Potency of some Photosensitizing Compounds against the Cotton Leaf Worm, Spodoptera littoralis (Boisduval) in Relation to some Biochemical Aspects

Abstract

The present study aimed to evaluate the toxicological as well as biochemical effects of the three photosensitizer compounds; rose bengal, eosin yellow lactone and methylene blue on the fourth larval instar of the cotton leaf worm, Spodoptera littoralis (Boisd.). Results of insecticidal activity against the fourth larval instar of S. littoralis revealed that rose bengal is the most toxic photosensitizer compound followed by eosin yellow lactone, then methylene blue. The corresponding LC 50 values were 37X10-5 M, 81X10-5 M and 136X10-5 M; respectively. Concerning, the photodynamic process of the thee photosensitizer compounds to control the 4 th instar larvae of S. littoralis , the LT 50 values of the lowest concentrations of rose bengal, eosin yellow lactone and methylene blue were >4hrs for each. On the other hand, the LT 50 values of the highest concentrations were 2.2, 3.25 and 2.50 hrs; respectively. This indicates that rose bengal was the most active compound. On the light of the median lethal effects of the three tested photosensitizer compounds on the total protein ,total lipids and total carbohydrates content in the tested fourth larval instar of the cotton leaf worm, the results proved that the three photosensitizer compounds decreased these biochemical contents except methylene blue slighty increased total protein content relative to control.

Field Application and Biochemical Studies of Certain Selected Photosensitizer Against Black Cutworm, Agrotis ipsilon

“…In addition, reduction % (-47.07 and -25.27%) at LC25 and LC50 treatments, respectively. Our results agree with El-Ghobary, et al, (2018) who stated that the treatment with rose bengal, eosin yellow lactone and methylene blue, showed a significant reduction -40.37%, -17.31 and -18.29%, respectively in total lipids compared with control. The total lipids are essential as a resource of energy in insects.…”

“…Photooxidation of tyrosine with methylene blue involves the break of the circle and configuration of CO2 (Attia, 2016). Our result agrees with El-Ghobary, et al, (2018) who proved that the treatment with LC50 of photosensitizer compounds caused decreased in the total lipids, total protein and total carbohydrates content of S. littoralis, while methylene blue slightly increased total proteins compared with control. Other studies in the same field mentioned the effect of LC50 value of rose bengal on the adults' flies and the untreated control showed a significant decrease in the total protein content (Attia, 2016).…”

“…Due to the arbitrary expend of pesticides treatments produce harm by exiting residues in the food. Therefore, it is becoming clear that alternative pest managing tools are required, to reduce hazardous to the human, environment and non-target organisms, at the same time must use in the field application with the lowest cost (El-Ghobary, et al, 2018). Photosensitizer compounds are considered an available substitute to conventional chemical compounds.…”

Acaricide resistance and novel photosensitizing approach as alternative acaricides against the camel tick, Hyalomma dromedarii

“…The arbitrary expenditure of organic chemical pesticides led to the development of tick resistance and environmental pollution; there are great challenges to using affordable alternatives to reduce the risks to humans, non-target organisms and the environment [11][12][13][14][15]. Plantbased pesticides [16] and photosensitizer are efficient substitutes to the ordinary conventional pesticides and might be environmentally sound [17,18].…”

The Toxicity Effect of Certain Photosensitizing Compounds on Some Biological Aspects of Field Strain of Agrotis ipsilon (Hufnagel) Larvae

“…Methylene blue was more toxic than hematomporphyrin on S. littoralis (Abd El-Naby, 2007). In contrast, El -Ghobary, et al, (2018) found that methylene blue was being less effective against the 4 th larval instar of S. littoralis by recording larval mortality 29.50 % with concentrations 78X10 -5 M and 89.50 % with 391X10 -5 M. in these fields of study, Junqueira et al (2002) and Tardivo et al (2015) recorded that rose bengal was the most poisonous photosensitizer of used compound followed by eosin yellow. In addition, methylene blue is playing an important role in photodynamic therapy as a drug in vivo and in vitro of the living cells.…”