scholarly journals Acute toxity and sublethal effects of pymetrozine on the whitefly parasitoid Encarsia formosa Gahan

2020 ◽  
Vol 35 (2) ◽  
pp. 81-95
Author(s):  
Tanja Drobnjakovic ◽  
Dejan Marcic
Keyword(s):  
Sublethal Effects ◽  
Integrated Control ◽  
Pupal Stage ◽  
Adult Emergence ◽  
Encarsia Formosa ◽  
Greenhouse Whitefly ◽  
Instantaneous Rate ◽  
Rate Of Increase ◽  
Juvenile Development ◽  
Total Parasitism

Sublethal effects of a pymetrozine-based product (commercial product Chess 50 WP) on life history traits and population growth of one commercialized strain (?Dutch? strain) and two local populations (Bujanovac and Negotin) of the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae) were evaluated in laboratory bioassays. All trials were carried out at 27?1?C temperature and under 60?10 % relative humidity and 16/8 h daylight/darkness photoperiod in four replications. Longevity of wasps exposed for 48 h to residues of the pymetrozine insecticide (LC50, 280 mg a.i./l) was shorter (by 2.7-3 days) than that of control wasps. Total parasitism of Negotin wasps was significantly reduced (by 8.2 %), as well as total parasitism and adult emergence of the Dutch strain (by 7.3 and 8.2 %, respectively), compared to control wasps. The instantaneous rate of increase (ri) of surviving adult wasps was also significantly reduced (by 6.6, 6.3 and 7.6 % in populations Negotin, Bujanovac and Dutch strain, respectively). Direct treatment of wasps at their pupal stage (LC50, 300 mg a.i./l) reduced total parasitism of Negotin wasps (by 8 %), and reduced ri levels, but the reduction was significant only for the Bujanovac (by 6.7 %) and Negotin (by 4.6 %) populations. Juvenile development of the parasitoid in treated pupae was significantly extended (by 0.3-1.1 days), compared to control wasps. The implications of these results on integrated control of the greenhouse whitefly are discussed.

scholarly journals Sublethal effects of imidacloprid on the whitefly parasitoid Ecarsia formosa Gahan

2017 ◽  
Vol 32 (3-4) ◽  
pp. 205-216 ◽  
Author(s):  
Tanja Drobnjakovic ◽  
Dejan Marcic ◽  
Mirjana Prijovic ◽  
Pantelija Peric ◽  
Slobodan Milenkovic ◽  
...  
Keyword(s):  
Acute Toxicity ◽  
Sublethal Effects ◽  
Integrated Control ◽  
Pupal Stage ◽  
Adult Emergence ◽  
Encarsia Formosa ◽  
Greenhouse Whitefly ◽  
Instantaneous Rate ◽  
Commercial Strain ◽  
Total Female

Acute toxicity of an imidacloprid-based product (Confidor 200 SL) to pupae of the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae), and its effects on life history traits and population growth in F1 generation of the surviving parasitoid females of a commercial strain (?Dutch? strain, D) and two local populations from Serbia (Bujanovac, B; Negotin, N) were examined in laboratory bioassays. All trials were carried out at 27?1?C temperature and 60?10% relative humidity, and under 16/8 h daylight/darkness photoperiod in four replications. In acute toxicity bioassays, tobacco leaves carrying parasitoid pupae were treated with a series of symmetrical concentrations (800, 400, 200, 100, 50 and 25 mg a.i./l) covering a 10-90% mortality range. The product based on imidacloprid, applied directly onto parasitoid pupae at mean lethal concentrations (LC50) determined in the acute toxicity assays (30 mg/l, 20 mg/l and 25 mg/l, for populations B, N and D, respectively), significantly affected the survival of females developed from the treated pupae, extended the duration of juvenile development (by 1.81, 1.59 and 1.73 days for populations B, N and D, respectively), significantly reduced total parasitism of females D (25.92 %), total female adult emergence in populations B (27.48 %) and D (17.92 %), and significantly reduced the instantaneous rate of increased only of females N (4.23 %). Considering the high acute toxicity of the imidacloprid product to the pupal stage of E. formosa, and significant reductions in life table and population parameters, imidacloprid is not considered compatible for simultaneous use with the parasitoid E. formosa. A more precise assessment of risks involved in the use of that insecticide requires a more detailed testing in the field. The implications of these results for the concept of integrated control of the greenhouse whitefly are discussed.

