scholarly journals Cross-Resistance Studies of Cry1Ac-Resistant Strains of Helicoverpa armigera (Lepidoptera: Noctuidae) to Cry2Ab

2007 ◽  
Vol 100 (3) ◽  
pp. 909-915 ◽  
Author(s):  
Shudong Luo ◽  
Kongming Wu ◽  
Yan Tian ◽  
Gemei Liang ◽  
Xue Feng ◽  
...  
Keyword(s):  
Helicoverpa Armigera ◽  
Cross Resistance ◽  
Helicoverpa Armígera ◽  
Resistant Strains ◽  
Lepidoptera Noctuidae

scholarly journals Mechanisms of Increased Indoxacarb Toxicity in Methoxyfenozide-Resistant Cotton Bollworm Helicoverpa armigera (Lepidoptera: Noctuidae)

Toxics ◽  
2020 ◽  
Vol 8 (3) ◽  
pp. 71
Author(s):  
Qinqin Wang ◽  
Changhui Rui ◽  
Qiyuan Wang ◽  
Li Wang ◽  
Fugen Li ◽  
...  
Keyword(s):  
Cytochrome P450 ◽  
Helicoverpa Armigera ◽  
Cross Resistance ◽  
Glutathione S Transferase ◽  
Cytochrome P450 Activity ◽  
Helicoverpa Armígera ◽  
Care Activity ◽  
Moderate Resistance ◽  
Lepidoptera Noctuidae

Indoxacarb is an important insecticide for the selective control of Helicoverpa armigera. It can be bioactivated to the more effective N-decarbomethoxylated indoxacarb (DCJW) by esterases in pests. It was observed that both field and laboratory selected populations of H. armigera showed negative cross-resistance between indoxacarb and methoxyfenozide. The Handan population exhibited moderate resistance to indoxacarb, but was susceptible to methoxyfenozide; the Baoding and Yishui populations exhibited moderate resistance to methoxyfenozide, but they were susceptible to indoxacarb. Moreover, the toxicity of indoxacarb was enhanced 1.83-fold in the laboratory methoxyfenozide-resistant H. armigera, and susceptibility to methoxyfenozide was increased 2.81-fold in the laboratory indoxacarb-resistant H. armigera. In vivo, DCJW concentrations in the susceptible and methoxyfenozide-selected (laboratory methoxyfenozide-resistant) populations were 4.59- and 4.31-fold greater than in the indoxacarb-resistant Handan population 1 h after dosing. After 2 h, the highest concentrations of DCJW and indoxacarb appeared in the methoxyfenozide-selected population. Meanwhile, increased carboxyl esterase (CarE) and decreased glutathione S-transferase (GST) activities were observed in the methoxyfenozide-selected population. However, the indoxacarb-selected (laboratory indoxacarb-resistant) and Handan populations showed a higher disappearance of indoxacarb and DCJW, and the activity of cytochrome P450 mono-oxygenase in these populations were significantly increased. This study showed that the improved toxicity of indoxacarb, as observed in the methoxyfenozide-selected H. armigera, was correlated with increased CarE activity, decreased GST activity, and the in vivo accumulation of indoxacarb and DCJW. The significantly increased cytochrome P450 activity and higher disappearance of indoxacarb and DCJW in indoxacarb-resistant H. armigera resulted in the decreased toxicity of indoxacarb.

scholarly journals Insecticide resistance in field populations of the tomato fruitworm, Helicoverpa armigera, from Senegal

2020 ◽  
Vol 14 (1) ◽  
pp. 181-191
Author(s):  
Serigne Omar Sene ◽  
Etienne Tendeng ◽  
Mamadou Diatte ◽  
Serigne Sylla ◽  
Babacar Labou ◽  
...  
Keyword(s):  
Insecticide Resistance ◽  
Helicoverpa Armigera ◽  
Cropping Systems ◽  
Resistance Mechanisms ◽  
Cross Resistance ◽  
Metabolic Resistance ◽  
Resistance Evolution ◽  
The North ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae

Monitoring of the evolution of insecticide resistance in the field is crucial to prevent pest control issues. The present study was conducted to assess insecticide resistance status of the fruitworm, Helicoverpa armigera (Hübner) (Lepidoptera, Noctuidae), the most destructive pest of field-grown tomato in Senegal. A sample of 11- 15 field populations were monitored for their susceptibility to abamectin, deltamethrin, and profenofos, using a standard leaf-dip bioassay method. Resistance ratios ranged from 1- to 30-fold to abamectin (4/15 populations with RR>10), 7- to 112-fold to deltamethrin (11/12 populations with RR>10), and 1- to 29-fold to profenofos (3/11 populations with RR>10). This indicates that resistance evolution to deltamethrin was widespread among field populations of H. armigera. However, an increasing trend of resistance to deltamethrin was observed from the South to the North of Niayes. Susceptibility to abamectin and profenofos was generally high but showed that resistance might be evolving within some populations. In addition, signs of cross-resistance to abamectin were detected, suggesting possible metabolic resistance mechanisms already selected in pyrethroid-resistant populations. The recorded high levels of pyrethroids resistance are a concern for the control of H. armigera in Senegal as the country is being currently embarking into economic expansion of tomato cropping systems. © 2020 International Formulae Group. All rights reserved. Keywords: Insecticide resistance, pyrethroids, avermectins, OPs, Helicoverpa armigera, West Africa

Incidence of Helicoverpa armigera (Lepidoptera: Noctuidae) and its natural enemies on smallholder crops in Kenya

1993 ◽  
Vol 83 (3) ◽  
pp. 321-328 ◽  
Author(s):  
H. van den Berg ◽  
M. J. W. Cock ◽  
G. I. Oduor ◽  
E. K. Onsongo
Keyword(s):  
Helicoverpa Armigera ◽  
Heliothis Armigera ◽  
Population Densities ◽  
Parasitoid Species ◽  
Larval Parasitoid ◽  
Total Percentage ◽  
Four Seasons ◽  
Helicoverpa Armígera ◽  
Lepidoptera Noctuidae ◽  
Experimental Plots

AbstractSmallholder crops (sunflower, maize, sorghum and cotton) were grown in experimental plots at seven sites, representing different agricultural zones of Kenya, over four seasons. Helicoverpa armigera (Hübner) (formerly Heliothis armigera) only occasionally achieved population densities sufficient to cause obvious damage to the crops, and was virtually absent from the coastal sites. At the inland sites, infestation and mortality levels varied greatly. Information is presented on the incidence of H. armigera, and the identity, distribution and frequency of its common parasitoids and (potential) predators, sampled in the experimental plots. Trichogrammatoidea spp., egg parasitoids, and Linnaemya longirostris (Macquart), a tachinid late-larval parasitoid, were the most common parasitoid species, but total percentage parasitism was rather low. Of the large complex of predators, only anthocorids and ants (predominantly Pheidole spp., Myrmicaria spp. and Camponotus spp.) were sufficiently common and widespread to be of importance in suppressing H. armigera. The abundance of predators fluctuated widely between sites, but anthocorids were most abundant at the western sites.

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