MODELLING SPRING EMERGENCE OF THE APPLE SAWFLY HOPLOCAMPA TESTUDINEA KLUG (HYMENOPTERA, TENTHREDINIDAE)

1996 ◽  
pp. 263-272 ◽  
Author(s):  
B. Graf ◽  
H.U. Höpli ◽  
H. Höhn
Keyword(s):  
Spring Emergence ◽  
Hoplocampa Testudinea

scholarly journals Monitoring of Sawfly Populations (Hymenoptera, Symphyta: Hoplocampa Spp.) In Plum And Apple Orchards Using Visual Traps

2013 ◽  
Vol 67 (2) ◽  
pp. 130-135 ◽  
Author(s):  
Rimantas Tamosiunas ◽  
Laisvune Duchovskiene ◽  
Alma Valiuskaite
Keyword(s):  
Population Density ◽  
Research Centre ◽  
Flight Period ◽  
Economic Threshold ◽  
Degree Days ◽  
Apple Cultivars ◽  
Trap Catches ◽  
Organically Managed ◽  
Spring Emergence ◽  
Hoplocampa Testudinea

The investigation of Hoplocampa minuta (Christ, 1791) (black plum sawfly), Hoplocampa flava (Linné, 1760) (yellow plum sawfly) and Hoplocampa testudinea (Klug, 1816) (apple sawfly) populations using white sticky traps Rebell®bianco was carried out in conventionally and organically managed apple and conventionally managed plum orchards of the Institute of Horticulture of Lithuanian Research Centre for Agriculture and Forestry in 2010 and 2011. Temperature sums for predicting sawfly spring emergence were determined: 120 ± 5 degree-days for apple sawfly, 85 ± 26 degree-days for black plum sawfly and 95 ± 28 degree-days for yellow plum sawfly. However, more years of the study are needed to confirm these temperature sums. The average densities of sawflies during the flight period were: H. minuta - 14.8 ± 7.3 sawfly trap-1 in 2010 and 54.2 ± 35.9 sawfly trap-1 in 2011; H. flava - 13.3 ± 5.2 sawfly trap-1 in 2010,and 16.6 ± 6.9 sawfly trap-1 in 2011; and H. testudinea in organic orchard - 38.3 ± 26.2 sawfly trap-1 in 2010 and 5.0 ± 2.8 sawfly trap-1 in 2011, in conventional orchard - 14.8 ± 8.1 sawfly trap-1 in 2010 and 9.3 ± 4.3 sawfly trap-1 in 2011. Conditions for development of both plum sawfly species were better in 2011, when abundance nearly reached the economic threshold. Population density, cumulative trap catches during the flight period, and damage caused by apple sawfly varied significantly between the study years and apple cultivars. In 2010, apple sawfly was more abundant and caused more serious damage than in 2011. The economic threshold of 30-40 individuals per trap was reached in 2010 due to the better conditions of development. The various apple cultivars suffered different damage levels: cv. ‘Aldas’, ‘Vitos’ and ‘Rubinola’ suffered the highest damage in the organic orchard, but no significant differences were observed. In the conventional garden, cv. ‘Auksis’ had the most damaged fruits.

Effect of climatic conditions on the annual activity and hibernation cycle of Richardson's ground squirrels and Columbian ground squirrels

1977 ◽  
Vol 55 (4) ◽  
pp. 693-703 ◽  
Author(s):  
Gail R. Michener
Keyword(s):  
Rocky Mountains ◽  
Climatic Conditions ◽  
Ground Squirrels ◽  
Active Season ◽  
Southern Alberta ◽  
Annual Activity ◽  
The Times ◽  
Columbian Ground Squirrels ◽  
Spring Emergence ◽  
Species Ecology

In 1975 and 1976 the times of spring emergence, breeding, and entry into hibernation were compared for Spermophilus richardsonii and S. columbianus in an area of sympatry in the foothills of the southern Alberta Rocky Mountains. Both species emerged earlier in 1976, which had a warmer than normal spring, than in 1975, which had a cooler than normal spring. In both years S. richardsonii emerged earlier than S. columbianus and remained active longer. Juvenile S. richardsonii entered hibernation when 17–20 weeks old whereas juvenile S. columbianus were 10–11 weeks old. Yearling S. richardsonii bred, whereas yearling S. columbianus did not. Breeding success affected the time of entry into hibernation but not the time of emergence from hibernation in the next spring. A possible relationship between the periodic arousals during hibernation and the emergence pattern of squirrels in spring is discussed. The significance of flexibility of spring emergence, length of the active season, and age at breeding to survival and species ecology is considered.

Fall and Spring Preplant Herbicide Applications Influence Spring Emergence of Glyphosate-Resistant Horseweed (Conyza canadensis)

2010 ◽  
Vol 24 (1) ◽  
pp. 11-19 ◽  
Author(s):  
Vince M. Davis ◽  
Greg R. Kruger ◽  
Bryan G. Young ◽  
William G. Johnson
Keyword(s):  
Early Spring ◽  
Late Spring ◽  
Conyza Canadensis ◽  
No Till ◽  
Early Fall ◽  
Winter Annual ◽  
Winter Annual Weeds ◽  
Annual Weeds ◽  
Spring Emergence ◽  
Residual Control

