جستجوی مقالات مرتبط با کلیدواژه « population dynamics » در نشریات گروه « گیاهپزشکی »

To have a better understanding of sustainable management strategies of Aphis gossypii Glover (Hemiptera: Aphididae), it is necessary to determine the role of bottom-up vs. top-down forces on its population dynamics. The present study examined the effect of fertilization (bottom-up force) and parasitoid release (top-down force) on population fluctuations of A. gossypii and its parasitoid (Aphidius matricariae Haliday (Hymenoptera: Braconidae)). A factorial experiment was carried out with two factors: fertilization (0, 0.5 and 1.0 g per plant per time with a fertilizer consisted of macro- and microelements) and initial parasitoid release (0, 2 and 10 1-day-old mated females of A. matricariae per cage). The experiment was started with a 5-week-old cucumber and 10 newly emerged A. gossypii adults. After one generation of A. gossypii, A. matricariae females were introduced into cages. The treatments replicated four times in a randomized complete block design, and maintained under a standard constant environment. The number of live A. gossypii and A. matricariae adults was weekly recorded until two generations of the parasitoid had been completed. The results indicated that an increase of nutrition increased aphid density and its percentage parasitism but did not affect the parasitoid population size. In addition, parasitoid release resulted in higher parasitoid density and percentage parasitism but a reduction of aphid population size. The interaction between factors influenced the aphid population only. These findings indicated that bottom-up and top-down forces play an important role in population regulation of A. gossypii, and hence, must be considered in the pest management.

The carob moth, Ectomyelois ceratoniae Zeller, is the most important pest on   pomegranate fruits and has several overlapping generations per year in Iran. This paper investigated the use of a mechanistic model for describing the effect of the control strategy on the size of the total population of the carob moth. The analytical solution of mechanistic model was written in the form of a logistic probability density function by Matis et al. (2006). The logistic probability density function fits this carob moth data very well for control and treatment fields (r2=0.91 and 0.95). The parameters of the model are the predicted peak size, Nmax, the predicted time of peak, tmax, and an approximate per capita birth and death rate, all of which are important in practical application. In general, this paper demonstrates the utility of analyzing carob moth population data using mechanistic models and their underlying rate parameters.

The sour oranges is a horticultural crop in Iran and planted as ornamental trees all over the world (except polar regions) such as the north of Iran. The citrus cottony scales Pulvinaria aurantii Ckll. feeds on the foliage and stems of citrus trees and cause tree dieback in heavy infestation. In order to estimate the seasonal population fluctuations in Babol (Mazandaran province, Iran), sampling were done at the height of 1.5 to 2.5 meter of citrus trees  and samples were collected from four  geographical directions and three points including initial, medial and apical 40 cm of the branches. Further information such as daily temperature, relative humidity, and the amount of rainfalls simultaneously were recorded in each sampling date. The maximum number of population was observed in the January of 2014. We found that this species completes four generations per year. Based on the results of this study the best time for managements of the 1st, 2nd, 3rd and 4th generation of P. aurantii Ckll. in Babol is May, September, and to spot spraying in November and December, respectively. Pruning can be usefull too. In this study, natural enemies’ minority were observed which may be related to the insecticide treatments, absence of intermediate host and also the environmental pollution. Our results could lead to improve integrated pest management for P. aurantii Ckll.populations in the north of Iran.

A field experiment was conducted in the 2 × 3 m plots to determine the effect of different initial population densities of Meloidogyne javanica on growth parameters and yield of okra (Abelmoschus esculentus; cv. Soltani) in 2013. This research was carried out based on completely randomized design (CRD) with five replications using a geometric series of 14 nematode population densities (0 to 512 eggs or second stage juveniles (J2) / cm3 soil). The plants died at high levels of nematode population (> 256). The relative shoot fresh and dry weight and relative yield fitted the Seinhorst damage model and the tolerance limit for those traits was 0.34, 0.33 and 0.28 eggs or J2 / cm3 soil, respectively. The maximum multiplication rate was 749 and the equilibrium density was 159 eggs or J2 / cm3 soil. Nematode reproduction factor was negatively correlated with the initial populations as the highest multiplication was occurred at the lowest initial population densities. Damage threshold (10% yield loss) of okra to M. javanica was estimated as 0.85 eggs or J2 / cm3 soil which represented the susceptibility of okra plant to M. javanica.

