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Abstrakt

Development and demography of Adalia decempunctata L. were studied under laboratory conditions at seven constant temperatures (12, 16, 20, 24, 28, 32 and 36°C). First instar larvae failed to develop to second instar at 12°С and no development occurred at 36°C. The total developmental time varied from 47.92 days at 16°C to 15.94 days at 28°C and increased at 32°C. The lower temperature thresholds of 11.05 and 9.90°C, and thermal constants of 290.84 day-degree and 326.34 day-degree were estimated by traditional and Ikemoto-Takai linear models, respectively. The lower temperature threshold (Tmin) values estimated by Analytis, Briere-1, Briere-2 and Lactin-2 for total immature stages were 11.99, 12.24, 10.30 and 10.8°C, respectively. The estimated fastest developmental temperatures (Tfast) by the Analytis, Briere-1, Briere-2 and Lactin-2 for overall immature stages development of A. decempunctata were 31.5, 31.1, 30.7 and 31.7°C, respectively. Analytis, Briere-1, Briere-2 and Lactin-2 measured the upper temperature threshold (Tmax) at 33.14, 36.65, 32.75 and 32.61°C. The age-stage specific survival rate (sxj) curves clearly depicted the highest and lowest survival rates at 16 and 32°C for males and females. The age-specific fecundity (mx) curves revealed higher fecundity rate when fed A. gossypii at 24 and 28°C. The highest and lowest values of intrinsic rate of increase (r) were observed at 28 and 16°C (0.1945 d–1 and 0.0592 d–1, respectively). Also, the trend of changes in the finite rate of increase (λ) was analogous with intrinsic rate of increase. The longest and shortest mean generation time (T) was observed at 16 and 28°C, respectively and the highest net reproductive rates (R0) was estimated at 24 and 28°C. According to the results, the most suitable temperature seems to be 28°C due to the shortest developmental time, highest survival rate, and highest intrinsic rate of increase.
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Abstrakt

The effect of monoterpenoid 1,8-cineol on the toxicity and physiology of elm leaf beetle, Xanthogaleruca luteola Müller under laboratory conditions (26 ± 1°C, 65 ± 10% RH and 16L : 8D h) was investigated. Initially, LC30 and LC50 values of the constituent were estimated to be 23.5 ppm and 31.9 ppm for the last instar larvae after 48 h, respectively. Significant changes were observed in the values of relative growth rate (RGR), efficiency of conversion of ingested food (ECI), efficiency of conversion of digested food (ECD), approximate digestibility (AD) and consumption index (CI) between control and treated larvae with 1,8-cineol. The amounts of protein, glucose and urea decreased in the treated larvae in comparison with control. Similar findings were observed in the activities of alkaline phosphatase and lactate dehydrogenase while the activities of glutathione S-transferase and esterase significantly increased in the treated larvae using CDNB and α-naphtyl acetates as the substrates. Morphological and histological changes brought about by 1,8-cineol in the present study are indicative of growth inhibition targeting specific organs such as those of reproduction. We believe that 1,8-cineol can be considered as a safe and environmentally friendly compound.
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Abstrakt

Protein digestion in insects relies on several groups of proteases, among which trypsin plays a prominent role. In the current study, larvae of Pieris brassicae L. were fed radish leaves treated with 1 mM concentrations of three specific inhibitors of trypsin: AEBSF.HCl [4-(2- -aminoethyl)-benzenesulfonyl fluoride, monohydrochloride], TLCK (N-a-tosyl-l-lysine chloromethyl ketone) and SBTI (Soybean Trypsin Inhibitor) to find their potential effects on gene expression of trypsin. Initially, RT-PCR analysis revealed a gene of 748 bp responsible for synthesizing the digestive trypsin in P. brassicae larvae. Also, qRT-PCR data indicated a statistically greater expression of trypsin gene in the larvae fed 1 mM concentrations of AEBSF.HCl, TLCK and SBTI than the control. Results of the current study indicated that synthetic inhibitors can not only negatively affect the gene expression of P. brassicae trypsin, but also the insect can activate a compensatory mechanism against interruption of protein digestion by inducing more expression of the gene and producing more trypsin into the midgut lumen.
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