Effect of Formulated Insecticides on Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae) and its Parasitoid Gonatocerus ashmeadi Girault (Hymenoptera: Mymaridae)

2007 ◽  
Vol 42 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Isabelle Lauzière ◽  
Gary Elzen
Keyword(s):  
Young Adults ◽  
Growth Regulators ◽  
Natural Enemies ◽  
Total Mortality ◽  
The Other ◽  
Insecticide Residue ◽  
Homalodisca Vitripennis ◽  
Insect Growth Regulators ◽  
Percent Mortality ◽  
Gonatocerus Ashmeadi

Eleven insecticides were tested using a bioassay of foliar insecticide residue to evaluate their impact on Homalodisca vitripennis nymphs and adults and on Gonatocerus ashmeadi parasitoid pupae and newly-emerged adults. Most compounds caused 100% mortality of H. vitripennis nymphs and adults within the first 24 h following exposure. Dimethoate was significantly less toxic to the nymphs than the other compounds. The insect growth regulators buprofezin and pyriproxifen caused high mortality levels at the end of the 72-h period of observation. They were efficacious against both the H. vitripennis nymphs and adults. Thiamethoxam, acetamiprid, cyfluthrin, fenpropathrin and endosulfan severely affected the immatures and newly-emerged adults of the parasitoid G. ashmeadi with total percent mortality exceeding 65%. Piriproxifen, methomyl, imidacloprid and carbaryl were moderately toxic to the parasitoid pupae and young adults (34–55% total mortality); whereas treatments using buprofezin or dimethoate allowed >89% survival of the parasitoids. These results may help predict the reliability of these compounds in the field and risks to natural enemies associated with their use. It is possible, however, to choose insecticides that are more selective in toxicity to the glassy-winged sharpshooter than to its natural enemies.

Modelling pesticide residues on greasy wool: experimental studies

1998 ◽  
Vol 38 (5) ◽  
pp. 441 ◽  
Author(s):  
N. J. Campbell ◽  
P. D. Hanrahan ◽  
I. M. Russell ◽  
G. S. Roberts ◽  
B. J. Horton
Keyword(s):  
Genetic Algorithm ◽  
Growth Regulators ◽  
Experimental Studies ◽  
The Other ◽  
Synthetic Pyrethroids ◽  
Insect Growth Regulators ◽  
Insect Growth ◽  
Experimental Application ◽  
Wool Growth ◽  
Breakdown Rates

Summary. A model has been fitted to results from experimental application of organophosphates, synthetic pyrethroids and insect growth regulators to sheep mostly in long wool. The model relates the rate of breakdown of pesticide to the chemical used, the method of application and the length of wool at the time of treatment. A genetic algorithm was used to combine a range of experimental results for each chemical group to determine the rate of breakdown, and also the effect of application method and length of wool on breakdown. Organophosphates break down very quickly when applied to the surface of the wool (initial half-lives of 9–12 days), but the rate of breakdown gradually slows as the proportion of pesticide near the surface of the wool decreases. When the pesticide is applied deep into the wool by hand jetting or dipping, the rate of breakdown is slower (average half-lives of 27–42 days) and more uniform. Synthetic pyrethroids applied by hand jetting or backliner to sheep with 6–9 months wool growth initially break down with half-lives of 32–39 days, but the rate of breakdown decreases to 59–215 days giving average half-lives of 48–103 days over the 3–6 months between application and shearing. Cyromazine applied by hand jetting to sheep with 6–8 months wool growth has an average half-life of 79–96 days, but less if applied by automatic jetting race. The other insect growth regulators have longer half-lives: triflumuron, off-shears backliner, 119 days; and diflubenzuron, long wool jetting on to 7–9 months wool, >119 days. The model allows for different breakdown rates due to the method of application and length of wool and for changes in the rate of breakdown between application and shearing. It can be used to estimate the expected residue on wool at any time after a specified treatment, provided the amount of chemical applied is known. Conversely, the amount applied can be estimated from the residue and treatment details.

scholarly journals Toxicity of insecticides to predators of rice brown planthopper: Wolf spider and carabid beetle.

