Spatial sampling of insects, plant parts and insect attacks in the soil of potato crops

1993 ◽  
Vol 83 (4) ◽  
pp. 607-612 ◽  
Author(s):  
J.N. Matthiessen ◽  
S.E. Learmonth
Keyword(s):  
Control Measures ◽  
Spatial Sampling ◽  
Potato Tubers ◽  
Plant Parts ◽  
Direct Assessment ◽  
African Black ◽  
Soil Insects ◽  
Insect Populations ◽  
The Hill ◽  
Potato Crops

AbstractA method was devised for spatial sampling within the soil in potato crops where the soil insects African black beetle, Heteronychus arator (Fabricius) (Coleoptera: Scarabaeidae) and whitefringed weevil, Graphognathus leucoloma (Boheman) (Coleoptera: Curculionidae) are pests. The number and position of potato plant parts, the soil insects, and their attacks on potatoes were defined within the hilled-up soil profile of sections of the planting rows. Neither potato tubers, nor insects nor insect attacks were uniformly distributed. Tubers occurred mainly in the middle of the hill, while the insects contrasted in their distribution in the soil. Most of the damaging H. arator adults and larvae occurred in upper middle areas; the damaging G. leucoloma larvae occurred deeper and were more damaging on the under-side of tubers. The method provides a means of simultaneously sampling soil insect populations in a crop and obtaining a direct assessment of their damage and the effectiveness of control measures.

The life-history and control of Hapatesus hirtus Candeze (Coleoptera: Elateridae) in Victoria

1991 ◽  
Vol 42 (5) ◽  
pp. 827 ◽  
Author(s):  
PA Horne ◽  
JA Horne
Keyword(s):  
Life History ◽  
Field Trials ◽  
Soil Samples ◽  
Control Measures ◽  
Potato Tubers ◽  
Larval Stages ◽  
Complete Development ◽  
History Of ◽  
And Control ◽  
Potato Crops

The incidence and life-history of potato wireworm, Hapatesus hirtus Candeze, in Victorian potato crops were studied, and insecticidal control measures assessed. Larval stages were present and active throughout the year. Ten larval instars were identified, probably requiring several years to complete development. Egg development occurred in October-November and the most likely timing of oviposition was December. The relative numbers of larval H. hirtus detected in soil samples, pre-planting baits and harvested tubers are presented. Baiting with halves of potatoes provided an efficient means of detecting areas likely to suffer wireworm damage. One formulation of chlorpyrifos ('Lorsban') was effective in reducing damage to, and larval numbers in, potatoes in field trials. The granular formulation of tefluthrin and the controlled release chlorpyrifos were not effective in protecting potato tubers.

Seasonally contrasting activity of African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae): implications for populations, pest status and management

1998 ◽  
Vol 88 (4) ◽  
pp. 443-450 ◽  
Author(s):  
J.N. Matthiesse ◽  
S.E. Learmonth
Keyword(s):  
Surface Activity ◽  
Population Regulation ◽  
High Surface ◽  
Light Trap ◽  
Pitfall Trap ◽  
Control Measures ◽  
Adult Density ◽  
African Black ◽  
Potato Crops ◽  
High Surface Activity

AbstractFlight and surface activity of the African black beetle, Heteronychus arator (Fabricius), detected by pitfall, light and window traps, was seasonally reversed. High surface activity relative to flight occurred in spring when beetles were mature, while relatively higher levels of flight occurred in autumn when they were immature. Pitfall trap captures were male-dominated in spring and female-dominated in autumn, and were a poor estimator of adult density. Light trap captures were consistently female-dominated. Although autumn flight was dispersive and inferred to have some role in population regulation, it was largely localized within the usual pasture habitat of the species. Some beetles flew into irrigated potato crops in autumn, but not specifically, as beetle abundance was consistently less than in surrounding dry pasture. High surface activity indicates spring is a strategic time for surface-applied control measures to prevent increase of H. arator in the next generation, a less disruptive alternative to conventional soil-incorporated insecticide directed at the new generation's larvae in summer. Such an approach would be best aimed early in the upsurge of activity, as most of the season's cohort of eggs was laid by the time surface activity peaked in mid-spring.

