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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Impact of neonicotinoids in mid-south row crop systems

North, John Hartley 27 April 2016 (has links)
<p> Neonicotinoid seed treatments are widely used and highly effective against early season insect pests of all row crops throughout the Mid-South region of the United States. An analysis was performed to determine the value of neonicotinoid seed treatments across multiple trials in soybean, <i> Glycine max</i> L.; corn, <i>Zea mays</i> L.; cotton, <i> Gossypium hirsutum</i> L.; and sorghum, <i>Sorghum bicolor</i> L. production systems across the mid-southern region. Neonicotinoid seed treatments provided significant yield and economic increases when utilized the majority of the time. A second experiment was performed to determine the value of various insecticide classes when utilized in an overall systems approach when managing cotton insect pest in the Delta and Hills region of Mississippi. When all classes of insecticides were used in rotation, significant yield and economic benefits were observed in the Delta Region compared to treatment scenarios where some insecticide classes were omitted.</p>
2

Mexican Rice Borer (Eoreuma loftini) Pheromone Trap Efficacy and Role in Invasive Species Monitoring and Pest Management

Wilson, Blake Emerson 11 May 2016 (has links)
The Mexican rice borer, Eoreuma loftini (Dyar) (Lepidoptera: Crambidae), is an invasive pest of sugarcane, Saccharum spp.; rice, Oryza sativa; and other graminaceous crops along the U.S. Gulf Coast. Identification of E. loftini sex pheromones led to the development of pheromone baited traps. Studies were conducted to determine strategies for the use of E. loftini pheromone traps in invasive species monitoring and pest management. A two-year field study demonstrated that E. loftini pheromone traps attract males from distances of up to 100m. A behavioral assay observed that detection of the pheromone by E. loftini males occurs at ≈48m from the source. A network of pheromone traps monitored E. loftini range expansion from 20092015. Eoreuma loftini is now present in nine Louisiana Parishes: Calcasieu, Cameron, Beauregard, Allen, Jefferson Davis, Acadia, Vermilion, Evangeline, and St. Landry. Crop surveys observed E. loftini infesting Louisiana rice and sugarcane. The E. loftini population is advancing eastward at 11 km/yr. The population is characterized by high density clusters and may be limited at higher latitudes. E. loftini is causing substantial yield reductions in unprotected commercial rice fields in southwestern Louisiana. Rice which received the Dermacor X-100® (chlorantraniliprole) seed treatment sustained reduced injury. Pheromone trap captures are correlated to larval infestations in adjacent unprotected rice fields. Infestations of E. loftini in Louisiana sugarcane have not reached damaging levels. Sugarcane infested with E. loftini is being transported to sugar mills east of the pests known range, however, it has not established in these regions. Studies indicated automated E. loftini pheromone trapping systems have potential to further reduce scouting efforts. This represents the first use of automated pheromone-based monitoring systems for Lepidopterous insect pests in field crops. Field studies indicate new diamide chemistries may improve chemical control of E. loftini in sugarcane. This research expands the use of E. loftini pheromone traps in invasive species monitoring and pest management. Continued monitoring of E. loftini range expansion and the use of pheromone trap-based scouting techniques should be further pursued to mitigate the impact of this pest along the U.S. Gulf Coast.
3

Integrated Multiple-tactic Management of the Redbanded Stink Bug on Soybeans in Louisiana

