RESUMO
The endoparasitoid wasp Cotesia flavipes (Cameron) (Hymenoptera: Braconidae) is inundatively released in Brazilian sugarcane plantations to control the sugarcane borers Diatraea saccharalis (Fabricius) and Diatraea flavipennella (Box) (Lepidoptera: Crambidae). In conjunction with these releases, several synthetic insecticides are used to control the neonate larvae of these pests. We assessed the lethal and transgenerational sublethal effects of seven of these insecticides on C. flavipes. Leaf discs were sprayed at the highest field concentrations of chlorantraniliprole, lambda-cyhalothrin + chlorantraniliprole, chlorfluazuron, triflumuron, lambda-cyhalothrin + thiamethoxam, tebufenozide, and novaluron. Distilled water was used as a negative control. Newly emerged females (24 h old) were placed in Petri dishes containing the treated leaves, and the lethal and transgenerational sublethal effects were assessed for the next two generations. Lambda-cyhalothrin + chlorantraniliprole and lambda-cyhalothrin + thiamethoxam caused 100% mortality of the parasitoid and were highly persistent, causing more than 30% mortality at 30 days after spraying. Chlorantraniliprole, chlorfluazuron, novaluron, and triflumuron did not cause significant mortality compared to the negative control, but did have transgenerational sublethal effects. The length of the tibia of the right posterior leg, used as a growth measurement, was reduced in the progeny (F1 generation) of exposed female parasitoids. In addition, chlorantraniliprole increased and chlorfluazuron reduced the proportion of females in the F1 generation, whereas novaluron reduced the proportion of females in the F2 generation. Overall, only tebufenozide was considered harmless to C. flavipes. The results of this study suggest that lambda-cyhalothrin + chlorantraniliprole and lambda-cyhalothrin + thiamethoxam are harmful to C. flavipes, although field studies are needed to obtain results for actual sugarcane crops.
Assuntos
Inseticidas/toxicidade , Vespas/efeitos dos fármacos , Animais , Brasil , Feminino , Interações Hospedeiro-Parasita , Controle de Insetos , Mariposas/parasitologia , Controle Biológico de Vetores , Vespas/anatomia & histologia , Vespas/fisiologiaRESUMO
The predator mite Iphiseiodes zuluagai Denmark & Muma is an important biological-control agent of mite pests, and it is one of the most common species found in citrus orchards. This study assessed, under laboratory conditions, the toxicity and duration of the harmful effects of five insecticides, the three pyrethroids deltamethrin, esfenvalerate and lambda-cyhalothrin, and the two neonicotinoids imidacloprid and thiamethoxam on I. zuluagai. Furthermore, we estimated the life-table parameters of the predator. Our results showed that deltamethrin and lambda-cyhalothrin caused higher mortality of larvae and adults than imidacloprid and thiamethoxam. In contrast, esfenvalerate provided larval mortality similar to imidacloprid and thiamethoxam, but it did not cause significant adult mortality of the predator. Mites that developed on pyrethroid residues showed lower survival of the immature stages, fecundity, and longevity compared to neonicotinoid residues and the control treatment. The estimated life-table parameters indicated that deltamethrin, lambda-cyhalothrin and esfenvalerate caused greater reduction in R o and r of I. zuluagai compared with imidacloprid and thiamethoxam, which were similar to the control treatment. Besides the impacts on biological and population parameters, the duration of the harmful activity of pyrethroid insecticides was longer than the neonicotinoids. Therefore, the use of pyrethroid insecticides to control pest insects may involve serious implications for integrated pest-management programs that aim to exploit the biological control by I. zuluagai in citrus orchards.