Impact of the soil insects African black beetle, Heteronychus arator (Coleoptera: Scarabaeidae) and Whitefringed weevil, Graphognathus leucoloma (Coleoptera: Curculionidae), on potatoes and effects of soil insecticide treatments in south-western Australia

1995 ◽  
Vol 85 (1) ◽  
pp. 101-111 ◽  
Author(s):  
J.N. Matthiessen ◽  
S.E. Learmonth
Keyword(s):  
Breeding Season ◽  
Western Australia ◽  
Tuber Yield ◽  
Relative Proportion ◽  
Soil Surface ◽  
Insect Species ◽  
African Black ◽  
Soil Insects ◽  
Winter Crops ◽  
Potato Crops

AbstractPopulations of the soil insects African black beetle, Heteronychus arator (Fabricius), and whitefringed weevil, Graphognathus leucoloma (Boheman), and the damage caused to potato crops in south-western Australia were measured with and without the insecticide chlorpyrifos incorporated into the soil prior to planting. Low populations of both insects were highly damaging. Destruction of stems by H. arator reduced tuber yield and both species damaged tubers from the time of their formation. Tuber damage increased with time because both insect species on average damaged multiple tubers and caused multiple attacks on tubers. Growth of G. leucoloma larvae caused increased abundance of the more damaging later instars in spring. The insecticide reduced resident H. arator abundance and hence damage to newly-emerging potato stems in summer, but had less effect on reducing attacks on tubers in summer crops because adult beetles flew into some crops during growth. Exceptionally high tuber damage per H. arator adult in winter crops was ascribed to enhanced activity during its spring breeding season. The insecticide was inconsistent in reducing the abundance of G. leucoloma larvae. Insecticidal effects were greatest near the soil surface, resulting in an increase in the relative proportion of both insects deeper in the soil. Since a greater proportion of the tubers occurred there, the resulting greater potential for the insects to cause tuber damage tended to outweigh reduction in their abundance.

scholarly journals Floral Plantings in Large-Scale Commercial Agroecosystems Support Both Pollinators and Arthropod Predators

Insects ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 91
Author(s):  
Eric G. Middleton ◽  
Ian V. MacRae ◽  
Christopher R. Philips
Keyword(s):  
Large Scale ◽  
Agricultural Land ◽  
Field Margins ◽  
Crop Fields ◽  
Pollinator Abundance ◽  
Arthropod Predators ◽  
Commercial Potato ◽  
Insect Populations ◽  
Beneficial Insect ◽  
Potato Crops

Beneficial insect populations and the services that they provide are in decline, largely due to agricultural land use and practices. Establishing perennial floral plantings in the unused margins of crop fields can help conserve beneficial pollinators and predators in commercial agroecosystems. We assessed the impacts of floral plantings on both pollinators and arthropod predators when established adjacent to conventionally managed commercial potato fields. Floral plantings significantly increased the abundance of pollinators within floral margins compared with unmanaged margins. Increased floral cover within margins led to significantly greater pollinator abundance as well. The overall abundance of arthropod predators was also significantly increased in floral plantings, although it was unrelated to the amount of floral cover. Within adjacent potato crops, the presence of floral plantings in field margins had no effect on the abundance of pollinators or predators, although higher floral cover in margins did marginally increase in-crop pollinator abundance. Establishing floral plantings of this kind on a large scale in commercial agroecosystems can help conserve both pollinators and predators, but may not increase ecosystem services in nearby crops.

scholarly journals Rhizoctonia solani Anastomosis Group 3 is Predominant in Potato Tubers in Poland

Plant Disease ◽  
2013 ◽  
Vol 97 (9) ◽  
pp. 1245-1245 ◽  
Author(s):  
J. W. Woodhall ◽  
B. Lutomirska ◽  
J. C. Peters ◽  
P. S. Wharton
Keyword(s):  
Rhizoctonia Solani ◽  
Tap Water ◽  
Anastomosis Group ◽  
Black Scurf ◽  
Crop Rotations ◽  
Potato Tubers ◽  
Hyphal Fusion ◽  
Group 3 ◽  
Plant Pathol ◽  
Potato Crops

