PLANT PEST RESEARCH
Year:2017 | Volume:6 | Issue:4|Papers Count:9

Neoseiulus californicus is an effective predatory mite to control of the spider mites. The functional response of three-day old mated female feeding on densities of Frankliniella occidentalis larvae (1, 2, 4, 8 and 16) was studied on seven commercial strawberry cultivars (‘Sequoia’, ‘Chandler’, ‘Camarosa’, ‘Marak’, ‘Aliso’, ‘Yalova’ and ‘Gaviota’) and predation interference of this predator in (1, 2, 4, 8 and 16) densities of the predatory mites on constant density of prey (40 larvae of thrips) were studied. These testswere conducted under laboratory condition (27±1oC, 16L: 8D photoperiod and 70-80% RH). The predatory mite exhibited type II on seven strawberry cultivars tested with Rogers equation. The attack coefficient and handling time were estimated on different strawberry cultivars (on ‘Sequioa (0.01, 4.77 hours), on ‘Chandler (0.03, 4.37 hours), ‘Camarosa’ (0.03, 5.49 hours), ‘Marak’ (0.03, 5.16 hours), ‘Aliso’ (0.02, 4.91 hours), ‘Yalova’ (0.05, 4.54 hours) and ‘Gaviota’ (0.02, 4.65 hours). The predatorymite ability in predation on F. occidentalis larvae on ‘Chandler’ and ‘Yalova’ were more than the othertested cultivars. It may be due to less trichome density on these cultivars or secondary chemical compounds. The relationship of logarithm of predator density and the logarithm of per capita searching efficiency was significant. The rate of predation increased as the host density increased and the predatorde creased. These results emphasize the importance of the host plant characteristic for optimizing the predatory mite use in biological control of pests.

Lectins are the proteins with the heterogenous structure that bind to mono- or oligosaccharides of cell surfaces leading to interference in cellular processes or even death. In the current study, effects of the different concentrations (0.5, 1 and 2 mg/ml) of Polygonum persicaria L. lectin were assessed on the intermediary metabolism of Pieris brassicae L. larvae to better understanding of its entomotoxicme chanism. Feeding of the larvae on the Polygonum persicaria lectin increased activities of aspartate aminotransferase and gamma-glutamyl transferase but the activity of alanine aminotransferase statistically decreased. Activity of aldolase increased in the treated larvae in a dose-dependent manner. Also, activityof acid phosphatase showed no statistical differences between treated and control larvae, but alkalin ephosphatase in the larvae fed on 2 mg/ml of lectin had the highest activity in comparison with other treatments. High density lipoprotein in the larvae fed on 2 mg/ml of lectin, had the lowest amount but low density lipoprotein showed the highest amount. Among storage macromolecules, glycogen showed nostatistical difference between control and treated larvae but the amounts of protein and trigly ceridestatistically decreased. Results of the current study showed that P. persicaria lectin can cause disturbancein intermediary metabolism of P. brassicae larvae in its highest use dose which may lead lower biological and reproductive efficiencies.

The sunn Pest, Eurygaster integriceps Put. (Heteroptera: Scutelleridae) is the most importantharmful insect in Iran, that feed on the leaf, stem and seed of wheat and reduce the quantity andquality of the crop. The method of quadrat sampling is among the oldest techniques in ecology. During2004 and 2005, spatial distribution and fixed precision sequential sampling plans of Sunn pestimmature stages by use of quadrate size 0.1m2 were investigated in rainfed wheat fields in Borujerdnorth of lorestan province, Iran. Based on R2 of regression, the Taylor's Power Law model provided amore adequate description of variance-mean relationships and Taylor's b were significantly>1 for allinsect stages, indicating that immature stages of sunn pest were aggregated in rainfed wheat fields. Green's fixed-precision sequential sampling plan was designed for estimating immature stages of pestdensity at three fixed precision levels (0.1, 0.15 and 0.25), then these models were validated using 7-9independent data. To achieve a precision of 0.25 in Green's model, which is generally accepted in integrated pest management, IPM programs, it is necessary to take samples for 2nd, 3rd, 4th instars and the total number of 5th instar plus new winged insect with an average sample numbers (ASN) of 62, 87, 67 and 25, respectively. As the precision level was increased to 0.10, average sample size sincreased to 320, 358, 325 and 145, respectively. Use of these models can provide an effective management of sunn pest E. integriceps in rainfed wheat fields and minimize sampling time and cost.

Olive fruit fly, Bactrocera oleae Rossi (Dip.: Tephritidae) is the most important pest of olive orchards in IRAN. There are different methods to control the pest such as using different types of traps by attractive compounds or sexual pheromones, Bait spray on canopy, trunk or spray on some rows of trees and cover spray. In this research, efficiency of a new technique "Lure and Kill" by using magnet-ol® traps was evaluated and compared with other kinds of traditional traps. The results were evaluated by two way attractions of traps and reduction of fruits infestation. Results showed that "Lure and Kill" technique using Magnet-ol® trap had no significant differences in comparison with other traps. Mean number of flies captured by yellow sticky traps using bicarbonate ammoniumas attractant was 1.00 ± 0.454, yellow sticky traps was 1.00±0.423, Magnet ol was 1.00±0.315 and Olipe traps was 0.75 ± 0.435. The total infestation index of Magnet ol® Traps in comparison was3.5% with control plot 6.7% until October that indicated a positive impact of magnet-ol® traps andthis method could be used as one of the olive fruit fly control

