scholarly journals Toxicity and Sublethal Effect of Farnesyl Acetate on Diamondback Moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 109
Author(s):  
Norazila Yusoff ◽  
Idris Abd Ghani ◽  
Nurul Wahida Othman ◽  
Wan Mohd Aizat ◽  
Maizom Hassan
Keyword(s):  
Plutella Xylostella ◽  
Sublethal Effects ◽  
Diamondback Moth ◽  
Sublethal Effect ◽  
Sublethal Concentration ◽  
Pupal Weight ◽  
Control Group ◽  
Hatching Rate ◽  
Egg Hatching ◽  
Female Ratio

The diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae), is the most important pest of cruciferous vegetables worldwide. In this study, we evaluated the properties of selected farnesyl derivative compounds against P. xylostella. The toxicity and sublethal concentration (LC50) of farnesyl acetate, farnesyl acetone, farnesyl bromide, farnesyl chloride, and hexahydrofarnesyl acetone were investigated for 96 h. The leaf-dip bioassays showed that farnesyl acetate had a high level of toxicity against P. xylostella compared to other tested farnesyl derivatives. The LC50 value was 56.41 mg/L on the second-instar larvae of P. xylostella. Then, the sublethal effects of farnesyl acetate on biological parameters of P. xylostella were assessed. Compared to the control group, the sublethal concentration of farnesyl acetate decreased pupation and emergence rates, pupal weight, fecundity, egg hatching rate, female ratio, and oviposition period. Furthermore, the developmental time of P. xylostella was extended after being exposed to farnesyl acetate. Moreover, the application of farnesyl acetate on P. xylostella induced morphogenetic abnormalities in larval–pupal intermediates, adults that emerged with twisted wings, or complete adults that could not emerge from the cocoon. These results suggested that farnesyl acetate was highly effective against P. xylostella. The sublethal concentration of farnesyl acetate could reduce the population of P. xylostella by increasing abnormal pupal and adults, and by delaying its development period.

Effects of rhizobacteria on the biology and behavior of Plutella xylostella (Lepidoptera: Plutellidae)

2017 ◽  
Vol 43 (2) ◽  
pp. 195
Author(s):  
Robson Thomaz Thuler ◽  
Fernando Henrique Iost Filho ◽  
Hamilton César De Oliveira Charlo ◽  
Sergio Antônio De Bortoli
Keyword(s):  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Insect Behavior ◽  
Control Treatment ◽  
Pupal Weight ◽  
Larval Feeding ◽  
Direct Effects ◽  
Plant Feeding ◽  
Kluyvera Ascorbata ◽  
And Behavior

Plant induced resistance is a tool for integrated pest management, aimed at increasing plant defense against stress, which is compatible with other techniques. Rhizobacteria act in the plant through metabolic changes and may have direct effects on plant-feeding insects. The objective of this study was to determine the effects of cabbage plants inoculated with rhizobacteria on the biology and behavior of diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae). Cabbage seeds inoculated with 12 rhizobacteria strains were sowed in polystyrene trays and later transplanted into the greenhouse. The cabbage plants with sufficient size to support stress were then infested with diamondback moth caterpillars. Later, healthy leaves suffering injuries were collected and taken to the laboratory to feed P. xylostella second instar caterpillars that were evaluated for larval and pupal viability and duration, pupal weight, and sex ratio. The reduction of leaf area was then calculated as a measure of the amount of larval feeding. Non-preference for feeding and oviposition assays were also performed, by comparing the control treatment and plants inoculated with different rhizobacterial strains. Plants inoculated with the strains EN4 of Kluyvera ascorbata and HPF14 of Bacillus thuringiensis negatively affected the biological characteristics of P. xylostella when such traits were evaluated together, without directly affecting the insect behavior.

scholarly journals Development and reproduction of Diadegma semiclausum (Hymenoptera Ichneumonidae) on diamondback moth Plutella xylostella (Lepidotera Plutellidae)

2008 ◽  
Vol 61 ◽  
pp. 322-327 ◽  
Author(s):  
D. Khatri ◽  
Q. Wang ◽  
X.Z. He
Keyword(s):  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Developmental Period ◽  
Fourth Instar ◽  
Pupal Weight ◽  
Diadegma Semiclausum

This study investigated the development emergence and mating of Diadegma semiclausum Hellen an important parasitoid of diamondback moth in the laboratory at 21 1C and 5060 RH with a photoperiod of 1212 h (lightdark) The parasitoids developmental period was significantly shorter and pupal weight significantly higher if their mothers parasitised the fourth instar larvae of DBM (P

scholarly journals Pyrethroid toxicity in silver catfish, Rhamdia quelen

2012 ◽  
Vol 32 (12) ◽  
pp. 1297-1303 ◽  
Author(s):  
Francisco P. Montanha ◽  
Luciana A.G. Galeb ◽  
Jorge D. Mikos ◽  
Luciana N. Ganeco ◽  
Tiago P. Pereira ◽  
...  
Keyword(s):  
Embryonic Development ◽  
Sublethal Concentration ◽  
Control Group ◽  
Average Weight ◽  
Hatching Rate ◽  
Silver Catfish ◽  
Rhamdia Quelen ◽  
Fish Tank ◽  
Average Size ◽  
Sublethal Concentrations

