Mean Relative Growth Rate Research Articles

Spirotetramat Resistance Selected in the Phenacoccus solenopsis (Homoptera: Pseudococcidae): Cross-Resistance Patterns, Stability, and Fitness Costs Analysis.

The Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae) is a major agricultural and horticultural pest of crops throughout the world. To develop a better resistance management strategy for P. solenopsis, we conducted a study on life history parameters of different populations of this pest, one selected with spirotetramat (Spiro-SEL), an unselected (UNSEL) population, and their reciprocal crosses. We also studied the cross-resistance and the stability of spirotetramat resistance. The Spiro-SEL of P. solenopsis exhibited a 328.69-fold resistance compared to the susceptible population (Lab-PK). The Spiro-SEL population also displayed a moderate level of cross-resistance to profenofos and bifenthrin and a high level of cross-resistance to abamectin. Resistance to spirotetramat in Spiro-SEL was unstable in the absence of selection. The study of life history parameters showed that there was a significant reduction in fitness parameters of Spiro-SEL population with a relative fitness value of 0.14. There was a significant decrease in survival rate, pupal weight, fecundity, egg hatching percentage, male and female generation time, intrinsic rate of population increase of males and females, biotic potential, and mean relative growth rate. It is concluded that selection with spirotetramat had marked effect on resistance development in P. solenopsis and upon removal of selection pressure spirotetramat resistance declined significantly, indicating unstable resistance. Development of resistance led to high fitness costs for the spirotetramat-selected population. Our study may provide the basic information on spirotetramat resistance and its mechanism to help develop the resistance management strategies.

Exotic Invasive Shrub Glossy Buckthorn Reduces Restoration Potential for Native Forest Herbs

Invasive glossy buckthorn could reduce restoration potential for understory native forest herbs by compromising their growth and biodiversity. Few studies of glossy buckthorn’s effects on forest herbs exist, and none were done in early-successional, partially open hardwood forests. This study was conducted in a mature hybrid poplar plantation invaded by buckthorn, located in southeastern Québec. We tested the effect of buckthorn removal on the growth of three forest herb species, whether this effect varied among species, and if canopy type (two poplar clones) influenced this effect. Forest herbs were planted in herbicide (buckthorn removed) and control treatments in the plantation understory, an environment similar to that of early-successional hardwood forests. Over the first two growing seasons, species showed specific reactions to buckthorn cover. Mean relative growth rate (RGR) for Asarum canadense and Polygonatum pubescens was increased in the herbicide treatment (48% and 33%, respectively) and decreased in the control treatment (−35% and −33%, respectively). Sanguinaria canadensis growth was the highest among species, with no difference between treatments. No effects of canopy type were detected. Results suggest that planting forest herbs for restoration purposes may be unsuccessful if buckthorn is present. Important changes in understory flora biodiversity are likely to occur over the long term in forests invaded by buckthorn.

Canopy treatment influences growth of replacement tree species inFraxinus nigraforests threatened by the emerald ash borer in Minnesota, USA

Fraxinus nigra Marsh. (black ash), a dominant tree species of wetland forests in northern Minnesota, USA, is imperiled by the invasive insect emerald ash borer (EAB; Agrilus planipennis Fairmaire, 1888). Regeneration of associated tree species is generally low in F. nigra forests and could be impacted further by climate change. Proactive management may be critical to maintaining tree cover and ecosystem function following EAB invasion. We investigated the mean height and diameter relative growth rate (RGR) of seedlings of 10 potential replacement tree species, including two from the next southern climate zone projected to be adapted to the future northern Minnesota climate. Seedlings were planted in F. nigra wetlands under four canopy treatments: unharvested control, clearcut, girdling F. nigra to emulate EAB-induced mortality, and group selection. Mean height and diameter RGR was fastest overall in the clearcut treatment, followed by the girdling, group selection, and control treatments. Depending on species, treatment significantly influenced RGR. Several species projected to be adapted to the future northern Minnesota climate had moderate to rapid mean RGR, including one from the next southern climate zone. Our results suggest that seedling plantings and overstory treatment represent an effective strategy for establishing F. nigra replacement tree species as EAB approaches, while reducing future risk from climate change.