Assuntos
Inseticidas/toxicidade , Ácaros/efeitos dos fármacos , Neonicotinoides/toxicidade , Animais , Testes de Toxicidade SubagudaRESUMO
Hippodamia convergens is an important predator found in different agroecosystems. We evaluated the impacts of six insecticides on eggs, larvae and adults of this predator. For eggs, all insecticides reduced larval hatching rates, but did not affect egg duration. Chlorpyrifos and phosmet reduced larval survival; and chlorpyrifos, etofenprox and phosmet prolonged the larva development time. The survival and duration of pupae were not affected by all insecticides tested. Chlorpyrifos reduced fecundity, fertility and longevity when eggs were sprayed. For first-instar larvae, chlorpyrifos, etofenprox, phosmet and imidacloprid caused 100% mortality, while azadirachtin and thiamethoxam caused 35.0 and 52.7% mortality, respectively. However, azadirachtin and thiamethoxam did not affect the other biological parameters of the predator. In adults, chlorpyrifos, etofenprox and phosmet reduced adult survival. Chlorpyrifos, etofenprox, and phosmet reduced fecundity and longevity, but did not affect fertility. Azadirachtin, imidacloprid and thiamethoxam did not affect fecundity, fertility or longevity. Based on demographic parameters, all insecticides reduced the net reproductive rate (Ro), intrinsic rate of increase (r) and finite rate of increase (λ) of the predator when eggs were treated directly. Azadirachtin, chlorpyrifos, etofenprox and phosmet increased the mean generation time (T), while the effects of imidacloprid and thiamethoxam were similar to the control. When first-instar larvae were treated, azadirachtin and thiamethoxam reduced the Ro, r and λ. Thiamethoxam increased the T value, while the effects of the other insecticides were similar to the control. These insecticides should be used with caution, in order to reduce their harmful effects on the predator in agroecosystems.
Assuntos
Besouros/efeitos dos fármacos , Inseticidas/toxicidade , Testes de Toxicidade , Animais , Clorpirifos/farmacologia , Imidazóis/farmacologia , Larva/efeitos dos fármacos , Limoninas , Neonicotinoides , Nitrocompostos , Oxazinas , Controle de Pragas , Fosmet , Pupa/efeitos dos fármacos , Piretrinas , Tiametoxam , TiazóisRESUMO
Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) and Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) are the main insect-pests of the persimmon in the Serra Gaúcha region, State of Rio Grande do Sul (RS). No informations are available about chemical control of these caterpillars. The effect of acephate, emmamectin benzoate (+ mineral oil), clorpyriphos-ethyl, spinosad, etofenprox, fenitrothion, fosmet, methoxyfenozide, tiacloprid and trichlorphon on H. andremona and A. sphaleropa were evaluated in laboratory. Acephate (g.a.i.100 L-1) (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (75.0), methoxyfenozide (14.4) and trichlorphon (120,0 and 150,0) resulted in a mortality of A. sphaleropa higher than 80.0%. For H. andremona, this effect was observed to acephate (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (50.0 and 75.0), fosmet (50.0 and 100.0), methoxyfenozide (9.6 and 14.4) and trichlorphon (120.0 and 150.0). These insecticides showed potential to control caterpillars in the persimmon culture, being necessary field evaluations to use the compounds in commercial orchards.
A Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) e a Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) são as principais pragas do caquizeiro na Serra Gaúcha contudo, há poucas informações sobre o controle químico dessas lagartas. Neste trabalho, avalia-se a eficácia dos inseticidas: acefato, benzoato de emamectina (+ óleo mineral), clorpirifós-etil, espinosade, etofemproxi, fenitrotiona, fosmete, metoxifenozida, tiacloprido e triclorfom no controle da A. sphaleropa e da H. andremona em laboratório. Os inseticidas (em gramas de ingrediente ativo por 100 litros de água - g i.a. 100L-1) acefato (37,5 e 75,0), benzoato de emamectina (0,375 e 0,5), clorpirifós-etil (45,0 e 67,5), espinosade (4,8 e 9,6), etofemproxi (10,0 e 15,0), fenitrotiona (75,0), metoxifenozida (14,4) e triclorfom (120,0 e 150,0) resultaram em mortalidade superior a 80,0% entre as lagartas de A. sphaleropa. Em relação à H. andremona, observou-se que o acefato (37,5 e 75,0), o benzoato de emamectina (0,375 e 0,5), o clorpirifós-etil (45,0 e 67,5), o espinosade (4,8 e 9,6), o etofemproxi (10 e 15,0), a fenitrotiona (50 e 75,0), o fosmete (50,0 e 100,0), a metoxifenozida (9,6 e 14,4) e o triclorfom (120,0 e 150,0) causaram mortalidade superior a 80%. Esses inseticidas apresentaram elevada eficiência em laboratório e características desejáveis para uso no manejo de lagartas do caquizeiro. No entanto, para validar o seu emprego em pomares comerciais é necessária avaliação de campo.
