scholarly journals Lethal and sublethal effects of spirotetramat and abamectin on predatory beetles (Menochilus sexmaculatus) via prey (Agonoscena pistaciae) exposure, important for integrated pest management in pistachio orchards

2020 ◽  
Vol 146 (2) ◽  
Author(s):  
Fahimeh Azod ◽  
Shahnaz Shahidi-Noghabi ◽  
Kamran Mahdian ◽  
Guy Smagghe

Menochilus sexmaculatus Fabricius (Coleoptera: Coccinellidae) is an important biological control agent in pistachio orchards, especially against Agonoscena pistaciae Burckhardt and Lauterer (Hemiptera: Psyllidae), which is the most damaging pest of pistachio. In this project we exposed M. sexmaculatus adults to two important commonly-used insecticides through feeding on treated prey (A. pistaciae) to evaluate the side-effects on this predator. We tested spirotetramat, which belongs to the keto-enol group inhibiting lipid biosynthesis in insects, at 2/1, 1/1 and 1/2 of the maximum field recommended concentration (MFRC), and abamectin, which is a mixture of avermectins and a natural fermentation product of the bacterium Streptomyces avermitilis, at 1/1, 1/2, 1/4, 1/8 and 1/16 of its MFRC. Spirotetramat did not affect adult survival of M. sexmaculatus at all three concentrations when ingested via treated prey, while in marked contrast abamectin caused 100% adult mortality of M. sexmaculatus when ingested via treated prey at 1/1, 1/2, 1/4 and 1/8 of the MFRC. At sublethal levels, spirotetramat reduced total and daily fecundity of M. sexmaculatus at all three concentrations tested, but did not affect egg hatching at 1/1 and 1/2 of the MFRC. Moreover, prey consumption was decreased when beetles were exposed to the prey treated with spirotetramat at 1/1 and 2/1 of the MFRC concentrations. With abamectin, even at 1/16 of the MFRC, total fecundity, daily fecundity and prey consumption of M. sexmaculatus adults were significantly affected. In conclusion, no acute toxicity was observed on M. sexmaculatus by ingestion of prey treated with spirotetramat, although reproduction parameters and prey consumption were affected at MFRC and lower concentrations. In marked contrast, abamectin was notably very harmful at its MFRC and also at lower concentrations. This research highlighted the importance of toxicity risk assessments, including lethal and sublethal effects, to obtain a more accurate estimation of the compatibility of insecticides in current integrated pest management (IPM) programs.

Insects ◽  
2019 ◽  
Vol 10 (8) ◽  
pp. 226 ◽  
Author(s):  
Dirk Babendreier ◽  
Min Wan ◽  
Rui Tang ◽  
Rui Gu ◽  
Justice Tambo ◽  
...  

The impact and sustainability of two interventions that have been formulated to introduce integrated pest management (IPM) into rice and maize crops in Southwestern China, Laos, and Myanmar between 2011 and 2016, and were assessed at the end of 2017. From 22 Trichogramma rearing facilities established during the interventions, 11 were still producing substantial quantities of biocontrol agents 1.5 years after project support had ended, while seven had stopped operations completely, and four were doing stock rearing only. Through the implementation of biological control-based IPM, slightly higher yields were achieved in maize and rice (4–10%), when compared to control farmers, but the difference was not statistically significant. However, the use of pesticides nearly halved when farmers started using Trichogramma egg-cards as a biological control agent. Support from either public or private institutions was found to be important for ensuring the sustainability of Trichogramma rearing facilities. Many of the suggested IPM measures were not adopted by smallholder farmers, indicating that the positive impacts of the interventions mostly resulted from the application of Trichogramma biological control agents. The following assessment suggests that further promotion of IPM adoption among farmers is needed to upscale the already positive effects of interventions that facilitate reductions in synthetic pesticide use, and the effects on sustainable agricultural production of rice and maize in the target area more generally.