Beauveria bassiana is one of the microbial control agents of sawtoothed beetle Oryzaephilus surinamensis. To study the epizootiology of the entomopathogen in O. surinamensis population, beetles were reared in insectaria filled with date fruits. Before transfer of the insects, date fruits were treated with 50% lethal dose of B. bassiana. Samplings of different life stages of the beetle were done during a 25 week period. The population density of O. surinamensis was estimated in 12 steps. The population fluctuations of the different beetles' life stages were estimated using SIR (Susceptible, Infected and Recovered), Anderson and May and general models. In treated and untreated populations, logistic growth model fitted well to population growth. Comparison of different models showed that the Anderson and May model explain better the various relationships between the populations and the pathogen. A sigmoid trend was observed in the population fluctuation curve in the treated populations, so that the population density of diseased individuals in prepizootic phase increased until attaining the peak where the epizooty took place. Thereafter the postepizootic phase begun with a drop in the density of the affected individual. Five epizootic waves recorded during the sampling period showing the occurrence of five epizootic periods. The peaks of these epizootic waves were recorded in the weeks 3, 13, 21 and 23. The 2nd period was the longest one that lasted 12 weeks being the shortest epizootic wave recorded.

The Cucurbits fly Dacus ciliates (Dip.,Tephritidae) is one of the most important pest on cucurbit crops in different parts of the Khuzestan province, Iran. Population dynamics of the pest was studied on three varieties (Spring cucumber, Armenian cucumber and Fall cucurbit) in Safi Abad agricultural and natural resource research and education center of Dezful, in spring and fall, in 2009. The number of adults caught in yellow sticky traps, the eggs and larvae of different ages were counted weekly in infected fruits. The results showed that there were three population peaks of immature stages in all varieties. The highest number of adults in Spring cucumber caught was 6.65 per trap in middle of Jun and in Armenian cucumber was 4.35 in the late of Jun and in Fall cucurbit was 9.5 adult per trap in the Oct. The Iwao, s Index and Taylor, power law were applied to evaluate spatial distribution of the egg and Immature stages. Results showed that Taylor, s power law gave a better fitness result for egg and Immature stages. The results of this research could be apply in integrated pest management of cucurbit fly.