RESUMO
Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) and Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) are the main insect-pests of the persimmon in the Serra Gaúcha region, State of Rio Grande do Sul (RS). No informations are available about chemical control of these caterpillars. The effect of acephate, emmamectin benzoate (+ mineral oil), clorpyriphos-ethyl, spinosad, etofenprox, fenitrothion, fosmet, methoxyfenozide, tiacloprid and trichlorphon on H. andremona and A. sphaleropa were evaluated in laboratory. Acephate (g.a.i.100 L-1) (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (75.0), methoxyfenozide (14.4) and trichlorphon (120,0 and 150,0) resulted in a mortality of A. sphaleropa higher than 80.0%. For H. andremona, this effect was observed to acephate (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (50.0 and 75.0), fosmet (50.0 and 100.0), methoxyfenozide (9.6 and 14.4) and trichlorphon (120.0 and 150.0). These insecticides showed potential to control caterpillars in the persimmon culture, being necessary field evaluations to use the compounds in commercial orchards.
A Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) e a Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) são as principais pragas do caquizeiro na Serra Gaúcha contudo, há poucas informações sobre o controle químico dessas lagartas. Neste trabalho, avalia-se a eficácia dos inseticidas: acefato, benzoato de emamectina (+ óleo mineral), clorpirifós-etil, espinosade, etofemproxi, fenitrotiona, fosmete, metoxifenozida, tiacloprido e triclorfom no controle da A. sphaleropa e da H. andremona em laboratório. Os inseticidas (em gramas de ingrediente ativo por 100 litros de água - g i.a. 100L-1) acefato (37,5 e 75,0), benzoato de emamectina (0,375 e 0,5), clorpirifós-etil (45,0 e 67,5), espinosade (4,8 e 9,6), etofemproxi (10,0 e 15,0), fenitrotiona (75,0), metoxifenozida (14,4) e triclorfom (120,0 e 150,0) resultaram em mortalidade superior a 80,0% entre as lagartas de A. sphaleropa. Em relação à H. andremona, observou-se que o acefato (37,5 e 75,0), o benzoato de emamectina (0,375 e 0,5), o clorpirifós-etil (45,0 e 67,5), o espinosade (4,8 e 9,6), o etofemproxi (10 e 15,0), a fenitrotiona (50 e 75,0), o fosmete (50,0 e 100,0), a metoxifenozida (9,6 e 14,4) e o triclorfom (120,0 e 150,0) causaram mortalidade superior a 80%. Esses inseticidas apresentaram elevada eficiência em laboratório e características desejáveis para uso no manejo de lagartas do caquizeiro. No entanto, para validar o seu emprego em pomares comerciais é necessária avaliação de campo.
RESUMO
Grape phylloxera Daktulosphaira vitifoliae (Fitch, 1856) (Hemiptera: Phylloxeridae) is the main grape pest. Adults and nymphs feeds on leaves and roots but major damage is observed on roots of own rooted Vitis vinifera. Damage on leaves is important in root stock nurseries where chemical control is necessary. This study was conducted to evaluate insecticides to control the leaf form in a Paulsen 1103 nursery in field condictions. Imidacloprid (Provado 200 SC, 40mL 100L-1) and thiamethoxam (Actara 250 WG, 30g 100L-1) reduced foliar damage in more than 90%, providing better control than deltamethrin (Decis 25 CE, 40mL 100L-1) and fenitrothion (Sumithion 500 CE, 150mL 100L-1) current standarts for pest control. Acephate (Orthene 750 BR, 100g 100L-1) and abamectin (Vertimec 18 CE, 80mL 100L-1) were not efficient.
