Digital Commons Network^™

Trapping Phyllophaga Spp. (Coleoptera: Scarabaeidae: Melolonthinae) In The United States And Canada Using Sex Attractants., Paul S. Robbins, Steven R. Alm, Charles D. Armstrong, Anne L. Averille, Thomas C. Baker, Robert J. Bauernfiend, Frederick P. Baxendale, S. Kris Braman, Rick L. Brandenburg, Daniel B. Cash, Gary J. Couch, Richard S. Cowles, Robert L. Crocker, Zandra D. Delamar, Timothy G. Dittl, Sheila M. Fitzpatrick, Kathy L. Flanders, Tom Forgatsch, Timothy J. Gibb, Bruce D. Gill, Daniel O. Gilrein, Clyde Gorsuch, Abner M. Hammond, Patricia D. Hastings, David W. Held, James L. Holliman, William G. Hudson, Michael G. Klein, Vera L. Krischik, David J. Lee, Charles E. Linn Jr., Nancy J. Luce, Kenna Mackenzie, Catherine M. Mannion, Sridhar Polavarapu, Daniel A. Potter, Daniel A. Potter, Wendell Roelofs, Brian M. Royals, Glenn A. Salsbury, Nathan M. Schiff, David J. Shetlar, Margaret Skinner, Beverly L. Sparks, Jessica A. Sutschek, Timothy P. Sutschek, Stanley R. Swier, Martha M. Sylvia, Neil J. Vickers, Patricia A. Vittum, Richard Weidman, Donald C. Weber, R. Chris Williamson, Michael G. Villani

Department of Entomology: Faculty Publications

The sex pheromone of the scarab beetle, Phyllophaga anxia, is a blend of the methyl esters of two amino acids, L-valine and L-isoleucine. A field trapping study was conducted, deploying different blends of the two compounds at 59 locations in the United States and Canada. More than 57,000 males of 61 Phyllophaga species (Coleoptera: Scarabaeidae: Melolonthinae) were captured and identified. Three major findings included: (1) widespread use of the two compounds [of the 147 Phyllophaga (sensu stricto) species found in the United States and Canada, males of nearly 40% were captured]; (2) in most species intraspecific male …

Laboratory Environment Effects On The Reproduction And Mortality Of Adult Screwworm (Diptera: Calliphoridae), Dennis Berkebile, Agustin Sagel, Steven R. Skoda, John E. Foster

Department of Entomology: Faculty Publications

The New World screwworm, Cochliomyia hominivorax Coquerel, is mass reared for screwworm eradication initiatives that use the sterile insect technique. New methods for rearing have helped to reduce the cost of the eradication program. We examined the effect and interaction of three temperatures (24.5, 29.5 and 34.5ºC), two diets (2% spray-dried blood plus 0.05% vitamins and corn syrup carrageenan) and three population densities (300, 400, and 500 flies/cage) on egg production, egg hatch, number of observable fertilized eggs, mortality (male and female) and ovarian development. The three population densities did not affect any of the parameters monitored. Using the protein …

Comparative Sensitivity Of Freshwater Algae To Atrazine, C. K. Lockert, Kyle D. Hoagland, Blair D. Siegfried

Department of Entomology: Faculty Publications

Widespread use of environmentally persistent herbicides has led to increasing concern over their impact on aquatic ecosystems and nontarget organisms. The triazine herbicide atrazine (6-chloro-N-ethyl-N ¹1-[1-methylethyl]-1,3,5-triazine-2,4- diamine) remains one of the most heavily used pesticides worldwide, and was the second most commonly used conventional pesticide in the U.S. agricultural market in 2001. Atrazine is an S-triazine herbicide that targets the photosynthetic process to control broadleaf weeds. Due to the moderate solubility (33 mg/L at 22°C) and relative persistence of atrazine in water (Solomon et al. 1996), contamination of surface waters as a result of non-point source …

Acute Contact Toxicity Of Oxalic Acid To Varroa Destructor (Acari: Varroidae) And Their Apis Mellifera (Hymenoptera: Apidae) Hosts In Laboratory Bioassays, Nicholas P. Aliano, Marion D. Ellis, Blair D. Siegfried

