Toxicity and sublethal effect of the main insecticides used in soybean toTrichogramma pretiosum(Hymenoptera: Trichogrammatidae)

2016 ◽  
Author(s):  
Ana Clara Ribeiro Paiva
Keyword(s):  
Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 109
Author(s):  
Norazila Yusoff ◽  
Idris Abd Ghani ◽  
Nurul Wahida Othman ◽  
Wan Mohd Aizat ◽  
Maizom Hassan

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.


2017 ◽  
Vol 22 (1) ◽  
pp. 148 ◽  
Author(s):  
Ya Ying Li ◽  
Xiao Fan ◽  
Guo Hao Zhang ◽  
YI QING LIU ◽  
HAN QIU CHEN ◽  
...  

Traditional estimating only by measuring the lethal effect of acaricides may underestimate the total effects of acaricides on the pest mites. In order to investigate the sublethal effect of bifenazate on life history and population parameters of the two-spotted spider mite, Tetranychus urticae Koch, the newly emerged females were treated with two lethal concentrations of bifenazate: LC10 (4.92 μg/mL) and LC20 (8.77 μg/mL). Subsequently, the development and fecundity of the progeny generations were observed. Compared to the control, exposure to the 10% lethal concentrations (LC10) and LC20 of bifenazate severely affected the parental generation of T. urticae, including survival rate (reduced 9% and 13%), oviposition period (reduced 77.6% and 83.1%), fecundity per female (decreased 89.2% and 76.9%) and longevity (decreased 79.2% and 83.1%). Besides, the population parameters of the progeny generation from the treated females were also investigated. The results showed that the progeny generation had lower intrinsic rate of increase (rm) and finite rate of increase (λ), longer mean generation time (Tc) compared to the control. The results suggested that the sublethal effects of bifenazate on population growth of T. urticae were significant, and the results of this study could be used as a guide for the rational use of bifenazate in the field for better managing pest mites.


Toxics ◽  
2019 ◽  
Vol 7 (2) ◽  
pp. 34
Author(s):  
Joanna Burger ◽  
Nellie Tsipoura ◽  
Larry Niles ◽  
Amanda Dey ◽  
Christian Jeitner ◽  
...  

Understanding the relationship between heavy metal and selenium levels in biota and their foods is important, but often difficult to determine because animals eat a variety of organisms. Yet such information is critical to managing species populations, ecological integrity, and risk to receptors (including humans) from consumption of certain prey. We examine levels of cadmium, lead, mercury, and selenium in biota from Delaware Bay (New Jersey, USA) to begin construction of a “springtime” food web that focuses on shorebirds. Horseshoe crab (Limulus polyphemus) eggs are one of the key components at the base of the food web, and crab spawning in spring provides a food resource supporting a massive stopover of shorebirds. Fish and other biota also forage on the crab eggs, and a complex food web leads directly to top-level predators such as bluefish (Pomatomus saltatrix) and striped bass (Morone saxatilis), both of which are consumed by egrets, eagles, ospreys (Pandion haliaetus), and humans. Metal levels in tissues were generally similar in algae, invertebrates, and small fish, and these were similar to those in blood of shorebirds (but not feathers). There was a significant direct relationship between the levels of metals in eggs of horseshoe crabs and mean metal levels in the blood of four species of shorebirds. Metal levels in shorebird feathers were higher than those in blood (except for selenium), reflecting sequestration of metals in feathers during their formation. Levels in feathers of laughing gulls (Leucophaeus atricilla) were similar to those in feathers of shorebirds (except for selenium). Selenium bears special mention as levels were significantly higher in the blood of all shorebird species than in other species in the food web, and were similar to levels in their feathers. Levels of metals in bluefish and striped bass were similar or higher than those found in the blood of shorebirds (except for selenium). The mean levels of cadmium, lead, and mercury in the blood and feathers of shorebirds were below any effect levels, but selenium levels in the blood and feathers of shorebirds were higher than the sublethal effect levels for birds. This is a cause for concern, and warrants further examination.


2011 ◽  
Vol 2011 ◽  
pp. 1-9 ◽  
Author(s):  
Melanie J. Dixon ◽  
Peter J. Shaw

Watercress releases phenethyl isothiocyanate (PEITC) upon wounding as a defence against herbivores. PEITC levels released from watercress farms are elevated due to cropping, washing, and processing and are thought to lead to adverse effects onGammarus pulexin chalk streams. This study elucidates the sublethal effect of PEITC on reproductive behaviour ofG. pulex, employingex situtests to investigate the disruption of precopular pairing under conditions simulatingin situexposure. Mean time to separation of precopular pairs was 89 ± 6 minutes for watercress wash water (1 g watercress per litre water) and 81 ± 15 minutes for pure PEITC (1 μL/L). Re-exposure to watercress wash water to simulate the pulsed operation at a watercress farm did not alter behavioural response. The repeated interruption of reproductive behaviour underin situconditions would impair long-term reproductive success and could explain in part low abundance ofG. pulexdownstream of watercress farms.


1982 ◽  
Vol 33 (4) ◽  
pp. 711 ◽  
Author(s):  
TJ Ward

Sydney rock oysters, S. commercialis (I. & R.); were exposed to a control and 10. 50 and 100 �g 1-1 cadmium in a flowing seawater system in the laboratory for 45 days. After this period the rates of particle clearance, assessed by using killed 14C-labelled Escherichia coli in suspension, were determined for each group of oysters. A small proportion of 14C-label from the E. coli was recovered from the non-gut tissues of the oyster, suggesting that the oyster digested, and may have derived some energy from, the bacteria. All cadmium- treated oysters displayed reduced efficiency of clearance compared to controls. If this sublethal effect of cadmium occurs in natural populations, oysters could suffer impaired feeding efficiencies with subsequent effects on growth and reproduction.