Moonga, Miyanda Nzala 29 July 2016 (has links)
Stink bugs (Hemiptera: Pentatomidae) are major pests of soybeans in Louisiana and heavy infestations often lead to economic losses. The stink bug species complex has changed in the past decade with the prevalence of the invasive redbanded stink bug, Piezodorus guildinii (Westwood), which causes greater damage than other stink bug species. Moreover, control of the redbanded stink bug has been faced with challenges because it is less sensitive to recommended insecticides. Therefore, studies were conducted to evaluate different control options for P. guildinii. Among the studies conducted was the current status of egg parasitoids of stink bugs in Louisiana. Telenomus podisi Ashmead (Hymenoptera: Platygastridae) was the predominant egg parasitoid of stink bugs. Field studies were also conducted to determine the combined effects of host plant resistance and insecticide application, on the abundance of stink bugs and their natural enemies. The soybean cultivar Pioneer 95Y20 had the least pest pressure, seed damage, and yields were higher from these plants. Insecticide application of thiamethoxam provided some control of stink bugs, although it did not impact yield. The combination of cultivar and insecticide application did not have a significant effect on natural enemies of stink bugs. Lastly, a study was also performed to demonstrate the effect of synthetic plant volatiles on natural enemies of stink bugs in the field. Results from this study showed that methyl jasmonate had a significant impact on the number of fire ants collected during a 5-minute time interval. Overall, results from this research provide important information on the integrated pest management (IPM) of P. guildinii and other stink bugs in Louisiana.
4

Results of Operation Full Stop: Terminix Service Co. Inc., control of Formosan Subterranean Termites (Coptotermes Formosanus) in the French Quarter of New Orleans

Martin IV, Edward Joseph 12 July 2016 (has links)
In New Orleans alone, the Formosan subterranean termite, Coptotermes formosanus, causes $300 million in damages annually. Formosan subterranean termites are the most destructive subterranean termite in the world wherever they occur. From 1998- 2011 Operation Full Stop was implemented in five phases. Basic parameters were set up through the LSU AgCenter. French Quarter Residents were allowed to select their own licensed pest control operator for approved termite treatments. The United States Department of Agriculture in New Orleans provided funds to Operation Full Stop to pay the pest control operator for initial treatment and yearly renewal of termite contracts. Terminix Service Co. Inc. in New Orleans participated fully in the program from 1998-2011 in New Orleans. Terminix Service Co. Inc. (Metairie, LA) had 404 Sentricon® baiting accounts in Operation Full Stop (Pest Control Solutions, Jackson Mississippi). From this list every 7th account was selected until one hundred accounts was achieved.From the master list each account was looked up on Dox Serve Software (Abita Spring, LA) where route sheets were stored. Each account had its own file stored in the Dox Serve system. Account information and route sheets were then individually analyzed and the information was manually implemented in an Excel spreadsheet, sorted by JMP statistical software by SAS and analyzed by SAS PROC MIXED. Termite activity was calculated based on an Attack Rate. Attack Rate was defined as the number stations with active termites/ number of stations divided by number of inspections and then multiplied by 100. Attack Rate average was calculated for each account per year. Our study measured termite activity based on sampled Terminix Sentricon® baiting accounts from 1998-2011 only. The main objective of this study was to determine if Terminix Service Co. Inc. decreased termite activity in sampled baiting accounts during Operation Full Stop. There was a significant decrease in Attack Rate from 1998-2011. The slope of this decreasing trend of Attack Rate observed from 1998-2011 was also significant. Our results suggest that termite baiting in Terminix Service Co. Inc. decreased Formosan subterranean termite activity in Operation Full Stop.
5