Process-based modeling of tree-ring formation and its relationships with climate on the Tibetan Plateau

Response of climate warming on tree-ring formation has attracted much attention during recent years. However, most studies are based on statistical analysis, lacking understanding of tree-physiological processes, especially in the mountainous regions of the Tibetan Plateau (TP). Herein, we firstly use an updated new version of the tree-ring process-based Vaganov-Shashkin model (VS-oscilloscope) to simulate tree-ring formation and its relationships with climate factors during the past six decades. Our analyses covered 341 sampled trees growing within elevations ranging from 2750 to 4575m a.s.l. at five sampling sites across the TP. Simulated tree-ring width series are significantly (p<0.01) correlated with actual tree-ring width chronologies during their common interval periods. Starting dates of tree-ring formation are determined by temperature at all five sampling sites. After the initiation of tree stem cambial activity, soil moisture content has a significant effect on tree radial growth. Ending dates of cambial activity are driven by temperature over the whole study region. Simulated results indicate differences between wide and narrow tree-rings are mostly induced by soil moisture content, especially during the first half of the growing season, when effects from temperature variations are minor. Interestingly, we detected significantly (p<0.001) increased relative growth rates due to higher soil moisture content after the year 1985 at the five sampling sites. However, the variability of mean relative growth rates due to temperature is negligible before and after that. Based on the successful application of VS-oscilloscope modeling on the high-elevation tree stands on the TP, our study provides a new perspective on tree radial growth process and their varying relationships to climate factors during the past six decades.

Larval Habitat Substrates Could Affect the Biology and Vectorial Capacity of Culex quinquefasciatus (Diptera: Culicidae).

Culex quinquefasciatus Say is an important disease vector throughout much of the world. Experiments were conducted to determine the effects of different larval habitat substrates on the fitness and biting efficiency of Cx. quinquefasciatus adults. Our findings indicate that the development time (egg to adult) of larvae reared in irrigation water was 8.63 d while that of larvae reared in distilled water was 17.10 d (Effect size = 0.95). However, the rate of adult emergence was similar for all the tested treatments. Furthermore, the mean weight of an egg raft varied between larval habitats: distilled water (1.83 mg), rainfall water (1.25 mg), irrigation water (1.52 mg), and sewerage water (2.52 mg) (Effect size = 0.91). But, the fecundity (eggs per female) and hatchability (%) were statistically similar in all the rearing mediums (Effect size = 0.79). Longevity of females in all the tested populations did not differ significantly (Effect size = 0.91). The mean relative growth rates of larvae reared in tap water (0.80) and distilled water (0.86) habitats were lower than growth rates in all other rearing habitats (Effect size = 0.96). The intrinsic rate of natural increase in tap water (0.27) and irrigation water (0.35) was significantly higher than that in distilled water (0.09) and sewerage water (0.16) (Effect size = 0.84). Adults reared in rain water had the highest biting efficiency among all the tested populations. These results provide useful information for the management of Cx. quinquefasciatus.

Ultraviolet radiation reduces lichen growth rates

We quantified relative growth rates (RGR) in shade-adapted and melanin-deficient thalli of Cetraria islandica and Lobaria pulmonaria cultivated in short-term growth chamber experiments with and without UV-B radiation. In the first experiment done under optimal PAR (125 μmol m−2 s−1), but high UV-B radiation (1 W m−2), UV-B radiation significantly reduced RGR (P < 0.001). The second experiment with higher PAR, but more natural ratios between wavelength ranges (PAR: 500 μmol m−2 s−1; UV-A: 7 W m−2; UV-B: 0.4 W m−2), caused a reduction in mean RGR in L. pulmonaria to just 45% of rates in experiment 1. Lobaria pulmonaria screened from UV-B radiation had 1.9 and 1.6 times higher RGR than non-screened thalli in experiment 1 and 2, respectively. UV-B radiation significantly induced melanin synthesis in the second experiment only, causing significantly less photoinhibition than in thalli receiving just PAR. This is consistent with PAR-protective roles of melanins. Chlorophylls were not affected by UV-B radiation in any experiment. Because UV-B radiation affected RGR more than pure photobiont responses, the mycobiont is likely the more UV-B-susceptible partner. Apart from reduced RGR, we found little evidence for adverse UV-B effects.

