Clyde E. Sorenson

Landowner attitudes regarding wildlife management on private land in North Carolina

Abstract Early-successional habitats across the southeast United States have declined considerably in recent years amid rising human population growth and associated development. Recognizing the declining wildlife populations associated with early-successional habitats and the need for influence over habitat on private land, the North Carolina Wildlife Resources Commission established the Cooperative Upland Habitat Restoration and Enhancement (CURE) Program in August 2000. The program targets private landowners in 3 select regions of the state (Upper Coastal Plain I, Upper Coastal Plain II, and Western Piedmont). Survey research was conducted in the 3 CURE Program areas to 1) evaluate demographic and landownership attributes of private landowners and associated land-use characteristics, 2) assess regional differences in landowner attitudes and behavior toward wildlife management on private land, 3) identify landowner attributes related to regional differences in attitude or behavior, and 4) evaluate how regional differences will impact future CURE Program guidelines. Landowner attitudes toward wildlife in North Carolina are closely linked to property use and reliance on land for direct economic income (i.e., agricultural production). Landowners who depended on their property for earned annual income were less likely to consider the aesthetic or intrinsic value of wildlife on their land than those who did not rely on their land for income. For some landowners, financial incentives alone appeared sufficient to encourage participation in the CURE Program. Other landowners were less interested in financial rewards. For these landowners, alternative forms of encouragement, such as partnerships with agencies and organizations, might be more effective. Understanding variability in landowner attitudes and behavior toward wildlife habitat is critical to the success of private-land wildlife habitat management programs. In North Carolina the success of the CURE Program will depend on tailoring the program to fit regional differences in landowner values, attitudes, and behavior.

The invasion route for an insect pest species: the tobacco aphid in the New World

Biological invasions are rapid evolutionary events in which populations are usually subject to a founder event during introduction followed by rapid adaptation to the new environment. Molecular tools and Bayesian approaches have shown their utility in exploring different evolutionary scenarios regarding the invasion routes of introduced species. We examined the situation for the tobacco aphid, Myzus persicae nicotianae, a recently introduced aphid species in Chile. Using seven microsatellite loci and approximate Bayesian computation, we studied populations of the tobacco aphid sampled from several American and European countries, identifying the most likely source populations and tracking the route of introduction to Chile. Our population genetic data are consistent with available historical information, pointing to an introduction route of the tobacco aphid from Europe and/or from other putative populations (e.g. Asia) with subsequent introduction through North America to South America. Evidence of multiple introductions to North America from different genetic pools, with successive loss of genetic diversity from Europe towards North America and a strong bottleneck during the southward introduction to South America, was also found. Additionally, we examined the special case of a widespread multilocus genotype that was found in all American countries examined. This case provides further evidence for the existence of highly successful genotypes or ‘superclones’ in asexually reproducing organisms.

Genetic Variation in the Myzus persicae Complex (Homoptera: Aphididae): Evidence for a Single Species

Abstract Genetic variation was assessed for the closely related aphids Myzus nicotianae Blackman and Myzus persicae (Sulzer), previously classified as a single species. Populations of both red and green color morphs, collected from tobacco and nontobacco hosts from 3 continents, were analyzed via random amplified polymorphic DNA (RAPD)-polymerase chain reaction (PCR) and mitochondrial cytochrome oxidase II (COII) and elongation factor- 1 alpha (EF-1α) gene sequencing. Three other Myzus species—M. cerasi (F.), M. hemerocallis Takahashi, and M. varians Davidson)—were used as outgroups in our analyses. RAPD-PCR analysis revealed many, easily detectable genetic polymorphisms between the Myzus persicae complex and the outgroup species. The small number of polymorphisms detected within the complex were not correlated with host plant or the geographic origin of populations. The sequences of both COII and EF-1α for all populations within the M. persicae complex were identical, although significant variation was evident between the M. persicae complex and outgroup taxa. These results strongly suggest the synonymy of M. persicae and M. nicotianae.

