Scarabaeid Pests: Subfamily Dynastinae

Author(s):  
Patricia J. Vittum

This chapter examines masked chafers, which belong to the large genus of North and South American beetles, the Cyclocephala, in the order Coleoptera, family Scarabaeidae, subfamily Dynastinae, tribe Cyclocephalini. Approximately a dozen of these species occur in North America, but only five species are regularly associated with turfgrass cultivation: the northern masked chafer; the southern masked chafer; Cyclocephala pasadenae (Casey); Cyclocephala hirta LeConte; and Cyclocephala parallela Casey. Masked chafer grubs are important turfgrass-infesting species, causing extensive damage to cultivated turf during late summer and early fall. They are the most injurious root-feeding pests of turfgrass throughout much of the Ohio River Valley and the midwestern United States. Adult masked chafers have blunt spatulate mandibles that are unsuited for feeding on plant tissues; as far as is known, they do not feed.

Plant Disease ◽  
2000 ◽  
Vol 84 (8) ◽  
pp. 901-906 ◽  
Author(s):  
Jerald K. Pataky ◽  
Lindsey J. du Toit ◽  
Noah D. Freeman

Maize accessions were evaluated in 1997, 1998, and 1999 to identify additional sources of Stewart's wilt resistance and to determine if reactions differed among accessions collected from various regions of the United States and throughout the world. The distributions of Stewart's wilt reactions rated from 1 (no appreciable spread of symptoms) to 9 (dead plants) were relatively similar among groups of accessions from all regions of the world except for those from the Mid-Atlantic/Ohio River Valley region of the United States, the southern United States, and the northeastern United States. The mean and median Stewart's wilt rating for 1,991 accessions evaluated in 1997 was 4. The mean Stewart's wilt rating for 245 accessions collected from the Mid-Atlantic/Ohio River Valley region was 3.1, which was significantly lower than that for accessions from all other regions. The mean rating for accessions from the southern United States was 3.7, which also was lower than mean ratings for accessions from all other regions. Ratings from trials in 1997 and 1998 were highly correlated (r = 0.87) for 292 accessions and 15 sweet corn hybrid checks evaluated in both years. Of 20 accessions rated below 2 in 1997 and 1998, seven were from Virginia, seven were from the Ohio River Valley or central Corn Belt of the United States, four were from the northern or western Corn Belt of the United States, and two were from Spain. Ratings for these accessions ranged from 1.7 to 3.1 in 1999. Ratings ranged from 2.6 to 3.7 for F1 hybrids of these accessions crossed with one of two susceptible sweet corn inbreds, CrseW30 or Crse16, which were rated 5.7 and 5.4, respectively. Based on the reactions of this collection of germ plasm, it appears that high levels of Stewart's wilt resistance are prevalent only among accessions collected from areas where the disease has been endemic for several years, whereas moderate levels of resistance can be found in accessions collected from nearly everywhere in the world.


2005 ◽  
Vol 52 (9) ◽  
pp. 235-242
Author(s):  
J.G. Schulte ◽  
A.H. Vicory

Source water quality is of major concern to all drinking water utilities. The accidental introduction of contaminants to their source water is a constant threat to utilities withdrawing water from navigable or industrialized rivers. The events of 11 September, 2001 in the United States have heightened concern for drinking water utility security as their source water and finished water may be targets for terrorist acts. Efforts are underway in several parts of the United States to strengthen early warning capabilities. This paper will focus on those efforts in the Ohio River Valley Basin.


1967 ◽  
Vol 47 (3) ◽  
pp. 251-261 ◽  
Author(s):  
I. J. Bassett ◽  
C. W. Crompton

Results from 17 pollen collecting stations in British Columbia indicate that air-borne pollen of ragweeds and their relatives, the principal causative agents of hay fever in North America, is practically absent throughout the province. Coniferous trees and shrubs such as pines, spruces, firs, cedars, Douglas fir, hemlocks and junipers produce the greater part of the air-borne pollen from March to early July. Pollen from alders, poplars, willows and birches is also prevalent in some areas in the early spring. The peak periods of grass pollen near the United States–Canadian border occur mainly in June and the early part of July, while further north they are about a month later. Of the four types of plantain pollen identified from the different collecting stations, English plantain was the most common, especially in the southwesterly part of the province. Pollen from the lambs’-quarters and amaranth families and wormwoods occurs mainly in the late summer and early fall and is more abundant in the dry interior than along the coast.


