RELEASE OF CHRYSOPERLA CARNEA STEPHENS (NEUROPTERA: CHRYSOPIDAE) FOR CONTROL OF THE GREEN APPLE APHID, APHIS POMI DEGEER (HOMOPTERA: APHIDIDAE)

1989 ◽  
Vol 121 (4-5) ◽  
pp. 309-314 ◽  
Author(s):  
Elmer A.C. Hagley

AbstractRelease of the chrysopid, Chrysoperla cornea Stephens, at a rate of ca. 335 000 eggs per hectare, reduced significantly the numbers of apterous adults and nymphs of the green apple aphid, Aphis pomi DeGeer, on dwarf apple trees. Greater reduction in aphid numbers occurred in 1984 than in 1985, and the efficiency of the predator might have been influenced by the predator:prey ratios (1:10 and 1:19) used and by the mean daily temperature that occurred during the test periods. Application of azinphosmethyl (Guthion 50% wp, 0.105 and 0.075 kg AI/100 L) did not adversely affect predation of apterous A. pomi by larvae of C. carnea.

Plant Disease ◽  
2017 ◽  
Vol 101 (1) ◽  
pp. 186-191 ◽  
Author(s):  
K. A. Tancos ◽  
E. Borejsza-Wysocka ◽  
S. Kuehne ◽  
D. Breth ◽  
Kerik D. Cox

Erwinia amylovora, the causal agent of fire blight, causes considerable economic losses in young apple plantings in New York on a yearly basis. Nurseries make efforts to only use clean budwood for propagation, which is essential, but E. amylovora may be present in trees that appear to have no apparent fire blight symptoms at the time of collection. We hypothesized that the use of infected budwood, especially by commercial nursery operations, could be the cause, in part, of fire blight outbreaks that often occur in young apple plantings in New York. Our goal was to investigate the presence of E. amylovora in asymptomatic budwood from nursery source plantings as it relates to trees with fire blight symptoms. From 2012 to 2015, apple budwood was collected from two commercial budwood source plantings of ‘Gala’ and ‘Topaz’ at increasing distances from visually symptomatic trees. From these collections, internal contents of apple buds were analyzed for the presence of E. amylovora. E. amylovora was detected in asymptomatic budwood in trees more than 20 m from trees with fire blight symptoms. In some seasons, there were significant (P ≤ 0.05) differences in the incidence of E. amylovora in asymptomatic budwood collected from symptomatic trees and those up to 20 m from them. In 2014 and 2015, the mean E. amylovora CFU per gram recovered from budwood in both the Gala and Topaz plantings were significantly lower in budwood collected 20 m from symptomatic trees. Further investigation of individual bud dissections revealed that E. amylovora was within the tissue beneath the bud scales containing the meristem. Results from the study highlight the shortcomings of current budwood collection practices and the need to better understand the factors that lead to the presence of E. amylovora in bud tissues to ensure the production of pathogen-free apple trees.


2012 ◽  
Vol 40 (2) ◽  
pp. 159 ◽  
Author(s):  
Maria BOROVINOVA ◽  
Vilina PETROVA ◽  
Svetla MANEVA

The presented study aimed to determine apples trunk and branch diseases and pests in three growing systems conventional, integrated and biological (organic). The investigations were made on an experimental apple orchard (1 ha) of the Institute of Agriculture at Kyustendil, Southwest Bulgaria in four consecutive years from 2007 to 2010. Three scab resistant cultivars Prima, Florina and Erwin Baur grafted on rootstocks MM106 were planted in 1996. The orchard was divided into four plots. One plot was treated conventionally with a normal pesticide programme, two plots were treated integrated according to the general principles, rules and standards of integrated apple production and one plot for biological (organic). The monitoring of pests and diseases and assessment of their density were done every two weeks. It was established that during the experimental period important disease and pests on apple trees in different growing systems were black rot Botryosphaeria obtusa, apple clearwig moth Synanthedon myopaeformis and shorthole borer Scolytus rugulosus. The damages by trunk and branch diseases and pests on apple were considerable higher in biological growing system. The mean rate of attack of cultivar Erwin Baur by Botryosphaeria obtusa in biological and conventional growing systems was 52.35% and 4.65%, respectively. The percentage of damaged by Scolytus rugulosus trunk and branch area per tree reach to 58.74 in biological and 0.23 in conventional system. Reduced vitality of apple trees growing with out pesticides and mineral fertilizers in biological growing system was the reason for strong infection of Botryosphaeria obtusa and attack of Synanthedon myopaeformis and Scolytus rugulosus.