scholarly journals Toxic and sublethal effects of buprofezin on the whitefly parasitoid Encarsia formosa Gahan

2019 ◽  
Vol 34 (3-4) ◽  
pp. 201-209
Author(s):  
Tanja Drobnjakovic ◽  
Dejan Marcic ◽  
Mirjana Prijovic ◽  
Slobodan Milenkovic
Keyword(s):  
Acute Toxicity ◽  
Emerging Adults ◽  
Sublethal Effects ◽  
Adult Emergence ◽  
Field Testing ◽  
Precise Determination ◽  
Encarsia Formosa ◽  
Instantaneous Rate ◽  
Commercial Strain ◽  
Rate Of Increase

Acute toxicity of a buprofezin-based product (commercial product Elisa 440 SC) to pupae of the whitefly parasitoid Encarsia formosa Gahan (Hymenoptera: Aphelinidae), and its effects on life history traits and population growth in F1 generation of a commercial strain (?Dutch? strain, D) and two local populations from Serbia (Bujanovac, B; Negotin, N) were examined in laboratory bioassays. All trials were carried out at 27?1?C temperature and 60?10% relative humidity, and under 16/8 h daylight/darkness photoperiod in four replications. In an acute toxicity bioassay, tobacco leaves carrying parasitoid pupae (20 pupae per replicate) were treated with a series of buprofezin concentrations covering a 10-90% mortality range, and mortality was calculated based on the number of emerging adults 9 days after treatment. The following LC50 (mg/l) estimates were obtained: 244.2, 281.5 and 199.5 (for B, N and D, respectively). The product based on buprofezin, applied to parasitoid pupae at concentrations within the LC50s and 95% confidence limits (264 mg/l for B and N; 220 mg/l for D), significantly prolonged the duration of juvenile development (2, 1.7 and 2.2 days for B, N and D, respectively, compared to control data). Females from all tested populations that emerged from the treated pupae and were exposed to the residual action of buprofezin lived shorter than control females (B, N and D by 1.5, 0.7 and 1.7 days, respectively). Also, females that emerged from the treated pupae achieved a significantly reduced level of parasitism (B, N and D by 11.7, 17.7 and 17.6 %, respectively), total adult emergence (B, N and D by 11.6, 17.8 and 17.8 %, respectively) and instantaneous rate of increase (B, N and D by 8.2, 6.8 and 12.5 %, respectively), compared to control. More precise determination of risks involved in the use of buprofezin requires its more detailed field testing.

Acaricidal activity and sublethal effects of the microbial pesticide spinosad on Tetranychus urticae (Acari: Tetranychidae)

2017 ◽  
Vol 22 (10) ◽  
pp. 1748 ◽  
Author(s):  
Irena Međo ◽  
Bojan Stojnić ◽  
Dejan Marčić
Keyword(s):  
Population Growth ◽  
Tetranychus Urticae ◽  
Sublethal Effects ◽  
Intrinsic Rate ◽  
Intrinsic Rate Of Increase ◽  
Instantaneous Rate ◽  
Leaf Discs ◽  
Rate Of Increase ◽  
Female Longevity ◽  
Microbial Pesticide