Department of Entomology: Faculty Publications

Laboratory bioassays were performed to characterize the acute contact toxicity of oxalic acid (OA) to Varroa destructor (Anderson & Trueman) and their honey bee hosts (Apis mellifera L.). Specifically, glass-vial residual bioassays were conducted to determine the lethal concentration of OA for V. destructor, and topical applications of OA in acetone were conducted to determine the lethal dose for honey bees. The results indicate that OA has a low acute toxicity to honey bees and a high acute toxicity to mites. The toxicity data will help guide scientists in delivering optimum dosages of OA to the parasite and …

Host Preference Of The Chinch Bug, Blissus Occiduus, Thomas Eickhoff, Frederick P. Baxendale, Tiffany Heng-Moss

Department of Entomology: Faculty Publications

The chinch bug, Blissus occiduus Barber (Hemiptera: Blissidae), is an important pest of buffalograss, Buchloë dactyloides (Nutall) Engelmann and potentially other turfgrass, crop, and non-crop hosts. Choice studies documented the number of B. occiduus present on selected turfgrasses, crops and weeds, and provided important insights into the host preferences of this chinch bug. Grasses with the most chinch bugs present included the warm-season turfgrasses B. dactyloides, zoysiagrass, Zoysia japonica Steudel, bermudagrass, Cynodon dactylon (L.) Pers., and St. Augustinegrass , Stenotaphrum secundatum (Walt.) Kuntze. The other grasses tested, green foxtail, Setaria viridis (L.) Beauv, Kentucky bluegrass, Poa pratensis L., perennial …

Analyses Of Cry1ab Binding In Resistant And Susceptible Strains Of The European Corn Borer, Ostrinia Nubilalis (Hubner) (Lepidoptera: Crambidae), Herbert A.A. Siquiera, Joel Gonzalez-Cabrera, Juan Ferre, Ronald Flannagan

Department of Entomology: Faculty Publications

Cry1Ab toxin binding analysis was performed to determine whether resistance in laboratory-selected Ostrinia nubilalis strains is associated with target site alteration. Brush border membrane vesicles were prepared using dissected midguts from late instars of susceptible and resistant strains (Europe-R and RSTT) of O. nubilalis. Immunoblot analysis indicated that three different proteins bound to Cry1Ab toxin and were recognized by an anticadherin serum. In a comparison of resistant and susceptible strains, reduced Cry1Ab binding was apparent for all three bands corresponding to cadherin-like proteins in the Europe-R strain, while reduced binding was apparent in only one band for the RSTT …

Xenobiotic Response In Drosophila Melanogaster: Sex Dependence Of P450 And Gst Gene Induction, Gaelle Le Goff, Frederique Hilliou, Blair Siegfried, Sam Boundy, Eric Wajnberg, Luc Sofer, Pascaline Audant, Richard H. Ffrench-Constant, Rene Feyereisen

Department of Entomology: Faculty Publications

The effect of xenobiotics (phenobarbital and atrazine) on the expression of Drosophila melanogaster CYP genes encoding cytochromes P450, a gene family generally associated with detoxification, was analyzed by DNA microarray hybridization and verified by real-time RT-PCR in adults of both sexes. Only a small subset of the 86 CYP genes was significantly induced by the xenobiotics. Eleven CYP genes and three glutathione S-transferases (GST) genes were significantly induced by phenobarbital, seven CYP and one GST gene were induced by atrazine. Cyp6d5, Cyp6w1, Cyp12d1 and the ecdysone-inducible Cyp6a2 were induced by both chemicals. The constitutive expression of several of the inducible …

Comparative Efficiency Of Six Stable Fly (Diptera: Muscidae) Traps, David B. Taylor, Dennis Berkebile