This study aimed to determine both the lethal and sublethal concentrations of Cypermethrin in young Silver Catfish (Brazilian "Jundiá", Rhamdia quelen) on aquatic environment during 96 hours, as well as to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development period of Rhamdia quelen, and to verify their respective rates of fertilization, hatching and survival. Pyrethroid nowadays is a widely used insecticide, which presents a high toxicity to fish. In order to determine lethal and sublethal concentrations, 120 silver catfish were used; each one had an average weight of 59.58±4.50g and an average size of 20.33±2.34cm. Concentrations used were 0, 1.0, 1.5, 2.0, 2.5, 3.0, 5.0, 10.0, 15.0 and 20.0mg of Cypermethrin per liter of water (mg/L). Fish were exposed to the product in 30-liter fish tanks. In each fish tank there were four fishes and the product was applied three times, i.e., a total of twelve fish were exposed to the product at each application, and a total of 120 fish during the entire experiment (n=120). In order to determine the Cypermethrin and Deltamethrin sublethal concentrations during the initial embryonic development, ovulation induction was performed on female fishes using hormones, and then and egg collection was performed. The eggs were then hydrated and fertilized in Cypermethrin and Deltamethrin in different concentrations: 0.001, 0.01, 0.1, 1.0 and 10.0mg/L of Cypermethrin and 0.001, 0.01, 0.1, 0.5 and 1.0mg/L of Deltamethrin, in addition to the control group (0mg/L). After fertilization, the eggs were kept in containers with the respective pesticides of Cypermethrin and Deltamethrin until hatching, when hatching rate was verified. Then the alevins, from the hatching, were kept on their respective concentrations of Cypermethrin and Deltamethrin so that the survival rate could be analyzed regarding the tested insecticides, during both 12-hour and 24-hour periods. Concerning the sublethal and lethal concentrations, Silver Catfish was sensitive to the tested concentrations of Cypermethrin, showing symptoms of poisoning, such as loss of balance, swimming alteration, dyspnea (they kept their mouths and opercula open), upright swimming and sudden spiral swimming movements. The intensity of such symptoms varied in proportion to the concentration used. The concentrations above 3.0mg/L were considered lethal to the species, since every animal exposed to concentrations between 3.0 and 20.0mg/L had died, while concentrations between 1.0 and 2.5mg/L were considered sublethal. Lethal concentration of Cypermethrin to Silver catfish, in 96 hours, was 1.71 milligram per liter of water. Concerning the sublethal concentration of Cypermethrin and Deltamethrin during the initial embryonic development, the results show that both pyrethroids had significantly decreased the analyzed parameters when comparing them with the control group. It was concluded that, even with the fish being more resistant to pyrethroids in comparison with other species, both the young animals and the ones in stage of embryonic development were susceptible to the effects of these pesticides.

scholarly journals Effects of Helicoverpa armigera Nucleopolyhedrosis virus (HaNPV) on the larvae of the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)

2014 ◽  
Vol 50 (No. 4) ◽  
pp. 184-189 ◽  
Author(s):  
Z. Magholi ◽  
H. Abbasipour ◽  
R. Marzban
Keyword(s):  
Plutella Xylostella ◽  
Diamondback Moth ◽  
Adult Emergence ◽  
Mortality Rates ◽  
Pupal Weight ◽  
Similar Response ◽  
Occlusion Bodies ◽  
Lethal Time ◽  
Nucleopolyhedrosis Virus ◽  
Leaf Disks

Laboratory studies were performed to determine the insecticidal activity of baculovirus against diamondback moth, Plutella xylostella. The nucleopolyhedrosis (HaNPV) was tested against 2<sup>nd</sup> instar larvae fed on cabbage leaf disks treated with aqueous suspensions of occlusion bodies (OB). Lethal concentrations values (LC<sub>25</sub>, LC<sub>50</sub>, and LC<sub>75</sub>) were 2.2&nbsp;&times; 10<sup>3</sup>, 3.8 &times; 10<sup>4</sup>, and 6.6 &times; 10<sup>5</sup> PIB/ml for 2<sup>nd</sup> larval instars, respectively. Median lethal time (LT<sub>50</sub>) to similar response levels (mortality rates 50&ndash;75%) decreased with decreasing larval age (from 114.23 to 106.05 h). Larval development time and pupal weight were not affected by different concentrations (LC<sub>25</sub>, LC<sub>50</sub>, and LC<sub>75</sub>) of HaNPV. Significant differences were found in the pupal rate and adult emergence in larvae treated by different concentrations. In conclusion, HaNPV treatment failed to cause high mortality rates in P. xylostella larvae, but it had prompt deleterious effects on survivor&rsquo;s development and emergence. &nbsp;