Seasonal Activity and Species Composition of Dung Beetles (Coleoptera: Scarabaeidae and Geotrupidae) Inhabiting Cattle Pastures in North Carolina

Abstract Species composition and seasonal distribution of dung beetles were studied on dairy and beef cattle pastures in North Carolina. Study sites included a dairy located in the piedmont region (North Carolina Department of Agriculture Piedmont Research Station, Salisbury, NC) and a combined dairy/beef facility in the coastal plain (North Carolina Department of Agriculture Center for Environmental Farming Systems, Goldsboro, NC). Dung beetles were trapped in cattle pastures from March 2002 through September 2003 by using dung-baited pitfall traps. Trapping yielded 4,111 beetles representing 14 species from the piedmont dairy, including Aphodius prodromus Brahm, a new record for North Carolina. Totals of 57,026 beetles representing 28 species and 28,857 beetles representing 26 species were trapped from the dairy unit and beef unit in the coastal plain site, respectively. Onthophagus gazella (F.), a second new record for North Carolina, was collected from the coastal plain. Beetles common to all collection sites include Aphodius erraticus (L.), Aphodius fimetarius (L.), Aphodius granarius (L.), Aphodius pseudolividus Balthasar, Onthophagus taurus Schreber, Onthophagus hecate hecate Panzer, and Onthophagus pennsylvanicus Harold. The introduced beetle O. taurus dominated the dung beetle population, accounting for >50% of the total beetles caught at either site. Beetle activity was greatest from March until November, with activity declining during the winter. Nine exotic species in the genera Onthophagus and Aphodius represented nearly 95% of the beetles trapped.

Genetic, biochemical, and behavioral uniformity among populations of Myzus nicotianae and Myzus persicae

Prior to designation as distinct species, an appellation presently in question, the tobacco aphid, Myzus nicotianae Blackman (Homoptera: Aphididae), was classified as a tobacco‐feeding form of the green peach aphid, Myzus persicae (Sulzer). In this study, RAPD polymorphisms distinguished members of the Myzus persicae complex (M. persicae and M. nicotianae) from three outgroup Myzus species (M. cerasi (F.), M. hemerocallis Takahashi, and M. varians Davidson). Polymorphisms within the complex did not separate populations on the basis of host association (tobacco versus other host plants) or geographic origin (collections from the United States, Europe, and Japan). Similarly, while GC‐MS analysis of cuticular hydrocarbon profiles revealed both developmental and inter‐populational differences within the M. persicae complex, it did not separate populations of tobacco feeding aphids from those collected off non‐tobacco hosts. Finally, with the exception of their responses to a choice between lettuce and collards, the host preference behavior of a green peach aphid population, a red tobacco aphid population, and a green tobacco aphid population was indistinguishable in host preference experiments. These results add to a growing body of evidence suggesting M. nicotianae and M. persicae are conspecific.

Species Diagnosis and Bacillus thuringiensis Resistance Monitoring of Heliothis virescens and Helicoverpa zea (Lepidoptera: Noctuidae) Field Strains from the Southern United States Using Feeding Disruption Bioassays

Abstract Validation of a feeding disruption bioassay for the detection of resistance to Bacillus thuringiensis toxin and species identification is reported using field strains of Heliothis virescens and Helicoverpa zea collected from the southern United States in 1998. Feeding disruption is measured by a lack of fecal production from larvae exposed to a diagnostic concentration of CryIAc in a blue indicator diet. The bioassay provided rapid (24 h) diagnosis of the species composition of larvae tested and also monitored for the presence of resistance in H. virescens. An additional diagnostic concentration was established for monitoring resistance in H. zea. A probit model was used to compare the fecal production responses of insect strains over a range of CryIAc doses. Probability calculations, derived from our assay results, are also presented to aid in the interpretation of future results from field trials. Integration of the feeding disruption bioassay into integrated pest management programs is discussed.

Geographical Variation in Pheromone Response of the European Corn Borer, Ostrinia nubilalis (Lepidoptera: Crambidae), in North Carolina: A 20-Y Perspective

Abstract Pheromone traps were used to assess the distribution of two pheromone races of European corn borer, Ostrinia nubilalis (Hübner), in North Carolina, ≈10 and 20 yr after previous, similar assessments. In the previous studies, moths responding to a 97Z: 3E isomeric blend (Z blend) of 11-tetradecenyl acetate predominated in the far western parts of the state, whereas moths responding to a 3Z: 97E blend (E blend) prevailed in the east, with a substantial zone of overlap occurring in the eastern Piedmont. There was evidence that the E responsive population had expanded westward between 1978 and 1988. In this study, the distribution of the two races seemed to remain essentially unchanged from that observed in the late 1980s, and no evidence of a continued westward expansion of E responsive moths was detected.

