Feeding habits of Thunnus albacares in Chabahar coastal waters, southeast Iran

During an I I months study period in Chabahar waters of Oman Sea, 350 Thunnus albacares were caught and their feeding habit investigated. Stomach contents and its emptiness were analyzed for different seasons using customary methods. Results showed squids as being the main food item in T. albacares. Seasonal variation in food items was observed such that squids were staple food item in spring and summer and other fish species in autumn and winter. Stomach emptiness was highest in winter and lowest in summer. Stomach emptiness index suggests the fish being a moderate feeder

Susceptibilities of two populations of Aphis gossiper Glover to selected insecticides

Two populations of Aphis gossypii were collected from cotton and melon crops treated with insecticides to control this aphid species. The  susceptibility of both aphid populations to pymetrozine, Pirimicarb, Oxydemeton-methyl and Imidacloprid was evaluated using leaf deep bioassays in Laboratory which were commonly used to control this aphid on both crops. Results showed that LC50 values of these insecticides against clones of cotton aphid were 452, 1427, 1810 and 209 ppm, respectively. LC50 values of the above mentioned pesticides against clones of melon aphid were 625, 688, 523 and 125 ppm, respectively. Lc50 data showed that aphids reared on melon was 2.07, 1.6 and 3.4 times more susceptible than cotton aphids to Pirimicarb, Imidaclopride and Oxydemeton-methyl and 1.4 times more resistant to Pymetrozine, respectively. In conclusion, it has been shown that clones of cotton aphid is on average 3.4-fold less susceptible to Oxydemeton- methyl, 2-fold less susceptible to pirimicarb, 1.6-fold less susceptible to Imidacloprid and nearly 0.7-fold more   susceptible to pymetrozine than clones of melon aphid. There was little difference in susceptibility to pymetrozine between the two populations. It is also suggested that continuous resistance monitoring should be conducted on a regional scale to identify the efficiency of compounds which are applied against this insect species.Key words: Aphis gossypii, cotton, melon, insecticide resistance

Biochemical characterization of digestive amylase of wheat bug, Eurygaster maura (Hemiptera: Scutelleridae)

Biochemical characterization of  -amylase in the midgut and salivary glands of Eurygaster maura was conducted. Results showed that -amylase activities were present in the salivary glands and gut. The activity of -amylase in the midgut and in the salivary glands was 0.098 and 0.057 U/ml, respectively. The pH of salivary glands and the gut was determined to be in the range of 5- 5.5 (for the salivary glands) and in the range of 6-6.5 (for the gut), using staining indicator. The optimum pH and temperature for salivary glands and midgut amylase activity was 6-7 and 35-40ºC, respectively. The stability of amylase was highest in the acidic pH (4-5). Ethylenediamine tetraacetic acid (EDTA), urea, sodium dodecyl sulfate (SDS) and Mg2+ inhibited the enzyme activity but, NaCl and KCl enhanced enzyme activity. Based on linear regression analysis of reciprocal starch concentration versus reciprocal amylase activity Km and Vmax were 0.11% and 0.04 mM maltose/min for midgut amylase and 0.298% and 0.071 mM maltose/min for salivary amylase, respectively. Sodium dodecyl sulfate electrophoresis (SDS-PAGE) showed that both midgut and salivary glands contain isozymes

Effect of plant seeds protein extract on the Sunn pest, Eurygaste integriceps Puton, growth and development and its gut serine protease activity

The sunn pest Eurygaster integriceps Puton (Hemiptera: Scutelleridae) is a major pest of wheat and barley in wide areas of the world that cause 100% crop loss when no control measures are taken. The aim of this study was to investigate the effect of the seed proteinous extract of different plant species including Chickpea Cicer arietinum (Fabaceae), bean Phaseolus vulgaris var. naz (Fabaceae), triticale Triticosecale wittmack (Poaceae), Celosia argentea (Amaranthaceae) in artificial diet against the Sunn pest growth and development as well as gut serine proteinase such as trypsin and chymotrypsin activities. The obtained results showed that protease inhibitors present in the seed extract affected nymphal development, adult weight and survivability to some extent. Mean developmental time of third and fourth instar nymphs were not significantly affected by the presence of seed extracts. However, developmental time of the fifth instar nymph was affected by seeds proteinous extracts. Bean proteinous extract increased developmental time significantly by almost two days followed by Chickpea that increased developmental time by one day (P < 0.01). Amaranthus seed proteinous extract caused slight increase in development time. Triticale extract did not affect nymph growth and development and there were no significant differences between developmental time of triticale extract and control. Azocaseinolytic activity of gut extract of E. integriceps was affected greatly by seed proteinous extracts. There were significant differences in general protease activity between control and all treatments. General protease activity dropped significantly low when treated with bean and cowpea extracts (P< 0.01). Almost the same trend was observed when trypsin and chymotrypsin activities were measured using BApNA and SAAPFpNA as substrates, respectively. It is concluded that seed extracts from non host plants of the Sunn pest caused significant reduction of general and specific protease activity in vitro.Key words: Sunn pest, growth, development, seed extracts, protease activity