Department of Entomology: Faculty Publications

Five adhesive traps and the Nzi cloth-target trap were compared to determine their trapping efficiency and biases for stable flies, Stomoxys calcitrans (L.) (Diptera: Muscidae). Two configurations of the BiteFree prototype trap, constructed of polyethylene terephthalate, were most efficient for trapping stable flies, whereas the EZ trap was least efficient. The two Alsynite traps, Broce and Olson, were intermediate to the BiteFree prototype and EZ traps. All adhesive traps collected a ratio of approximately two males for each female. Approximately 50% of the flies collected on the adhesive traps, both male and female, were blood fed, and 20% were vitellogenic. …

Coordinated Diabrotica Genetics Research: Accelerating Progress On An Urgent Insect Pest Problem, Thomas W. Sappington, Blair D. Siegfried, Thomas Guillemaud

Department of Entomology: Faculty Publications

Diabrotica spp. (western, northern, and Mexican corn rootworms) represent the main pest complex of continuous field corn, Zea mays (L.), in North America. The western corn rootworm, Diabrotica virgifera virgifera LeConte, also has become the main pest of continuous corn in Central and Southeastern Europe since its introduction near Belgrade 15–20 years ago, and it represents a major risk to Western Europe. It has already caused economic losses in Eastern Europe, and Western countries such as France have committed large expenditures for containment and/or eradication.

Rootworm larvae feed on corn roots, and damaged plants are more susceptible to drought and …

Effects Of Aphid (Homoptera) Abundance And Surrounding Vegetation On The Encounter Rate Of Coccinellidae (Coleoptera), Chrysopidae (Neuroptera), And Nabidae (Hemiptera) In Alfalfa, James C. Kriz, Stephen D. Danielson, James R. Brandle, Erin E. Blankenship, Geoff M. Henebry

Department of Entomology: Faculty Publications

Predaceous insect encounter rate was measured in 21 southeast Nebraska alfalfa fields through weekly sweep net sampling during 2002-03. The most frequently encountered predaceous insect families were Coccinellidae (Coleoptera), Nabidae (Hemiptera), and Chrysopidae (Neuroptera). The study used multiple regression analysis to examine the effect of aphid abundance and the surrounding vegetative patch composition on predaceous insect abundance. In 2002, Hippodamia parenthesis Say was encountered more frequently in fields with lower aphid abundances, and Hippodamia convergens Guerin-Meneville, Coccinella septempunctata L., and Nabis americoferus Carayon were encountered more frequently in fields with higher aphid abundances. In 2003, Coleomegilla maculata DeGeer was encountered …

Effect Of Bacillus Thuringiensis Cry3bb1 Protein On The Feeding Behavior And Longevity Of Adult Western Corn Rootworms (Coleoptera: Chrysomelidae), Timothy M. Nowatski, Xugou Zhou, Lance J. Meinke, Ty Vaughn, Blair Siegfried

Department of Entomology: Faculty Publications

The first transgenic corn hybrids expressing the Bacillus thuringiensis (Bt) Cry3Bb1 protein to control corn rootworm (Diabrotica spp.) larvae were registered for commercial use in 2003. This study was conducted to investigate the effect of Cry3Bb1 protein in combination with a cucurbitacin bait on adult feeding and longevity of both organophosphate-resistant and -susceptible western corn rootworms, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae). In choice and no-choice tests, possible repellency to the Bt protein was quantified by comparing beetle consumption of cellulose disks treated with three concentrations of Bt in combination with a feeding stimulant (Invite EC) to disks treated …

Microbial Decomposition Of Skeletal Muscle Tissue (Ovis Aries) In A Sandy Loam Soil At Different Temperatures, David O. Carter, Mark Tibbett

Department of Entomology: Faculty Publications

A laboratory experiment was conducted to determine the effect of temperature (2, 12, 22 °C) on the rate of aer­obic decomposition of skeletal muscle tissue (Ovis aries) in a sandy loam soil incubated for a period of 42 days. Measurements of decomposition processes included skeletal muscle tissue mass loss, carbon dioxide (CO₂) evo­lution, microbial biomass, soil pH, skeletal muscle tissue carbon (C) and nitrogen (N) content and the calcula­tion of metabolic quotient (qCO₂). Incubation temperature and skeletal muscle tissue quality had a significant effect on all of the measured process rates with 2 °C …