Cabbage aphid (Brevicorynebrassicae L.) is one of the most important pests of canola in Iran. The pest attacks to the leaves, stems, flowers and pods of the host plant. Feeding and sucking the sap from the plant tissues normally cause leaf and stem deformities and reduce the quality and quantity of the seeds. It was reported that damage caused by the pest can reduce 9 to 77% of the canola yield. Several studies indicated that host plant resistance is an important method which influences population dynamics of B. brassicae and reduces damage of the pest in the field conditions.Using resistant varieties can be the simplest, practical, effective and economical method for the pest control ascomparedwith other control methods. The aim of this investigation was to study population dynamics of the cabbage aphid on different canola cultivars under the natural field infestation and evaluate thepest influence on the studied cultivars/hybrids yield and yield components in Shahre-kord.
Material and Population dynamics and damage of cabbage aphid were studied on five cultivars (including: Okapi, Licord, Talaye, Modena, Tasilo) and two hybrids (Hyola 308 and Hyola 401) of canola based on the completely randomized block design in three replicates under the field conditions. To study population dynamics of the pest, sampling was started from the beginning of the infestation (the first decade of April) and continued weekly until harvesting time. For this purpose, five plants in each replicates were selected randomly and the number of aphids (nymphs and adults) was counted on 10 cm of each stem. Moreover, at the harvesting time, 10 plants from each replicate were selected randomly and the yield and yield components includingnumber of pods, number of seed per pods, weight of 1000 seeds were measured. Statistical analysis was done using Proc ANOVA in SAS 9.1 software.
Ourstudy addressed the seasonal activity and population dynamics of the canola aphid on different canola varieties under the field conditions.The results indicated that the activity of cabbage aphidwas started from the first decade of April and reached to the highest level at the flowering stage at the third decade of May. The highest (450 aphids/plant) and lowest (200 aphids/plant) population density were observed on Talaye cultivar and Hyola 401 hybrid, respectively. Similar results were reported by KhazduziNejadJamali et al. (2012) and Sarwar et al (2002).Mean comparison of yield and yield components in different canola cultivars and hybrids under the field infestation to cabbage aphid showed the highest (83.47) and lowest (12.69) number of pods in Hyola308 hybrid and Modena cultivar, respectively. Moreover, the highest (13.27) number of seeds per pod was observed in Tasilo cultivars, whereasthe highest seed weight was identifiedin Tasilo and Hyola hybrids. Themaximum and minimumyieldwere, respectively, recorded forTasilocultivar(0.41 gr/plant) and Modenacultivar(0.01 gr/plant).Our finding was similar to the results of Monfared et al (2003) who reported that Hyola 308 and Hyola 401 hybrids and Talaye and Licord varieties were resistant to the cabbage aphid. Keyhanian et al (2008) observed the highest pest population on Licord cultivar which supports our findings. However, they reported the lowest yield in Hyola401 which is in contrast with our results. The differences between the results canbe due to the influence of environmental factors on the studied cultivars.
Our results demonstrated that Hyola 401 hybrid had the highest number of pods per plantand number of seed per pod and Tasilo cultivar had the highest yield and seed weight. In addition, the lowest yield and yield components was found for Modena cultivar. Therefore, Tasilo was the most suitable and Modena was the least suitable cultivar for growingin Shahre-kord.Sincepesticide applicationto control the pest has several disadvantages such as increasing production cost, developing resistant races, destroying natural enemies and environmental hazards,integrated pest management based on the host plant resistance is, therefore, essential for controlling the canola aphid. Usingthe resistant hybrids and cultivars can reduce insecticides hazards, protect natural enemies and help integrated management of the canola aphid.

