Toxicicological evaluation and biochemical impacts for radient as a new generation of spinosyn on Spodoptera littoralis (Boisd.) larvae

Abstract

Radiant SC12% (Spinetoram) is a new generation of spinosyn group. Effect of this bio-insecticide against larvae of Spodoptera littoralis (Boisd) was studied to evaluate the susceptibility of 2 nd and 4 th larval instars in laboratory. The LC 50 of radiant was 0.05 and 0.03 ppm. After 24 and 48 hours, respectively for the 2 nd larval instars. Where the LC 50 were 6.67 and 2.86 ppm after 24 and 48 hours, respectively for the 4 th larval instars. In the semi-field experiment, recommended doses of radiant exhibited high mortality 100 & 95.7 % after 0 and 1 days, respectively then decreased gradually to reach 58.1 % after 7 days. Also the field experiment showed high mortality 91.4% after 2 days then reduced gradually to reach 83.1% after 8 days. The effect of different concentrations in laboratory and recommended doses in field showed 100% mortality of entire hatched egg masses. Effect of recommended doses of radiant against predators inhabiting cotton field demonstrated that radiant was safe to natural enemies. The effect of LC 50 of radiant on the major biochemical component of 4 nd larval instars after 24 hours showed that, the amount of total carbohydrates, total proteins, carbohydrate hydrolyzing enzymes (invertase, trehalase and amylase), and acid & alkaline phosphates were significantly decreased. Where the acetylcholinstrase activity was significantly increased.

Efficiency of some new insecticides on physiological, histological and molecular level of cotton leafworm.

“…Sometimes, eggs can be seen with the head of the neonate larvae protruding (Plate 1-B,C and D). These findings are in full agreement with (Elbarky Nehad et al, 2008). In the case of methoxyfenozide, failure of the eggs hatching could be explained by the known mode of action of this compound, which act as ecdysone agonists.…”

“…As shown in (Plate 3-D) the thickness of the cuticle decreased, some hypodermal cells became separated from the endocuticle. Elbarky et al (2008) showed that, the amount of total carbohydrates, total proteins, carbohydrate hydrolyzing enzymes were significantly decreased when S. littoralis treated with spinetoram. These components are necessary for building cuticle and lake of them may lead to abnormal endocuticular deposition and abortive molting.…”

Effects of some Insecticide Mixtures on Toxicity and Some Biochemical Parameters of Cotton Leafworm, Spodoptera littoralis (Boisd.)

“…The decrease of the total protein may reflect the decrease in the enzymatic activities of various enzymes. These results in accordance with the demonstrated by Abd El-Aziz et al, (2007) and Elbarky et al, (2008). However, our results disagree with results obtained by Raja et al, (1986) and Lohar and Wright (1990).…”

Potency and Residual Activity of Emamectin Benzoate and Spinetoram onSpodoptera littoralis(Boisduval)

“…The results reported in this study agree with those of Elbarky et al (2008) who observed that spinetoram has short residual time in cotton under field conditions. This also appears to apply to spinosyns sprayed on kiwi fruit foliage where the half-lives of 10-20 days compared well with the several days reported on the surfaces on the other plant species (McDonald et al 1998).…”