Pyemotes Herfsi (Acari: Pyemotidae), A Mite New To North America As The Cause Of Bite Outbreaks, Alberto B. Broce, Ludek Zurek, James A. Kalisch, Robert Brown, David L. Keith, David Gordon, Janis Goedeke, Cal Welbourn, John Moser, Ronald Ochoa, Eduardo Azziz-Baumgartner, Fuyuen Yip, Jacob Weber

Department of Entomology: Faculty Publications

High incidences of red, itching, and painful welts on people in the midwestern United States led to the discovery of a European species of mite, Pyemotes herfsi (Oudemans) (Acari: Pyemotidae), preying on gall-making midge larvae on oak leaves. The mites' great reproductive potential, small size, and high capacity for dispersal by wind make them difficult to control or avoid.

Assessing Risk Of Resistance To Aerial Applications Of Methyl-Parathion In Western Corn Rootworm (Coleoptera: Chrysomelidae), Michael A. Caprio, Tim Nowatski, Blair Siegfried, Lance J. Meinke, Robert J. Wright, Larry D. Chandler

Department of Entomology: Faculty Publications

We validated a stochastic model of the evolution of resistance to adulticidal sprays of methyl-parathion in western corn rootworm, Diabrotica virgifera virgifera LeConte, populations in Nebraska. The population dynamics predicted by the model resembled that reported for field populations, and time until control failures occurred closely matched reports by commercial crop consultants. We incorporated uncertainty about the values used for 18 model parameters by replacing default values with random draws taken from a normal distribution. One parameter, the initial resistance allele frequency, was no longer measurable because of the evolution of resistance. We therefore proposed five candidate initial allele frequencies …

Inheritance Of Resistance To The Cry1ab Bacillus Thuringiensis Toxin In Ostrinia Nubilalis (Lepidoptera: Crambidae), Analiza P. Alves, Terrence A. Spencer, B.E. Tabashnik, Blair Siegfried

Department of Entomology: Faculty Publications

Laboratory selection with Cry1Ab, the predominant Bacillus thuringiensis (Bt) toxin in transgenic corn, Zea mays L., produced >1000-fold resistance in two laboratory strains of European corn borer, Ostrinia nubilalis (Hubner). We tested the offspring of various crosses to determine the mode of inheritance of resistance to Cry1Ab. Patterns of inheritance of resistance were similar in the two resistant strains. The progeny of reciprocal F₁ crosses (resistant male x susceptible female and vice versa) responded alike in bioassays, indicating autosomal inheritance. The median lethal concentrations (LC₅₀ values) of F₁ were intermediate between the resistant and susceptible parents, indicating …

Effect Of Investigator Disturbance In Experimental Forensic Entomology: Succession And Community Composition, G. D. De Jong, W. W. Hoback

Department of Entomology: Faculty Publications

Carrion insect succession studies have historically used repeated sampling of single or a few carcasses to produce data, either weighing the carcasses, removing a qualitative subsample of the fauna present, or both, on every visit over the course of decomposition and succession. This study, conducted in a set of related experimental hypotheses with two trials in a single season, investigated the effect that repeated sampling has on insect succession, determined by the number of taxa collected on each visit and by community composition. Each trial lasted at least 21 days, with daily visits on the first 14 days. Rat carcasses …

Creating & Evaluating Artificial Domiciles For Bumble Bees, Douglas A. Golick, Marion D. Ellis, Brady Beecham

Department of Entomology: Faculty Publications

Most biologists agree that the availability of suitable nesting sites is a limiting factor for bumble bee populations (Free, 1959). Bumble bees always select areas with preexisting insulation for nesting. Fur-lined abandoned rodent dens are especially attractive, but occasionally, abandoned man-made materials are inhabited. It is not rare to find multiple dead queens in a nest indicating that they have fought for ownership.