Pest and disease problem with the extension of fruit orchards, becomes a serious and restricted factor for orchard growers. Most of the scale insect of cold region fruit trees in Iran belongto family Diaspididae. One of the most important pests in the fruit orchards of Chaharmahal and Bakhtiari Province are scale insects. Hall scale, Mercetaspis halli (Green) (Hemiptera: Diaspididae) ), which is armoured scale, is known as a primarily pest of stone fruits. They are the most prevalent pests on trees mostly on Almond and Nectarine . In Iran, this pest is reported in the regions such as Khorasan, Marcazi, Semnan on Cherry, Almond and Apricot trees . Rajabi also reported the pest in Tehran, Esfahan, Yazd, Kermanshah, Fars and Kerman province on apricot, peach, cherry trees . Moghaddam in 2004 reported the pest distribution in Fars, Isfahan, Kerman, Sistan and Baluchestan on almond, peach and pistacia. Monthly abundance monitoring of M. halli, which was conducted by Berlinger et al in 1996 , indicated that adult population had three generations per year. From the ecological and biological aspects, no enough information is available in Iran about M. halli scale. Thus, the aim of this research was to investigate aspects of the biology and ecology and seasonal changes of M. halli on Almond and peach trees to clarify the effectiveness of nonchemical management strategy.
A field study carried out by weekly sampling of different growth stages of M. halli (egg, nymph, male and female) on twigs in two the Almond and the Peach orchards in Saman restrict in Chaharmahal and Bakhtiari Province. Different growth stages of armoured scales (egg, nymph, male and female) were counted and its population seasonal changes were studied. The population density was determined and compared on different twigs with different ages. The period for ovoviviparously and emergence of 1st and 2nd nymphal instars and matured insects were estimated. Based on Berlinger et al. (3), growth stages were collected and counted on branches especially in join sections of old and new branches and cracks of branches. The data were normalized by changing to ( ). Figure of population changes were drawn by Excel.
Berlinger et al. (3) studied the biology of M. halli and found that this armoured scale is a primarily pest of stone fruits especially on Peaches and Nectarines. These researchers reported 3 generations per year for the pest. In California, M. halli has one full and one partial generation per year and overwinters as adult females. The results of the present study was exactly in accordance to the results of Berlinger et al. (3) in that M. halli scales settle in all parts of the tree, but are more abundant beneath buds of current growth, or in bark crevices of the main branches, either in the lower tree center or on the trunk. Berlinger et al. (3) studies, showed that infestation and feeding of M. halli weakens fruit trees and reduces their growth and functionality. Feeding by hall scale weakens plants and may reduce the yield. However, the most important and direct economic damage is caused by nymphs settling on the fruit. Females settle in all parts of the tree and male were rare and emerged only in summer. In this survey, winged adult males didn’t emergeMeanwhile, the important economical damage is observed by settled nymphs on the fruits. Damage due to feeding of this insect appears as red depressions (2mm diameter) in the skin or as red spots which develop after the death of the scales and expand as the fruit grows. This case reduces the fruit market price. Berlinger et al. (3) and Gill (6) also reported that this pest overwinters as mated adult females. According to their results more than 90 percent of overwintering females had velum, which is an indication of mated female materials.
Infestation of the M. halli on the trees of Plum, Almond, Apricot and Peach in Saman region indicated that the pest is polyphagous and can damage to the different Rosaceae trees. Our results showed that this insect produced nymphs ovoviviparously. This stage lasted for a very long period. Since after the first generation being finished the next generations overlapped and in its population, all different growth stages were observed. This pest had two complete generations and the third incomplete generation in nymphal stages appeared when weather was getting cold. Males and females were seen simultaneously. Mated females overwintered on beneath buds or in bark crevices of the twigs and branches of host trees. Finally, all nymphs died. Thus only mated females overwintered on cracks of trunks and branches of Peach and Almond trees.

Rose (Rosa hybrida (L.), Rosaceae) has been grown on earth for millions of years and has been used for beauty and decoration of gardens, extraction of perfume and in medicine. But main use of roses is in cut flower industry and landscaping. Roses are attractive for insects, especially aphids (2, 3, 5, 6, 7, 11, 17, 27, 28, 35, 38). Among them, the predominant aphid that feeds on the cultivated roses in outdoors is the rose aphid, Macrosiphum rosae (13, 27, 28, 29). The rose aphid has a wide distribution throughout Iran and the world (27, 28, 29). Rose aphids generally initiate feeding on roses in early spring as the new flush of growth emerges. Like other aphid species, rose aphids tend to congregate or cluster in large numbers feeding on the terminal growth including leaves and stems, and developing flower buds, and on leaf undersides. Their feeding causes deformity flower buds and leaves which may result in flower buds aborting or falling off prematurely before opening. In addition, aphids secrete honeydew, which attracts ants, wasps, hornets and serves as a growing medium for certain black sooty mold fungi. Rose aphids are attacked by anvarray of natural enemies including parasitoids and predators such as ladybird beetles, green lacewings, syrphids and several other groups of arthropods. These may provide natural regulation depending on the number of rose aphids present and other biotic and abiotic factors. Although many herbivorous arthropods may attack roses but many roses cultivar can resist against these pests (23, 26, 28, 40). An important factor influencing this success is careful selection of varieties, which vary significantly in susceptibility to pests and disease problems (9, 13, 19, 21, 23, 30, 40). Of course, other factors such as agricultural practices and the presence and activities of natural enemies of pests are also important. This study aimed to determine any resistance against rose aphid in different rose cultivars in landscapes of Mashhad and also to determine the diversity and abundance of the rose aphid predators throughout the seasonal growth in the study area.
Material and Research to investigate the resistance of different rose cultivars against rose aphid and the biodiversity of its predators was conducted at the campus of Ferdowsi University of Mashhad from Mid-March of 2013 to late march 2014. Six rose cultivars including Ice berg, Miniature, Josephine bruce, Piccadilly, Fairy & Blessing were sampled weekly in three sampling sites. For sampling, four cut sections (5 centimeters of terminal part of randomly selected shoot) of each cultivar in each site were cut and put in a plastic bag and brought to the laboratory for counting the number of different stages of rose aphid as well as the associated predators. For purpose of identification of immature stages of the aphid predators, immature stage was kept until they reach to adult stage in the laboratory.
A seasonal fluctuation of rose aphid was recorded throughout the season on six rose cultivars (Table 1). Overall, this aphid was more numerous in spring and early fall on all studied cultivars (Figure 1). By approaching the summer, the population of rose aphid on all rose cultivars, except the Fairy and Miniature varieties declined to zero. Analysis of variance showed that differences in mean population of rose aphid among studied cultivars was significant (P