Study on feeding and spawning behavior of Otolithes rubber (Croaker Fish) in Sistan & Baluchestan (Chahbahar) coasts in 1995, Iran

Otolithes ruber is one of the valuable commercial fishes in the South coasts of Iran and has been classified at the top level of commercial categorization, so owing to its economic importance, its biological characteristics were studied in Sistan & Baluchestan coasts in 1995. Three landing called Pozm, Bris and Remin were chosen for commercial catch sampling in this respect and 111 male fish and 149 female ones were autopsied within 7 months of evaluation. In feeding evaluation through numerical method, Squilla with 42.8% and Engraulidae with 1.4% consisted maximum and minimum percent of male fish stomach contents, respectively, and for female maximum and minimum percent of stomach contents were unidentified bony fishes with 35.7% and polynemidae family with 7%. The results showed that male fishes mature prior to females as they are smaller than females and no important difference was seen in sexual ratios in various month except March. Spawning was from December to the end of April and an outstanding spawning surge was observed from March to April. However, there was a light surge in November. The least coefficients of fatness in terms of male and female were 0.9 and 1 in April respectively and the most ones were 1.33 for male and 1.20 for female in January

Effect of an anti-juvenile hormone agent (Precocene I) on Sunn pest, Eurygaster integriceps (Hemiptera: Scutelleridae) development and reproduction

Sunn pest (Eurygaster integriceps Put.) (Hemiptera: Scutelleridae) is a serious pest of cereals causing severe quantitative and qualitative damage by feeding on leaves, stems and grains. Pesticide application is the main method of Sunn pest control, thus a search for developing new control methods is needed to diminish reliance on insecticides for insect control. So in the current study, the effect of an anti-juvenile hormone agent (precocene I) on the growth, reproductive biology and adult hemolymph proteins of E. integriceps females and males were investigated. The results indicated that precocene I had no acute toxicity to adults and second instars of E. integriceps. The treatment of second instars did not lead to death even in high doses, nor did it induce abnormality. The treatment of the third instar nymphs caused disorder in the physiology and increased mortality. The mortality of third instar was dose dependent (R2 = 0.9774). Hemolymph protein concentrations in control males and females were high (2497.95 ± 0.04 and 2088 ± 0.04, respectively), but they decreased with the starting of oviposition. Hemolymph protein concentrations in treated females were lower than the control, at first day after treatment. With passage of time, hemolymph protein concentrations remained constant and decreased near oviposition. Total protein concentration in males and females was nearly equal, and there were no significant differences among them (P > 0.01). Precocene I also affected the number of eggs laid by females and the percentage of hatched eggs. It can be said that the effect of precocene I was stage- and age-specific, that is, its effects were varied with stage of the insect and its age in that stage. When used in early growth stage, its effect was less. However, when used in the late developmental stage its effect was more apparent and increased mortality as well as abnormalities.Keywords: Eurygaster integriceps Put, precocene I, hemolymph protein concentration, immature development, reproductionAfrican Journal of Biotechnology Vol. 9(36), pp. 5859-5868, 6 September, 201

CEMENT TRANSPORTATION LIMITED-FLEET MODELING AND ASSIGNING TO RATED DEMANDS

Summary. Transportation is an inseparable part of the supply chain, with a key role in product distribution. This role is highlighted when ratio of "the cost of transportation" to "the value of goods" such as cement is significant. Iran has recently become one of the main centers of cement production in the world. However, transportation is the most important challenge in cement distribution because of weak structure of the transportation fleet and its independent action. Independence of and lack of commitment on the part of transportation fleets to cement companies as well as lack of timely delivery due to shortage of transportation in some routes and seasons lead to customers` dissatisfaction and even market loss or lack of market development. One of the significant differences between the transportation system in Iran and that in developed countries is lack of complete productivity of the transportation fleet. It means that trucks are driver-based in Iran. This paper introduces a model considering some issues such as driver-based trucks, size of the transportation fleet based on the number of active trucks, and demand priorities in the cement company. Taking the relation between the number of active trucks and the cement company into account, this model assigns weekly demands to the transportation fleet. It also tries to minimize the delay to respond to demands and increases the efficiency of the transportation fleet. Finally, this current condition-based model is compared with two other models including "no constraints on different routes of trucks" as well as single-route model for trucks