Laboratory bioassays were conducted to evaluate the toxicity of the microbial pesticide spinosad to different life stages of the two-spotted spider mite, Tetranychus urticae Koch, as well as its sublethal effects on reproduction and population growth of this important mite pest. The biopesticide was applied to bean primary leaves or leaf discs carrying spider mites using a Potter spray tower (2.7 mg/cm2 aqueous deposit). The following LC50 and LC90 (mg/L) estimates for motile stages were obtained in acute toxicity bioassays: 27.52 and 116.72 (larvae), 36.55 and 136.20 (protonymphs), 82.76 and 721.28 (female deutonymphs), and 61.47 and 457.21 (adult females). Spinosad showed no significant ovicidal action: toxic effect observed after spraying eggs (LC50 = 105.78 mg/L, LC90 = 596.95 mg/L) was the result of its residual action on larvae that hatched from the treated eggs. The effects of spinosad on life history traits and population growth of adult female survivors from treatments with 240, 120 and 60 mg/L were evaluated in two successive 7-day bioassays on untreated leaf discs. In the first bioassay, females that survived treatments as 24 h old eggs and completed their juvenile development on treated leaves had significantly lower gross fecundity, net fecundity and instantaneous rate of increase (ri) but the reduction was merely 4–6%, 9–11%, and 2–3%, respectively. Female longevity was significantly reduced (approximately by half a day) only after treatment with 240 mg/L. In the second bioassay, in which females were treated during their pre-ovipositional period, the treatments with 240 and 120 mg/L significantly reduced their gross fecundity (16–17%), net fecundity (28–31%), ri values (8–9%) and female longevity (approximately by one day). Spinosad effects on the intrinsic rate of increase (rm) and other demographic parameters were evaluated in two successive bioassays in which life tables were constructed for females that survived treatment with 120 mg/L at the egg stage (first demographic bioassay) or pre-ovipositional period (second demographic bioassay). In the first bioassay, the intrinsic rate of increase was significantly higher in treated (rm = 0.278) than control mites (rm = 0.267) as a result of higher net fertility at the beginning of reproduction of treated females. In the second bioassay, treated females had significantly lower rm than control females (0.254 and 0.283, respectively). The results obtained in this study indicate that spinosad, applied against insect pests (at field relevant rates of 60–240 mg/L), could eliminate a part of T. urticae population as well, but survivors would retain a significant potential for population recovery. 

scholarly journals Selectivity of pesticides used in peach orchards to eggs and pupae of the predators Chrysoperla externa and Coleomegilla quadrifasciata

2019 ◽  
Vol 40 (4) ◽  
pp. 1427 ◽  
Author(s):  
Franciele Silva de Armas ◽  
Anderson Dionei Grützmacher ◽  
Dori Edson Nava ◽  
Matheus Rakes ◽  
Flávio Amaral Bueno ◽  
...  
Keyword(s):  
Pest Control ◽  
Sublethal Effects ◽  
Integrated Control ◽  
Pupal Stage ◽  
Direct Application ◽  
International Organization ◽  
Total Effect ◽  
Laboratory Conditions ◽  
Larval Hatching ◽  
Class 1

This study aimed to assess, under laboratory conditions, the selectivity of nine pesticides used in peach to the egg and pupal stages of the predators Chrysoperla externa and Coleomegilla quadrifasciata. Tests consisted of the direct application of pesticides on eggs and pupae of predators and assessment of sublethal effects on fertility and fecundity of emerged adults. For eggs, the pesticides were classified according to the effects on the reduction of the percentage of larval hatching, while for pupae they were classified as a function of the total effect, according to the toxicity scale proposed by the International Organization for Biological and Integrated Control (IOBC). All the pesticides (used dose) were harmless (class 1) to eggs of C. externa, but abamectin (80) and copper + calcium (1%) were considered slightly harmful (class 2) to pupae. In bioassays with C. quadrifasciata, abamectin (80), deltamethrin (40), and malathion (150) were classified as slightly harmful (class 2), while fenitrothion (100) was moderately harmful (class 3) to predator eggs; in the pupal stage, abamectin (80), fenitrothion (100), and malathion (150) were considered harmful (class 4). Azadirachtin (1%), chlorantraniliprole (14), deltamethrin (40), copper + calcium (25% + 10%), and sulfur + calcium (3.5 Ba) were harmless (class 1) to eggs and pupae of C. externa and C. quadrifasciata and thus should be prioritized in sprayings for pest control in the IPM of peach.

