ORIGINAL_ARTICLE
Biological and Biochemical Effects of Bacillus thuringiensis, Serratia marcescens and Teflubenzuron and their Sequential Combined Effects on Cotton Leafworm, Spodoptera littoralis (Boisd.).
Two biopesticides Serratia marcescens [Eubacteriales: Enterobacteria] (used at MC50, concentration caused 50% malformation )and Bacillus thuringiensis Var. kurstaki (used at LC50) and insect growth regulator Teflubenzuron (used at LC 50 value) were used for treatment of 2nd instar larvae of cotton leafworm, Spodoptera littoralis (Boisd.). Sequential combined Effect was carried out bytreating 2nd instar larvae with LC50 value of B. thuringiensis or Teflubenzuron then the larvae allowed to pupate on sawdust treated with S. marcescens at MC50.The effects of these three agents were assessed by toxicity, fecundity, fertility, phosphatases activity and total carbohydrates. The obtained results revealed that Teflubenzuron is a potent toxin (LC50 = 0.113 ppm) compared to B. thuringiensis (LC50 = 165.64 ppm). On the other hand, the mode of action of S. marcescens is through malformation (MC50= 3.09x108 cfu). All treatments caused a significant reduction in fecundity and fertility. The sequential combined effect showed more reducing effect on the fecundity and fertility than the individual treatments. Moreover, the activity of phosphatases and total carbohydrates were significantly fluctuated during the different periods of pupal stage. The sequential combined effect of Teflubenzuron with S. marcescens caused more significant effect on alkaline phosphatase activity than the individual treatment with S. marcescens but it was somewhat similar to Teflubenzuron. Also the sequential combined effect treatment of B. thureinginsis with S. marcescens had more effect than the individual treatment either with S. marcescens or B. thureinginsis. Moreover, all treatments caused significant decreases in total carbohydrates during the pupal stage and the sequential combined effect treatments had more decreasing effect than the individual treatments. According to the obtained result, S. marcescens could be considered as a biopesticide, and become more effective when used in sequential treatment with either Teflubenzuron or B. thuringiensis.
https://eajbsf.journals.ekb.eg/article_17267_112a1623a41cab837360d5c592b1aa38.pdf
2013-06-01
1
13
10.21608/eajbsf.2013.17267
Serratia marcescens
Bacillus thuringiensis Var. kurstaki. Teflubenzuron
Spodoptera littoralis
biological
Biochemical aspects
El-Aasar
M.
1
Faculty of Agriculture , Ain –Shams- University, Egypt
AUTHOR
El-Sheikh
A.
2
Plant Prot. Res. Inst., Agric Res. Centre, Dokki, Giza, Egypt
AUTHOR
Ali
H.
3
Faculty of Agriculture , Ain –Shams- University, Egypt
AUTHOR
ORIGINAL_ARTICLE
Time-dependent effects of the venom of the scorpion Leiurus q. quinquestriatus on Na⁺, K⁺ and Ca⁺⁺ ion concentrations of rabbit’s plasma
Many neurotoxic polypeptides (NPs) from venom of the scorpion Leiurus quinquestriatus (LqV) have been isolated and functionally characterized that were found to block voltage-activated ion channels in excitable tissues in both mammals and insects. This study aims to reveal the time-dependent alternations of these electrolytes in plasma that induced by (LqV) in vivo.
Rabbits were injected subcutaneously with a sub-lethal dose of approximately 0.12 mg/km body weight of crude (LqV). Photometric techniques have been used to monitor changes in the concentrations of Na⁺, K⁺, and Ca⁺⁺ in plasma six times; the first sample considered as control, the other five samples were collected in 36 minutes interval (after LqV injection). Correlation and regression analysis have shown that potassium and Calcium concentration tended to decrease (r=-0.706) and (r=-0.586) respectively whereas, concentration of Sodium tended to increase (r=0.635). Percentage of concentration change from control showed highly significant fluctuation during the first two hours, sodium was highly decreased by -72.29% below control 36 minutes after injection, for potassium and calcium, concentrations were increased; after 72 minutes potassium raised by 173.76% above control, calcium highest reading observed after 36 minutes (44.03% above control). 108 minutes after injection, percentage of change from control for all the ions was very close to each other (30.54%, 26.31% & 31.67% above control for sodium, potassium and calcium respectively). 144 and 180 minutes after injection, less fluctuation was observed.