Horseweed (Conyza canadensis) is a common weed in no-till crop production systems. It is problematic because of the frequent occurrence of biotypes resistant to glyphosate and acetolactate synthase (ALS)-inhibiting herbicides and its ability to complete its life cycle as a winter or summer annual weed. Tactics to control horseweed while controlling other winter annual weeds routinely fail; herbicide application timing and spring emergence patterns of horseweed may be responsible. The objectives of this experiment were to (1) determine the influence of fall and spring herbicides with and without soil residual horseweed activity on spring-emerging glyphosate-resistant (GR) horseweed density and (2) evaluate the efficacy and persistence of saflufenacil on GR horseweed. Field studies were conducted in southern Indiana and Illinois from fall 2006 to summer 2007 and repeated in 2007 to 2008. Six preplant herbicide treatments were applied at four application timings: early fall, late fall, early spring, and late spring. Horseweed plants were counted every 2 wk following the first spring application until the first week of July. Horseweed almost exclusively emerged in the spring at both locations. Spring horseweed emergence was higher when 2,4-D + glyphosate was fall-applied and controlled other winter annual weeds. With fall-applied 2,4-D + glyphosate, over 90% of the peak horseweed density was observed before April 25. In contrast, only 25% of the peak horseweed density was observed in the untreated check by April 25. Starting from the initiation of horseweed emergence in late March, chlorimuron + tribenuron applied early fall or early spring, and spring-applied saflufenacil at 100 g ai/ha provided greater than 90% horseweed control for 12 wk. Early spring–applied saflufenacil at 50 g ai/ha provided 8 wk of greater than 90% residual control, and early spring–applied simazine provided 6 wk of greater than 90% control. When applied in late spring, saflufenacil was the only herbicide treatment that reduced horseweed densities by greater than 90% compared to 2,4-D + glyphosate. We concluded from this research that fall applications of nonresidual herbicides can increase the rate and density of spring emerging horseweed. In addition, spring-applied saflufenacil provides no-till producers with a new preplant herbicide for foliar and residual control of glyphosate- and ALS-resistant horseweed.

scholarly journals Spring emergence of Canadian Delia radicum and synchronization with its natural enemy, Aleochara bilineata

2010 ◽  
Vol 142 (3) ◽  
pp. 234-249 ◽  
Author(s):  
L.D. Andreassen ◽  
U. Kuhlmann ◽  
J.W. Whistlecraft ◽  
J.J. Soroka ◽  
P.G. Mason ◽  
...  
Keyword(s):  
Adult Emergence ◽  
Development Rate ◽  
Delia Radicum ◽  
Aleochara Bilineata ◽  
Development Rates ◽  
Models Of Development ◽  
Soil Temperatures ◽  
Truncated Normal ◽  
Diapause Development ◽  
Spring Emergence

AbstractTo characterize time of spring emergence following post-diapause development, Delia radicum (L.) (Diptera: Anthomyiidae) from Saskatchewan, Manitoba, and southwestern Ontario were collected in fall, maintained over winter at 1 °C, then transferred to higher constant temperatures until adult emergence. At each location there were “early” and “late” phenotypes. Truncated normal models of temperature dependency of development rate were fitted for each phenotype from each location. We provide the first evidence of geographic variation in the criteria separating these phenotypes. Separation criteria and models for early and late phenotypes at the two prairie locations, approximately 700 km apart, were indistinguishable, but differed from those for Ontario. Prairie phenotypes developed more slowly than Ontario phenotypes, and more prairie individuals were of the late phenotype. Poor synchronization of spring emergence could impair predation of D. radicum eggs by adult Aleochara bilineata Gyllenhal (Coleoptera: Staphylinidae). Aleochara bilineata from Manitoba were reared and development rates modelled as for D. radicum. Models of development rates for the two species, when combined with simulated soil temperatures for two prairie locations, suggest that emergence of adult A. bilineata is well synchronized with availability of D. radicum eggs in prairie canola.

scholarly journals A New Look at Cultivar Preference in Hoplocampa testudinea (Hymenoptera: Tenthredinidae) on Apple in the Annapolis Valley of Nova Scotia, Canada

Insects ◽  
2021 ◽  
Vol 12 (9) ◽  
pp. 769
Author(s):  
Suzanne Blatt ◽  
Kim Hiltz
Keyword(s):  
Nova Scotia ◽  
Physicochemical Properties ◽  
Larval Survival ◽  
Larval Performance ◽  
Differential Survival ◽  
Eastern Canada ◽  
Weak Evidence ◽  
Important Pest ◽  
Annapolis Valley ◽  
Hoplocampa Testudinea

(1) Background: The European apple sawfly, Hoplocampa testudinea Klug (Hymenoptera: Tenthredinidae), can be an economically important pest in eastern Canada and shows preference for apple cultivars in Nova Scotia, Canada. We hypothesized that this preference could be due to oviposition by female H. testudinea (preference-performance hypothesis) during the bloom period or differential larval survival during development due to fruitlet physicochemical properties. (2) Methods: Fifteen commercial and experimental apple (Malusdomestica Borkh.; Rosaceae) cultivars located at the Kentville Research and Development Centre (Kentville, Nova Scotia) were chosen and examined for H. testudinea oviposition, larval performance during fruitlet development, fruitlet physicochemical properties and damage assessment at harvest from 2016–2019, inclusive. (3) Results: H. testudinea showed significant cultivar preference during oviposition, during development and at harvest, but the ranking of these cultivars was not the same throughout the season. Total impact by H. testudinea was consistent for most cultivars over multiple years of the study. (4) Conclusion: Correlation of oviposition with damage provided weak evidence for the preference-performance hypothesis. We propose that this relationship is weak due to differential survival of larvae during development.

A Descriptive Model for Predicting Spring Emergence of Heliothis zea Populations in North Carolina 12

1979 ◽  
Vol 8 (1) ◽  
pp. 141-146 ◽  
Author(s):  
J. A. Logan ◽  
R. E. Stinner ◽  
R. L. Rabb ◽  
J. S. Bacheler
Keyword(s):  
North Carolina ◽  
Heliothis Zea ◽  
Descriptive Model ◽  
Spring Emergence
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