Residual and sublethal effects of fenpyroximate and pyridaben on the instantaneous rate of increase of Tetranychus urticae

2006 ◽  
Vol 25 (6) ◽  
pp. 542-548 ◽  
Author(s):  
Minsik Kim ◽  
Cheolho Sim ◽  
Dongyoung Shin ◽  
Eunho Suh ◽  
Kijong Cho
Keyword(s):  
Tetranychus Urticae ◽  
Sublethal Effects ◽  
Instantaneous Rate ◽  
Rate Of Increase

scholarly journals The effect of spiromesifen on the reproductive potential of Tetranychus urticae koch (Acari: Tetranychidae)

2009 ◽  
Vol 24 (3) ◽  
pp. 203-209 ◽  
Author(s):  
Dejan Marcic ◽  
Irena Ogurlic ◽  
Slavka Mutavdzic ◽  
Pantelija Peric
Keyword(s):  
Tetranychus Urticae ◽  
Sublethal Effects ◽  
Reproductive Potential ◽  
Instantaneous Rate ◽  
Control Value ◽  
Rate Of Increase ◽  
Significant Difference ◽  
L 51 ◽  
Two Spotted Spider Mite ◽  
Tetranychus Urticae Koch

Laboratory bioassays were conducted to evaluate the effects of spiromesifen on the fecundity, fertility and population growth of two-spotted spider mite (Tetranychus urticae Koch) after treatment of pre-ovipositing females with five acaricide concentrations: 180 mg/l (maximum recommended concentration for use in glasshouses against spider mites), 18 mg/l, 1.8 mg/l and 0.18 mg/l (the last one was discriminative for eggs and immatures in preliminary studies, i.e. produced 100% mortality of those stages) and 0.018 mg/l. After 24h exposure, the percentages of females surviving treatment without visible symptoms of poisoning were 50% (180 mg/l), 45% (18 mg/l), 51% (1.8 mg/l), 74% (0.18 mg/l), 96% (0.018 mg/l) and 98% (0 mg/l). Over the first four days after treatment, the females that survived 180 mg/l and 18 mg/l laid no eggs. The total number of eggs laid after treatment with these two concentrations was reduced to less than 2% against the control by the end of the trial. The females that survived 1.8 mg/l laid 50% less eggs, compared to the control, while the number of eggs laid by the females treated with 0.18 mg/l and 0.018 mg/l were 19% and 4% lower, respectively. Over the initial four days, egg hatch rates in treatments were 73-87%, and 92-93% in the control. Significant statistical differences between gross fecundity (FCg) and gross fertility (FTg) values in the control and treatments were detected for females surviving 180 mg/l, 18 mg/l and 1.8 mg/l. On the other hand, only the net fertility (FTn) value of females treated with 0.018 mg/l showed no statistically significant difference from the control value. Treatments with 180 mg/l and 18 mg/l significantly reduced the instantaneous rate of increase (ri) 6, 8 and 10 days after treatment, compared to the control. The negative ri values in those treatments indicated a declining population. Sublethal effects of spiromesifen and its impact on T. urticae management are discussed.

scholarly journals Effects of spirodiclofen on the reproductive potential of two-spotted spider mite (Acari: Tetranychidae) ovipositing females

2009 ◽  
Vol 61 (4) ◽  
pp. 777-785 ◽  
Author(s):  
D. Marcic ◽  
Irena Ogurlic ◽  
P. Peric
Keyword(s):  
Spider Mite ◽  
Population Decline ◽  
Survival Rates ◽  
Reproductive Potential ◽  
Adult Emergence ◽  
Egg Laying ◽  
Instantaneous Rate ◽  
Rate Of Increase ◽  
Survival And Reproduction ◽  
Two Spotted Spider Mite

