An investigation was conducted to identify volatiles associated with active Formosan termites. Using a combined technique of short path thermal desorption-gas chromatography/mass spectrometry (SPTD-GC/MS), qualitative comparisons were made between compounds detected in treatments containing active Formosan termites versus those detected in controls without Formosan termites. Except for dimethyl disulfide, none of the compounds were consistently detected in the treatments but not the controls for the four termite groups tested. However, in each of the three groups that dimethyl disulfide was detected, dead termites that were decomposing along with active termites were present. Therefore, none of the compounds could be classified as volatiles associated with active Formosan termites. Qualitative and quantitative comparisons were made between compounds detected in treatments that contained carton nests with active Formosan termites and controls that contained neither Formosan termites nor carton nests. Two methods were used, one using unwashed Nalgene 550 platinum-cured silicone tubing and the other using unwashed fluorinated ethylene propylene (FEP) teflon tubing in the experimental set-up. Qualitative analysis for both methods indicated that none of the compounds could be consistently detected in treatments but not the controls. Quantitative analysis for both methods indicated that the concentrations of naphthalene, and butylated hydroxytoluene and nine unknown volatiles were not significantly different between the treatments and controls at the 0.01 level as determined by the paired t-test. Therefore, using the methods described herein, none of the analyzed compounds could be classified as volatiles associated with active Formosan termites. However, changes in the methods may enable the detection of volatiles associated with active Formosan termites. The concentrations of three suspect reporter molecules, which include naphthalene and two unknown compounds, were significantly lower using fluorinated ethylene propylene (FEP) teflon tubing than using unwashed Nalgene 550 platinum-cured silicone tubing in the experimental set-up as determined by 95% confidence intervals. This suggested that a source of these volatiles was unwashed silicone tubing, which was relevant to this study because it aided in the determining whether the volatiles are associated with active Formosan termites.

Interactions between graminaceous weed and insect pests of rice and between management practices for these pests were investigated. Studies were conducted to examine preference and performance of rice water weevil, <i>Lissorhoptrus oryzophilus</i> Kuschel, on several weeds commonly found in rice fields. Several weeds were more preferred than rice, and larvae were present on several dicotyledonous weeds, suggesting the host range of <i>L. oryzophilus</i> is broader than previously thought. Effects of the presence of barnyardgrass, (<i>Echinochloa crus-galli</i> Beauv.), on rice stink bugs, <i>Oebalus pugnax</i> F., and <i>L. oryzophilus</i> populations in rice fields were investigated. Presence of barnyardgrass and the synchrony of barnyardgrass seed heads and rice panicles influenced <i>O. pugnax</i> densities on rice. Barnyardgrass served as a trap crop or as a source of infestation of <i>O. pugnax</i> depending on the developmental stage of barnyardgrass relative that of rice. Presence of barnyardgrass had little impact on <i>L. oryzophilus</i> . Similar studies conducted with borers and Amazon sprangletop, <i>Leptochloa panicoides</i> (Presl.) Hitchc. revealed that injury to rice was greater in weedy plots of rice than in pure plots of rice. Studies were conducted to determine how density of weeds affected <i>O. pugnax</i> populations and how weeds and <i>O. pugnax</i> combined to reduce grain yield and quality. Numbers of <i>O. pugnax</i> and percentages of filled seeds, pecky rice, and broken kernels increased as weed density increased. Increases were less severe in insecticide-treated than non-treated plots. However, yield losses from weeds and insects were not significantly greater than from weeds alone. Preference and performance of <i>L. oryzophilus</i> on herbicide-treated and non-treated glufosinate-tolerant rice were investigated. Glufosinate applications on glufosinate-tolerant rice reduced weevil oviposition by 30% and reduced larval densities by 20% compared to non-treated glufosinate-tolerant rice. Glufosinate was not toxic to <i>L. oryzophilus</i> at rates used in these experiments, and feeding was not deterred by glufosinate, suggesting that glufosinate application induced resistance. Larval densities on glufosinate-treated and non-treated glufosinate-tolerant rice in field experiments did not differ; however, delayed floods reduced numbers of larvae on rice compared to those on early flooded rice.

Over three decades have passed since the completion of Moser and Blum's (1960) treatment of the ants of Louisiana. This research represents a significant contribution to and update of their work. I report the first-ever comprehensive assessment of the Louisiana Formicid fauna. More than 100 species from 38 genera and eight subfamilies are covered. This faunistic survey gives valuable data of biodiversity and macro/microhabitat selection of ant species. Included are keys to all subfamilies, genera, and species with illustrations photographs, and a regional map for each species.