Despite our knowledge of bumble bee nest site selection, most efforts to attract bumble bees to artificial domiciles have been met with limited success (Fye & Medler, 1954; Hobbs et al.,1960). Creating and evaluating artificial domiciles provides …

Movement Of Cicindela Hirticollis Say Larvae In Response To Moisture And Flooding, Mathew L. Brust, William Wyatt Hoback, Kerri Farnsworth Skinner, Charles Barry Knisley

Department of Entomology: Faculty Publications

The larvae of the tiger beetle, Cicindela hirticollis Say, inhabit sandy shoreline areas that flood periodically. This species has declined over much of its range and at least one subspecies is near extinction, possibly as a result of human alteration of waterways. In addition to physiological tolerance for anoxia, the larvae have physical and behavioral adaptations to avoid drowning. We hypothesized that C. hirticollis larvae would exhibit behavioral responses to soil moisture change and flooding because, unlike most other tiger beetles, they frequently relocate their burrows. Our laboratory studies demonstrated that larvae select surface soil moisture levels of 7–50% saturation …

Physiological Responses Of Resistant And Susceptible Buffalograsses To Blissus Occiduus (Hemiptera: Blissidae) Feeding, Tiffany Heng-Moss, Tulio Macedo, Lisa Franzen-Castle, Frederick P. Baxendale, Leon G. Higley, Gautam Sarath

Department of Entomology: Faculty Publications

The impact of Blissus occiduus Barber feeding on resistant (‘Prestige’) and susceptible (‘378’) buffalograsses, Buchloe dactyloides (Nuttall) Engelmann, was evaluated through measurement of carbon exchange rate, light and carbon assimilation (A-C) curves, chlorophyll a fluorescence, and nonstructural carbohydrates. No significant differences in carbon exchange rates were observed between infested and control plants for 378 at 5 and 10 d after infestation; however, at 20 d after chinch bug introduction, significant differences in carbon exchange rates between infested and control 378 plants were detected. Carbon exchange rates were similar between infested and control Prestige plants at 5, 10, and 20 d …

Evaluation Of Cool- And Warm-Season Grasses For Resistance To Multiple Chinch Bug (Hemiptera: Blissidae) Species, Wyatt G. Anderson, Tiffany Heng-Moss, Frederick P. Baxendale

Department of Entomology: Faculty Publications

Chinch bugs are common pests of many agronomic and horticulturally important crops and turfgrasses. The extensive overlap of plant hosts and geographic distribution of Blissus leucopterus leucopterus (Say), Blissus leucopterus hirtus Montandon, Blissus insularis Barber, and Blissus occiduus Barber underscores the importance of identifying resistant germplasm. Cool- and warm-season turfgrasses and sorghum, Sorghum bicolor (L.) Moench, were evaluated for resistance to chinch bugs in the Blissus complex, and the presence of multiple resistance was documented. Greenhouse studies established that B. occiduus-resistant (‘Prestige’, formerly NE91-118) and -susceptible (‘378’) buffalograsses, , Buchloe dactyloides (Nuttall) Engelmann, were susceptible to all other chinch …

Stability And Persistence Of Aldrin And Methyl-Parathion Resistance In Western Corn Rootworm Populations (Coleoptera: Chrysomelidae), Srinivas Parimi, Lance J. Meinke, B. Wade French, Laurence D. Chandler, Blair D. Siegfried

Department of Entomology: Faculty Publications

The susceptibilities of laboratory and field-collected western corn rootworm populations (Diabrotica virgifera virgifera LeConte) to methyl-parathion and aldrin were estimated by topical application of insecticide during 2002 to determine the stability of resistance in the absence of selective pressures. Most of the laboratory-reared and field-collected populations were significantly resistant to both insecticides. Average LD ₅₀ values of laboratory and field-collected populations were 19- and 13-fold greater than the susceptible population in methyl-parathion bioassays, respectively, and 204- and 125-fold greater in the aldrin bioassays, respectively. The presence of aldrin and methyl-parathion resistance in field-collected populations strongly suggests that both resistance …

