فصلنامه تحقیقات حشره شناسی
سال سیزدهم شماره 4 (پیاپی 52، زمستان 1400)

Aphids are among the most important economic pests and vectors of many plant pathogens in horticultural, agricultural and greenhouse crops in world. In this study, the effect of ethanolic extract of nettle Urtica dioica L. (Rosales: Urticaceae), Palizin® soap and Firooz® baby shampoo on three species of aphids (black alfalfa aphid, Aphis fabae (Scopoli), wheat poison aphid, Schizaphis graminum (Rondani), and cowpea aphid, Aphis craccivora (Koch)) were examined. Several experiments included evaluation of the birth percentage of adult insects, total mortality and mortality of 5-6- and 1-2-day-old nymphs and also adult insects treated with the above compounds. Hosts of these pests in all steps of this study were included wheat plants for poisonous wheat aphids, alfalfa for black alfalfa aphids and beans for black bean aphids. The results of this study showed that ethanolic extract of nettle has a significant effect on pest mortality. The result showed the ethanolic extract of nettle has a significant effect with the means ± SE percentage of mortality (90.50±3.76) and (87.78±3.92) in wheat poison aphid, (74.00±9.30) and (79.00±5.76) in black alfalfa aphid and (62.00±9.20) and (64.50±4.56) in cowpea aphid on 1-2-and 5-6- day-old nymphs, respectively, in comparing to control. So, according to the results, ethanolic extract of nettle has a significant effect on the control of these pests and it can have capacities that suggest conducting further studies in the management of Aphids.

Most agricultural products are viscoelastic, showing a complex behavior during transport, grading, and separation. Thus, it seems necessary to determine the mechanical properties of these materials to analyze their behavior and minimize losses. Accordingly, this study investigated the effect of hybrid type (154×153, 31×32, and 154×151), loading rate (10 and 20 mm/min), and loading direction (horizontal and vertical) on the mechanical properties of silkworm cocoons. A factorial experiment was used in a completely randomized design to analyze the data, and the means were compared by the multiple range Duncan test at a probability level (α) of 5%. The results showed the significant impact of the hybrid type, loading direction and speed, and their interaction on all mechanical properties of specimens. All mechanical properties of hybrids decreased as the loading speed increased from 10 to 20 mm/min. On the other hand, the rupture force, rupture energy, toughness, and deformation at rupture point were higher in horizontal loading than in vertical loading. According to the results, the highest rupture force (10.05 N) was measured for the hybrid 154×153. However, the highest rupture energy (2.78 J), deformation at rupture point (610 mm), and toughness (3.6×10-4 J/mm3) were measured for the hybrid 31×32 under horizontal loading at a loading speed of 10 mm/min. The lowest rupture force (3.83 N), rupture energy (0.27 J), deformation at rupture point (160 mm), and toughness (0.34×10-4 J/mm3) were obtained for the hybrid 154×151 under vertical loading at a loading speed of 20 mm/min.

The effect of different diets were examined. on the growth period , fecundity and life table parameters of Habrobracon hebetor Say against the Plodia interpunctella Hübner under laboratory conditions at 26±2 °C, 65±5% R.H. and photoperiod 16:8hours (L:D). Six diets were included pistachio, walnut, almond, date, figs and artificial diet. Results of this research revealed that the shortest period of pre-adult durations of parasitoid wasps on pistachio (9.92 days) and the longest period on figs diet (15.61 days). The highest sex ratio was observed on pistachio and artificial diets (0.52) and the lowest in figs and dates (0.46). The longest adult female longevity was on pistachio diet (30.50 days) and the shortest on fig (28.35days). The highest mean total number of eggs laid by H. hebetor was observed in pistachio diets (348.5-eggs) and the lowest in figs (306.09 eggs). The lowest duration of one generation (T) was on pistachio diet (15.61days) and the highest duration on figs (22.05days). Pistachio and artificial diet had the highest intrinsic rate of increase (rm) with 0.332 and 0.327 (day-1). Similarly, pistachio and artificial diet had the highest finite rate of increase ( ) with 1.39 (day-1). According to the results of the present study, pistachio and artificial diets were identified as the best diet for rearing H. hebetor. However, due to the fact that artificial diet is cheaper and more economical compared to other diets studied, so artificial diet can be used for mass-rearing programs of H. hebetor.

