Mortality factors affecting Agrilus auroguttatus Schaeffer (Coleoptera: Buprestidae) eggs in the native and invaded ranges

AbstractMortality factors affecting populations of the leafminers Argyresthia thuiella (Pack.) and Pulicalvaria thujaella (Kft.), on eastern white cedar in the area of Guelph, Ontario were identified and summarized in life tables. During the two annual generations studied from 1975 to 1977, overwintering mortality varied widely. Winterkill increased from 6.8% to 62.9% for A. thuiella and from 8.1% to 54.6% for P. thujaella, from 1976 to 1977. Several parasitoids produced substantial mortality of each host species, but their effect may have been superseded by winterkill in 1977. Data indicate that both populations of leafminers increased from 1975 to 1976 but decreased substantially from 1976 to 1977.

Download Full-text

Germination, Establishment, and Mortality of Naturally Seeded Southwestern Ponderosa Pine

Western Journal of Applied Forestry ◽

10.1093/wjaf/18.2.109 ◽

2003 ◽

Vol 18 (2) ◽

pp. 109-114 ◽

Cited By ~ 14

Author(s):

Steven J. Stein ◽

Diana N. Kimberling

Keyword(s):

Pinus Ponderosa ◽

Ponderosa Pine ◽

Mineral Soil ◽

Mortality Data ◽

Mortality Factors ◽

Seedling Mortality ◽

Prescribed Burns ◽

Factors Affecting ◽

Northern Arizona ◽

Lepidopteran Larvae

Abstract Information on the mortality factors affecting naturally seeded conifer seedlings is becoming increasingly important to forest managers for both economic and ecological reasons. Mortality factors affecting ponderosa pine (Pinus ponderosa) seedlings immediately following natural germination and through the following year were monitored in Northern Arizona. The four major mortality factors in temporal order included the failure of roots to establish in the soil (27%), herbivory by lepidopteran larvae (28%), desiccation (30%), and winterkill (10%). These mortality factors were compared among seedlings germinating in three different overstory densities and an experimental water treatment. Seedlings that were experimentally watered experienced greater mortality than natural seedlings due to herbivory (40%), nearly as much mortality due to the failure of roots to establish in the soil (20%), less mortality due to winterkill (5%), and no mortality due to desiccation. The seedling mortality data through time were summarized using survivorship curves and life tables. Our results suggest that managers should consider using prescribed burns to decrease the percentage of seedlings that die from failure of their roots to reach mineral soil and from attack by lepidopteran larvae. West. J. Appl. For. 18(2):109–114.

Download Full-text

Two methods of assessing the mortality factors affecting the larvae and pupae of Cameraria ohridella in the leaves of Aesculus hippocastanum in Switzerland and Bulgaria

Bulletin of Entomological Research ◽

10.1017/s0007485307005111 ◽

2007 ◽

Vol 97 (5) ◽

pp. 445-453 ◽

Cited By ~ 17

Author(s):

S. Girardoz ◽

R. Tomov ◽

R. Eschen ◽

D.L.J. Quicke ◽

M. Kenis

Keyword(s):

Leaf Senescence ◽

Sampling Method ◽

Plant Defence ◽

Leaf Miner ◽

Mortality Factor ◽

Horse Chestnut ◽

Mortality Factors ◽

Grab Sampling ◽

Defence Reaction ◽

Factors Affecting

AbstractThe horse-chestnut leaf miner, Cameraria ohridella, is an invasive alien species defoliating horse-chestnut, a popular ornamental tree in Europe. This paper presents quantitative data on mortality factors affecting larvae and pupae of the leaf miner in Switzerland and Bulgaria, both in urban and forest environments. Two sampling methods were used and compared: a cohort method, consisting of the surveying of pre-selected mines throughout their development, and a grab sampling method, consisting of single sets of leaves collected and dissected at regular intervals. The total mortality per generation varied between 14 and 99%. Mortality was caused by a variety of factors, including parasitism, host feeding, predation by birds and arthropods, plant defence reaction, leaf senescence, intra-specific competition and inter-specific competition with a fungal disease. Significant interactions were found between mortality factors and sampling methods, countries, environments and generation. No mortality factor was dominant throughout the sites, generations and methods tested. Plant defence reactions constituted the main mortality factor for the first two larval stages, whereas predation by birds and arthropods and parasitism were more important in older larvae and pupae. Mortality caused by leaf senescence was often the dominant mortality factor in the last annual generation. The cohort method detected higher mortality rates than the grab sampling method. In particular, mortality by plant defence reaction and leaf senescence were better assessed using the cohort method, which is, therefore, recommended for life table studies on leaf miners.

