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Aida Ghasemi, Jalal Sendi and Mohammad Ghadamyari

Physiological and Biochemical Effect of Pyriproxyfen on Indian Meal Moth Plodia Interpunctella (Hübner) (Lepidoptera: Pyralidae)

Insect growth regulators generally have a selective effect on the target insects and have practically no apparent side effect on non-target organisms especially vertebrates. Hence, insect growth regulators could be a suitable choice to control pests in stored products. Ten-day-old larvae of Indian meal moth Plodia interpunctella (Hübner) were expressed to the juvenile hormone analogue pyriproxyfen in order to have an effect on growth, metamorphosis, reproduction, lipid and protein contents of ovaries. The larvae were treated by 0.02, 0.04, 0.08, 0.16, and 0.3 ppm of JHA in an artificial diet where controls received acetone alone. The results indicated significant differences in duration of growth, mean longevity of hatched adults, percentage of emerged normal adults, abnormal pupae, hatched larvae and mean oviposition ratein addition to the lipid and protein of ovaries compared to the controls. An inhibition concentration of fifty (IF50) for prevention of emerging adults was recorded 0.134 ppm. Pyriproxyfen caused significant defects in the legs and wings of some adults and sever morphological changes in the ovaries of emerged adults. The results showed that pyriproxyfen may be applied as an insecticide to decrease the damage caused by Indian meal moth on stored products. Pyriproxyfen can be used with low side effects to humans.

Open access

Roya Khosravi, Jalal Sendi and Mohammad Ghadamyari

Effect of Artemisia Annua L. On Deterrence and Nutritional Efficiency Of Lesser Mulberry Pyralid (Glyphodes Pylolais Walker) (lepidoptera: Pyralidae)

Methanolic extract of Artemisia annua L. were evaluated on growth and nutritional efficiency of lesser mulberry pyralid Glyphodes pyloalis (Lepidoptera: Pyralidae) in laboratory conditions (24±1°C, 75±5% RH and 16 L : 8 D). Feeding deterrence index was evaluated by a choice test method on < 24 h fifth instar larvae with 5, 2.5, 1.25 and 0.625 percent of the extract. The result indicated that increasing the concentration resulted in higher deterrence. The extract retarded larval growth significantly (EC50 = 3.63%) and also showed significant effects on the 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). Lipid, protein and carbohydrate in treated insects were significantly reduced compared to the controls. Hence, methanol extract of A. annua could be considered as a strong deterrent which also affects the biochemical metabolism of the target pest. Methanol extract of A. annua has the potential for development as a botanical insecticide.

Open access

Negar Aghaali, Mohammad Ghadamyari, Vahid Hosseininaveh and Nasir Saberi Riseh

Abstract

Proteases are one of the most important digestive enzymes in the midgut of Hyphantria cunea Drury. Proteases are responsible for protein digestion. In the present study, we evaluated the efficiency of some plant inhibitors on proteases in the gut of the H. cunea. Last instar larvae were collected from mulberry trees. The digestive system of the larvae was used as an enzyme source. The total proteolytic and trypsin activity were assessed by the hemoglobin and BApNA, respectively, as the substrate. The evaluation of the total proteolytic and trypsin activities in various pHs showed the highest relative activity at a pH of 11. Also, the inhibitory effect of inhibitors extracted from Alhagi maurorum Medik., Lathyrus sativus L., Vicia faba L., Prosopis farcta (Banks & Sol.) Eig., and Panicum miliaceum L. on the digestive protease of the fall webworm was measured. Protease inhibitors extracted from A. maurorum, P. farcta and P. miliaceum showed negligible inhibition but L. sativus was able to inhibit 34.72% and 100% of the total activity of proteolytic and trypsin, respectively. Also, the total proteolytic and trypsin activities were inhibited by the inhibitor from V. faba, at 22.27% and 100%, respectively. The zymogram pattern of trypsin with nitro-cellulose membranes showed 2 isoforms in the gut of H. cunea. The inhibitor from L. sativus completely inhibited both isoforms. Gel electrophoresis of proteolitytic activity revealed at least 6 isoforms the inhibitor extracted from L. sativus; completely inhibiting some of them. The inhibitor from L. sativus was purified by ammonium sulfate precipitation and gel-filtration. The molecular mass of the inhibitor was determined as 45 kDa. The highest inhibition of trypsin activity by the inhibitor from L. sativus occurred at a pH of 10. The stability of the inhibitor from L. sativus was evaluated at different pHs and temperatures. The results showed that the inhibitor from L. sativus was stable at a pH of 11.0, and showed 45% inhibition on trypsin activity at a pH of 11. Also, this inhibitor revealed stability up to 50°C.

