Life Sciences Commons^™

Parasitism Of Greenbugs (Homoptera: Aphididae) By Lysiphlebus Testaceipes (Hymenoptera: Braconidae) In Grain Sorghum: Implications For Augmentative Biological Control, Odair A. Fernandes, Robert J. Wright, Z. B. Mayo

Department of Entomology: Faculty Publications

Field cage studies were conducted to describe the relationship between the percentage of Lysiphlebus testaceipes (Cresson) parasitism (as measured by aphid mummies) and densities of greenbug, Schizaphis graminum Rondani, on grain sorghum, Sorghum bicolor L. In 1993 and 1994, a biotype E-susceptible grain sorghum hybrid was grown in field cages and L. testaceipes adults were released after each plant was infested with 20 biotype E greenbugs. The release rates were 0, 0.5, 1.0, and 2.0 wasps per plant in 1993, and 0, 0.16, 0.33, and 0.5 wasps per plant in 1994. Greenbugs and mummies were counted 1-2 times a week …

Beneficial Arthropods Associated With Buffalograss, Tiffany Heng-Moss, Frederick P. Baxendale, Terrance P. Riordan

Department of Entomology: Faculty Publications

Beneficial arthropods collected from buffalograss, Buchloe dactyloides (Nuttall) Engelmann, evaluation plots and vegetatively established buffalograss lawns included predatory ants, spiders, ground beetles, rove beetles, big-eyed.bugs, and several species of hymenopterous parasitoids. Ants and spiders were the most abundant beneficial arthropods collected, representing 84% of the total beneficial arthropods captured. Pitfall traps collected >2.5 times as many (16,094) beneficial arthropods as sod plug samples (6,054), demonstrating that pitfall traps are a more effective technique than sod plugs for capturing highly mobile surface-dwelling arthropods. Families of parasitoids captured on sticky traps during the 2-yr sampling period included Scelionidae, Encyrtidae, Mymaridae, and Trichogrammatidae. …

Supplement To: Bt Corn & European Corn Borer: Long-Term Success Through Resistance Management, Ncr-602, Regional Research Committee, Nc 205

Department of Entomology: Faculty Publications

1. NC-205 is a regional research committee supported by Land Grant Universities, USDA-CSREES and ARS. It is comprised of scientists from 20 states, Mexico and Canada who have conducted research on stalk-boring pests since 1954.

2. The Committee re-examined many of the assumptions upon which our previous scientific assessments were based. This update http://ent.agri.umn.edu/ecb/nc205doc.htm summarizes our scientific understanding and recommendations for resistance management of Bt corn. Our initial recommendations were published in North Central Regional Publication 602 during 1997. An electronic version of NCR-602 is located at http://www.extension.umn.edu/Documents/D/C/DC7055.html.

3. The Committee reaffirmed, as a premise, the importance of prolonging the …

Adult Susceptibility Of Nebraska Western Corn Rootworm (Coleoptera: Chrysomelidae) Populations To Selected Insecticides, Lance . J. Meinke, Blair D. Siegfried, Robert J. Wright, Laurence D. Chandler

Department of Entomology: Faculty Publications

Topical bioassays were conducted in 1995 to estimate the susceptibility of adult western corn rootworm, Diabrotica virgifera virgifera LeConte, populations from Nebraska to technical grade methyl parathion, carbaryl, and bifenthrin. Significant differences in susceptibility occurred among populations for each insecticide. The largest relative differences in LD₅₀ values between the most tolerant and susceptible field populations were 16.4- and 9.4-fold for methyl parathion and carbaryl, respectively. The F₁ colonies also exhibited significant differences in susceptibility to methyl parathion and carbaryl indicating that susceptibility traits are heritable. The response to bifenthrin (up to 4-fold difference in LD₅₀ values) was …

Uptake And Bioconcentration Of Atrazine By Selected Freshwater Algae, Jixin Tang, Kyle D. Hoagland, Blair Siegfried