Analysis of Insect Pest Reports at LSU Residential Life

Acharya, Namoona 12 July 2016 (has links)
Urban insect pests are adversely affecting student living on campus at LSU. Insect pest reporting was started systematically in 2000 at LSU Residential Life after introducing Maximo database. To analyze the insect pest reports, complaints from students on ants, bed bugs and cockroaches were selected from the database. From the 16-year data set, the growth trend of reports of ants, bed bugs and cockroaches was found to be increasing. The highest reported month and year for ants was September 2004. In August 2008, cockroaches were most reported on. Bed bug reports peaked in October 2009. Based on the reports, the highest degree of infestation was found in Highland Hall for ants and West Nicholson for bed bugs and cockroaches. To calculate the degree of infestation for each 20 dorms, 2 single student apartments and 2 family apartments, total reports of a particular insect group was divided by 16 years to calculate the averages and then divided by the number of students residing in that dorm/apartment and then multiplied by hundred to convert the value to a percentage. All halls/apartments were divided into 3 age groups (< 30 years, 30-60 years, and > 60 years) to determine the relationship between the degree of infestation and the age of halls/apartments. The oldest halls/apartments had significantly higher ant infestations/students, while halls/apartments age was not significant for bed bugs and cockroaches. A negative slope was found between the degree of infestation and the number of floors among all dorms and apartments which was linearly significant with bed bugs and cockroaches. From our visual inspections of 21 apartments/halls with bed bug reports, only 3 actually had bed bugs. Most of the reports were possibly related other insect bites/stings, allergies and a negative perception toward bed bugs. A web survey Residential Life Entomology Survey was also developed and sent to students living on campus. From this study, the LSU Residential Life came to know the present situation of insects among all halls and apartments. From 392 respondents, mosquitoes, cockroaches, long horn crazy ants, gnats, bees and wasps were found as the most common insects reported. Students were positive toward the use of preventative chemicals measure. More than half of the students were satisfied with the insect pest control. In this case, the pest management team of Residential Life as well as the Pest Control Company (PCO) should work better and while using pest control strategies, students should be advised about the prevention procedure. Linearly significant relationship was observed between the number of insects observed and the level of satisfaction, in which for every one unit increase of insects observed, the satisfaction level decreases by -1.61. From this overall study, LSU Residential Lifes insect problem is minor with 2.64% of reports while comparing all reports in Maximo Database. Although this percentage is low, insects should be considered important. Residential Life has been working with different PCOs and students consider that PCOs and Residential Life are responsible for insect control in their living areas. However, students could also prevent many insects in their halls and apartments. As for ants and cockroaches, students can prevent these insects by improving their habits. As sanitation is the key to prevent many insects, students can protect themselves from many allergic reactions after insects bites/stings. Similarly, disease vectors could be prevented along with the clean environment in dorms and apartments. To prevent and control insect pests at the LSU Residential Life, PCOs working as contractors, pest management team of LSU Residential Life and students collaborate together to make LSU Residential Life a great place.
6

Genetics and Management of Resistance to Pyriproxyfen in the Whitefly Bemisia tabaci

Crowder, David William January 2008 (has links)
Selective insecticides such as insect growth regulators that kill pests but cause little or no harm to non-target organisms have become increasingly important in crop production systems worldwide. The insect growth regulator pyriproxyfen has been successfully used for the last decade in Arizona as part of an integrated pest management (IPM) program for the sweetpotato whitefly, Bemisia tabaci, a problematic pest in Arizona and other regions of the world throughout the world.A serious threat to the continued success of the IPM program in Arizona is the evolution of insecticide resistance in B. tabaci. To enhance the ability to design sound strategies for managing whitefly resistance to pyriproxyfen we: 1) compared susceptibility to pyriproxyfen between male and female B. tabaci; 2) determined the dominance of pyriproxyfen resistance; 3) determined if fitness costs were associated with resistance; 4) estimated the number of genes affecting resistance; 5) developed resistance management models.Laboratory and field bioassays investigated the genetics of pyriproxyfen resistance in males and females from a pyriproxyfen-susceptible and pyriproxyfen-resistant strain (>1000 fold resistance). Results showed that male and female B. tabaci did not differ in susceptibility to pyriproxyfen, resistance was partially to completely dominant under approximated field conditions, and fitness costs were not associated with resistance. Similar traits in field populations could threaten the efficacy of pyriproxyfen. Model results indicated that the current IPM program for B. tabaci could be improved by curtailing the use of pyriproxyfen in cotton-intensive regions, synchronizing the use of pyriproxyfen with key crop production stages in the field, and applying the lowest pyriproxyfen concentration needed to provide effective control.Knowledge generated from this research has provided insight into factors affecting B. tabaci resistance to pyriproxyfen, which could improve management strategies for B. tabaci in Arizona cotton and other crops. This project represents a proactive approach to understanding pyriproxyfen resistance and its potential impacts before resistance evolves to problematic levels in the field. In addition, the project provided insight into mechanisms affecting resistance in a haplodiploid pest. Thus, the research can serve as a model for basic research on other haplodiploid pests.
7