2020 ◽  
Vol 3 ◽  
Author(s):  
Md. Jahangir Alam ◽  
Gopal Das
Keyword(s):  
Adverse Effects ◽  
Growth Regulators ◽  
Field Condition ◽  
Brown Planthopper ◽  
Wolf Spider ◽  
Carabid Beetle ◽  
The Other ◽  
Insect Growth Regulators ◽  
Wolf Spiders ◽  
Rice Ecosystem

Field toxicity two insect growth regulators (IGR) viz. Award 40 SC (Buprofezin) and Haron 5 EC (Lufenuron) and one newer Thiacloprid viz. Calypso 280 SC against wolf spider, Lycosa pseudoannulata and carabid beetle, Ophionea indica, the predators of rice brown planthopper (BPH) was examined in the Entomology field laboratory, Bangladesh Agricultural University, Mymensingh. Effectiveness of insecticides was assessed on the basis of populations of wolf spider and carabid beetle under field condition at 1, 2, 3, 5 & 7 days after treatment. The abundances of wolf spider and carabid beetle were not changed significantly even when rice plants were treated with either Award or Haron. In contrast, Calypso 280 SC had significantly reduced wolf spiders (about 78%) and carabid beetle (about 57%) populations compared to the control. Therefore it is concluded from the present study that Award 40 SC @ 0.75 ml/L or Haron 5 EC @ 1.00 ml/L would be applied as the protector of predators of BPH in rice-ecosystem. On the other hand, Calypso 280 SC has adverse effects on the populations of wolf spider and carabid beetle in rice-ecosystem as well as other environmental components.

scholarly journals Application of Plant Extracts in Micropropagation and Cryopreservation of Bleeding Heart: An Ornamental-Medicinal Plant Species

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 542
Author(s):  
Dariusz Kulus ◽  
Natalia Miler
Keyword(s):  
Tissue Culture ◽  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Plant Extracts ◽  
The Other ◽  
White Gold ◽  
Natural Extracts ◽  
Other Hand ◽  
The Impact

Lamprocapnos spectabilis (L.) Fukuhara (bleeding heart) is valued both in the horticultural and pharmaceutical markets. Despite its great popularity, information on the in vitro tissue culture technology in this species is limited. There is also little knowledge on the application of plant extracts in the tissue culture systems of plants other than orchids. The aim of this study is to compare the utility of traditional plant growth regulators (PGRs) and natural extracts—obtained from the coconut shreds, as well as oat, rice, and sesame seeds—in the micropropagation and cryopreservation of L. spectabilis ‘Gold Heart’ and ‘White Gold’. The biochemical analysis of extracts composition is also included. In the first experiment related to micropropagation via axillary buds activation, the single-node explants were cultured for a 10-week-long propagation cycle in the modified Murashige and Skoog medium fortified either with 1.11 µM benzyladenine (BA) and 1.23 µM indole-3-butritic acid (IBA) or with 10% (v/v) plant extracts. A PGRs- and extract-free control was also considered. In the cryopreservation experiment, the same 10% (v/v) extracts were added into the medium during a seven-day preculture in the encapsulation-vitrification cryopreservation protocol. It was found that the impact of natural additives was cultivar- and trait-specific. In the first experiment, the addition of coconut extract favoured the proliferation of shoots and propagation ratio in bleeding heart ‘Gold Heart’. Rice extract, on the other hand, promoted callus formation in ‘White Gold’ cultivar and was more effective in increasing the propagation ratio in this cultivar than the conventional plant growth regulators (4.1 and 2.6, respectively). Sesame extract suppressed the development of the explants in both cultivars analysed, probably due to the high content of polyphenols. As for the second experiment, the addition of plant extracts into the preculture medium did not increase the survival level of the cryopreserved shoot tips (sesame and oat extracts even decreased this parameter). On the other hand, coconut extract, abundant in simple sugars and endogenous cytokinins, stimulated a more intensive proliferation and growth of shoots after rewarming of samples. Analysing the synergistic effect of conventional plant growth regulators and natural extracts should be considered in future studies related to L. spectabilis.

Insect growth regulators. Analogs of TH-6038 and TH-6040

1976 ◽  
Vol 24 (5) ◽  
pp. 1065-1068 ◽  
Author(s):  
James E. Oliver ◽  
Albert B. DeMilo ◽  
Charles F. Cohen ◽  
Thomas J. Shortino ◽  
William E. Robbins
Keyword(s):  
Growth Regulators ◽  
Insect Growth Regulators ◽  
Insect Growth
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