Rhizoctonia solani is a species complex of 13 related but genetically distinct anastomosis groups (AGs). In potato, R. solani can infect the stems, stolons, and roots, resulting in quantitative losses. It can also cause qualitative losses through blemishes occurring on progeny tubers, such as black scurf and elephant hide (corky cracking). Knowledge of the AG in local populations is important because they differ in host range, fungicide sensitivity, and disease severity (2). To determine the AGs present in Poland, 54 tuber samples displaying typical R. solani symptoms were taken from six different fields in 2011. The fields were representative of five different administrative regions of Poland and from at least 10 different varieties. Rhizoctonia was isolated from tubers by placing symptomatic material on to tap water agar amended with streptomycin and penicillin and after 2 to 3 days Rhizoctonia colonies were identified and hyphal tips of these transferred to potato dextrose agar. Rhizoctonia was successfully isolated from 48 tubers displaying black scurf and two tubers displaying elephant hide symptoms. DNA was extracted from Rhizoctonia cultures using a Wizard Food kit (Promega) and the AG was determined using specific real-time PCR assays (1). All Rhizoctonia isolates were determined to be AG3 and this was confirmed for 10 selected isolates by observing hyphal fusion with a known AG3 tester isolate (Rs08) as described previously (3). Pairings were also conducted amongst the 10 Polish isolates, C2 reactions were typically observed indicating numerous vegetative compatible groups are present. This study shows that AG3 is likely to be the predominant AG in potato tubers in Poland. This is similar to other studies in Europe, which have all determined that AG3 accounts for at least 92% of isolates from potato (2,3). AG2-1, 4, and 5 have also been found in tubers worldwide and climate and certain crop rotations can influence the presence of these other AGs in potato tubers (2). However, climate and crop rotations in Poland are similar to other parts of Europe so the predominance of AG3 is expected. AG3 was also isolated from elephant hide symptoms; however, it was more frequently isolated from sclerotia. The ability of AG3 to prolifically produce sclerotia and thereby survive on seed tubers may explain its predominance in potato crops (4). Therefore, studies focusing on the management of Rhizoctonia potato disease in Poland should consider AG3 in the first instance. References: (1) G. E. Budge et al. Plant Pathol. 58:1071, 2009. (2) L. Tsror. J. Phytopathol. 158:649, 2010. (3) J. W. Woodhall et al. Plant Pathol. 56:286, 2007. (4) J. W. Woodhall et al. Plant Pathol. 57:5, 2008.

Study on the Geological Disasters of Heap Leaching Field and the Prevention of a Copper Mine in Inner Mongolia

2013 ◽  
Vol 748 ◽  
pp. 1164-1167
Author(s):  
Fei Zhang ◽  
Mo Shu Wang ◽  
Rui Tian ◽  
Bing Wang
Keyword(s):  
Underground Mining ◽  
Heap Leaching ◽  
Control Measures ◽  
Geological Hazards ◽  
Copper Mine ◽  
Geological Disasters ◽  
Geological Disaster ◽  
Deep Underground ◽  
Disaster Control ◽  
The Hill

The heap leaching field of a copper mine located at the top of the hill border of the open mining pit, also in the collapse zone of the underground mined area. With deep underground mining activities are carrying out, there are more and more prominent risks of geological disasters. In order to effectively prevent and reduce the occurrence of geological hazards, researching and exploring the law of the disaster, and making a geological disaster control measures.

scholarly journals Modeling tuberculosis incidence in Nepal

2010 ◽  
Vol 4 (2) ◽  
pp. 355-360 ◽  
Author(s):  
Sampurna Kakchapati ◽  
Sulawan Yotthanoo ◽  
Chamnein Choonpradup
Keyword(s):  
Urban Areas ◽  
Negative Binomial ◽  
Control Measures ◽  
Tuberculosis Incidence ◽  
Term Basis ◽  
Objective Model ◽  
Period Data ◽  
The Hill ◽  
Male To Female

Abstract Background: Tuberculosis (TB) constitutes a large burden of infectious disease in Nepal. Objective: Model incidence of TB between 2003 and 2008 in Nepal. Methods: A retrospective study was conducted in Nepal of tuberculosis incidence by gender and location over the six years period. Data were obtained for 198,719 tuberculosis cases from the Nepal Tuberculosis Center (NTC). A negative binomial model with two multiplicative components as predictors was used and provided a good fit. Results: The model extracted a decreasing trend during the first five years followed by a drop in 2008.The overall incidence of TB was 1.31 cases per 1,000 population with a male to female incidence rate ratio of 1.86. There were pronounced spatial variations with higher rates occurring in the Terai region, followed by the Hill, and Mountain regions. Conclusion: Tuberculosis incidence showed a steady decreasing trend, but the number of cases was still very high. Gender differences existed in TB incidence in Nepal. Higher rates were observed in the Terai Region and urban areas. These findings highlight the need for the tuberculosis control measures to remain on a sustained and long-term basis for the high TB burden rate of Nepal.