Relative Influence of Plant Quality and Natural Enemies on Population Dynamics of Bemisia tabaci and Lygus hesperus in Cotton

Asiimwe, Peter January 2011 (has links)
The bottom-up effects of plant quality and the top-down effects of natural enemies are two of the most important factors governing the abundance, distribution and performance of insect herbivores. Plant quality effects are generally manifested through changes in nutrients, morphology, size or host availability. Natural enemy effects are mainly observed through the action of arthropod predators and parasitoids. The relative influence of these effects has been well studied in several natural and forest ecosystems but has rarely been evaluated in agro-ecosystems. In manipulative field experiments, I examined the relative influence of plant quality and natural enemies on the abundance and performance of Bemisia tabaci and Lygus hesperus, two important pests of cotton.This dissertation begins with an evaluation of the relative influences of plant quality (manipulated through differential irrigation) and natural enemies (manipulated by insecticide exclusion) on the seasonal dynamics of B. tabaci in cotton. I found higher densities of all B. tabaci stages when natural enemy densities were reduced, regardless of level of plant quality. Generally, densities of B. tabaci did not vary with plant quality. Similarly, natural enemy densities and predator:prey ratios were not affected by plant quality, indicating that natural enemies exert a greater influence on seasonal dynamics of B. tabaci than plant quality. I then evaluated the mechanism responsible for herbivore density patterns using cohort-based life table studies. I found lower rates of predation and parasitism when natural enemy densities were reduced across all levels of plant quality, with predation the primary key factor associated with changes in generational mortality. Levels of B. tabaci mortality did not vary with plant quality indicating that the impact of natural enemies was not mediated by the bottom-up effects of plant quality. Finally, I evaluated these effects on L. hesperus and found that plant quality significantly affected seasonal dynamics with the greatest and smallest densities on the highest and lowest quality plants, respectively. These effects did not translate to natural enemy effects, as their density and impact were not affected by plant quality. The implications of these findings for the management of these pests in cotton are discussed.
8

The biology and external morphology of the Hemlock Looper, Lambodina Fiscellaria Fiscellaria (Guenee), in Newfoundland (Lepidoptera, Geometridae).

Carroll, William Joseph. January 1952 (has links)
The hemlock looper, Lambdina fiscellaria fiscellaria (Guenée), has been an important forest pest in Newfoundland for many years. Outbreaks have been reported from widely separated parts of the province, and in most cases, there has been a high mortality of balsam fir, Abies balsamea (L.) Mill. (Fig. l). A study of the insect was initiated in the spring of 1950, in Newfoundland, by the Division of Forest Biology, Dominion Department of Agriculture. The object of the study was to determine what factors influence the rise and fall of looper populations. Unfortunately, the outbreak had reached its peak when the study was started. In 1951 populations had fallen to an endemic level, resulting in rather meagre information on many aspects of the investigation. Biological and population studies of the hemlock looper and associated insects were carried out by the writer and an assistant at a summer field station established near Lake St. George, St. George’s District, Newfoundland. The station was used from May to September in 1950 and 1951. Studies on the external morphology of all developmental stages of the species were made at the Dominion Entomological Laboratory, Fredericton, N. B. Morphological studies were conducted to discover if specimens found in Newfoundland and New Brunswick are conspecific. Although climatic conditions and forest composition are fairly similar in both provinces the looper has never been a serious pest in the latter. [...]
9

Resistance of Fall armyworm, Spodoptera frugiperda (J.E. Smith) to Bacillus thuringiensis