The biology of Phyllophaga ephilida (Say) was studied in Louisiana with both laboratory and field experiments from 1998 through 2003. The seasonal occurrence of common adult Phyllophaga species in sweet potato growing areas was surveyed with blacklight traps. P. ephilida and P. crinita (Burmeister) were the most common species at all locations. The attractiveness of seven methyl esters of L-isoleucine and L-valine blends to P. ephilida males was evaluated in sweet potato fields in 1999 and 2000. The 100% methyl ester of L-isoleucine was significantly more attractive than all other blend ratios that were tested. The life cycle of P. ephilida in southern Louisiana was determined to be univoltine. In the laboratory, the effect of three physical factors (soil moisture, organic matter content and soil texture) on the depth of adult Phyllophaga diurnal burrowing was investigated. Soil moisture and organic matter content had a significant effect on the depth of burrowing, while soil texture did not affect burrowing depth. The feeding preference of adult P. ephilida for the foliage of eight tree species was determined in the laboratory with choice tests. Beetles exhibited a significant preference for pecan, oak and elm, with maple, and sweetgum being less preferred. Magnolia and slash pine were not fed upon at all. Pheromone traps were operated in grower fields in 2001 and 2002. Data on percent white grub injury to sweet potatoes in these fields, the proximity of traps to tree lines, and the harvest date of the crop were collected. An analysis of covariance revealed that percent white grub damaged roots was significantly affected by mean adult P. ephilida captured in pheromone traps, whereas proximity to tree lines and harvest date were not significant. The year effect was significant as were interactions between year and tree line, year and harvest date, and year and mean adult capture. The covariance model had an r-square of 0.29. A linear polynomial regression model predicting white grub damage as a function of trap catch, tree line proximity and harvest date was developed. The model had an r-square of 0.18 and estimates a damage threshold (5% root damage) of one to two P. ephilida per week in pheromone traps. The pheromone trap provides sweet potato growers with a practical means to monitor adult activity and thereby determine the peak flight period and assess the need for an insecticide application timed to coincide with beetle oviposition.

Mesynodites is the largest genus within the exclusively inquilinous (social insect-associated) histerid beetle subfamily Hetaeriinae (Insecta: Coleoptera: Histeridae). The 44 described species are systematically revised, and new taxa are described based on newly discovered species and the results of a cladistic analysis. The work was based on available type specimens representing 42 species and approximately 2500 specimens of non-type material. Phylogenetic hypotheses were based on maximum parsimony analysis of 150 morphological characters derived from a selection of Mesynodites species and representatives of related genera. This analysis confirmed that, in its current concept, Mesynodites is not a monophyletic taxon. Species included currently in Mesynodites were scattered among 11 distinct lineages. As a result, in the revised sense, Mesynodites includes only nine species, two of which are of uncertain affinities (type specimens of these species were not located). Revision of Mesynodites species in the context of the phylogenetic analysis allowed numerous taxonomic changes to the Hetaeriinae. Presentation of those changes in this dissertation does not constitute formal publication. The following taxonomic changes are introduced: two new tribes are described and all genera of Hetaeriinae, excluding 12 genera of doubtful affinities, received tribal assignments; eight new genera and three new species are described; 37 new combinations and five new synonimities are established. The phylogenetic hypothesis of relationships within Mesynodites and allies (tribe Nymphisterini) provided some insight into evolution of host use in the lineage. This group evolved with army ants (Hymenoptera: Ecitoninae) and are known to occur with several species within the genera Eciton, Labidus, Neivamyrmex and Nomamyrmex. The ancestral host genus washypothesized to be either Eciton or Labidus. Contrary to previous opinions, species in several genera of Nymphysterini live with multiple host ant genera. Two separate host switches from army ants (Nomamyrmex and possibly Neivamyrmex) to leaf cutter ants Atta are hypothesized for species in Mutodites and Mesynodites. Analysis of host use and speciation revealed a trend of 1.5-2.5 times fewer species per strictly specialized (single host genus) guest genus, and this trend was consistent across different levels of analysis (Nymphysterini, all ecitophiles and all Hetaeriinae).

