevalence of adverse effects and disturbance in the going on biological performance through the period of (p) generation; which is followed by the distinct failure of insect development in (f1) generation were recorded for each of the tested menthol oil at 0.5 and 1.5% (v/v); camphor oil at 1.5 and 2.5% and red basil oil at 2.5% (v/v). While anise and rose oils were somewhat less efficient causing the distinct failure of the following generations up to the 3rd and/or the 6th ones. That observed distinct failure of the insect development could be attributed to the rapid or/and slow cumulative effect of the induced recessive lethal genes in both influenced sexes along the interval of the following developed generations (fs) after (p) one treatment, causing apparent adverse disturbance of the normal biological performance, which finally appears at the beginning of the failed generation.
Subject(s)
Insecticides/toxicity , Moths/drug effects , Ocimum basilicum/chemistry , Pest Control, Biological/methods , Pimpinella/chemistry , Plant Oils/toxicity , Rosa/chemistry , Animals , Female , Insecticides/chemistry , Larva/drug effects , Larva/growth & development , Male , Moths/growth & development , Oils, Volatile/chemistry , Oils, Volatile/toxicity , Plant Oils/chemistry , Pupa/drug effects , Pupa/growth & developmentABSTRACT
The present study is initiated to determine the toxic and delayed effects of four botanical oils on the greasy cutworm A. ipsilon, aiming to attain an alternative environmentally safe and effective phytochemicals against the insect-pest. Four botanical oils (camphor, red basil, menthol and rose oil) were added at rates of 0.5 and 1.0% (v/w). The tested oils were added alone, and/or admixed at proportional rate of 1:1 in the prepared baits against the exposed 4th instar till the 6th instar larvae of the insect. The study was run under the laboratory higrothermic conditions of 25±2°C and 65±5% R.H. The results showed that the tested baits of camphor, red basil and menthol oils at concentration rates of 0.5 and 1.0% (v/w) adversely affected the inspected parameters of fitness components of the treated individuals of parent (p) generation. They gave more or less fewer numbers of weak unviable adult-moths, which were either sterile or they laid few numbers of infertile eggs and died before the induction of (F1) progeny. That failure could be elucidated by the rapid occurrence of drastic effects on the biological performance of both the influenced sexes of adult-moths along the period of parent's development. Finally it ended by the inhibited induction of (F1) progeny. A delayed effect of the prepared baits of rose oil at 0.5 and 1.0% (v/w), was assessed on the following raised F1, F2, F3 and F4 generations after parent's treatment. The delayed effect was detected as less efficient latent effect on each of these consequently raised generations; characterized by the gradual decrease of the number of alive immatures and adult-moths. The effect was recorded as gradual increase of dead and malformed individuals and adult-moths. In addition to the gradual decrease of deposited and/or hatched eggs up to the 4th generation, which ended by the complete failure of the development. That failure could be also attributed to the cumulated effects of the induced recessive lethal genes in both the influenced sexes during the periods of raised F1, F2 and F3 generations. The recessive lethal genes caused drastic unprofitable effects that appeared at the beginning of the 4th generation that failed. Also, the tested baits (0.5 and 1.0%, v/w) of each of admixed camphor, red basil and menthol oil with rose oil (1:1), greatly affected the developmental parameters of the treated insects. The highest efficient toxicity and an adverse biological performance of the admixed camphor and/or red basil oils with rose oil at 0.5 and 1.0 (v/w), and menthol/rose oil at 0.5% (v/w) on the treated parent generation were detected. The previous treatment gave unviable sterile adults, which died before the induction of (F1) progeny. That recorded failure of (F1) proves the fastest toxic efficiency and a drastic biological performance which were entirely unable to induce (F1) progeny. The tested bait of mixed menthol/rose oils (1.0%, v/w), showed significant reduction in all studied parameters of F1 and F2 fitness components. The tested bait raised sterile unviable adult-moths of (F2) generation which furtherly ended by the distinct failure of (F2) development. This effect may be caused by the cumulative effects of the induced recessive lethal genes in both of the affected sexes through the developmental period of (F1) generation after (P) one treatment, inducing apparent drastic effects, which were revealed at the beginning of (F2) generation. Remarkably, the inspected faster or slower occurred toxicity and drastic biological performance of these admixed botanical oils, may be referred to the synergistic action for most of the evaluated mixtures or/and the additive one for menthol/rose oil (1.0%), which needs further investigation.