Department of Entomology: Faculty Publications

Atrazine bioconcentration and uptake were determined for eight freshwater green algae and diatoms. Atrazine uptake was extremely rapid in all species examined, with nearly 90% of total uptake occurring within the first hour of exposure. Within each division, different species had different bioconcentration capacities, although the accumulation of atrazine was consistently higher in green algae (5.43–12.73 ng/mg) than in diatoms (0.33–1.69 ng/mg). Atrazine concentrations in the algal cells were much higher than in the medium, although the total amount of atrazine taken up by algae was small relative to the total atrazine in solution (1–3%). The ability of algal cells …

Effects Of Preservation Methods, Parasites, And Gut Contents Of Black Flies (Diptera: Simuliidae) On Polymerase Chain Reaction Products, D. A. Koch, G. A. Duncan, T. J. Parsons, K. P. Pruess, T. O. Powers

Department of Entomology: Faculty Publications

Molecular analysis of biological specimens usually requires extraction of high-molecular-weight DNA free of foreign DNA contaminants. DNA was extracted from black flies at different life stages that had been preserved by 4 methods: larvae and adults in ethanol, larvae in Carnoy’s solution, adults on card-points, and adults hand-swatted and sun-dried. Using specific primers for the mitochondrial ND4 gene, a 257-bp amplicon was obtained from specimens preserved by ethanol, card-point mounting, and sun-drying. Successful amplification often required DNA dilutions ≥ 1:20 (<1–10 ng). DNA from specimens preserved in Carnoy’s solution (ethanol: acetic acid, 3:1) yielded degraded DNA, resulting in fewer successful amplifications. Parasitic nematodes and, to a lesser extent, gut contents resulted in extra products when amplified with randomly amplified polymorphic DNA (RAPD) primers. Sufficient DNA was extracted from the head of a larva for a successful polymerase chain reaction (PCR), eliminating the need to remove the contaminating gut and parasites.

New Species, Combinations, Synonymies, And Records Of Clytini (Coleoptera: Cerambycidae), Osvaldo R. Di Iorio

Department of Entomology: Faculty Publications

Megacyllene (Megacyllene) cryptofrasciata n. sp. from Argentina is described and illustrated. M. quinquefasciata (Melzer, 1931), and Megacyllene rotundicollis Zajciw, 1963 are transferred from the subgenus Megacyllene Casey 1912 to Sierracyllene Tippmann, 1960. Megacyllene (Sierrocyllene) tafivallensis n. sp. is described from northwestern Argentina. Dexithea spixii (Laporte & Gory, 1836), and Plagionotus latreillei (Laporte & Gory, 1836) are transferred to Megacyllene (sensu stricto), excluding Dexithea, and Plagionotus from the South American fauna of Clytini. Neoclytus famelicus(Burmeister, 1865) is synonymized with N. ypsilon Chevrolat, 1861. Additional new records of Clytini from Argentina, Paraguay, and Ecuador are also presented here. A …

Identification Of Mealybug- (Homoptera: Pseudococcidae) Resistant Turf-Type Buffalograss Germplasm, Jennifer Johnson-Cicalese, Frederick P. Baxendale, Terrance P. Riordan, Tiffany Heng-Moss

Department of Entomology: Faculty Publications

Two species of mealybugs, Tridiscus sporoboli (Cockerell) and Trionymus sp., have emerged as potentially serious pests of turf-type buffalograss, Buchloë dactyloides (Nuttall) Engelmann. Sixty-two buffalograss selections were screened for resistance to these mealybugs in 4 greenhouse trials. Using a 1-6 rating scale (1 = no signs of mealybugs, 6 = >75% of tillers infested), 'Prairie' and '609' showed high levels of resistance to mealybugs, whereas several experimental selections, including 90-157,84-512 and 84-412, exhibited moderate resistance. Most selections were moderately susceptible, and 85-97 was highly susceptible with almost every tiller infested and plants near death. In field tests, mealybug infestations were …

Genetic Variation In North American Black Flies In The Subgenus Psilopelmia (Simulium: Diptera: Simuliidae), Jianming Tang, John K. Moulton, Kenneth Pruess, Eddie W. Cupp, Thomas R. Unnasch