A filoxera Daktulosphaira vitifoliae (Fitch, 1856) (Hemiptera: Phylloxeridae) é considerada a principal praga da videira. O inseto se alimenta da parte aérea e raízes sendo que os maiores prejuízos são observados em raízes de Vitis vinifera cultivada como pé-franco. O dano nas folhas é importante em viveiros, quando o ataque ocorre nos ramos utilizados como porta-enxertos, resistentes à forma radícola. Este trabalho foi realizado com o objetivo de selecionar inseticidas que possam ser empregados como substitutos aos fosforados e piretróides no manejo da forma galícola da filoxera. Os inseticidas imidacloprid, thiamethoxam, acephate, abamectin, deltamethrin e fenitrothion, foram avaliados em condições de campo, sob infestação natural, em plantas matrizes do porta-enxerto Paulsen 1103. Imidacloprid (Provado 200 SC, 40mL 100L-1) e thiamethoxam (Actara 250 WG, 30g 100L-1) reduziram as injúrias causadas pela forma galícola da filoxera nos ponteiros em nível superior a 90%, proporcionando controle superior aos inseticidas deltamethrin (Decis 25 CE, 40mL 100L-1) e fenitrothion (Sumithion 500 CE, 150 mL/100L) considerados referência no controle do inseto. Os inseticidas acephate (Orthene 750 BR, 100g 100L-1) e abamectin (Vertimec 18 CE, 80mL 100L-1) não foram eficientes.
RESUMO
Grape phylloxera Daktulosphaira vitifoliae (Fitch, 1856) (Hemiptera: Phylloxeridae) is the main grape pest. Adults and nymphs feeds on leaves and roots but major damage is observed on roots of own rooted Vitis vinifera. Damage on leaves is important in root stock nurseries where chemical control is necessary. This study was conducted to evaluate insecticides to control the leaf form in a Paulsen 1103 nursery in field condictions. Imidacloprid (Provado 200 SC, 40mL 100L-1) and thiamethoxam (Actara 250 WG, 30g 100L-1) reduced foliar damage in more than 90%, providing better control than deltamethrin (Decis 25 CE, 40mL 100L-1) and fenitrothion (Sumithion 500 CE, 150mL 100L-1) current standarts for pest control. Acephate (Orthene 750 BR, 100g 100L-1) and abamectin (Vertimec 18 CE, 80mL 100L-1) were not efficient.
A filoxera Daktulosphaira vitifoliae (Fitch, 1856) (Hemiptera: Phylloxeridae) é considerada a principal praga da videira. O inseto se alimenta da parte aérea e raízes sendo que os maiores prejuízos são observados em raízes de Vitis vinifera cultivada como pé-franco. O dano nas folhas é importante em viveiros, quando o ataque ocorre nos ramos utilizados como porta-enxertos, resistentes à forma radícola. Este trabalho foi realizado com o objetivo de selecionar inseticidas que possam ser empregados como substitutos aos fosforados e piretróides no manejo da forma galícola da filoxera. Os inseticidas imidacloprid, thiamethoxam, acephate, abamectin, deltamethrin e fenitrothion, foram avaliados em condições de campo, sob infestação natural, em plantas matrizes do porta-enxerto Paulsen 1103. Imidacloprid (Provado 200 SC, 40mL 100L-1) e thiamethoxam (Actara 250 WG, 30g 100L-1) reduziram as injúrias causadas pela forma galícola da filoxera nos ponteiros em nível superior a 90%, proporcionando controle superior aos inseticidas deltamethrin (Decis 25 CE, 40mL 100L-1) e fenitrothion (Sumithion 500 CE, 150 mL/100L) considerados referência no controle do inseto. Os inseticidas acephate (Orthene 750 BR, 100g 100L-1) e abamectin (Vertimec 18 CE, 80mL 100L-1) não foram eficientes.