Open access

Tahareh Gholami, Mohammad Ghadamyari, Ali Olyaie Oliaee and Maryan Ajamhasani

Abstract

The rosaceous branch borer, Ospheranteria coerulescens, is an important pest of rosaceous trees. This insect feeds on the twigs and branches of living trees and causes their death. The characterization of the insect phenoloxidase (PO) is of interest when doing comparative investigations, and so that we may be able to understand its biochemical properties. When designing new methods of insect control such as the use of PO inhibitors, an understanding of the biochemical properties is fundamental. In this study, PO from hemolymph of the rosaceous branch borer was purified using ammonium sulfate precipitation, gel-filtration, and ion-exchange chromatography. The biochemical properties were characterized using l-dihydroxyphenylalanine (L-DOPA) as the specific substrate. The apparent molecular weights of the three isoforms of PO were determined by SDS-PAGE to be 85.23, 79.45, and 66.06 kDa. Optimal pH for PO activity was pH 8, and the optimal temperature was 45°C. Phenoloxidase lost less than 50% of its relative activity after a 60 min incubation at the optimal temperature. The effects of ions and chemical materials such as K+, Ba2+, Zn2+ and EDTA on PO showed that PO activity was strongly inhibited by Zn2+. The Michaelis constant (Km) and maximum velocity (Vmax) were 88.61 mM and 0.14 μmol/min, respectively. The inhibitory effects of kojic acid, 4-hexylresorsinol, and quercetin on PO were determined, and the IC50s (inhibitory concentration) were estimated as 23.31 for kojic acid, 35.75 for 4-hexylresorcinol, and 60.8 μM for quercetin. The inhibitory potency of kojic acid was 1.54 times higher than that of 4-hexylresorcinol and 2.58 times higher than that of quercetin. Phenoloxidase was effectively inhibited by 4-hexylresorcinol, and the inhibition type was competitive. The inhibition types of PO by kojic acid and quercetin were found to be mixed.

Open access

Moloud Gholamzadeh Chitgar, Jalil Hajizadeh, Mohammad Ghadamyari, Azadeh Karimi-Malati, Mahbobe Sharifi and Hassan Hoda

Abstract

It is necessary to study the biochemical changes in insects exposed to toxicants if we want to predict the potential of various chemicals on the natural enemy. Physiological energy, as a biochemical biomarker, may be affected by many pesticides including organophosphate compounds. Therefore, in this study, the sublethal effects of diazinon, fenitrothion, and chlorpyrifos on the cellular energy allocation (CEA) of the predatory bug, Andrallus spinidens Fabricius (Hemiptera: Pentatomidae), a potential biological control agent, was studied on 5th-instar nymphs. Among the energy reserves of the A. spinidens nymphs, only total protein was significantly affected by pesticide treatments, and the highest value was observed in chlorpyrifos treatment. The energy available (Ea) and energy consumption (Ec) in A. spinidens were significantly affected by these pesticides. In exposed bugs, these parameters were affected by fenitrothion and chlorpyrifos more than diazinon. The activity of the electron transport system (ETS) in the Ec assay showed that A. spinidens exposed to chlorpyrifos had the highest rate of oxygen consumption. Although, there was no significant change in CEA, the insecticides caused a marked change in the physiological balance of A. spinidens. The results suggested that the adverse effect of these insecticides on A. spinidens should be considered in Integrated Pest Management (IPM) programs.