1974 ◽  
Vol 12 (3) ◽  
pp. 312-319 ◽  
Author(s):  
George Post ◽  
Robert A. Leasure

2013 ◽  
Vol 35 (1) ◽  
pp. 93-101 ◽  
Author(s):  
Márcio Alves Silva ◽  
Gerane Celly Dias Bezerra-Silva ◽  
José Djair Vendramim ◽  
Thiago Mastrangelo

The sublethal effect of extracts of Azadirachta indica on Ceratitis capitata was evaluated. Two pairs of flies were treated in plastic tubes with cotton placed in plastic cages. An artificial diet (hydrolyzed protein + sugar) was provided ad libitum. The extracts affected significantly the longevity of C. capitata. The pre-oviposition period were not significantly affected by the extracts. The A. indica branches extracted with dichloromethane (888 ppm) affected significantly the fecundity and fertility, reducing the number of eggs laid to approximately 80 % and the egg hatching by 30 % at the 8th day. Therefore, the neem branches extracted with dichloromethane affected the reproduction of C. capitata.


2016 ◽  
Vol 21 (1) ◽  
pp. 33 ◽  
Author(s):  
GUSTI INDRIATI ◽  
DADANG DADANG ◽  
DJOKO PRIJONO

<p>ABSTRAK<br />Helopeltis antonii merupakan salah satu hama pada tanaman kakao,<br />teh, dan jambu mete yang menyerang pucuk dan buah dengan menusukkan<br />stiletnya untuk mengisap cairan sehingga menyebabkan kerusakan.<br />Penelitian bertujuan menguji toksisitas ekstrak buah Piper retrofractum<br />(cabai jawa) terhadap imago, pengaruh konsentrasi subletal terhadap nimfa<br />keturunan, persistensi terhadap mortalitas dan oviposisi H. antonii.<br />Penelitian dilaksanakan di Laboratorium Fisiologi dan Toksikologi<br />Serangga, Institut Pertanian Bogor dan Laboratorium Proteksi Tanaman,<br />Balai Penelitian Tanaman Industri dan Penyegar Sukabumi, mulai Mei<br />2013 sampai April 2014. Buah mentimun digunakan sebagai inang<br />pengganti untuk perbanyakan serangga uji H. antonii di laboratorium dan<br />media pengujian. Hasil penelitian menunjukkan kematian imago H.<br />antonii, akibat perlakuan ekstrak P. retrofractum 0,05-0,3%, sudah terjadi<br />pada 24 jam setelah perlakuan (JSP). Sementara itu, pada 24 dan 48 JSP<br />terjadi penurunan tingkat kematian H. antonii. Setelah 48 JSP, hanya<br />terjadi sedikit peningkatan kematian H. antonii. LC 50 dan LC 95 ekstrak P.<br />retrofractum pada 120 JSP masing-masing 0,20 dan 0,49%. Jumlah nimfa<br />keturunan yang dihasilkan pada perlakuan subletal ekstrak P. retrofractum<br />0,203% (LC 50 ) lebih sedikit dibandingkan dengan konsentrasi 0,141%<br />(LC 25 ). Ekstrak P. retrofractum yang dipajankan di bawah sinar matahari<br />hingga 5 hari masih efektif terhadap imago (mortalitas 80%), tetapi tidak<br />efektif dalam menghambat peletakan telur H. antonii. Penghambatan<br />peletakan telur terhadap imago H. antonii pada perlakuan ekstrak P.<br />retrofractum 0,98% (2 × LC 95 ) yang dipajankan di bawah sinar matahari<br />selama 0 dan 1 hari, dengan indeks penghambatan oviposisi 22,7 dan<br />23,8%. Keefektifan ekstrak P. retrofractum perlu diuji di lapangan untuk<br />menilai kelayakan dalam pengendalian H. antonii.<br />Kata kunci: insektisida botani, mortalitas, oviposisi, persistensi</p><p>ABSTRACT<br />Helopeltis antonii is cocoa, tea, and cashew nuts important pest that<br />causes damage by sucking plant sap from shoots and nuts. This study was<br />conducted to test toxicity of Piper retrofractum fruit extract on adults,<br />sublethal effect on the production nymphal progeny, and persistence<br />against mortality and oviposition of H. antonii. This study was conducted<br />at The Fisiology and Insect Toxicology Laboratory, Plant Protection<br />Departement, Bogor Agricultural University and The Plant Protection<br />Laboratory of Indonesian Industrial and Beverage Crops Research Institute<br />from Mey 2013 to April 2014. Cucumber was used as a host substitute for<br />rearing the test insect and as the testing medium. The results show that<br />adult mortality, due to the P. retrofractum leaf extract treatment 0.05-<br />0.3%, has occured at 24 hours after treatment (HAT). Meanwhile, H.<br />antonii mortality has decreased on 24 and 48 HAT. After 48 HAT, only a<br />slight increased in H. antonii mortality. LC 50 and LC 95 of P. retrofractum<br />extract at 120 HAT were 0.20 and 0.49%, respectively. The treatment at<br />sublethal concentrations (LC 25 and LC 50 ) markedly decreased nymphal<br />progeny number. P. retrofractum extract suspensions at LC 95 and 2 × LC 95<br />exposed under sunlight for 5 days were still effective against H. antonii<br />adults (80% mortality), but were not effective in females inhibiting<br />oviposition. The oviposition inhibiting activity was observed only in the<br />treatment with P. retrofractum extract at 2 × LC 95  exposed under sunlight<br />for 0 and 1 day in which the oviposition deterrency indices were 22.7 and<br />23.8% respectively. <br />Key words: botanical insecticides, mortality, oviposition, persistence</p>


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