Effect of Amitraz on Colorado Potato Beetle (Coleoptera: Chrysomelidae) Feeding, Development and Survival

1996 ◽  
Vol 31 (1) ◽  
pp. 89-101 ◽  
Author(s):  
Craig A. Longtine ◽  
Geoff W. Zehnder ◽  
Edward B. Radcliffe
Keyword(s):  
Colorado Potato Beetle ◽  
Adult Emergence ◽  
Field Trials ◽  
Long Term Effects ◽  
Potato Beetle ◽  
Adult Feeding ◽  
Leptinotarsa Decemlineata Say ◽  
Contact Exposure ◽  
Early Instar ◽  
And Control

Effects of amitraz, a formamidine insecticide, were studied in Colorado potato beetle, Leptinotarsa decemlineata (Say), populations from Minnesota, North Dakota and Virginia. Contact exposure or ingestion of leaves dipped in 4000 ppm amitraz was not lethal to adults. However, adult feeding was reduced 50% upon exposure to 90 ppm amitraz, a rate <1/8 that recommended by the manufacturer for testing as a foliar insecticide. Ingestion of foliage treated with 945 ppm amitraz by early instar larvae had long-term effects on Colorado potato beetle development and survival, delaying adult emergence 4.7 days and causing 87% mortality. In 72 h bioassays, LC50s by contact exposure or ingestion were > 3.2× the suggested field rate. LC50s determined by exposure of larvae to treated foliage were greater than LC50s determined by immersing larvae. Egg hatch was not reduced by application of ≤ 1840 ppm amitraz. In field trials, amitraz reduced defoliation as effectively as esfenvalerate, the insecticide of choice when these trials were conducted. Amitraz-treated plots had yields intermediate between esfenvalerate and control treatments.

scholarly journals Biological efficacy of some biorational and conventional insecticides in the control of different stages of the Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae)

2010 ◽  
Vol 46 (No. 3) ◽  
pp. 123-134 ◽  
Author(s):  
M.A.M. Osman
Keyword(s):  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Residual Activity ◽  
Adult Emergence ◽  
Mortality Rates ◽  
Field Conditions ◽  
Biological Efficacy ◽  
Potato Beetle ◽  
Leptinotarsa Decemlineata Say ◽  
Third Instar Larvae

The biological efficacy of some biorational and conventional insecticides against different stages of Colorado potato beetle, Leptinotarsa decemlineata (Say) (Coleoptera: Chrysomelidae) was evaluated under laboratory and semi-field conditions. Seven different commercial products were tested, including the biorational insecticides: Spinosad, Mectin, Fitoverm, Match, Neemix in addition to two conventional insecticides: Actara and Actellic. Data indicated that all tested insecticides showed low toxic effects to L. decemlineata eggs, but most hatching neonates died shortly after hatching. All tested insecticides at their field rates showed high toxicity to larvae of L. decemlineata. The highest mortality was obtained in earlier instars, as compared to older ones, and mortality increased with the time of exposure. Moreover, the lower concentrations (up to 25% of the field rate) of Actara, Mectin, Spinosad, and Fitoverm showed high efficacy against L. decemlineata third instar larvae. Also, Actara caused the highest mortality in L. decemlineata adults, followed by Spinosad, Mectin, and Fitoverm as compared to Actellic, Match, and Neemix. In pupal bioassay, Fitoverm caused the greatest reduction in L. decemlineata adult emergence followed by Mectin, Actara, Actellic and Spinosad. In translocation bioassays, Actara caused the highest mortality in L. decemlineata 3<sup>rd</sup> instar larvae or adults followed by Spinosad and Mectin. The residual activity of tested insecticides against third instar larvae was also evaluated. Actara, Spinosad, and Mectin were more persistent under field conditions, consequently the mortality rates after 30 days of application were 46.67%, 44.44%, and 35.56%, respectively.

THE EFFECT OF WATER STRESS AND LEAFLET SIZE ON THE DENSITY OF TRICHOMES AND THE RESISTANCE TO COLORADO POTATO BEETLE LARVAE (LEPTINOTARSA DECEMLINEATA [SAY]) IN SOLANUM BERTHAULTII HAWKES

1990 ◽  
Vol 122 (6) ◽  
pp. 1141-1147 ◽  
Author(s):  
Yvan Pelletier
Keyword(s):  
Water Stress ◽  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Solanum Berthaultii ◽  
Abaxial Surface ◽  
First Instar ◽  
Potato Beetle ◽  
Resistance To Insects ◽  
Leptinotarsa Decemlineata Say ◽  
Growing Conditions

AbstractSolanum berthaultii Hawkes bears trichomes reportedly providing resistance to insects. Results indicated that the density of types A and B trichomes was linearly related to the inverse of the leaflet area. The number of trichomes on the adaxial and on the abaxial surface of terminal leaflets was not affected by two levels of water stress or by growing conditions in the greenhouse or the field. The leaflets of the water-stressed plants were generally smaller and, consequently, the density of trichomes higher.The survival of first-instar Colorado potato beetle larvae was similar on S. berthaultii grown under varying drought conditions and on leaves from field-grown plants bearing different densities of trichomes.

scholarly journals Screening test for detection of Leptinotarsa decemlineata (Say) sensitivity to insecticides

2012 ◽  
Vol 27 (1) ◽  
pp. 59-67
Author(s):  
Dusanka Indjic ◽  
Slavica Vukovic ◽  
Snezana Tanaskovic ◽  
Mila Grahovac ◽  
Tatjana Keresi ◽  
...  
Keyword(s):  
Colorado Potato Beetle ◽  
Leptinotarsa Decemlineata ◽  
Screening Test ◽  
Rapid Assessment ◽  
Potato Beetle ◽  
Highly Sensitive ◽  
Leptinotarsa Decemlineata Say ◽  
Two Populations ◽  
Insight Into

In 2009, the sensitivity of 15 field populations of Colorado potato beetle (Leptinotarsa decemlineata Say.) - CPB was assessed to chlorpyrifos, cypermethrin, thiamethoxam and fipronil, four insecticides which are mostly used for its control in Serbia. Screening test that allows rapid assessment of sensitivity of overwintered adults to insecticides was performed. Insecticides were applied at label rates, and two, five and 10 fold higher rates by soaking method (5 sec). Mortality was assessed after 72h. From 15 monitored populations of CPB, two were sensitive to label rate of chlorpyrifos, one was slightly resistant, 11 were resistant and one population was highly resistant. Concerning cypermethrin, two populations were sensitive, two slightly resistant, five were resistant and six highly resistant. Highly sensitive to thiamethoxam label rate were 12 populations, while three were sensitive. In the case of fipronil applied at label rate, two populations were highly sensitive, six sensitive, one slightly resistant and six were resistant. The application of insecticides at higher rates (2, 5 and 10 fold), that is justified only in bioassays, provided a rapid insight into sensitivity of field populations of CPB to insecticides.

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