Department of Entomology: Faculty Publications

Resolution of the genetic heterogeneity of closely related insect species depends on the selection of reliable genetic markers derived from representative specimens. We report the results of a survey of genetic variability in nine species of black flies in the subgenus Psilopelmia Enderlein. Three regions of the mitochondrial genome and an amplicon including the internal transcribed spacer 1 of the nuclear ribosomal RNA gene cluster (ITS1) were amplified using the polymerase chain reaction (PCR), and the amplicons were examined for intraspecific and interspecific polymorphisms. Six of the seven Psilopelmia species that yielded PCR products in the ITS1 PCR reaction were …

Susceptibility Of House Fly (Diptera: Muscidae) Larvae To Entomopathogenic Nematodes (Rhabditida: Heterorhabditidae, Steinernematidae, David B. Taylor, Allen L. Szalanski, Byron J. Adams, Richard D. Peterson Ii

Department of Entomology: Faculty Publications

The potential for entomopathogenic nematodes to control flies in cattle feedlots was determined by screening 40 strains representing 8 species of Heterorhabditis Poinar and 5 species of Steinernema Travassos for virulence toward 3rd-instar house flies (maggots), Musca domestica L. None of the 22 strains of Heterorhabditis infecting maggots caused significant levels of mortality in a filter paper assay. Ten strains of Steinernema infected maggots, of which 7 strains--4 S. carpocapsa (Weiser), 2 S. feltiae (Filipjev), and 1 S. scapterisci (Nguyen & Smart) caused significant mortality. Ten Heterorhabditis strains and 10 Steinernema strains successllly reproduced for 22 generations in maggots. No …

Susceptibility Of House Fly (Diptera: Muscidae) Larvae To Entomopathogenic Nematodes (Rhabditida: Heterorhabditidae, Steinernematidae), David B. Taylor, Allen L. Szalanski, Byron J. Adams, Richard D. Peterson Ii

Department of Entomology: Faculty Publications

The potential for entomopathogenic nematodes to control flies in cattle feedlots was determined by screening 40 strains representing 8 species of Heterorhabditis Poinar and 5 species of Steinemema Travassos for virulence toward 3rd-instar house flies (maggots), Musca domestica L. None of the 22 strains of Heterorhabditis infecting maggots caused significant levels of mortality in a filter paper assay. Ten strains of Steinemema infected maggots, of which 7 strains (4 S. carpocapsae (Weiser), 2 S.feltiae (Filipjev), and 1 S. scapterisci Nguyen & Smart) caused significant mortality. Ten Heterorhabditis strains and 10 Steinemema strains successfully reproduced for ≥ 2 generations in maggots. …

Sunflower Resistance To The Red Sunflower Seed Weevil (Coleoptera: Curculionidae), Huihua Gao, Gary J. Brewer

Department of Entomology: Faculty Publications

The red sunflowerseed weevil, Smicronyx fulvus LeConte (Coleoptera: Curculionidae), is a major insect pest of sunflower in North Dakota, South Dakota, and Minnesota. Economic damage is caused by the larvae which are internal seed feeders. During the 1992-1995 growing seasons, sunflower accessions were artificially infested and evaluated for resistance to the red sunflower seed weevil. Accessions 170411, 253417, and 170424 were resistant to the red sunflower seed weevil. Morphological types within accessions170411 and 170424 varied for seed and pollen color and resistance to the red sunflower seed weevil. The resistant variant of accession170424 had 45% of the seed damage of …

Development Of Banded Sunflower Moth (Lepidoptera: Cochylidae) And Sunflower Moth (Lepidoptera: Pyralidae) On Three Diets, Jawahar L. Jyoti, Gary J. Brewer

Department of Entomology: Faculty Publications

A comparative study of the effects of sunflower moth diet, banded sunflower moth diet, and a modified sunflower moth diet was conducted on banded sunflower moth, Cochylis hospes Walsingham, and sunflower moth, Homoeosoma electellum (Hulst). Developmental times and survival to the pupal and adult stages were measured for each diet and pest species. Modified sunflower moth diet with incorporated sunflower leaf tissue gave faster developmental times and a higher percent pupation and adult eclosion for both sunflower moth species than either sunflower moth diet or banded sunflower moth diet. The modified sunflower moth diet that incorporates sunflower leaf tissue provides …