Isolates of Beauveria bassiana (Balsamo) Vuillemin were tested for biological control of rice stink bug, Oebalus pugnax (Fab.), in the laboratory, in small-plot field experiments compared with conventional insecticides, and in a large-plot experiment to determine the spread and persistence of the fungus. The soil-derived isolate LRC28 was more virulent to O. pugnax adults than the rice stink bug-derived isolate RSB in a laboratory experiment. The fungal isolates did not differ from one another in reducing insect numbers or in infecting rice stink bugs in the small-plot experiments. A single application of B. bassiana reduced rice stink bug nymphs on six of nine sampling dates and adults on two of nine sampling dates from two to 10 days after application, and prevalence of the fungus was higher in the B. bassiana treatment than in controls for nymphs on four dates versus none for adults. Mixtures of B. bassiana and insecticide provided better control of rice stink bug than a single application of either material alone. Fungal epizootics lasted 17-22 days after application. High temperatures probably were the major factor limiting B. bassiana epizootics. Thus, B. bassiana has potential for integrated management programs of O. pugnax in rice, since it was moderately effective against nymphs and had an additive effect with insecticides. Greenhouse experiments were conducted to evaluate the effects of panicle age and grain maturity on quantitative and qualitative damage caused by stink bug infestations on rice. The effects were measured for two infestation levels (one and two bugs per panicle). Insect feeding during anthesis and the early milk stage of grain development caused substantially higher numbers of empty kernels than feeding during later grain development and the control. Average grain weights were lower in infestations during anthesis and milk stage than in infestations during later grain development and the control. Pecky rice was significantly higher during late milk and soft dough stages compared with remaining stages of grain development and the control. Damage was higher in the experiment in which panicles were infested with two bugs.

Interactions between sugarcane, <i>Saccharum</i> spp., and the invasive species Mexican rice borer, <i>Eoreuma loftini</i> (Dyar), were evaluated in field experiments and in the greenhouse with rice, <i>Oryza sativa</i> L., as an additional host. By determining adult emergence holes together with percent bored internodes, a novel method for evaluating sugarcane cultivar resistance was developed. In 2001, LCP 85-384 had the greatest moth production per hectare, significantly higher (P ≤ 0.05) than HoCP 85-845. High levels of sodium and magnesium salt stress in the soil were associated with higher <i>E. loftini</i> injury in all cultivars except HoCP 91-555 and CP 70-321. Irrigation reduced injury in both susceptible (LCP 85-384) and resistant (HoCP 85-845) cultivars by 2.5-fold. The combination of irrigation, plant resistance, and insecticide applications of tebufenozide decreased injury from 70% bored internodes to less than 10%. Several free amino acids essential for insect development increased in sugarcane leaves under drought stressed conditions, which exacerbated <i>E. loftini</i> infestations. Drought stressed sugarcane was 1.8-fold more attractive based on egg masses/plant than non stressed sugarcane. Based on egg masses/plant and eggs/egg mass, cultivar LCP 85-384 was more attractive than the resistant HoCP 85-845. Egg masses were 9.2-fold more abundant on sugarcane than on rice. Oviposition on sugarcane occurred exclusively on dry leaf material, and the number of dry leaves was positively correlated with egg masses per plant. Several free amino acids essential for insect development increased in sugarcane leaves under drought stressed conditions, and were highly correlated with egg masses per plant. Rice leaves, despite being less attractive for oviposition, had higher levels of free amino acids than sugarcane. Based on boundary movement monitoring with pheromone traps, the average rate of spread from 1980 (Weslaco, TX) to 2004 (Chambers County, TX) was 23.2 km/yr. From 2000 to 2004, annual mean centroids of moth trap counts moved 29.3 km, however 95% C.I. overlapped across years. Minimizing sugarcane stress will play a major role in managing this invasive pest when it becomes established in Louisiana.

In order to accurately test liquid bait effectiveness in the lab, we determined that a starvation time of 96h is more appropriate than 72h of starvation time for laboratory fire ants (Solenopsis invicta Buren) to better simulate foraging ants in the field. Densities and viscosities of two commercial baits and 20% sugar water at 25C were measured then compared to amount of material consumed per ant at these physical properties. Mean densities of 20% sugar water, Dr. Moss, and Terro were 1.051, 1.287, and 1.354 g/mL, respectively, and viscosity of each bait treatment varied in the same order but more drastically (1.7, 32, 400 centipoise, respectively). Ants that feed on formulated baits exhibit feeding behaviors different from those which occur when feeding on sugar water. At first glance, one might conclude that the difference is due to the toxicant, but our findings suggest that physical properties of baits may be a factor in this change in feeding behavior. In order to determine the effect of liquid physical properties on feeding, the method of liquid feeding was first determined. Next, sucrose solutions were prepared to test effects of viscosity and sucrose concentration on Solenopsis invicta separately. Solutions containing boric acid were also prepared to record the toxicant effect in these tests. Individual ants were offered a droplet of solution, then amount taken and time was recorded. Fire ants used suction to feed, whereas lapping movements of the glossa were not observed. Initial weight of ants explained about 40% of the variability in total crop load. Total crop load was found to depend on viscosity as well as initial ant weight. As viscosity increased in a 30% sucrose solution, relative crop load and intake rate decreased. According to these results, individual ants feeding from solutions without boric acid will leave with a total crop load that is 54% dependent on individual motivation whereas the crop load of ants feeding from a 0.5% boric acid solution only 46% depended on individual motivation. One explanation may be that boric acid solutions in this study acted as unique food sources.