Acute and Chronic Toxicity of Indoxacarb in Two Populations of Plutella xylostella (Lepidoptera: Plutellidae)

2020 ◽  
Author(s):  
Amanda A F Lemes ◽  
Thamiris P Sipriano-Nascimento ◽  
Natalia F Vieira ◽  
Camila P Cardoso ◽  
Alessandra M Vacari ◽  
...  
Keyword(s):  
Plutella Xylostella ◽  
Sublethal Effects ◽  
Diamondback Moth ◽  
Control Treatment ◽  
Adult Survival ◽  
Mean Values ◽  
Treatment Groups ◽  
The Mean ◽  
Two Populations ◽  
Selection Of

Abstract The diamondback moth, Plutella xylostella (Linnaeus, 1758), is one of the main pests of brassicas, and various insecticides, such as indoxacarb, are used to control it. However, frequent insecticide applications favor the selection of resistant individuals. Thus, the residual and sublethal effects of indoxacarb in two populations of P. xylostella, one collected in the field (FP) and one from the laboratory (LP), were evaluated and compared. The objective of this research was to investigate the toxicity of indoxacarb at residual and sublethal levels in a field population of P. xylostella from Brazil and a population from the laboratory. Leaf-dip bioassays showed high toxicity, with LC50 values after 48 h of 3.7 and 6.9 mg/liter for the LP and FP, respectively. Sublethal effects were indicated by significant reduction in the survival of larvae, pupae, and offspring. There was an increase in foliar consumption and a decrease in adult survival in the LP, and a decrease in fecundity in the FP. For the LP and FP population, the mean values for R0, rm, and λ for the control treatment were significantly higher than for the treatment groups (CL15 and CL25). Exposure of larvae to sublethal indoxacarb concentrations significantly reduced larval and pupal survival. Larval and pupal survival decreased as the indoxacarb concentration increased. Fecundity was significantly lower for the FP at LC15 (96.2 eggs per female) and LC25 (69.2 eggs per female) concentrations compared with the other treatments.

scholarly journals Effects of Pyriproxyfen on Life Table Indices ofPlutella xylostellain Multigenerations

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Mohammad Mahmoudvand ◽  
Saeid Moharramipour ◽  
Mehrdad Iranshahi
Keyword(s):  
Sublethal Effects ◽  
Diamondback Moth ◽  
Reproductive Rate ◽  
Good Choice ◽  
Pupal Weight ◽  
Moth Population ◽  
Net Reproductive Rate ◽  
Treatment Groups ◽  
Rate Of Increase ◽  
Major Pest

The diamondback moth (DBM),Plutella xylostella(L.) (Lepidoptera: Plutellidae), is a major pest of Brassicaceae family in Iran. This study investigated the sublethal effects of pyriproxyfen, a juvenile hormone analogue, on DBM, for two subsequent generations. The leaf dip bioassay method was adopted in conducting this experiment. Sublethal concentrations resulted in a significant decrease in fecundity, oviposition period, and pupal weight of parents and offspring generations. Also, the development time of DBM was prolonged after exposure to pyriproxyfen. The biological parameters such as net reproductive rate (R0) and intrinsic (rm) and finite (λ) rate of increase were lower than control in treatment groups, significantly. From our investigations, pyriproxyfen is a good choice for control of the diamondback moth population through continuous generations.

scholarly journals Change in Life Expectancy and Stable Age Distribution of the Diamondback Moth, Plutella Xylostella (L.) After Indoxacarb Treatment

2012 ◽  
Vol 52 (3) ◽  
pp. 342-346 ◽  
Author(s):  
Mohammad Mahmoudvand ◽  
Habib Abbasipour ◽  
Aziz Garjan ◽  
Ali Bandani
Keyword(s):  
Life Expectancy ◽  
Plutella Xylostella ◽  
Sublethal Effects ◽  
Diamondback Moth ◽  
Age Distribution ◽  
Oviposition Period ◽  
Stable Age Distribution ◽  
Sublethal Doses ◽  
High Doses ◽  
Sublethal Concentrations

Change in Life Expectancy and Stable Age Distribution of the Diamondback Moth,Plutella Xylostella(L.) After Indoxacarb TreatmentUsing high doses of insecticides is very dangerous for the environments and for humans. Decreased concentrations are necessary. Insecticides have lethal and sublethal effects. The aim of the present study was to determine the behavior ofPlutella xylostellawhen exposed to sublethal doses of indoxacarb in terms of the age-specific fecundity (mx), life expectancy (ex) and stable age distribution (Cx). Also, the effects of sublethals on the pre-oviposition, oviposition and post-oviposition period of this insect were investigated. The results show that exposure to this insecticide decreased the age-specific fecundity (mx) and life expectancy (ex) of the insect. Although the pre-oviposition period was delayed in the treated groups, the post-oviposition period significantly decreased when exposed to LC10and LC25doses (the dose concentrations killed 10 and 25% of the populations) of indoxacarb. The oviposition period did not change. Furthermore, sublethal concentrations of the applied insecticide caused changes in the exposed structure.

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