Lysiphlebus fabarum Marshall, an endoparasitoid of the black bean aphid, Aphis fabae Scopoli is an important component of integrated pest management of this pest and it is necessary to study it sinteraction with insecticides used against this pest. In this study, the lethal effects of recommended concentrations of three insecticides, thiacloprid+deltamethrin, pirimicarb and pymetrozine were investigated on pupal and adult stages of the parasitoid under laboratory conditions. The pupae and the adults were exposed to insecticides with mummy dipping and dry residues of insecticides on glassplates methods, respectively. Thiacloprid+deltamethrin and pirimicarb significantly caused mortalityrates in pupal and the adult stages, while pymetrozine had no significant effect. According to International organization for biological control (IOBC) (toxicity of insecticides), thiacloprid+deltamethrinat the pupal and the adult stages were classified as moderately harmful (class 3) and harmful (class 4), respectively. Pirimicarb was also classified as slightly harmful (class 2) and harmless (class 1), respectively. Pymetrozine in the two tested stages were classified as harmless (class 1). In this study, the persistent toxicity of insecticides against the adult wasps was also investigated under semifield conditions. According to the IOBC (persistence) classification, thiacloprid+deltamethrin, pirimicarb and pymetrozine were classified as moderately persistent (class C), slightly persistent (class B) and short lived (class A), respectively. According to the present study, pymetrozine and pirimicarb hadlow side effects on L. fabarum at the pupal and adult stages, but thiacloprid+deltamethrin caused deleterious effects on this parasitoid at two stages tested.

The life table parameters are the most appropriate index for comparing the fitness of a population to diverse climatic and food-related conditions. In this study, the effect of three photoperiods of 8: 16, 12: 12 and 16: 8 h (L: D) on the life table parameters of Nysius cymoides was studied under laboratory conditions (24±1oC, 65±5% RH). Data were analyzed based on the age-stage, two-sex life table theory. Immaturedevelopmental times of N. cymoides under 12-and 8h photoperiods were significantly shorter than that oftreatment with 16h photoperiod. The adult pre-oviposition period (APOP), total pre-oviposition period (TPOP), mean fecundity and adult longevity reared under three photoperiods showed significantdifferences. The highest and lowest fecundity were 56.65 eggs and 10.1 eggs at 12- and 8h photoperiods, respectively. Intrinsic rates of increase (r) were 0.011±0.004, 0.044 ± 0.003 and 0.039 ± 0.003 (day-1) at8-, 12- and 16h (L), respectively; and net reproductive rates (R0) were 2.02 ± 0.52, 13.02 ± 2.65 and 11.41 ± 2.12 (off spring per individual) for the respective treatments. The mean generation times (T) were56.11 ± 1.26, 57.16 ± 1.53 and 62.32 ± 1.41 days, at 8-, 12- and 16h (L), respectively. The life expectancy (exj), survival rate (sxj) and cumulative reproductive rate (Rx) at 12-and 16h (L) were higher than those of8h photoperiod. Generally, 12- and 16h photoperiods were more reasonable for N. cymoides rearin gcomparing with 8h photoperiod.

The crapemyrtle aphid, Tinocallis kahawaluokalani Kirkaldy, is an important pest of or namental woody plant, Lagerstroemia spp. causes premature drop of leaves and decline of summer flowering and reduces the commercial market. Effect of botanical insecticide, Palizin at the recommended concentrations of 1500, 2000 and 2500 ppm evaluated on aphid and its predator, Harmonia axyrid is Pallas. Experiment was done on aphids by two methods leaf dipping and spraying and then the numbers of dead aphids were recorded at 24 after treatment. The results showed that spraying method was more effective than other method and caused 86.6%, 90% and 95% mortality at 1500, 2000 and 2500 ppm of Palizin, respectively. By dipping eggs of coccinellid in insecticide solutions the low esteggs hatching percent (50%) and the longest developmental period (19 days) were observed at 2500ppm of Paliz in. Eggs hatching percent and developmental period were slightly affected by 1500 ppm of Palizin in comparison with the control. By topical application of Palizin on the fourth instar larvae, the survival of larvae and pupal developmental period were not significantly affected. However, thehighest survival of treated fourth instar larvae (96.9%) than control (100%) was observed at 1500 ppmof Palizin. According to the results, Palizin at 1500 ppm had remarkable mortality on aphids without affecting many of tested characteristics of H. axyridis. So, Palizin at 1500 ppm can be used forintegrated pest management in integration with H. axyridis to control of T. kahawaluokalani.

Sugarcane is one of the strategic agricultural products of Khuzestan province, Iran. Regarding to large-scale monoculture of sugarcane in this region, there are always concerns on secondary pest outbreaks or emergence of new pests. Therefore, monitoring of insect fauna in sugarcane fields is necessary. Here, we report a chrysomelid beetle, Rhoptrispa dilaticornis (Duvivier, 1891) as a leaf miner of sugarcane in Khuzestan Province. Both the species and genus are new for the Iranian fauna. The symptoms of its damage to sugarcane plants are described and illustrated. It seems that this beetle is not widely distributed in the sugarcane fields currently.

In order to identify parasitoids of White peach scale, Pseudaulacaspis pentagona (TargioniTozzetti) in Mazandaran province, sampling was carried out from kiwi orchards of Qaemshahr region during 2014-2016. Among the collected specimens, a parasitic species was identified as Aphytis chrysomphali (Mercet, 1912) (Hymenoptera: Aphelinidae). This is the first record of A. chrysomphali associated with P. pentagona in Iran.