1961 ◽  
Vol 41 (2) ◽  
pp. 407-412 ◽  
Author(s):  
D. P. Pielou

Very effective control of the apple aphid, Aphis pomi DeG., on dwarf apple trees, has been obtained by two paintings of an undiluted emulsifiable concentrate of dimethoate (30 per cent active ingredient) on the basal part of the trunk of the tree. Approximately 2 millilitres are applied per tree, and application is made with a 1-inch paint brush around the trunk over a distance of approximately 12 inches. A single application in early July, at a time when the seasonal upsurge of aphids is beginning, gave excellent control for 3 to 4 weeks, even where conditions for reinfestation were favourable. A second application at the end of that period ensured full seasonal control. Almost equally good control was obtained by diluting the concentrate with an equal volume of water. At greater dilutions less effective control resulted. The use of a slurry made from dimethoate, 50 per cent wettable powder, in place of the emulsion, was reasonably effective but slower in action.


Author(s):  
Catherine Lacny ◽  
Andrew Kirk ◽  
Debra G. Morgan ◽  
Chandima Karunanayake

Objective:To determine whether day length affects cognitive performance in rural and remote memory clinic patients.Methods:A rural and remote memory clinic in Saskatoon, Saskatchewan provided an opportunity to examine how cognitive performance on the Mini-Mental State Exam (MMSE) is influenced by day length. Saskatchewan is an ideal location to test this association as day length varies greatly both seasonally and geographically. Following an initial assessment by the Rural and Remote Memory Clinic (RRMC) team in Saskatoon, patient follow-up appointments were performed either in-person or via telehealth videoconference. At each follow-up appointment the clinic neurologist administered the MMSE. The relationship between day length and MMSE scores at the sixweek follow-up appointment was analyzed in 154 patients. The mean daily temperature was controlled for in the analysis. Bivariate correlate and linear regression analyses were conducted.Results:There was no significant association between MMSE scores and either minutes of day length or mean daily temperature.Conclusion:Day length does not appear to have significant effect on cognitive performance of rural and remote memory clinic patients.


1961 ◽  
Vol 54 (5) ◽  
pp. 1034-1037 ◽  
Author(s):  
E. R. Oatman ◽  
F. E. Legner
Keyword(s):  

2017 ◽  
Vol 17 ◽  
pp. 12 ◽  
Author(s):  
D. Perdikis ◽  
D. Lykouressis ◽  
G. Mitropoulou ◽  
P. Tsiantis

The species composition and seasonal abundance of aphids and their natural enemies were investigated in an apple orchard located in central Peloponnese. For that purpose shoots were collected at weekly intervals. The aphid species Aphis pomi De Geer (Hemiptera: Aphididae), Dysaphis plantaginea (Passerini) (Hemiptera: Aphididae) and Eriosoma lanigerum (Hausmann) (Hemiptera: Eriosomatidae) were recorded. In both years of the study, A. pomi developed higher populations than the other two species. The population of A. pomi was high in June and July. D. plantaginea was present in April and May, with high numbers mainly in May, whilst E. lanigerum was recorded in low numbers from May to July. The number of aphids was not found to differ significantly between samples collected from the northern and southern part of the trees. The species composition of aphid population on each sampled shoot, documented spatial segregation between A. pomi and D. plantaginea. It was proved that the eggs were more commonly laid near the buds of the central part of the twigs. The natural enemies found were predators belonging to the families of Coccinellidae, Chrysopidae, Syrphidae and Anthocoridae. Generally, their numbers were low.


2017 ◽  
Vol 32 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Farag Mahmoud ◽  
Mohamed Osman ◽  
Kariman Mahmoud