Effects of simulated microgravity on the performance of the duckweeds Lemna aequinoctialis and Wolffia globosa

Duckweed is considered to be one of the most attractive higher plants to provide the life support requirements of the crew in long-duration space missions. Two species of duckweed, Lemna aequinoctialis and Wolffia globosa, were comparatively studied with focus on the effects of simulated microgravity conditions. A significant enhancement of plant relative growth rate (RGR) was observed under simulated microgravity conditions. The mean RGR of L. aequinoctialis was 32% increased, and W. globosa was 12% increased compared to control. Light and electron microscope analyses showed that the mesophyll cells of duckweed fronds were loosely arranged and many intercellular air spaces enclosed by mesophyll cells were observed in reaction to simulated microgravity, and few starch grains were detected in root tip cells in L. aequinoctialis under simulated microgravity conditions. For L. aequinoctialis, the starch content was significantly increased under simulated microgravity conditions. Thus, the starch content of W. globosa under simulated microgravity conditions was kept stable during all growth periods. This pattern might be associated with the different expression change of the rate-limiting gene APL in regulating starch levels. Taking into consideration of the duckweed growth, ultra-structure and starch content changes, we considered that simulated microgravity conditions do not have a significant adversely affect on the duckweed growth.

Laboratory selection of chlorpyrifos resistance in an Invasive Pest, Phenacoccus solenopsis (Homoptera: Pseudococcidae): Cross-resistance, stability and fitness cost

The cotton mealybug, Phenacoccus solenopsis is an important polyphagous sucking pest of ornamentals, horticultural and fiber crops worldwide. Some P. solenopsis populations have developed insecticide resistance. This study evaluated cross-resistance, stability of insecticide resistance and life history traits affected by chlorpyrifos resistance in P. solenopsis. After nine generations selected with chlorpyrifos, P. solenopsis exhibited a 539.76-fold resistance level compared to an unselected population (UNSEL Pop). Chlorpyrifos selected population (Chlor-SEL Pop) displayed moderate cross-resistance to profenofos, nitenpyram and high cross-resistance to lambda-cyhalothrin. Biological parameters of P. Solenopsis were affected by chlorpyrifos resistance. The Chlor-SEL Pop had a significant reduction in fitness (relative fitness=0.10), along with significant decreases in pupal weight, fecundity, egg hatching %, intrinsic rate of natural population increase, biotic potential, and mean relative growth rate. It is concluded that selection with chlorpyrifos had marked effect on resistance development in P. solenopsis and upon removal of selection pressure chlorpyrifos resistance declined significantly indicating unstable resistance. Development of resistance led to high fitness costs for the chlorpyrifos-selected strain. These findings should be helpful for better and more successful resistance management of P. solenopsis.

A Bibliometric Study on Photosynthesis Research Output Based on Web of Science Database During 1989 to 2014

This study aims to research output of photosynthesis indexed in the Web of Science database during 1989-2014. About 53,839 bibliographical records were down loaded from Web of Science database during 1989-2014. It is observed that its relative growth rates contracted progressively from 0.302 at 1989 to 0.116 in the year of 2014. The whole study period sample mean relative growth rate is 0.10. Contrary to this, the Doubling Time for publication of all sources in Photosynthesis research output decreased from 2.29 years in 1989 to 5.97 years in 2014 during the study period, doubling time value is 25.11 years.

A Bibliometrics Analysis of Photosynthesis Research Productivity: Study Based on Web of Science Database

An analysis of 53839 publications published by scientist during the time span of 1989 to 2014 and indexed by Web of Science online Database indicates that the publications output in the Photosynthesis Research. The Chinese Academic Sciences, Russian Academic Sciences and Australian National University were the most producers of research output in Photosynthesis. It is observed that its relative growth rates contracted progressively from 0.302 at 1989 to 0.116 in the year of 2014. The whole study period sample mean relative growth rate is 0.10. Contrary to this, the Doubling Time for publication of all sources in Photosynthesis research output decreased from 2.29 years in 1989 to 5.97 years in 2014. During the study period, doubling time value is 25.11 years. This work is to provide a profile of research in Photosynthesis research publications in global level.