Comparison Of Esterases Between Life Stages And Sexes Of Resistant And Susceptible Strains Of German Cockroach (Dictyoptera: Blattellidae), No-Joong Park, Shripat T. Kamble

Department of Entomology: Faculty Publications

Esterase activity between the resistant Crawford and susceptible CSMA strains of German cockroach, Blattella germanica (L.), was compared with the substrates α- and β-naphthyl acetate across sex and nymphal age classes. Esterase isozyme analysis with native polyacrylamide gel electrophoresis also was conducted to identify quantitative and qualitative differences between strains, sexes, and age classes. The Crawford strain was highly resistant to cypermethrin, propoxur, and permethrin with a resistant ratio (RR) of 17.26,15.75,and 13.53, respectively, and mildly resistant to chlorpyrifos (RR 5.62). The α-NA and β-NA esterase activities in the Crawford strain were significantly higher than those activities in the CSMA …

Entomology In The Developing World, Elvis A. Heinrichs

Department of Entomology: Faculty Publications

The global population continues to increase at an alarming rate, with 90% of the added population, or 85 million per year, occurring in the developing nations of the world. From 1950 to 1980, world food production doubled, with increases in the developing countries exceeding that of the developed countries. However, food production was not able to keep pace with the population in the developing world, where population increases were twice the rate of those in the developed world. Increases in per capita food production since the 1950s have been only one-third of the developed world because increased food production has …

Random Amplified Polymorphic Dna Used To Identify Genetic Variation In Ecotypes Of The European Corn Borer (Lepidoptera: Pyralidae), Saowaluck Pornkulwat, Steven R. Skoda, Gustave D. Thomas, John E. Foster

Department of Entomology: Faculty Publications

The European corn borer, Ostrinia nubilalis (Hubner), has 3 morphologically indistinguishable voltinism ecotypes. Random amplified polymorphic DNA-polymerase chain reaction (RAPD-PCR) was used to discriminate ecotypes of the European corn borer. Genomic DNA samples from the European corn borer were screened with a total of 120 random primers. Ten of these primers yielded 21 clear and reproducible RAPD markers after agarose gel electrophoresis. Dendrograms constructed using the Nei and Li distance matrix of the phylogenetic relationships, among and within ecotypes, of the European corn borer showed the multivoltine ecotype to be genetically separated from univoltine and bivoltine ecotypes. The dendrogram of …

Parasitoids Recovered From European Corn Borer, Ostrinia Nubilalis Hübner, (Lepidoptera: Pyralidae) Larvae In Nebraska, Thomas L. Clark, John E. Foster, John F. Witkowski, Blair D. Siegfried, Terence A. Spencer

Department of Entomology: Faculty Publications

Information about the current status of parasitoids attacking European com borer, Ostrinia nubilalis (Hübner). larvae is lacking in Nebraska. This study was conducted at multiple sites in 5 counties during 1995 and 1996 to determine the presence and prevalence of European com borer parasitoids in Eastern Nebraska. The braconid, Macrocentrus grandii Goidanich. was recovered from 8.9 and 10.2% of collected 5th instar European com borer larvae during 1995 and 1996, respectively. Recovery of this parasitoid had not been previously reported in Nebraska. Meanwhile. the ichneumonid, Eriborus terebrans (Gravenhorst), was recovered from 7.6 and 7.5% of collected larvae during the same …

Arthropods On Pine Foliage In Urban Landscapes, Mary Ellen Dix, Frederick P. Baxendale

Department of Entomology: Faculty Publications

Urban landscapes are dense heterogenous matrices composed of turf broken up by tree patches or corridors (Forman and Godron, 1986, Landscape ecology. John Wiley, NY). Trees and their associated understory vegetation in the urban landscape provide food and protective habitat for many arthropods and their natural enemies and increase biological and spatial diversity (Andow, 1991, Annu. Rev. Entomol. 36:561-586). Pest management strategies that enhance the abundance of natural predator populations are alternatives to chemical pesticides. The goal of this research was to obtain essential baseline information on pine trees in turf landscapes by identifying common families or classes of arthropod …