The Heart moth, Dicycla oo (L.) (Lepidoptera: Noctuidae), attacked a part of oak forests in Fars province of Iran in recent years. The larvae severely feed on buds and sprouts and cause the tree to be defoliated from leaves. The pest biological characteristic was studied in the Moordak region of the Kazeroon district during 2004-2007. The results showed that the pest had only one generation in a year. The life of the pest in egg stage was spent beneath the egg scales which had the same color to the oak barks in a part of spring, whole summer and winter. The neonate larvae appeared on the swelling buds from the first half of the March. The duration of embryonic period, larval stages, pre-pupae, pupae and adult longevity took long (320±8.37), (25±2.12), (3±0.34), (8±0.84), and (10±0.71) days respectively. The sex ratio was estimated 1:1 in laboratory and field conditions. The male and female adult longevity was determined 7 and 9 days, respectively. The first moths appeared in the late of April. The peak of moth’s flight occurred on 30th April to 9th May. The morphological characteristics including oviposition rate, body dimensions, head capsule width, pupae body dimensions, and adults were measured. The Male and female moths after forming was sent to Dr. Michael Fibiger in Denmark for confirmed of genus and species.

Tortrix viridana is a serious pest of oaks in the Kamfirooz oak forests.Oak bud tortricid (Tortrix viridana) has five larval instars in Kamfirooz oak forests. The pest overwinters as diaposed eggs. The first larval instar emergence coincides with tree budburst when they enter bud scales. First instar larvae appear between 10th to late march, depending on weather condition. Weather parameters such as low temperature at the time of egg hatching determine losses of the pest to the host tree. First, second, third, fourth and fifth instars of the pest take 4-7, 5-8, 5-8, 6-12 and 7-14 days respectively. Pest larvae make their feeding sites by attaching leaves in clusters through webbing. Larvae suspend themselves from a fine silken thread until they find a suitable feeding site and when there is a crowd of larvae on the some branches of the trees, larval movement between trees through hanging can be facilitated by wind. Many predators including spiders, ants, beetles and occasionally birds feed on pest larvae. The pest finishes its larval stages between 26 and 47 days (with an average 31.5 days). Pupal stage lasts 1-2 weeks. Trees can offset pest damages after pest outbreak, provided rainy winter precede, but if pest outbreak occurs in a year with low precipitation followed by a dry and hot summer, high losses due to pest will be unavoidable. Egg, larva, pupa and adult temporal distribution frequencies were 72.61, 10.14, 2.73, and 14.52 percent respectively. Direction had no significant effect on pest damage. Pest moths emerge during late April up through mid may. Moth population reaches its peak within 2-3 weeks after its appearance, and gradually disappears after its unimodal peak. Swarming as a social phenomenon may be observed during the emergence of adults. Twenty species of Aranidae belong to more than 7 families including Lycacidae, Oplinoidae, Clubionidae, Araneidae, Ulobridae, Phomicidae, Salticidae, four species of Coleoptera including Tenebrionidae (one unidentified species) and three coccinellids (Coccinellidae) as well as four species of Hymenoptera were among frequently collected natural enemies of the pest. Population dynamics of Exochomus quadripustulatus, one of the important coccinellids was also studied in sampling plots.