Partially purified Glycine max proteinase inhibitors: potential bioactive compounds against tobacco cutworm, Spodoptera litura (Fabricius, 1775) (Lepidoptera: Noctuidae)

Spodoptera litura (Fabricius, 1775), a polyphagous defoliator with broad host spectrum, causes significant damage to agriculturally important crops. Serine protease is primarily responsible for most of the proteolytic activity in the larval gut of lepidopteran insects. Second-instar larvae were reared on an artificial diet containing serine trypsin inhibitor partially purified from Glycine max seeds. Different concentrations were amended in the diet, i.e. 25, 50, 100, 200, and 400 μg/mL. The larval development period, total developmental period, longevity, fecundity, larval weight, and mean relative growth rate were decreased at the 100 μg/mL concentration. However, with further increase in concentration, the above parameters were all found to increase. Nutritional indices revealed reduction in efficiency of conversion of digested food and approximate digestibility, whereas increase in efficiency of conversion of ingested food had significant influence on food assimilation. Trypsin activity was suppressed at 100 μg/mL with increase in exposure interval. Results reveal that soybean protease inhibitor inhibited S. Litura gut proteinase and it was more effective at lower concentrations. Thus, low levels of inhibitor would be enough to affect the growth and development of the target pest for the development of transgenic plants.

CULTIVO PILOTO DE MACROALGAS ROJAS (RHODOPHYTA) EN BAHÍA PORTETE, LA GUAJIRA, COLOMBIA

A seaweed pilot culture was developed in Portete bay, La Guajira, Colombia, between July 2005 and June 2006. The aim of this study was to evaluate the potential of this activity as a productive alternative to coastal communities thriving in the region. One hundred fourteen kilograms of the red algae Gracilaria cervicornis, Hydropuntia cornea, Hypnea musciformis and Grateloupia sp. were attached to polypropylene ropes and cylindrical meshes, at two sites of the bay. Gracilaria cervicornis had relative growth rates (RGR) between 0.1 % day-1 and 1.22 % day-1, with a mean of 0.44 % day-1, strong epiphytism and high loss rates. Hydropuntia cornea had a mean RGR of 0.91 % day-1 varying between 0.02 % day-1 and 3.5 % day-1 at site one, while at site two it had an average RGR of 0.97 % day-1 with a range between 0.03 % day-1 to 4.1 % day-1 with the maximum value recorded in February 2006. Small sized fragments exhibited the best RGR and biomass increase in comparison to larger fragments. Hypnea musciformis and Grateloupia sp. did not fare well under culture conditions due to their fragility. Environmental factors such as temperature and salinity had great variation in time, but no correlation was evident with RGR. The greatest RGR and epiphytism reduction were observed during the dry season where minimum temperatures were registered and there was an increase in nutrient availability due to a seasonal upwelling event. Different factors, such as water motion, nutrient concentration, temperature, salinity, herbivory, and epiphytism, exert some influence on seaweed growth, although is necessary to perform a complete characterization of physicochemical parameters in order to assess the bay’s productivity. It is also necessary to develop experiments aimed at reducing the incidence of different factors in the cultures. The RGR of some local algae species reported in this study suggest that Portete bay has adequate conditions to develop seaweed culture but, in order to do so, it is necessary to improve some of the culture techniques.

Testing the fecundity advantage hypothesis with Sitobion avenae, Rhopalosiphum padi, and Schizaphis graminum (Hemiptera: Aphididae) feeding on ten wheat accessions.

The fecundity advantage hypothesis suggests that females with a large body size produce more offspring than smaller females. We tested this hypothesis by exploring the correlations between life-history traits of three aphid species feeding on ten wheat accessions at three levels of analysis with respect to the host plant: overall, inter-accession, and intra-accession. We found that fecundity was significantly correlated with mean relative growth rate (MRGR), weight gain, and development time, and that the faster aphid develops the greater body and fecundity, depending on aphid species, wheat accession, and analyses level. Larger aphids of all three species produced more offspring overall; this held true for Sitobion avenae and Schizaphis graminum at the inter-accession level, and for S. avenae, Rhopalosiphum padi, and S. graminum for three, five, and eight accessions respectively at the intra-accession level. Only one correlation, between intrinsic rates of natural increase (rm) and MRGR, was significant for all aphid species at all three analysis levels. A more accurate statement of the fecundity advantage hypothesis is that cereal aphids with greater MRGR generally maintain higher rm on wheat. Our results also provide a method for exploring relationships between individual life-history traits and population dynamics for insects on host plants.