Download Full-text

Mortality factors affecting the cabbage seedpod weevil, Ceutorhynchus obstrictus (Marsham), in its area of origin: A life table analysis

Biological Control ◽

10.1016/j.biocontrol.2010.06.004 ◽

2010 ◽

Vol 54 (3) ◽

pp. 331-341 ◽

Cited By ~ 13

Author(s):

T. Haye ◽

P.G. Mason ◽

L.M. Dosdall ◽

U. Kuhlmann

Keyword(s):

Life Table ◽

Life Table Analysis ◽

Mortality Factors ◽

Factors Affecting ◽

Ceutorhynchus Obstrictus ◽

Table Analysis ◽

Cabbage Seedpod Weevil ◽

Area Of Origin

Download Full-text

FACTORS AFFECTING MORTALITY OF THE EUROPEAN CORN BORER, OSTRINIA NUBILALIS (HÜBNER), IN ALBERTA

The Canadian Entomologist ◽

10.4039/ent120841-10 ◽

1988 ◽

Vol 120 (10) ◽

pp. 841-853 ◽

Cited By ~ 14

Author(s):

Dennis A. Lee

Keyword(s):

Ostrinia Nubilalis ◽

European Corn Borer ◽

Larval Mortality ◽

Reproductive Potential ◽

Moisture Stress ◽

Mortality Factors ◽

Corn Borer ◽

Factors Affecting ◽

Rainy Weather ◽

Early Instar

AbstractA combination of laboratory and field trials, from 1983 to 1985, were used to determine mortality factors affecting all life stages of Alberta populations of the European corn borer, Ostrinia nubilalis (Hübner), feeding on corn. The resulting life table demonstrated that greatest mortality occurred during the first and second larval instars (62.2%), when mature larvae are in diapause (69.5%), and from moth migration and loss in reproductive potential (70.3%). Stages where mortality was slight included the egg stage (11.7%), non-diapausing third- to fifth-instar larvae (2%), and pupae (10.4%).Laboratory trials showed that greater egg mortality occurred at relative humidities (RH) of 35 and 55% than at a RH of 75%. In the field, egg parasitism was nil, predation of early-instar larvae (5.2%) and diapausing larvae (6%) was low, and parasitoids were scarce (emerging from ca. 2% of pupae). Sustained periods of hot, dry weather with high moisture stress were related to mortality of both eggs and early-instar larvae. Death of early-instar larvae also was related to periods of rainy weather with low evaporation. The 64% non-diapause larval mortality was much lower than that reported elsewhere. The dramatic increase in the corn borer since its recent introduction to Alberta may be due to a lack of natural enemies, and because only non-resistant corn hybrids are grown.

Download Full-text

Factors affecting wing molt chronology of female mallards

Canadian Journal of Zoology ◽

10.1139/z91-137 ◽

1991 ◽

Vol 69 (4) ◽

pp. 924-928 ◽

Cited By ~ 7

Author(s):

James O. Leafloor ◽

C. Davison Ankney

Keyword(s):

Social Environment ◽

Positive Relationship ◽

Anas Platyrhynchos ◽

Nest Success ◽

Breeding Period ◽

Social Environments ◽

Mortality Factors ◽

Factors Affecting ◽

Breeding Seasons

We manipulated nest success of captive mallards (Anas platyrhynchos) during two breeding seasons to determine the effects of different breeding events on the timing of wing molt initiation in females. We also studied the effect of different social environments during the postbreeding period on female wing molt chronology. Late (renesting) brood hens molted their remiges later than did early brood hens in both years of the study. Unsuccessful nesters showed a late, asynchronous wing molt when they molted solitarily, but an early, synchronous wing molt when they were placed together during the postbreeding period. There was a positive relationship between the last date of incubation and the date of wing molt initiation when birds were placed in a group after the breeding period. Social environment appeared to influence the timing of wing molt, particularly among unsuccessful nesters. We discuss the implications of these results in terms of postbreeding mortality factors and potential fall banding bias.

Download Full-text