Author(s):  
Fateme Ranjbar ◽  
Stuart Reitz ◽  
M Amin Jalali ◽  
Mahdi Ziaaddini ◽  
Hamzeh Izadi

Abstract Pistacia vera L. is one of the most important horticultural crops in Iran. The stink bugs Acrosternum arabicum and Brachynema germari are two of the key pests that cause significant direct and indirect damage on Pistacia vera. Egg parasitoids have been considered as potential biological control agents of pistachio green stink bugs. Among them, Trissolcus semistriatus and Psix saccharicola are the most abundant and efficient parasitoid for A. arabicum in pistachio orchards. In this study, we assessed lethal and sublethal effects of two commonly used insecticide products (fenitrothion and a binary mixture of lambda-cyhalothrin + thiamethoxam) on these two parasitoid wasps under laboratory conditions. The median lethal concentration (LC50) values for fenitrothion and thiamethoxam + lambda-cyhalothrin in P. saccharicola and T. semistriatus were estimated as 1.03, 0.48 and 0.87, 0.98 mg a.i./liter, respectively. In terms of sublethal effects, insecticide treatments altered the type of functional response from type III to type II in T. semistriatus. However, P. saccharicola exhibited a type II functional to density of A. arabicum for all treatments, although attack rates were lower for insecticide-exposed wasps while handling times increased. Our results show that sublethal effects of insecticides further reduce the efficacy of biological control agents. Effective integrated pest management programs should avoid antagonistic interactions between chemical and biological control methods. The results of this study provide useful information to develop comprehensive integrated pest management programs for stink bugs in pistachio orchards.


Insects ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 274
Author(s):  
Nomi Sarmah ◽  
Athanasios Kaldis ◽  
Clauvis Nji Tizi Taning ◽  
Dionysios Perdikis ◽  
Guy Smagghe ◽  
...  

RNAi-mediated insect pest management has recently shown promising results against the most serious pest of tomato, the tomato leafminer, Tuta absoluta. This study aimed to investigate whether dsRNA (dsTa-αCOP) designed to target the T. absoluta-αCOP gene could cause adverse effects to its biocontrol agent, the mirid predator, Nesidiocoris tenuis. Oral exposure of N. tenuis to dsRNA (dsNt-αCOP) designed to target N. tenuis-αCOP resulted in a 61%, 67% and 55% reduction in its transcript level in comparison to the sucrose, dsGFP and dsTa-αCOP treatments, respectively. In addition, significantly higher mortality of 57% was recorded in dsNt-αCOP-treated N. tenuis when compared to the sucrose (7%), dsGFP (10%) and dsTa-αCOP (10%) treatments. Moreover, the predation rate of ~33–39 Ephestia kuehniella eggs per N. tenuis adult dramatically reduced to almost half in the surviving dsNt-αCOP-treated N. tenuis. This worst-case exposure scenario confirmed for the first time that the RNAi machinery is functional in this species and that the risk of exposure through the oral route is possible. In contrast, dsTa-αCOP did not cause any sub-lethal effects to N. tenuis upon oral exposure. Oral exposure of T. absoluta to dsTa-αCOP resulted in 50% mortality. In the context of a biosafety risk assessment of RNAi-mediated insect management, investigating the effects on non-target organisms is essential in order to include this method as part of an integrated pest management strategy. Based on our laboratory assays, RNAi-mediated control is compatible with the biological control of T. absoluta by its natural enemy N. tenuis, adding the RNAi approach in the armoire of integrated pest management of T. absoluta.


2007 ◽  
Vol 97 (3) ◽  
pp. 281-290 ◽  
Author(s):  
P.R. Grundy

AbstractHelicoverpa spp. and mirids, Creontiades spp., have been difficult to control biologically in cotton due to their unpredictable temporal abundance combined with a cropping environment often made hostile by frequent usage of broad spectrum insecticides. To address this problem, a range of new generation insecticides registered for use in cotton were tested for compatibility with the assassin bug, Pristhesancus plagipennis (Walker), a potential biological control agent for Helicoverpa spp. and Creontiades spp. Indoxacarb, pyriproxifen, buprofezin, spinosad and fipronil were found to be of low to moderate toxicity on P. plagipennis whilst emamectin benzoate, abamectin, diafenthiuron, imidacloprid and omethaote were moderate to highly toxic. Inundative releases of P. plagipennis integrated with insecticides identified as being of low toxicity were then tested and compared with treatments of P. plagipennis and the compatible insecticides used alone, conventionally sprayed usage practice and an untreated control during two field experiments in cotton. The biological control provided by P. plagipennis nymphs when combined with compatible insecticides provided significant (P<0.001) reductions in Helicoverpa and Creontiades spp. on cotton and provided equivalent yields to conventionally sprayed cotton with half of the synthetic insecticide input. Despite this, the utilization of P. plagipennis in cotton as part of an integrated pest management programme remains unlikely due to high inundative release costs relative to other control technologies such as insecticides and transgenic (Bt) cotton varieties.