Previous infestation withPsammotettix alienuson spring wheat seedlings decreased the fitness ofSitobion avenaein a subsequent infestation

Previous feeding by herbivores may influence the performance of other herbivores by altering the morphological and physiological properties of the shared host. The present study aimed to examine the fitness of the apterous aphid Sitobion avenae (Fabricius) (Hemiptera: Aphididae) when fed spring wheat that was previously attacked by the leafhopper Psammotettix alienus Dahlbom (Hemiptera: Cicadellidae), with an evaluation of the differences in aphid weight (WD), development time (D), mean relative growth rate (MRGR), daily production of nymphs (MDNP) and intrinsic rate of population increase (rm) under controlled greenhouse conditions. For the S. avenae reared on the two spring wheat cultivars that were previously infested with P. alienus, the WD and the MRGR decreased significantly. The S. avenae reared on the previously infested cv. Leguan had significantly prolonged D values and a lowered rm, whereas these parameters did not differ significantly when S. avenae was reared on the cv. Bobwhite. Overall, the fitness of the aphid S. avenae was adversely affected when reared on the two spring wheat cultivars that were previously infested with P. alienus.

Research Growth and Author Collaboration Trends in DESIDOC Journal of Library and Information Technology

This study analysed the growth of contributions and collaboration research trends among the authors of DESIDOC Journal of Library and Information Technology covering the period 1996-2013. The number of contributions has increased from 27 to 66 in a period of eighteen years. Average number of contributions per volume has come around more than 33. Mean doubling time of this journal has come out to be 5.95 where as mean relative growth rate has come out 0.17. Single author contributions are 48.49% and multiple authors contributions are 51.51%.

Altered seawater salinity levels affected growth and photosynthesis of Ulva fasciata (Ulvales, Chlorophyta) germlings

Seawater salinity is greatly influenced by tide, evaporation and rain falls. In this study, we investigated the growth and photosynthetic responses of zygote-derived Ulva fasciata Delile germlings to short-term (minutes) and prolonged (days) exposure to different salinity gradients, to evaluate the effect of salinity variation on the early stage of life history in this seaweed. The results showed that, the maximum net photosynthetic rates (NPRm) of U. fasciata germlings was observably decreased in desalted (25 and 15) and high (45) salinity seawater in short-term exposure tests (in minutes). However, after 30 min, the photosynthesis activity in medium salinity (25) was maintained at a relative high level (above 70%). After 8 d prolonged culture, the photosynthesis and mean relative growth rate (RGR) of germlings were all markedly lowered, whereas the malondialdehyde (MDA) contents increased as the salinity desalted from 34 to 15. The salinity decrease from 34 to 25 had no significant effect on the RGR, but obviously influenced the morphology of the germlings. High salinity level (45) significantly depressed the RGR and photosynthesis of U. fasciata germlings, while it notably increased the MDA contents. The results showed that the salinity elevation had more detrimental effects on Ulva fasciata germlings than salinity decrease did. The germlings grown at the salinity seawater levels from 25 to 34, performed preferable photosynthetic acclimation both in temporary and prolonged culture. Broad salinity tolerance from 25 to 34 in U. fasciata germlings may have partly evolved as a response to regular diurnal tides.

Direct Effects of Elevated CO2 Levels on the Fitness Performance of Asian Corn Borer (Lepidoptera: Crambidae) for Multigenerations.

Understanding direct response of insects to elevated CO2 should help to elucidate the mechanistic bases of the effects of elevated CO2 on interactions of insects with plants. This should improve our ability to predict shifts in insect population dynamics and community interactions under the conditions of climate change. Effects of elevated CO2 levels on the fitness-related parameters were examined for multigenerations in the Asian corn borer, Ostrinia furnacalis (Guenée). The larvae were allowed to feed on artificial diet, and reared in the closed-dynamic environment chambers with three CO2 levels (ambient, 550 μl/liter, and 750 μl/liter) for six generations. In comparison with the ambient CO2 level, mean larval survival rate decreased 9.9% in 750 μl/liter CO2 level, across O. furnacalis generations, and larval and pupal development times increased 7.5-16.4% and 4.5-13.4%, respectively, in two elevated CO2 levels. Pupal weight was reduced more than 12.2% in 750 μl/liter CO2 level. Across O. furnacalis generations, mean food consumption per larva increased 2.7, 7.0% and frass excretion per larva increased 14.4, 22.5% in the two elevated CO2 levels, respectively, compared with ambient CO2 level. Elevated CO2 levels resulted in the decline mean across O. furnacalis generations in mean relative growth rate, but increased in relative consumption rate. These results suggested that elevated CO2 would reduce the fitness-related parameters such as higher mortality, lower pupal weight, and longer development times in long term. It also reduced the larval food digestibility and utilizing efficiency; in turn, this would result in increase of food consumption.