2008 ◽  
Vol 47 (6) ◽  
pp. 1573-1589 ◽  
Author(s):  
Steven A. Mauget ◽  
Jonghan Ko

Abstract Simple phase schemes to predict seasonal climate based on leading ENSO indicators can be used to estimate the value of forecast information in agriculture and watershed management, but may be limited in predictive skill. Here, a simple two-tier statistical method is used to hindcast seasonal precipitation over the continental United States, and the resulting skill is compared with that of ENSO phase systems based on Niño-3 sea surface temperature anomaly (SSTA) and Southern Oscillation index (SOI) persistence. The two-tier approach first predicts Niño-3 winter season SSTA, and then converts those predictions to categorical precipitation hindcasts via a simple phase translation process. The hindcasting problem used to make these comparisons is relevant to winter wheat production over the central United States. Thus, given the state of seasonal SOI and Niño-3 indicators defined before August, the goal is to predict the tercile category of the following November–March precipitation. Generally, it was found that the methods based on either predicted or persisted winter Niño-3 conditions were skillful over areas where ENSO affects U.S. winter precipitation—that is, the Southeast and the Gulf Coast, Texas, the southern and central plains, the Southwest, Northwest, and the Ohio River valley—and that the two-tier approach based on predicted Niño-3 conditions was more likely to provide the best skill. Skill based on SOI persistence was generally lower over many of those regions and was insignificant over broad parts of the central and southwest United States, but did lead the other methods over the Ohio River valley and the northwest. A more restrictive test of leading hindcast skill showed that the skill advantages of the two-tier approach over the central and western United States were not substantial, and mainly highlighted SOI persistence’s lack of skill over the central United States and leading skill over the Ohio River valley. However, two-tier hindcasts based on neural-network-predicted Niño-3 SSTA were clearly more skillful than both ENSO phase methods over areas of the Southeast. It is suggested that the relative skill advantage of the two-tier approach may be due in part to the use of arbitrary thresholds in ENSO phase systems.


2018 ◽  
Vol 52 (9-10) ◽  
pp. 5709-5721 ◽  
Author(s):  
Binod Pokharel ◽  
S.-Y. Simon Wang ◽  
Jonathan Meyer ◽  
Robert Gillies ◽  
Yen-Heng Lin

2016 ◽  
Vol 43 (1) ◽  
pp. 95-108 ◽  
Author(s):  
Neal Woodman

The North American naturalist Constantine S. Rafinesque spent much of the year 1818 engaged in a solo journey down the Ohio River Valley to explore parts of what was then the western United States. Along the way, he visited a number of fellow naturalists, and he spent more than a week at the Henderson, Kentucky, home of artist and ornithologist John James Audubon. During the succeeding two years, Rafinesque published descriptions of new species that resulted from his expedition, including eleven species of fishes that eventually proved to have been invented by Audubon as a prank on the credulous naturalist. Less well known are a number of “wild rats” described by Rafinesque that include one recognized species (Musculus leucopus) and ten other, imaginary “species” fabricated by Audubon (Gerbillus leonurus, G. megalops, Spalax trivittata, Cricetus fasciatus, Sorex cerulescens, S. melanotis, Musculus nigricans, Lemmus albovittatus, L. talpoides, Sciurus ruber). Rafinesque's unpublished sketches of these animals provide important insight regarding the supposed nature of the animals invented by Audubon and ultimately published by Rafinesque.


1976 ◽  
Vol 108 (7) ◽  
pp. 693-699 ◽  
Author(s):  
Judy Bodenham ◽  
Robert E. Stevens ◽  
T. O. Thatcher

AbstractConotrachelus neomexicanus Fall occurs throughout the range of Pinus ponderosa Laws. in the central and southwestern United States. It is commonly found infesting ponderosa pine cones in north-central Colorado. C. neomexicanus is univoltine. Eggs are laid in second-year cones from May through July. Larvae mine extensively in the cones and drop to the ground for pupation in the soil. Adults emerge from the soil in late summer and early fall, return to the trees to feed on twigs, and presumably hibernate in sheltered locations during the winter A tachinid fly, Myiophasia sp. nr. ruficornis Tns., is an internal parasitoid of weevil larvae.


Sign in / Sign up

Export Citation Format

Share Document