2006 ◽  
Vol 138 (5) ◽  
pp. 712-722 ◽  
Author(s):  
S. Jandricic ◽  
C.D. Scott-Dupree ◽  
A.B. Broadbent ◽  
C.R. Harris ◽  
G. Murphy

AbstractFungus gnats (FG) (Diptera: Sciaridae: Bradysia spp.) are economically important pests of greenhouse flowers. Larvae feed on root tissue and transmit a variety of phytopathogens. Atheta coriaria (Kraatz) (Coleoptera: Staphylinidae) is a new biological control agent (BCA) for FG. To support its successful use by the greenhouse industry, its compatibility with current integrated pest management (IPM) programs used in floriculture was assessed. This included investigations of prey preference, possible detrimental interactions with other soil-dwelling BCAs, and the toxicity to A. coriaria of registered and novel insecticides. Atheta coriaria showed little preference among eggs of different pest species or between pest eggs and eggs of the intraguild predator Hypoaspis aculeifer (Canestrini) (Acari: Mesostigmata: Laelapidae). It preferred FG 1st-instar larvae to larvae and pupae of other soil-dwelling pests. The entomopathogenic nematode Steinernema feltiae (Filipjev) (Rhabditida: Steinernematidae) was compatible with A. coriaria, but H. aculeifer mites fed on A. coriaria larvae. Insect growth regulators with limited contact activity (e.g., diflubenzuron) were compatible with adult A. coriaria and had minimal effects on larvae compared with other insecticides. Atheta coriaria can be incorporated into an IPM program for FG if harsh insecticides are avoided, but interactions with predatory mites, as well as its effectiveness against other greenhouse pests when FG are present, require further investigation.


2011 ◽  
Vol 4 (2) ◽  
pp. 49-55 ◽  
Author(s):  
Flávio Costa Miguens ◽  
Jorge André Sacramento De Magalhães ◽  
Livia Melo De Amorim ◽  
Viviane Rossi Goebel ◽  
Nicola Le Coustour ◽  
...  

Palm weevils have been reported as a pest and red ring nematode vectors for several palms of the Arecaceae family. Rhynchophorus palmarum L (Coleoptera: Curculionidae) is a pest for coconut crop and other palms. It is vector of Bursaphelencus cocophilus (Cobb) Baujard (Nematoda) etiological agent of Red Ring disease and other nematodes. Current methods recommended use of enemies and parasites in integrated pest management of Rhynchophorinae. In addition, mass trap reduce environmental damage. The objectives of our study on coconut plantations were: (1) to determine the efficiency of low expensive kariomones traps and (2) low expensive kariomones and pheromones traps using adult males; and (3) to examine R. palmarum using light and scanning electron microscopy searching for ectoparasites which can be proposed in integrated pest management. Handmade kariomones mass traps were efficient to R. palmarum and other Curculionidae capture but kariomones plus adult male R. palmarum was maintained inside trap enhanced its attractiveness for this palm weevil and Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae). R. palmarum presented occasionally fungal infection. In contrast, mites infested more than 50% of palm weevils. Infestation level was always high. Surface morphology of the mites and its interaction with R. palmarum were briefly described. All stages of ectoparasites life cycle were observed onto weevil elytra compartments. In this way, morphological evidences suggest the hypothesis of these mites as used as biological control agent in R. palmarum integrated pest management. Coleta Massal e Controle Biológico de Rhynchophorus palmarum L: Uma hipótese baseada me evidências morfológicas Resumo. Coleópteros têm sido descritos como pragas e vetores de nematódeos causadores de Anel Vermelho em diversas palmeiras da família Arecaceae. Rhynchophorus palmarum L (Coleoptera: Curculionidae) é uma praga que afeta a cocoicultura e outras palmeiras; e, vetor de Bursaphelencus cocophilus (Cobb) Baujard (Nematoda), agente etiológico de Anel Vermelho e de outros nematódeos. Atualmente, recomenda-se o emprego de inimigos naturais e parasitas no manejo integrado de pragas; dentre elas, Rhynchophorinae. Armadilhas de coleta massal são recomendadas no manejo integrado de pragas. Nosso estudo relata, na cocoicultura, a eficiência de armadilhas artesanais de baixo custo e a utilização cariomônios (toletes de cana-de-açúcar) e cariômonios mais feromônios (toletes de cana-de-açúcar e machos adultos de R. palmarum) como atrativos nas armadilhas. Ácaros ectoparasitas foram identificados nestes coleópteros, por microscopia, que podem ser propostos como parte do manejo integrado desta praga. Armadilhas de coleta massal com cariômonios foram eficientes na captura de R. palmarum e outros Curculionidae. No entanto, armadilhas de coleta massal com cariômonios e feromônios aumentaram a atratividade, em relação às primeiras, para este Coleoptera e Cosmopolites sordidus (Germar) (Coleoptera: Curculionidae). Eventualmente, exemplares de R. palmarum apresentavam infecção fúngica. Ácaros ectoparasitas infestavam mais de 50% dos exemplares de R. palmarum. A microanatomia destes ácaros e sua interação com R. palmarum foi preliminarmente descrita. Todos os estágios do ciclo de vida destes ácaros foram identificados no compartimento dos élitros. As evidências morfológicas suportam a hipótese de que estes ácaros podem ser empregados no controle biológico de R. palmarum em um programa de manejo integrado.