Aphids are the most important pests on wheat in Egypt and worldwide. Field trials were conducted to assess the efficacy of the neonicotinoid insecticides imidacloprid (Nufidor 60% FS; at the doses of 2.1, 1.05 and 0.525 g a.i./kg of seeds) and thiamethoxam (Cruiser 70% WS; at the rates of 14.4, 7.2 and 3.6 g a.i./kg of seeds) as seed treatments, and thiamethoxam (Actara 25% WG; at the rates of 0.1, 0.05 and 0.025 g a.i./l) as foliar application, against three wheat aphids: bird cherry oat aphid, Rhopalosiphum padi (L.), greenbug, Schizaphis graminum (Rondani), and corn leaf aphid, Rhopalosiphum maidis (Fitch). Their effects on the aphids? natural enemies: lacewings, Chrysoperla carnea Stephens, ladybird beetles, Coccinella spp., and syrphid flies Syrphus spp. were assessed as well. The trials were conducted on the farm of the Faculty of Agriculture, Suez Canal University, Ismailia Governorate, during 2013/14 and 2014/15 seasons. Our results showed significant differences between the tested insecticides at all concentrations and clearly indicated that the recommended doses of all insecticides were more efficient against aphids on wheat plants than half- and quarter-doses. Also, the data revealed significant differences between the two seed treatments at all doses before and after foliar application, as compared to the control at all time intervals of inspection regarding the mean number of aphids on wheat plants, from the 3rd until 13th week after sowing, except in the 8th week after seed treatment before foliar application. The results clearly indicated that the weekly reduction of infestation and the general efficacy was higher at the recommended doses of Nufidor, Cruiser and Actara than the half and quarter doses in both seasons. Also, reduction in infestation decreased over the following weeks until the 8th week, when Actara insecticide was sprayed. Data revealed that there were no significant differences between treatments and control in the mean number of Chrysoperla carnea and Syrphus spp., while a significant difference in the mean number of coccinellids was observed on wheat plants treated with imidacloprid seed treatment before foliar application 6 and 7 weeks after sowing, and also after foliar application with thiamethoxam 9, 10, 11, 12 and 13 weeks after sowing. Regarding thiamethoxam seed treatment, significant differences were revealed in the ladybird population on wheat plants 3, 4, 7 and 8 weeks before foliar application, and only in the 10th week after spraying with thiamethoxam.


2009 ◽  
Vol 2 ◽  
pp. ASWR.S2488 ◽  
Author(s):  
Guoju Xiao ◽  
Qiang Zhang ◽  
Runyuan Wang ◽  
Yubi Yao ◽  
Hong Zhao ◽  
...  

In this study, a field experiment was used to evaluate a pea crop ( Pisum sativum L.) at Tongwei Experimental Station (35°13'N, 105°14'E), which is in a semiarid region of China. In this experiment, the mean daily temperature was designed to increase by 0.6-2.2 °C throughout the complete growth stage of the pea crop. When the mean daily temperature increased by approximately 2.2 °C, the water use efficiency (WUE) of the pea crop decreased by 30.4%, the duration of the growth stage was shortened by approximately 17 days, the yields were decreased by 17.5%, the number of stems with root-rot sickness were increased by 50.6%, and the input-output ratio (In/Ou) of the pea crop was 1.20. When the mean daily temperature was increased by approximately 1.4 °C, the WUE decreased by 26.1%, the growth stage duration decreased by 10 days, the yields decreased by 11.1%, the number of stems with root-rot sickness increased by 23.3%, and the input-output ratio (In/Ou) was 1.11. In addition, supplementary irrigation was found to be beneficial to the pea yields when the temperature increased. Indeed, application of 60 mm of supplementary irrigation during the complete growth stages of crops that were subjected to an increase in mean daily temperature of 0.6-2.2 °C resulted in crop yields improving by 8.3%-12.8%. Consequently, in this region, supplementary irrigation may play an important role in maintaining pea yields that would otherwise be affected by climate warming. However, the results also show that application of 60 mm of supplementary irrigation does not decrease the number of stems with root-rot sickness and that the In/Ou ratio of pea crops subjected to the same temperature conditions will increase.


1972 ◽  
Vol 104 (5) ◽  
pp. 731-749 ◽  
Author(s):  
F. T. Lord

AbstractA 5 year study of the foliage inhabiting fauna of young apple trees which had never been treated with insecticides or miticides showed there were large numbers of species varying considerably in quantity. The study also showed that the manner in which the foliage is distributed by cluster type and the distribution of the many species on the clusters are important factors in the sampling of mixed populations of arthropods.The leaf clusters were classified into six types based on stem length and on the presence or absence of fruit. The mean number of leaves per cluster for all types combined increased until mid July but no further increase occurred after that. The variation in leaves per cluster on the longer clusters, however, continued throughout the summer even though the mean number of leaves per cluster did not.The relative abundance of each of the arthropod species, whether it was identifiable to name or not, was given a quantitative rating by using random clusters as a common sampling unit. Eleven orders, 38 families, and over 100 species were recorded. The species making up the fauna were nearly all at a low density and in general remained low during the study. All the common pests were found but only four were at a level where economic damage to the foliage resulted. Very few of the species were present in numbers sufficiently large for analysis of the factors influencing their population density or theirA list is given of those species which were sufficiently abundant to show that differences in preference for some cluster types over others is common.


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