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 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 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.

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.

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.

Acute toxicity, accumulation and sublethal effects of four neonicotinoids on juvenile Black Tiger Shrimp (Penaeus monodon)

Chemosphere ◽  
2021 ◽  
Vol 275 ◽  
pp. 129918
Author(s):  
Peter Butcherine ◽  
Brendan P. Kelaher ◽  
Matthew D. Taylor ◽  
Corinne Lawson ◽  
Kirsten Benkendorff
Keyword(s):  
Acute Toxicity ◽  
Sublethal Effects ◽  
Penaeus Monodon ◽  
Black Tiger Shrimp ◽  
Tiger Shrimp

Acute toxicity and sublethal effects of ammonia and nitrite for juvenile cobia Rachycentron canadum

Aquaculture ◽  
2007 ◽  
Vol 271 (1-4) ◽  
pp. 553-557 ◽  
Author(s):  
Ricardo V. Rodrigues ◽  
Michael H. Schwarz ◽  
Brendan C. Delbos ◽  
Luı˙s A. Sampaio
Keyword(s):  
Acute Toxicity ◽  
Sublethal Effects ◽  
Rachycentron Canadum

scholarly journals Phototoxicity of Ultraviolet-A against the Whitefly Bemisia tabaci and Its Compatibility with an Entomopathogenic Fungus and Whitefly Parasitoid

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Muhammad Musa Khan ◽  
Ze-Yun Fan ◽  
Dylan O’Neill Rothenberg ◽  
Jing Peng ◽  
Muhammad Hafeez ◽  
...  
Keyword(s):  
Biological Control ◽  
Bemisia Tabaci ◽  
Exposure Time ◽  
Entomopathogenic Fungus ◽  
Light Exposure ◽  
Adult Emergence ◽  
Biological Control Agents ◽  
Encarsia Formosa ◽  
Parasitism Rate ◽  
Invertebrate Pests

Ultraviolet (UV) radiation significantly affects insect life and, as a result, has been widely used to control different invertebrate pests. The current results demonstrate that when Bemisia tabaci first instar nymphs are exposed to UV-A light for 12, 24, 48, and 72 h, their developmental and biological parameters are negatively affected by UV-A exposure; the effect increased with an increase in exposure time. We hypothesized that UV-A light is compatible with other biological control agents. Results showed that when the entomopathogenic fungus Cordyceps fumosorosea was applied to third instar nymphs of B. tabaci previously exposed to UV-A light, the LC50 was 3.4% lower after 72 h of exposure to UV-A light compared to the control. However, when the fungus was exposed to UV-A light, its virulence decreased with an increase in UV-A exposure time. The parasitism rate of Encarsia formosa against 24 h UV-A-exposed third instar nymphs of B. tabaci increased while the adult emergence from parasitized nymphs was not affected after UV-A light exposure. Parasitism rate was significantly reduced however following E. formosa exposure to UV-A light; but again, adult emergence was not affected from parasitized nymphs. The percentage mortality of E. formosa increased with increasing exposure time to UV-A light. The enzyme activity of SOD, CAT, GST, and AChE and the energy reserve contents were negatively affected due to UV-A exposure. Collectively, this study has demonstrated that UV-A light significantly suppresses the immune system of B. tabaci and that UV-A light is compatible with other biological control agents if it is applied separately from the biological agent.

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