A laboratory bioassay was conducted to evaluate the effects of spirodiclofen on the survival and reproduction of young and mated females of two-spotted spider mite (Tetranychus urticae Koch). The females were sprayed with a series of acaricide concentrations (96, 48, 24, 12, and 6 mg/l) 24-30 h after adult emergence, i.e., at the age most likely to exhibit dispersal behavior and close to their reproductive maximum. The proportions of T. urticae females that survived treatment without symptoms of poisoning were concentration-dependent, ranging between 0.41 and 0.88 (0.96 in the control). With the exception of females that survived 6 mg/l, fecundity of the treated female mites was strongly affected during the exposure, compared to the control. The mean daily fecundity (EL) and mean daily fertility (EH) of surviving females, transferred daily to new leaf disks over the following five days, significantly decreased as spirodiclofen concentrations increased. In treatments with 6 mg/l and 12 mg/l, only the latter concentration significantly reduced both EL and EH, compared to the control. In females that survived 24 mg/l and 48 mg/l, these life history parameters were reduced by over 90%, while treatment with 96 mg/l completely terminated egg-laying. The treated females lived for a significantly shorter time than untreated ones, with the exception of females that survived 6 mg/l. Compared to the control females, gross fecundity (GL) and gross fertility (GH) of the treated females were strongly reduced on the first and second day; from the third day onward, females treated with the lowest concentrations achieved marked recovery, their GL and GH going even above the values in the control. However, net fecundity (NL) and net fertility (NH) of all treated females decreased considerably throughout the trial, indicating that survival rates of these females were lower, compared to the control. Calculated as total sums of gross and net daily schedules within five days, fecundity and fertility significantly decreased as spirodiclofen concentration increased. The two lowest concentrations failed to achieve a significant reduction of GL, while GH, NL, and NH were significantly lower than control values starting with the females treated with 6 mg/L. A high percentage of unhatched eggs, especially during the initial two days after treatment (35-100%), further contributed to the significant reduction in fertility of the females treated with spirodiclofen. All concentrations of spirodiclofen significantly reduced the instantaneous rate of increase. Regression analysis showed a linear population decline with increased acaricide concentrations (y = 1.13 - 0.24x; R2 = 0.91, p < 0.05).

scholarly journals The application of an Integrated Control on Eggplant for the Greenhouse Whitefly, Triαleurodes vαporαriorum

2017 ◽  
Vol 10 ◽  
pp. 25
Author(s):  
SAFEL DAWLA Abdalla ◽  
S. Michelakis
Keyword(s):  
Biological Control ◽  
Integrated Control ◽  
Encarsia Formosa ◽  
Greenhouse Whitefly ◽  
Whitefly Population ◽  
Low Level ◽  
Adequate Control ◽  
Release Ratio ◽  
Biological Methods

Integrated control of the greenhouse whitefly on eggplant, using physical (traps), chemical and biological methods, was tested. The mort efficient combination was the use of Quinomethionate and traps. Applaud and Actellic mixture was fairly effective in controlling the greenhouse whitefly. Biological control by the parasite Encarsia formosa (Gahan), resulted in moderate, but adequate control when combined with traps. Traps clone gave reasonable results. All treatments were effective in reducing whitefly population to a satisfactory low level, when compared to the untreated populations. Parasitoid/host release ratio play an important rote in the results of biological control using E. formosa. The higher relcase ratio of 4:1, parasitoid:host, gave the maximum parasitization percentage.

scholarly journals Life history traits and population growth of greenhouse whitefly (Trialeurodes vaporariorum westwood) on different tomato genotypes

2013 ◽  
Vol 28 (4) ◽  
pp. 239-245 ◽  
Author(s):  
Mirjana Prijovic ◽  
Dejan Marcic ◽  
Tanja Drobnjakovic ◽  
Irena Medjo ◽  
Pantelija Peric
Keyword(s):  
Population Growth ◽  
Integrated Management ◽  
Trialeurodes Vaporariorum ◽  
Laboratory Population ◽  
Greenhouse Whitefly ◽  
Instantaneous Rate ◽  
Rate Of Increase ◽  
Significant Difference ◽  
Increase Rate ◽  
Tomato Genotypes