Black soldier fly (BSF) larvae, Hermetia illucens L. (Diptera: Stratiomyidae), can effectively convert the organic wastes into a nutrient-rich biomass and appropriate for animal feed, the composition of larve largely dependent on the composition and structure of the side stream which are used. The polyphage diet and the quality of the larvae's macronutrients (mainly lipids and proteins) make them suitable candidates for different applications such as organic side-streams management and using as protein sources in animal feed. In the present study, BSF larvae were reared on feed substrates composed of Mix of fruit and date pulp, Mix of fruit and olive pulp, mix of waste fruit and bread and waste fruit which is a readily available and cheap source of agriculture,s by product in Iran. The dry matter, crude fat, crude protein and ash of the BSF larvae fed each feed waste organic were quantified by chemical analyses. Larval weight, survival and feed conversion were also recorded. The results showed that the mixed of date and fruit pulp and the mixed of olive and fruit pulp are suitable diets for BSF rearing. Our findings may provide important supporting information to support the use of BSF larval meal as potential new source of nutrient- rich and supportable animal feed ingredients to substitute expensive and limited protein sources such as fishmeal and soya beanmeal.

Macrolophus caliginosus (Het: Miridae) is one of the biological control factors of some plant pests in Iran. In this study, the parameters of life table and reproduction of this insect in the growth chamber under temperature conditions of 25±1 °C, relative humidity of 65±10% and light period of 14 hours of light and 10 hours of darkness by feeding from different age stages of two-part tartan mite (TU) ) was evaluated. The experiment was started by using 100 one-day-old insects and the mortality rate of different age stages was determined daily. The results showed that the age-specific (qx) mortality of Macrolophus caliginosus nymphs started at 4 days of age and gradually increased with slight fluctuations. Life expectancy increased slightly after the nymphs hatched, but then declined. Life expectancy at the time of nymph hatching was 17.75 days and at the time of emergence of adult insects was estimated to be 13.95 days. Net fertility and fertility rates, which indicate the reproductive participation of females in each generation for the next generation, were set at 32.91 t 0.17 and 26.35 t 1.02, respectively. Also, the average number of eggs produced by each female was 4.18 eggs per day.

In this study,symbiotic bacteria of Sitotorga cerealella were identified. Containers containing barley were stored in a growth chamber at a temperature of 24 ° C and a relative humidity of 65% after contamination. To separate the bacteria of Sitotorga cerealella gastrointestinal tract,10 healthy larvae were selected from the reared population. After disinfection, the larvae gastrointestinal tract was removed with ethanol 70%, sodium hypochlorite and distilled water5%. Then, one milliliter of 0.1 M phosphate buffer with pH 7 was used to homogenize the gastrointestinal tract. The homogeneous and diluted contents were cultured in nutrient agar medium. To perform polymerase chain reactions from 5 μl of Master Mix ,2 μl of extracted DNA, 1.5 μl of RP2 primer and 1.5 μl of FD1 primer and 15 μl Distilled Water that the total volume of these materials should reach 25 microliters. The PCR process was performed using general primers FD1 and RP2 and 16srRNA gene sequence in a thermocycle.The PCR product sequencing was performed in collaboration with South Korea&amps Bioneer and the results were reviewed at the NCBI site. The phenotypic characteristics of the isolated bacteria were determined by standard bacteriological methods. After reviewing all the prepared colonies and comparing the obtained results, the highest frequency in terms of number of colonies was specific to Enterococcus mundtii and Enterobacter hormaechei was less abundant in the gastrointestinal tract of Sitotorga cerealella. Also, according to electrophoresis, the highest bands observed belong to Enterobacter hormaechei and the shortest band belongs to Enterococcus mundtii.