TECHNIQUES FOR EVALUATING VECTOR CONTROL MEASURES

1963 ◽  
Vol 26 (8) ◽  
pp. 255-258
Author(s):  
Eldon P. Savage
Keyword(s):  
Insect Pests ◽  
Control Measures ◽  
Population Characteristics ◽  
Direct Count ◽  
Flying Insects ◽  
Monitoring Tools ◽  
Complete Exclusion ◽  
Insect Populations ◽  
Rodent Populations ◽  
Monitoring Devices

Summary Monitoring devices for determining population characteristics of the fly, roach, miscellaneous insect pests, and rodents are described along with ecologic factors. Entomologic surveillance of fly populations is accomplished by use of the fly grill, fly trap, and visual observations. These all require periodic evaluations to determine population changes. Cockroach evaluations are made by direct count and observations, coupled with nocturnal inspection of premises timed to coincide with peak roach activity. Other insect populations are monitored for presence or absence by checking sites such as windows for flying insects, and examining floors, pallets, and walls for insects that have emerged. Sacked grains and cereal infestations are checked for insect presence by examining the exteriors of the bags and the stitched ends. Presence or absence of rodents is usually determined by searches for rodent signs. However, total rodent populations can be estimated. Most sanitarians consider the presence of a single fly, rat, or other pest in a milk or food establishment objectional. Until this goal of complete exclusion of insects and rodents is reached, food and milk sanitarians should give serious thought to developing improved monitoring tools based on insect and rodent ecology.

DISPERSAL OF CONE AND SEED INSECTS TO AN ISOLATED DOUGLAS-FIR TREE IN WESTERN OREGON

1984 ◽  
Vol 116 (10) ◽  
pp. 1437-1438 ◽  
Author(s):  
T. D. Schowalter
Keyword(s):  
Pacific Northwest ◽  
Gall Midge ◽  
Douglas Fir ◽  
Control Measures ◽  
Host Trees ◽  
The Pacific ◽  
Major Species ◽  
Insect Populations ◽  
Cone And Seed Insects ◽  
Seed Insects

Cone and seed insects frequently cause severe losses to Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) seed production in the Pacific Northwest (Hedlin et al. 1981; Ruth 1980). Two of the major species west of the Cascades are the Douglas-fir cone gall midge (Contarinia oregonensis Foote (Diptera: Cecidomyiidae)) and the Douglas-fir seed chalcid (Megastigmus spermotrophus Wachtl. (Hymenoptera: Torymidae)). These two species are host specific on Douglas fir and exhibit an extended diapause in which more than 50% of each year's cohort may remain in diapause under host trees for 1 or more years (Annila 1982; Hedlin 1961; Hedlin et al. 1981; Johnson 1962). The economic and biological costs of chemical control have supported recommendation of alternative control measures, particularly (1) establishing seed orchards some distance from sources of coneand seed-insect populations, and (2) removing all cones and burning litter as a means of reducing such populations (Hedlin et al. 1981; Ruth 1980). The success of these two options depends on the dispersal strategies of cone and seed insects (Johnson 1962), but information on dispersal has been lacking. The purpose of this study was to obtain such information.

Infection of Kennebec potato with Verticillium albo-atrum

1980 ◽  
Vol 31 (3) ◽  
pp. 525 ◽  
Author(s):  
PJ Sampson
Keyword(s):  
Potato Crop ◽  
Current Season ◽  
Plant Parts ◽  
Systemic Movement ◽  
Stem Infection ◽  
Apical Half ◽  
Subsequent Crop ◽  
Soil Mix ◽  
Potato Crops ◽  
Verticillium Albo Atrum

Infection of Kennebec potato plants by Verticillium albo-atrum (dark mycelium form) occurred when they were grown in soil samples collected after 4 years under perennial ryegrass-white clover pasture following an affected potato crop. Tuber transmission averaged 8 %, 13 % in the stolon half and 4% in the apical half. Infection readily spread from diseased to healthy plants that were growing in the same container of a peat-sand soil mix. Infection was detected in stems from the stage of early flowering; infection of a proportion of tubers had occurred by the stage of rapid tuber expansion. In some plants, tuber infection occurred in the absence of detectable stem infection. Latent infection was common and systemic movement was incomplete. The fungus was cultured from the above-ground stem more frequently than from other plant parts. In a field study, an infected potato crop produced soil-borne inoculum (which included infected dead haulms) that resulted in infection of 75 % of previously healthy plants of a subsequent crop. Current season spread was not detected in infector or bait crops by a runs test based on sequences of healthy and diseased plants. The use of pathogen-free stock and the removal of diseased plants from seed potato crops are unlikely to control the disease where V. albo-atrum is endemic.

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