scholarly journals Chlorfenapyr and Methomyl Deterioration on Spinach Plants and Their Residual Effects in Vitro on Egyptian cotton Leafworm (Spodoptera littoralis)

2021 ◽  
Vol 4 (7) ◽  
pp. 01-08
Author(s):  
Badr El-Sabah A. Fetoh ◽  
Mahmoud M. Ramadan ◽  
Abdelhadi A. I. Ali
Keyword(s):  
Spodoptera Littoralis ◽  
Field Trials ◽  
Residual Effects ◽  
Single Application ◽  
Quechers Method ◽  
The Mean ◽  
Egyptian Cotton ◽  
Egyptian Cotton Leafworm ◽  
Spinach Leaves

Field trials conducted to determine the degradation of chlorfenapyr and methomyl insecticides in/on spinach leaves. Spinach plants sprayed with chlorfenapyr (Challenger Super™ 24% SC) and methomyl (Neomyl™ 90% SP) at the rates of 50 cm3/100 L water and 715 g/ ha, respectively. The QuEChERS method used for the extraction and clean-up of the samples. Residue amounts determined at 2 h, 2, 4, 6, 9, 13 and 16 days after application by UHPLC-UV. The mean of recovery percentages was 98.78 and 99.05 % for chlorfenapyr and methomyl, respectively. The initial deposits of chlorfenapyr and methomyl on/in spinach leaves, two hours after a single application of the insecticides were 23.17 and 235.37 mg/kg, respectively. The percentages of dissipation of chlorfenapyr were 37.68, 55.29, 69.45, 84.45 and 96.83% for 2, 4, 6, 9 and 16 days after application. The corresponding dissipation percentages of methomyl were 38.27, 56.01, 71.44, 84.34 and 97.81%. The rates of degradation (k values) were 0.212 and 0.223, while the corresponding half-life times (t0.5) were 3.27 and 3.11 days with chlorfenapyr and methomyl, respectively. It could be recommended that single application of chlorfenapyr on Spinach plants at the early ages followed by single application of methomyl at least 17 days before harvest.

Distribution of moths of the Egyptian cotton leafworm, Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae), in the Nile Delta interpreted from catches in a pheromone trap network in relation to meteorological factors

1984 ◽  
Vol 74 (3) ◽  
pp. 487-494 ◽  
Author(s):  
El-Sayed A. Nasr ◽  
M. R. Tucker ◽  
D. G. Campion
Keyword(s):  
Seasonal Variation ◽  
Spodoptera Littoralis ◽  
Nile Delta ◽  
Meteorological Factors ◽  
Source Area ◽  
Pheromone Trap ◽  
Seasonal Migrations ◽  
Egyptian Cotton ◽  
Lepidoptera Noctuidae ◽  
Egyptian Cotton Leafworm

AbstractRecords of daily catches of males of Spodoptera littoralis (Boisd.) at pheromone traps in or near the Nile Delta, Egypt, during 1979 and 1980 were used to investigate both the seasonal variation in catch and the possibility that migration, associated with particular weather systems, may significantly affect moth numbers in a particular area. Although more moths were caught in 1979 than in 1980, in both years there was a similar seasonal variation in catch, with low numbers in January and February followed by an increase to a maximum in June or August. There was no systematic seasonal change in the area of highest catch that would suggest seasonal migrations. On some nights, large increases in catch were associated with weather disturbances, notably windshift lines, suggesting that flying moths are sometimes redistributed by wind systems. Catches at two traps far from the main source area suggest that moths may have flown at least 50 km downwind from sources in the Nile Delta. The pattern of nightly catches at most traps indicated that build-up of local populations is the most important factor affecting the population dynamics of the pest but that some, mainly local, redistribution by wind systems takes place.

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