Genetic Analysis Of Resistance To European Corn Borer (Ostrinia Nubllalls Hub. Lepidoptera:Crambidae) Damage In Eight Maize Germplasm, Cengis Ikten, John E. Foster

Department of Entomology: Faculty Publications

The inheritance of resistance to Oslrinia nubilalis (ECB) damage in eight breeding maize lines was studied by Griffing's diallel analysis (Griffing 1956) under two water regimes. One hundred fifty neonate larvae of second generation of ECB were infested around ear node of maize germplasm and approximately two months later, the potentials of the germplasm were determined by measuring stalk and shank tunneling damage in plants. General combining ability (GCA) was more important than specific combining ability (SCA) in determining resistance to both stalk and shank tunneling. Although mean squares for GCA accounted for 76.1% of the variation for stalk tunneling …

Relative Index Of Susceptibility To The Maize Weevil, Sitophilus Zeamais, Among Some Qpm Corn Lines, Jamilton P. Santos, Paulo E. O. Guimaraes, Jose M. Waquil, John E. Foster

Department of Entomology: Faculty Publications

The maize weevil, Sitophilus zeamais, is one important pest of stored corn grain. It is difficult to control and causes large weight and nutritional losses to the grains. The discovery of the gene Opaque-2 (O-2) that enhances the protein quality with Lysine and Tryptophane opened new perspectives to use corn to feed monogastric animals and for human nutrition. However, the soft and farinaceous consistency of the endosperm in the O-2 gene corn increased the susceptibility to maize weevil. To solve this problem the O-2 gene was transferred to normal corn. This new corn was called Quality Protein Maize (QPM). …

Relative Abundance Of Exotic And Native Coccinellidae (Coleoptera) In Southeast Nebraska Alfalfa, James C. Kriz, Stephen D. Danielson, James R. Brandle, Erin E. Blankenship

Department of Entomology: Faculty Publications

The seven-spotted lady beetle, Coccinella septempunctata L., and the multicolored Asian lady beetle, Harmonia axyridis Pallas, are exotic Coccinellidae (Coleoptera) that are regularly encountered in southeastern Nebraska. Harmonia axyridis, a native of eastern Asia, was first reported in an established population near Abita Springs, St. Tammay Parish, Louisiana, in 1988. It was hypothesized that the introduction was accidental through commerce in Louisiana and not from introduction for biological control. Coccinella septempunctata, a native of Eurasia, was introduced for biological control several times and at a variety of locations across North America during the last century. As is the case …

Analyses Of Cry1ab Binding In Resistant And Susceptible Strains Of The European Corn Borer, Ostrinia Nubilalis (Hübner) (Lepidoptera: Crambidae), Herbert A. A. Siqueira, Joel Gonzalez-Cabrera, Juan Ferre, Ronald Flannagan, Blair Siegfried

Department of Entomology: Faculty Publications

Cry1Ab toxin binding analysis was performed to determine whether resistance in laboratory-selected Ostrinia nubilalis strains is associated with target site alteration. Brush border membrane vesicles were prepared using dissected midguts from late instars of susceptible and resistant strains (Europe-R and RSTT) of O. nubilalis. Immunoblot analysis indicated that three different proteins bound to Cry1Ab toxin and were recognized by an anticadherin serum. In a comparison of resistant and susceptible strains, reduced Cry1Ab binding was apparent for all three bands corresponding to cadherin-like proteins in the Europe-R strain, while reduced binding was apparent in only one band for the RSTT …

An Update On The Distribution And Diversity Of Bombus In Nebraska (Hymenoptera: Apidae), Douglas A. Golick, Marion D. Ellis

Department of Entomology: Faculty Publications

From 1999–2002, the University of Nebraska Department of Entomology, Folsom’s Children Zoo, and Lincoln Public Schools Science Focus High School initiated a program called Bumble Boosters. Forty schools participated to conduct a general survey of Nebraska bumble bees to: 1) determine whether the 20 species of bumble bees previously identified can still be found in Nebraska, 2) collect in areas that were not included in previous surveys, and 3) discover any additional species in the state. This study provides an update to previous surveys including; new distribution maps for species, and a discussion of findings.