Insects ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1092
Author(s):  
Thaís Fagundes Matioli ◽  
Mariana Rosa da Silva ◽  
Juliano de Bastos Pazini ◽  
Geovanny Barroso ◽  
Júlia Gabriela Aleixo Vieira ◽  
...  

The generalist mirid predator Macrolophus basicornis may contribute to Integrated Pest Management (IPM) of Bemisia tabaci in tomato crops. It is important to know the compatibility of the chemicals used to control this pest with this promising biological control agent. Seven insecticides were tested to investigate their toxicity to the predator. For four of the products, the LC50 for adults were determined. Buprofezin, cyantraniliprole and spiromesifen did not cause lethality and were classified as harmless. Acetamiprid, bifenthrin, etofenprox + acetamiprid and pyriproxyfen + acetamiprid caused acute toxicity and were classified as harmful. LT50 for all harmful insecticides were relatively low, ranging from 1.8 to 3.2 days. Moreover, these four insecticides have low LC50, with acetamiprid (0.26 mg a.i. L−1) as the lowest, followed by bifenthrin (0.38 mg a.i. L−1), etofenprox + acetamiprid (4.80 mg a.i. L−1) and pyriproxyfen + acetamiprid (8.71 mg a.i. L−1). However, the calculated risk quotient (RQ) values demonstrated that these insecticides were mostly ecologically safe for this predator, except for acetamiprid, classified as slightly to moderately toxic. The present study can contribute to the use of M. basicornis as a biological control agent on tomato crops and to compatible use with the insecticides tested, according to IPM strategies.


Author(s):  
J. R. Adams ◽  
G. J Tompkins ◽  
A. M. Heimpel ◽  
E. Dougherty

As part of a continual search for potential pathogens of insects for use in biological control or on an integrated pest management program, two bacilliform virus-like particles (VLP) of similar morphology have been found in the Mexican bean beetle Epilachna varivestis Mulsant and the house cricket, Acheta domesticus (L. ).Tissues of diseased larvae and adults of E. varivestis and all developmental stages of A. domesticus were fixed according to procedures previously described. While the bean beetles displayed no external symptoms, the diseased crickets displayed a twitching and shaking of the metathoracic legs and a lowered rate of activity.Examinations of larvae and adult Mexican bean beetles collected in the field in 1976 and 1977 in Maryland and field collected specimens brought into the lab in the fall and reared through several generations revealed that specimens from each collection contained vesicles in the cytoplasm of the midgut filled with hundreds of these VLP's which were enveloped and measured approximately 16-25 nm x 55-110 nm, the shorter VLP's generally having the greater width (Fig. 1).


2019 ◽  
Vol 30 (1) ◽  
pp. 25-32 ◽  
Author(s):  
Elizabeth H. Beers ◽  
Adrian Marshall ◽  
Jim Hepler ◽  
Josh Milnes

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