Niu, Ying 08 May 2014 (has links)
The fall armyworm, Spodoptera frugiperda (J.E. Smith), is a target pest of Bacillus thuringiensis (Bt) corn in North and South America. In this study, multiple tests were conducted in the laboratory and greenhouse to 1) determine the susceptibility of two field populations of S. frugiperda collected from Florida (FL) and Puerto Rico (PR) to purified Cry1F protein and Bt corn leaf tissue and 2) evaluate larval survival of and plant injury by Cry1F-susceptible, -resistant, and heterozygous genotypes of S. frugiperda on whole plants of transgenic corn containing single and pyramided Bt genes. Corn hybrids evaluated in this study included five non-Bt corn hybrids, two single-gene Bt corn products, Herculex®I (Cry1F corn) and YieldGard® (Cry1Ab corn), and four pyramided Bt corn traits: Genuity®VT Double ProTM, VT Triple ProTM, SmartStaxTM, and Agrisure® VipteraTM 3111. Diet-incorporated bioassays showed that FL was susceptible to Cry1F protein with a LC50 value of 0.13-0.23 µg/g, while PR was highly resistant to Cry1F (>137-fold). Leaf tissue bioassays also exhibited that FL was susceptible to all Bt corn hybrids, while PR was highly resistant to Cry1F corn leaf tissue. Both FL and PR could not survive on leaf tissue of VipteraTM 3111. However, PR exhibited a significant cross-resistance to the leaf tissue of the other three pyramided Bt corn traits. In greenhouse whole plant tests, larvae of the three insect genotypes on non-Bt corn hybrids survived well and caused serious plant damage. Cry1Ab corn was ineffective against all three insect genotypes. On Cry1F corn plants, resistant larvae survived on 72.9% plants after 12-15 d and caused significant leaf injury. In contrast, no live larvae and little or no leaf injury were observed on the Cry1F corn plants that were infested with susceptible or heterozygous genotypes, or on the pyramided Bt plants infested with the three insect genotypes. The results demonstrated that the Puerto Rico population of S. frugiperda was highly resistant to both purified Cry1F protein and Cry1F corn plants and the resistance was recessive. Corn hybrids containing any one of the four pyramided Bt traits are effective for managing the Cry1F resistance in S. frugiperda.
10

Evaluation of Economic Injury Levels and Chemical Control Recommendations for Rice Stink Bug (Oebalus Pugnax) in Louisiana

Blackman, Bryce 30 July 2014 (has links)
Experiments were carried out from 2010 to 2013 to investigate multiple aspects of rice stink bug (RSB) integrated pest management (IPM): insecticide recommendations, sampling efficiency, treatment thresholds, farmer practices, and improved educational tools. The first objective of this research was to compare the efficacies of currently used insecticides with that of a new product from the neonicotinoid class of insecticides. Experiments were carried out in the laboratory, small field plots, and commercial fields across Louisiana. Results from efficacy trials showed that the neonicotinoid was comparable to pyrethroid products used most by rice producers in Louisiana. Conversely, in separate experiments the organophosphate malathion was shown to be highly ineffective in small plot tests. Glass-vial bioassays showed elevated levels of pyrethroid tolerance in a Texas RSB population. The second objective was to evaluate the density-damage relationship for rice stink bugs feeding in rice. The efficiency of sweep-net sampling was first determined using a mark-recapture study in small plots to establish the necessary density for infesting caged rice plots. Cage studies were carried out in 2010-2012, and RSB were infested at levels estimated to be 1 to 20 times the current economic thresholds. No significant relationships among rice stink bug densities and measures of damage were seen. Objective three was to assess the adoption of recommended IPM practices by rice-industry professionals in southern rice producing states and create original internet-based delivery of extension recommendations for RSB management. Rice producers in Louisiana and Texas were shown to prefer the use of pyrethroid insecticides above all other labeled products for RSB control. Growers in Texas averaged more applications of pyrethroids than respondents in Arkansas and Louisiana. Seed treatments to combat rice water weevils have been adopted rapidly in all states surveyed.

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