Pre-release efficacy assessment of the leaf-mining moth Digitivalva delaireae (Lepidoptera: Glyphipterigidae), a potential biological control agent for Cape-ivy, Delairea odorata (Asteraceae), in western North America

The leaf-mining moth Digitivalva delaireae Gaedike & Kruger (Lepidoptera: Glyphipterigidae) is a potential biological control agent for the invasive vine Cape-ivy, Delairea odorata Lemaire (Asteraceae), in western North America, where two morphological varieties (stipulate and exstipulate) of Cape-ivy occur. Two laboratory experiments were conducted to assess (1) the oviposition preference of D. delaireae for either of the two varieties and (2) its impact on plant performance using low and high densities of the moth on both varieties. There was no difference between the two varieties in the proportion of leaves oviposited on or damaged by D. delaireae. Similarly, the effect of D. delaireae herbivory on plant performance was not influenced by Cape-ivy variety. Independent of moth density treatment (low or high), herbivory by D. delaireae resulted in an overall reduction in plant growth and biomass accumulation, and Cape-ivy was unable to compensate for D. delaireae damage: mean relative growth rate, main stem length increment, dry shoot biomass, and leaf mass fraction were reduced 22%, 27%, 22%, and 17% in plants exposed to D. delaireae herbivory compared to unexposed plants. These results indicate that once released, D. delaireae has the potential to negatively affect stem growth, biomass accumulation and rate of stand expansion of Cape-ivy in the field.

The effect of using eshnan (Seidlitzia rosmarinus) and some biological treatments to reduce Mycotoxins effect an broiler breeders (Ross308) progene performance of the descendants

This study had been conducted in the animal resources department, college of agriculture, university of Anbar. eshnan (seidlitzia rosemarinus) used in order to reduce undesirable effects of Flatoxine in comparison with some biological cures such as saccharomyces and Iraqi probiotic. This experiment had been done within 24 weeks (168 days) for the period from 17/1/2013 till 3/7/2013. Two hundred broiler breeder chickens (Ross 308) used, starting with the age of 27 weeks and finishing by 50 weeks at the end of the 168 days. The chickens grew up in coops and the process of artificial insemination had been done twice in the week. Experimental treatments were T1 / ration without any addition as (control), T2/ ration contaminated with 1.5 mg aflatoxin B1/kg feed +2% Shinan, T4/ ration contaminated with 1.5 mg aflatoxin B1/kg feed +4% eshnan, T5/ ration contaminated with 1.5 mg aflatoxin B1/kg feed +2 kg probiotic / ton feed, T6/ ration contaminated with 1.5 mg aflatoxin B1/kg feed + 50% probiotic fermentation daily and T7/ ration contaminated with 1.5 mg aflatoxin B1/kg feed + 1 kg saccharomyces / ton feed. Two shots of baby chicks had been breaded. The first broiler breeder age were 33 weeks (7 weeks of the experiment's age). The second was at 47 weeks (20 weeks of the experiment's age).They weight the chicks in earth treatment. Each treatment had been divided into three replicates, each replicate contain six chicks. The body weight, weight gain, feed and feed consumption had been studied. Then, at the end of growing Perrier, relative growth rate and production efficiency factor had been calculated. The results showed that adding (4%) of eshnan to the diets contaminated breeders with Aflatoxin led to significant increase (P<0.05) in the mean weight gain, body weight and relative growth rate in comparison to the Aflatoxin treatment. There was not any significant differences between the treatments in feed consumption, feed conversion coefficient, mortality rate and production efficiency factor in the first experiment. There was not any significant differences in all traits studied during 42 days of the second experiment.

Impact of winter pruning of pomegranate trees on Aphis punicae (Hemiptera, Aphididae) and its natural enemies in Tunisia

SummaryWinter pruning is a cultural practice used to modify vegetative growth, which is likely to affect the development of pests. However, it has been poorly defined as a cultural method for diminishing the population levels of the pomegranate aphid Aphis punicae (Hemiptera, Aphididae) in pomegranate orchards. This study aimed to evaluate the impact of winter pruning of pomegranate on A. punicae population and their natural enemies. The results showed that winter pruning significantly decreased the population of A. punicae (p < 0.05) in pomegranate. Also, number of natural enemies decreased in pomegranate trees after winter pruning. This technical practice affects the number of winged and wingless individuals, the mean relative growth rate, the specific age of the population and the infestation rate. Winter pruning for A. punicae control in pomegranate orchards is highly recommended.