Effects of vegetated field borders on arthropods in cotton fields in eastern North Carolina

Abstract The influence, if any, of 5m wide, feral, herbaceous field borders on pest and beneficial arthropods in commercial cotton, Gossypium hirsutum (L.) (Malvales: Malvaceae), fields was measured through a variety of sampling techniques over three years. In each year, 5 fields with managed, feral vegetation borders and five fields without such borders were examined. Sampling was stratified from the field border or edge in each field in an attempt to elucidate any edge effects that might have occurred. Early season thrips populations appeared to be unaffected by the presence of a border. Pitfall sampling disclosed no differences in ground-dwelling predaceous arthropods but did detect increased populations of crickets around fields with borders. Cotton aphid (Aphis gossypii Glover) (Hemiptera: Aphididae) populations were too low during the study to adequately assess border effects. Heliothines, Heliothis virescens (F.) and Helicoverpa zea (Boddie) (Lepidoptera: Noctuidae), egg numbers and damage rates were largely unaffected by the presence or absence of a border, although in one instance egg numbers were significantly lower in fields with borders. Overall, foliage-dwelling predaceous arthropods were somewhat more abundant in fields with borders than in fields without borders. Tarnished plant bugs, Lygus lineolaris (Palisot de Beauvois) (Heteroptera: Miridae) were significantly more abundant in fields with borders, but stink bugs, Acrosternum hilare (Say), and Euschistus servus (Say) (Hemiptera: Pentatomidae) numbers appeared to be largely unaffected by border treatment. Few taxa clearly exhibited distributional edge effects relative to the presence or absence of border vegetation. Field borders like those examined in this study likely will have little impact on insect pest management in cotton under current insect management regimens.

Overwintering Refuge Sites for Megacopta cribraria (Hemiptera: Plataspidae)

Megacopta cribraria F. (Hemiptera: Plataspidae) was first reported in the United States near Atlanta, Georgia, in fall 2009 (Suiter et al. 2010, J. Integr. Pest Manag. 1: 1–4) and has since spread throughout the southeastern United States (http:// www.kudzubug.org/distribution_map.cfm). In Asia and the United States, it is commonly associated with its preferred host plant, kudzu, Pueraria montana Lour (Merr.) var. lobata (Willd.) (Fabales: Fabaceae) (Medal et al. 2013, Fla. Entomol. 96: 631–633). Nonetheless, M. cribraria has emerged as a significant pest of soybean, Glycine max (L.) Merrill and may damage a few other legumes in the United States (Eger et al. 2010, Insecta Mundi 0121: 1–11; Hu and Carroll 2012, htpp://agfax.com/2012/05/18/Alabama-soybean-kudzubugs-making-their-move/). In Georgia and South Carolina, yield losses in untreated soybean fields averaged 18% and ranged up to 59.6% (Greene et al. 2012, United Soybean Board, Chesterfield, MO; Seiter et al. 2012, J. Econ. Entomol. 106: 1676–1683). Apart from being odoriferous, crushed nymphs have reportedly caused skin rashes, thereby raising health concerns for workers in soybean fields (Ruberson et al. 2013, Appl Entomol Zool. 48: 3–13). Megacopta cribraria is also viewed as a nuisance pest in fall through spring when adults aggregate on or around homes to overwinter, apparently close to kudzu patches (Eger et al. 2010, Insecta Mundi 0121: 1–11; Ruberson et al. 2013). Little is known about the biology and ecology of M. cribraria in North America. Prominently, we do not understand their behavior and population dynamics when host plants are not available, as in the winter. Knowledge of the overwintering behavior and biology of this species could inform surveillance and management. This study was undertaken to identify overwintering refuge areas preferred by M.

Effects of the Insect Growth Regulator, Methoprene, on Onthophagus taurus (Coleoptera: Scarabaeidae)

ABSTRACT A bioassay was conducted to determine the impact of methoprene, an insect growth regulator (IGR), on fecundity, larval survival, and size of progeny for Onthophagus taurus Schreber. Adult O. taurus dung beetles were offered methoprene-treated manure in three to five replications each at concentrations of 0.08, 0.45, and 4.5 ppm, respectively. An additional group of adult beetles was immersed in a methoprene-water solution and allowed to reproduce in containers with untreated manure. Data from all treatment groups were compared with untreated control groups. Methoprene did not seem to hinder brood production at 0.45 ppm. Survival of O. taurus was not affected by methoprene-treated manure at 0.08 ppm or when parent beetles were immersed in methoprene-water solution. However, progeny survival was significantly reduced on manure treated with methoprene at 4.5 ppm. Mean pronotal width of O. taurus progeny was significantly smaller in beetles fed methoprene-treated manure (4.5 ppm). The low dose of 0.08 ppm did not affect pronotal widths nor did topical application of methoprene to adults affect pronotal widths in resulting offspring. Although some adverse effects of methoprene were observed at higher concentrations, use of methoprene at concentrations of 0.08 ppm as part of a horn fly control program likely would not greatly affect populations of O. taurus, the most common paracoprid dung beetle in North Carolina.