Studies on population dynamics and identification of fruit flies were done in mango and guava orchards at Kahir village (80 km to Chabahar) in 2010-2011, using Macphail pheromone traps baited with a mixture of methyl eugenol and protein hydrolyzate, sugar and technical malathion. Five species, Bactrocera zonata (Saunders), Bactrocera dorsalis Hendel, Dacus (Leptoxyda) persicus Hendel, Dacus (Didacus) ciliatus Loew and Carpomya vesuviana Costa were caught in the traps. Observations showed that Bactrocera zonata was the dominant species and its population was significantly higher than other species. It appears to be a severe pest of these fruits. Generally, flies were caught in higher numbers in guava orchard than in mango orchard. However, the difference was not statistically significant. The fruit flies were present in the field throughout the year. They were caught in the traps in greater numbers from April to August and their population was at the peak in August in both mango and guava orchards, then population decline continued until February. Effect of climatic factors on the population of fruit flies also showed that temperature and Relative humidity have no effect on population fluctuation. Availability of host fruits was essential factor affecting population fluctuation.

According to this research the population dynamics of cabbage aphid and identification the natural enemies in canola farms in the north of the Fars province that have been done during the years 2009 – 2010. Three species of aphids have been known; Myzus persica Sulzer, Brevicoryne brassicae (L.) and Aphis gossypii Glover. The cabbage aphid was the dominate species with 75.5% abundance. M. persicae and A. gossypii with 16.5% and 8% relative abundance in order were in the second ranges. Also in order to consider the population dynamics of cabbage aphid in the selected farms with 2 hectare spaces for each, gathering 30 leaves regularly by random from canola bushes weekly. So on the basis of these samplings it has been considered that the aphid population began at the middle of March until the middle of May at the time of blossom and sheathes was at the highest point, with the average temperature 7.5ºC daily and 77% R.H. Also regarding the natural enemies, 13 species of predatory and 1 species of parasitoid in the Coccinelledae, Syrphidae, Chrysopidae and Braconidae families have been gathered. This study revealed that in the canola farms the peak of natural enemies density occurred after the aphid's population peak of the late growing season. The most abundant predators were as follow: Coccinella septempunctata (L.), Scaeva albomaculata (Macquart 1842) and Chrysoperla carnea (Stephens 1836). Also a species of parasitoid Diaeretiella rapae (MIntosh 1855) has been found.

A research was conducted in Yasouj region to determine population dynamics of the gypsy moth in 2006 and 2007. Also it was aimed to calculate the correlation coefficient between the population densities of 2006 and 2007, in order to build a predictive model for the pest. The number of overwintering egg masses was counted during the winter months in ten different orchards. The number of egg masses of the pest was recorded at weekly intervals in ten orchards during the growth seasons in 2006 and 2007. Results indicated that the egg mass densities were 1.71 ± 0.2 and 2.88 ± 0.3 per fifty squares meter and 342 ± 22 and 576 ± 37 egg masses per hectare in winters 2006 and 2007, respectively. Regression analysis of the pest population density in 2006 and 2007 indicated that only 32.37% of the 2007 population variance could be accounted for the population density in 2006. It was obvious that more than 68% of the population changes are under the influence of unknown biotic and abiotic environmental factors.