The seasonal abundance and species composition of ceratopogonids (Diptera: Ceratopogonidae) in East Baton Rouge parish was described from light trap collections at 15 sites. A total of 4,968 collections were processed, and 48,667 ceratopogonids were collected from 20 November, 2002 through 25 November, 2004. Three genera of ceratopogonids (<i>Forcipomyia</i> Meigen, <i>Atrichopogon</i> Kieffer, and <i>Culicoides</i> Latrielle) and a total of 18 species of the genus <i>Culicoides</i> were identified. Ceratopogonids had distinctive spring and fall population peaks. Ceratopogonids were collected in every month during the study, with the exception of February 2004. These results suggest that certain species of <i>Culicoides</i> may overwinter as adults in Louisiana, which could provide an important maintenance mechanism for arboviruses. New information on the other four species of biting midges was obtained. This study represents the first report of <i>Culicoides edeni</i> Wirth and Blanton in Louisiana and the first description of the seasonal abundance of <i>Culicoides neopulicaris</i> Wirth in Louisiana. The data also showed that <i>Culicoides debilipalpis</i> Lutz and <i>Culicoides stellifer</i> Coquillett have longer seasonal activity periods than previously reported for Louisiana. Pools of specimens of ceratopogonids collected from the 15 sites in East Baton Rouge parish in 2004 were prepared for West Nile virus (WNV) detection assays. Eighty-nine pools with specimens of <i>Culicoides</i>, four pools with specimens of <i>Atrichopogon</i>, and two pools with specimens of <i>Forcipomyia</i> were processed. One pool containing specimens of <i>Culicoides arboricola</i> Root and Hoffman, two pools containing specimens of <i>Culicoides biguttatus</i> Coquillett, and two pools containing specimens of <i>C. stellifer</i> tested positive for WNV RNA. This is the second study in which WNV has been detected in field collected ceratopogonids in the United States. The estimated numbers of plaque-forming units (PFU) found in the pools of specimens of Culicoides were within the range of PFU found in known mosquito vectors of WNV. Based on host availability specimens of <i>C. stellifer</i>, <i>C. biguttatus</i>, and <i>C. arboricola</i> feed on both birds and/or mammals, suggesting that these species could play an important role in transmitting WNV from birds to mammals. These results indicate that the importance of biting midges as vectors of WNV should be investigated in future studies.

The Formosan subterranean termite, Coptotermes formosanus Shiraki, is responsible for over $1 billion in property damage, repairs, and control in the United States. Presently, control of this exotic pest depends mainly on chemical methods. There is an increasing interest in using natural products in pest control because of their low mammalian toxicity and environmental safety. Chemical components of the roots of vetiver grass, Vetiveria zizanioides (L.) Nash, have shown to be effective repellents and toxicants to Formosan subterranean termites. Objectives of this research were to evaluate: 1) vetiver grass root growth and its oil distribution; 2) vetiver oil, nootkatone, and tetrahydronootkatone as wood treatments; and 3) understanding alate flight biology as preventative measures against Formosan subterranean termites. The amount of vetiver oil present in the root system increased as root weight increased at each sampling date. At the final sampling period, mean root weight increased 520% from the previous sampling period. The highest vetiver root mulch to sand ratio tested was effective against Formosan subterranean termites by decreasing tunneling activity and increasing termite mortality, thus decreasing wood consumption. In field and laboratory studies, wood samples treated with 5% nootkatone or 5% tetrahydronootkatone solutions showed good potential as possible wood treatment options. These studies indicated significantly less consumption of treated wood samples verses untreated controls. Significantly higher termite mortality was observed with treated wood samples as opposed to untreated controls in the laboratory evaluation. Analysis of annual flights of the Formosan subterranean termite monitored for 16 years in New Orleans, Louisiana, indicated the timing of peak flights was non-random, suggesting a mechanism, either external or internal to the colony, triggers peak alate flights. No relationship was observed between any of the extrinsic factors tested in relation to the largest flight of the year. A degree day model was constructed to aid in predicting each years largest Formosan subterranean termite flight, which indicated peak flights did not occur before an average of 2611 heat units had accumulated.