Spatiotemporal Patterns Of Host-Seeking Ixodes Scapularis Nymphs (Acari: Ixodidae) In The United States, M. A. Diuk-Wasser, A. G. Gatewood, M. Roberto Cortinas, S. Yaremych-Hamer, J. Tsao, Uriel Kitron, G. Hickling, J. S. Brownstein, E. Walker, J. Piesman, D. Fish

Department of Entomology: Faculty Publications

The risk of Lyme disease for humans in the eastern United States is dependent on the density of host-seeking Ixodes scapularis Say nymphal stage ticks infected with Borrelia burgdorferi. Although many local and regional studies have estimated Lyme disease risk using these parameters, this is the first large-scale study using a standardized methodology. Density of host-seeking I. scapularis nymphs was measured by drag sampling of closed canopy deciduous forest habitats in 95 locations spaced among 2° quadrants covering the entire United States east of the 100th meridian. Sampling was done in five standardized transects at each site and repeated …

Long-Term Reduction Of Trypanosoma Cruzi Infection In Sylvatic Mammals Following Deforestation And Sustained Vector Surveillance In Northwestern Argentina, L. A. Ceballos, M. V. Cardinal, G. M. Vazquez-Prokopec, M. A. Lauricella, M. M. Orozco, M. Roberto Cortinas, A. G. Schijman, M. J. Levin, Uriel Kitron, R. E. Gürtlera

Department of Entomology: Faculty Publications

Long-term variations in the dynamics and intensity of sylvatic transmission of Trypanosoma cruzi were investigated around eight rural villages in the semiarid Argentine Chaco in 2002–2004 and compared to data collected locally in 1984–1991. Of 501 wild mammals from 13 identified species examined by xenodiagnosis, only 3 (7.9%) of 38 Didelphis albiventris opossums and 1 (1.1%) of 91 Conepatus chinga skunks were infected by T. cruzi. The period prevalence in opossums was fourfold lower in 2002–2004 than in 1984–1991 (32–36%). The infection prevalence of skunks also decreased five-fold from 4.1–5.6% in 1984–1991 to 1.1% in 2002–2004. Infection in opossums increased …

Effects Of Insect Herbivory On Physiological And Biochemical (Oxidative Enzyme) Responses Of The Halophyte Atriplex Subspicata (Chenopodiaceae), P. D. Nabity, Tiffany Heng-Moss, Leon G. Higley

Department of Entomology: Faculty Publications

Physiological responses of the halophyte, Atriplex subspicata Nutt. Rydb., to defoliation injury were evaluated through a series of experiments measuring plant gas exchange, fluorometry, and enzyme activity. Leaves exposed to simulated insect herbivory exhibited reductions in photosynthesis, stomatal conductance, and transpiration. Carboxylation efficiency, maximum assimilation, and CO₂ compensation were also negatively associated with mechanical leaf injury. Insect injury by a herbivore generalist, Spilosoma virginica, also reduced photosynthesis and carboxylation efficiency within the saturated spectrum of A/C_i response curves. Initially, declines in photosynthesis occurred because of transient stomatal limitations. However, after time, mesophyll limitations impaired photosynthesis and the …

Oil-Soluble Dyes For Marking Spodoptera Frugiperda (Lepidoptera: Noctuidae), Elis Christine Vilarinho, Odair Aparecido Fernandes, Celso Omoto, Thomas E. Hunt

Department of Entomology: Faculty Publications

Although various biological aspects of Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) have been examined, adult movement and dispersal of this insect pest is not well understood. Release-recapture techniques by using marked insects is a useful approach for dispersal studies; however, the marking technique should not significantly affect insect biology or behavior. Therefore, the effect of different concentrations of oil-soluble dyes (Solvent Blue 35 [C.I. 61554], Sudan Red 7B [C.I. 26050], Sudan Black B [26150], Sudan Orange G [C.I. 11920], and Sudan I 103624 [C.I. 12055]) on development, mortality, and fecundity of S. frugiperda was evaluated. Dyes were added to artificial …