The effects of five tomato genotypes (cv. Narvik and hybrids NS-6, Tamaris, Alliance and Marko) on the survival, reproduction, development and population growth of the greenhouse whitefly Trialeurodes vaporariorum were examined. A laboratory population of T. vaporariorum had been reared on tobacco plants for three years before the study. Females that laid eggs on the genotype Marko lived significantly longer and their offspring needed significantly shorter periods to develop than females on the genotype Narvik. The highest gross and net fecundity rates were found in females on the genotype Marko (36.74 eggs/ female and 27.93 eggs/female, respectively) and they differed significantly from the corresponding rates of females living on the genotype NS-6 (18.55 eggs/female and 15.33 eggs/ female), who had the lowest fecundity rates. The highest gross and net fertility rates were also found in females on the genotype Marko (31.24 adults/female and 23.73 adults/female), and they were significantly higher than those of females living on NS-6 (14.85 adults/female and 12.53 adults/female). Besides, net fertility rate of the females living on the genotype Narvik (13.80 adults/female) was also significantly lower than the rate of females on Marko. The instantaneous rates of increase showed no significant difference over a 10-day interval following the start of oviposition, while the increase rate was significantly higher on the genotype Marko after 12, 14 and 16 days, compared to the genotype NS-6. Eighteen, 20 and 22 days after the beginning of oviposition, the instantaneous rate of increase on the genotype Marko was significantly higher than it was on NS-6 and Narvik. Our data provide a basis for further research aiming to improve programs of integrated management of greenhouse whitefly.

scholarly journals Hosts of Raoiella indica Hirst (Acari: Tenuipalpidae) Native to the Brazilian Amazon

2017 ◽  
Vol 9 (4) ◽  
pp. 86 ◽  
Author(s):  
Cristina A. Gómez-Moya ◽  
Talita P. S. Lima ◽  
Elisângela G. F. Morais ◽  
Manoel G. C. Gondim Jr. ◽  
Gilberto J. De Moraes
Keyword(s):  
Plant Species ◽  
Native Species ◽  
Brazilian Amazon ◽  
Intrinsic Rate Of Increase ◽  
Native Plant ◽  
Instantaneous Rate ◽  
Net Reproductive Rate ◽  
Musa Paradisiaca ◽  
Rate Of Increase ◽  
Raoiella Indica

The expansion of red palm mite (RPM), Raoiella indica (Acari: Tenuipalpidae) in Brazil could impact negatively the native plant species, especially of the family Arecaceae. To determine which species could be at risk, we investigated the development and reproductive potential of R. indica on 19 plant species including 13 native species to the Brazilian Amazon (12 Arecaceae and one Heliconiaceae), and six exotic species, four Arecaceae, a Musaceae and a Zingiberaceae. Values of the instantaneous rate of increase (ri) were initially estimated at 7, 14, 21 and 28 days after infestation of each species. Higher values of ri (> 0.05) were determined on the Arecaceae Adonidia merrillii, Astrocaryum jauari, Cocos nucifera, Bactris simplicifrons, Mauritia flexuosa, Phoenix dactylifera and Socratea exorrhiza, and on the Heliconiaceae Heliconia psittacorum Sassy; these were classified as “potential primary hosts”. Lower, but still positive values of ri (0-0.05) were determined on the Arecaceae Bactris maraja, Oenocarpus bacaba, Oenocarpus bataua and on the Musaceae Musa × paradisiaca (Prata variety); these were classified as “potential secondary hosts”. Negative values of ri were determined for the remaining plants, i.e., the Arecaceae Astrocaryum aculeatum, Attalea maripa, Bactris gasipaes, Elaeis guineensis, Euterpe oleracea, Euterpe precatoria, and the Zingiberaceae Alpinia rosea; these were considered “non-hosts”. Species with ri < 0.05 were considered not to be threatened by the RPM. Biological parameters of RPM were evaluated on the plant species with positive ri (except B. maraja) and two native species with negative ri (E. oleracea and E. precatoria). Mean developmental time ranged from 14.7 days on C. nucifera to 21.4 days on Musa × paradisiaca, showing a significant influence of the plant substrate. Immature viability, oviposition rate, net reproductive rate (R0) and intrinsic rate of increase (rm) were affected by the plant species.

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