Population dynamics and spatial distribution of two harmful species of Thysanoptera prevalent on cereal crops (Thrips tabaci Lindman، 1888 and Haplothrips tritici Kurdjomove، 1912)، were investigated during 2009-2011. Weekly sampling was carried out in a one hectar of wheat field in Ramin University of Khuzestan، South-West of Ahvaz. Spatial distribution of immature as well as adults of either species was investigated through Taylor’s power law and Iwao’s patchiness regression methods. The results revealed that the population peak for either species occurs in late March and on the first to middle of April respectively for adults and for larvae. Results of correlation between population dynamics (larval and adult stages) and the factors temperature and precipitation revealed that there is positive vs negative correlations between population fluctuation and the factors of temperature vs humidity. An investigation of the spatial distribution through Taylor’s power law and Iwao’s patchiness regression method indicated that larval stage and total stages in both species are clumped. Based upon R2 and F of regression analysis، Iwaos patchiness provided a more adequate description of spatial distribution than Taylor’s power law for either of the species. Because the seasonal peak in these two species'' density corresponded with the period of peak bloom، thus، in order to study the population dynamics، the earing stage is the most suitable for sampling the thrips on wheat.

Cottony cushion scale، Icerya purchasi Maskell is one of the most important pests of citrus orchards in Mazandaran province and the east of Guilan province. The biology and dynamism of this pest was studied in orange trees، Citrus sinensis. Samples of 10 trees (from the end of twigs) were randomly taken weekly. The results indicated that the pest has two or three generations in a year in the west of Mazandaran province. In the first two years of this study، the first nymphal instars of the first generation were emerged in the late of May and the population peak was occurred in the early of July، while in the third year the population peak was observed in the middle of June. In the first two years of this study، in the second generation، the first nymphal instars were emerged in September and the population peaks was occurred in the late of September but in the third year the population peak of second and third generation were in the middle of August and in the early of October، respectively. The average fecundity was 645±108 eggs. The eggs were hatched into crawlers in 12±2 days and development time of first and second instars were 17±4 and 20±3 days، respectively. Cottony cushion scale was hibernated as second instar nymph، third instar nymph or adult female under leaves. The cardinal lady bird، Rodalia cardinalis Mulsant were scattered in citrus orchards، especially in gardens that did not receive periodic applications of herbicides and insecticides.

The common pistachio psylla, Agonoscena pistaciae Burckhardt & Lauterer is known as the major pest in the pistachio plantation areas of Iran. The psyllid’s density on different pistachio cultivars is usually varied. Density and population dynamics of A. pistaciae were monitored at field condition on Badami-riz Zarand and Momtaz as two native and local pistachio cultivars in Zarand vicinity, Kerman province, South of Iran. Results showed that the psyllid nymphs’ density on Momtaz was larger than on Badami-riz Zarand through the whole sampling time from April to October significantly. Psyllid nymphs’ density was grown up from late July, however this trend was drastically high from August and afterward. In addition the adult psyllid abundance was 3 times larger on Momtaz cultivar twigs than Badami-riz Zarand through the growing seasons. The relative abundances of adult psyllid on yellow sticky traps in the Momtaz pistachio orchard was significantly larger than the Badami-riz Zarand orchard, however the fluctuations’ trends were similar at both orchards. The population dynamics and density of A. pistaciae on two pistachio cultivars were compared and discussed in present article.

Increasing of population and outbreak of the turnip sawfly Athalia rosae (Hym.: Tenthredinidae) caused severe damages in many fields of Marivan region in 2001. In this study, biological traits and population dynamics of this pest were investigated in Marivan region during 2004-2005. Results showed that this pest has 3 generations per year and main damage to canola caused by larvae of 3rd generation that its adults emerged in mid of September. The larvae of first and second generations feed on weeds and vegetables in Brassicaceae family. The adult of first generation emerge at early of April and they mate immediately then lay the eggs. Maximum number of laid eggs by one female sawfly in laboratory condition was 57 and mean was 28.2±14. The average developmental periods of egg and larvae were 5.1±0.59 and 17.65± 1.57 days, respectively and the means of pupa stage for females and males were 9.8±1.29 and 12±1.95 days, respectively and total life span was 32-38 days. Average longevity of adult female and male was 9.4±2.24 and 5.7±1.42 days respectively. Sexual ratio (male: female) in the natural condition were 1: 2.68 and 1: 3.03 in 2004 and 2005 respectively. This insect overwinters as final instar larva in a coccon in a few centimeters deep in the soil.