Subject(s)
Insecticides/toxicity , Moths/drug effects , Ocimum basilicum/chemistry , Pest Control, Biological/methods , Pimpinella/chemistry , Plant Oils/toxicity , Rosa/chemistry , Animals , Drug Synergism , Female , Larva/drug effects , Larva/growth & development , Male , Moths/growth & development , Moths/physiology , Oils, Volatile/toxicity , Pupa/drug effects , Pupa/growth & development , Reproduction/drug effectsABSTRACT
This study aims to evaluate the efficacy of five measures; including the release of two strains of Trichogramma, Bacillus thuringiensis (B.t.). Sweetened B.t. and the environmentally friend insecticide (Tracer®), to manage the grape moth, Lobesia botrana that infested the grape vines c.v. "Thompson seedless " in Egypt severely during the two successive years of 2011 and 2012. In concern to the release of the worldwide, Trichogramma evanescens Westwood., the mean total grape yield ranged from 8.00 to 14.00 ton/fed and from 6.90 to 11.9, in respect to the two seasons and the mean infestation percentages fluctuated between 50.00 and 16.14; 43.48 and 21.01 in sequence for the same years. The corresponding grape bunches loss percentages averaged from 21.43 to 6.91; 18.63 to 9.00,respectively for the same periods of this study. Whereas, it was noticed that in releasing the indigenous T. bourarchae was more effective than T. evanescens in reducing all the above mentioned grape yield particularly. Applying Bacillus thuringiensis (B.t.) and/or adding sugar as a stimulant to improve yields reduced the infestation and the crop loss percentage. However, Bacillus thuringiensis mixed with sugar which overweighed the use of Bacillus thuringiensis alone. Although Tracer® provided good harvest in both years, but unfortunately it affected the grape berries components rather than the other treatments. Control plots indicated 48 and 50% infestation, with very low yield compared with the other five trials to manage the assigned insect pest. For the first time worldwide economics and profits were computed taking into account the whole market sale, the total control costs and the gross income to decide the most profitable treatment for the table grape growers under the Egyptian conditions. It was found that the mean (L.E.) profits/fed were arranged in a descending order as follows: 470.95, 513.28, 504.78, 500.82, 397.25 and 0.00 for Bacillus thuringiensis + sugar, Trichogramma bourarchae, Trichogramma evanescens Westwood, Dipel-2x®, Tracer® and control in respect in 2011. The corresponding values in the year 2012 were 453.85, 445.58, 427.18, 377.00, 349.18 and 0.00 for Trichogramma bourarchae, Bacillus thuringiensis + sugar, Dipel-2x®, Trichogramma evanescens Westwood, Tracer® and control in respect. The obtained results were analysed and discussed in the text.
Subject(s)
Insect Control/methods , Lepidoptera/growth & development , Moths/growth & development , Pest Control, Biological/methods , Plant Diseases/prevention & control , Vitis/parasitology , Animals , Bacillus thuringiensis/physiology , Egypt , Lepidoptera/microbiology , Moths/microbiology , Plant Diseases/parasitologyABSTRACT
The present study was initiated to elucidate the effect of potato tubers treatment using fine dusts of Psidium guajava, Cymbopogon citratus, talc powder and their progressive dilutions(w/w) on the fitness components of raised generations of the potato tuber moth (PTM), Phthorimaea operculella. Results showed a direct as well as cumulative delayed effect of the tested plants fine dusts, either alone or admixed with talc powder in progressive dilutions from 5% up to 50% w/w on the viability of developing immatures and potentiality of adult moths. The revealed effects of each of the tested crude plant fine dusts or talc powder alone and/or their progressive dilutions (w/w) could be explained briefly as gradual significant shortening of life span of both sexes, prolongation of larval duration, reduction in number of raised pupae, increase of malformed ones, sharp decrease in the rate of emerged moths, deposited eggs, and developing of immatures; According to lower used dilutions of each tested plant fine dust from 5% to 20%, the complete inhibition of reproductive potential of both adult sexes, the going on metamorphic development of deposited eggs and/or raised immatures of the following generation, after the treatment of parent one, had been revealed the following distinct failure of: a) F1 development after former treatment of parent generation with the higher concentrations of 30-50% of both tested plant fine dusts and the lower prepared dilutions (10% and 20% (w/w)) of both the tested Psidium guajava and (20% (w/w)) Cymbopogom citratus plant fine dusts, resulted in fewer number of the emerged moths that were unviable, weak, sterile and died before induction the F1 progeny, b) F2 development due to the former treatment of the parents with talc powder, Psidium guajava fine dusts alone or its prepared dilutions of (5% (w/w)) and Cymbopogom citratus dilution of (10%(w/w)) gave unviable weak and sterile moths unable to induce the F2 progeny, c) F3 development post former treatment of the parent generations with Cymbopogom citratus dilution of 5% (w/w) induced unviable sterile moths and died after emergence and d) F4 development owing to the former parent treatment with Cymbopogon citratus fine dust alone; The complete failure of each of the above mentioned generations could be attributed to the cumulative effect of induced recessive lethal genes in both sexes along the extended period of each of these following generations, post former treatment of parent one, causing apparent undesirable effects, that appeared at the beginning of each of them.