Neurotoxic venom of this scorpion was found to change serum concentration of three fundamental electrolytes in nervous system biochemical mechanism. In addition this change may greatly affect toxin binding to ion channels as well as homeostatic balance. We suggest that, fatal symptoms due to scorpion stings are not only limited to direct interactions of PNs with VGSCs, but also toxin-affected neuro-chemical homeostasis could affect the behaviour of VGSCs.
https://eajbsf.journals.ekb.eg/article_17268_5264e6a6d7ba2c7cd4b7361c36221497.pdf
2013-06-01
15
26
10.21608/eajbsf.2013.17268
LqV
neurotoxins
plasma electrolytes
voltage-gated sodium channels
neural homeostatic plasticity
Ibrahim El-khalil
A.
1
University of Khartoum, faculty of science, department of zoology, Khartoum, Sudan
AUTHOR
Fadol
El-rabaa
2
University of Khartoum, faculty of science, department of zoology, Khartoum, Sudan
AUTHOR
Eihab
Idris
3
University of Khartoum, faculty of science, department of zoology, Khartoum, Sudan
AUTHOR
ORIGINAL_ARTICLE
Determination of chlorofenapyr residues in squash during crop production cycle.
A method for determination of chlorofenapyr residues in squash by HPLC is described. Samples were extracted with methanol/water, followed by liquid- liquid partitioning and clean-up in chromatographic column, concentrated to a small volume. Analysis was then determined by HPLC equipped with UV-vis detector at 260 nm. The degradation rate of chlorfenapyr SC was studied and the results indicated that final residue in squash leaves reached 0.1 mg/kg after 14 day and was undetected for the fruits, which was considered safe for human beings and animal consumption.
https://eajbsf.journals.ekb.eg/article_17269_7a16422ab137330d1590cf5291ae14ec.pdf
2013-06-01
27
32
10.21608/eajbsf.2013.17269
chlorfenapyr
insecticide residue
HPLC
squash
Farida
El-Dars
1
Chemistry Department, Faculty of Science, Helwan University, Ain Helwan, Helwan, 11795 Cairo, Egypt
AUTHOR
Marguerite
Rizk
2
- Plant Protection Research Institute, Agriculture Research Center, Dokki, Giza, Egypt
AUTHOR
Shiry
Takla
3
- Plant Protection Research Institute, Agriculture Research Center, Dokki, Giza, Egypt
AUTHOR
ORIGINAL_ARTICLE
The Effect of Water Hyacinth, Eichhornia Crassipes, and King-Bo Compound on Some Biological and Biochemical Aspects on Cotton Leaf Worm Spodoptera littoralis (Boisd).
Water hyacinth, Eichhornia crassipes, is considered as the worst aquatic plant in the world that causes a serious hazard to nation’s developmental activities. The present study was planned to explore the potential of E. crassipes by making its positive attributes outweigh the negative ones. Thus, the present study was carried out to disclose to the effect of E. crassipes extracts "extracted by different solvents pet.ether, acetone and ethanol” and kingbocommercial formulations of plant extract on 4th larval instar of Spodoptera littoralis. Some biological aspects were recorded. Also, the phytochemical scanning was carried out to E. crassipes extract. In addition, the efficiency and residual effects of kingbo against S. littoralis under field conditions were also investigated.
Obtained results revealed that the percentage of larval mortality was increased with increasing the concentrations of all tested compounds. It also showed that all tested compounds caused reduction in pupal weigh compared with control. Results showed that, sterols/terpenoid and flavonoids were the most constitute of E. crassipes. In addition, the present findings showed inhibition effect on total protein content except petroleum ether extract which clarify non significant effect on 6th instar larval haemolymph. Also, in Esterases pattern were differed than the normal pattern.
https://eajbsf.journals.ekb.eg/article_17270_237d110143d6177d732f833252ddc295.pdf
2013-06-01
33
45
10.21608/eajbsf.2013.17270
Spodoptera littoralis
Water hyacinth
Plant extracts – kingbo
Toxicological
biological activities
physiochemical scanning – Total protein – Total lipid – Total carbohydrates
Esterases pattern
Heba
Hassan
1
Plant Protection Research Inistitute, A.R.C., Dokki - Giza, Egypt.
AUTHOR