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

(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.

2016 ◽  
Vol 148 (6) ◽  
pp. 724-735
Author(s):  
Christopher Burgart ◽  
Neil K. Hillier ◽  
Suzanne Blatt

AbstractThe European apple sawfly, Hoplocampa testudinea (Klug) (Hymenoptera: Tenthredinidae), is an economically important pest in eastern Canada. Growers can experience significant crop losses as management of this species is difficult because it is present during bloom. As a result, management strategies other than pesticides are required for this pest. Eleven commercial and experimental apple (Malus pumila Miller; Rosaceae) cultivars were studied to evaluate host resistance as a potential management strategy. Preferences were determined using field surveys of adult visitation, larval infestation of apples, damage at harvest, behavioural bioassays, and electrophysiological tests. Significant differences in visitation and infestation were observed. H. testudinea preferred “Zestar!”, “s23-06-153”, and “Pinova” over other cultivars examined. Comparison with subsequent larval counts and damage also suggest differential performance of larvae in several cases, irrespective of the adult preference. Y-tube bioassays and electroanntennography results indicate that olfaction plays a role in cultivar discrimination for this species.


2012 ◽  
Vol 144 (6) ◽  
pp. 779-791 ◽  
Author(s):  
G.C. Cutler ◽  
J.M. Renkema ◽  
C.G. Majka ◽  
J.M. Sproule

AbstractThe Carabidae (Coleoptera) are a diverse family of beetles with almost 300 species identified in Nova Scotia, Canada. Carabid beetle communities have been studied in several agricultural systems, but not wild blueberries, an important crop in eastern Canada. In the interest of potentially developing conservation biological control programs in wild blueberry, we collected Carabidae in crop (fruit-bearing) and sprout (vegetative) blueberry fields in Nova Scotia in order to assess species diversity and abundance over space and time. Over 3200 specimens were collected, representing 51 species. A large portion of collected specimens (39%) were nonnative, and the most abundant species were generally predacious and synanthropic. Species diversity tended to be higher near forest edges than further into fields, but not for all abundant species. Several of the most prominent predators showed significant differences in preference of crop versus sprout fields, distribution throughout fields, and seasonable abundance. These findings have implications for conservation biological control efforts with carabid beetles against several insect pests in wild blueberry.


2009 ◽  
Vol 6 (2) ◽  
pp. 2751-2793 ◽  
Author(s):  
M. J. Gauthier ◽  
M. Camporese ◽  
C. Rivard ◽  
C. Paniconi ◽  
M. Larocque

Abstract. A modelling study of the impacts of subsurface heterogeneity on the hydrologic response of an 8 km2 catchment in the Annapolis Valley (Eastern Canada) is reported. The study is focused in particular on the hydraulic connection and interactions between surface water and groundwater. A coupled (1-D surface/3-D subsurface) numerical model is used to investigate, for a range of scenarios, the spatio-temporal patterns of response variables such as return flow, recharge, groundwater levels, surface saturation, and streamflow. Eight scenarios of increasing geological complexity are simulated, introducing at each step more realistic representations of the geological strata and corresponding hydraulic properties. In a ninth scenario the effects of snow accumulation and snowmelt are also considered. The results show that response variables and significant features of the catchment (e.g., springs) can be adequately reproduced using a representation of the geology and model parameter values that are based on targeted fieldwork and existing databases, and that reflect to a sufficient degree the geological and hydrological complexity of the study area. The hydraulic conductivity values of the thin surficial sediment cover (especially till) and of the North Mountain basalts emerge as key elements of the basin's heterogeneity for properly capturing the overall catchment response.


1955 ◽  
Vol 87 (11) ◽  
pp. 503-505 ◽  
Author(s):  
D. M. MacLeod

During an investigation into the importance of fungal disease as a factor in the control of orchard pests throughout the Annapolis Valley, Nova Scotia, the haemocoele of large numbers of Macrosiphum pisi (Kaltenbach) was found to be infected with a fungal growth that resulted in death. This fungus was identified from mounted specimens as Empusa (= Entomophthora) aphidis Hoffman.


2020 ◽  
Vol 152 (3) ◽  
pp. 374-388
Author(s):  
Suzanne Blatt ◽  
Deney Augustine Joseph ◽  
G. Christopher Cutler ◽  
A. Randall Olson ◽  
Scott White

AbstractCarrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), is a pest of carrot (Daucus carota var. sativus Hoffmann; Apiaceae) throughout eastern Canada. Carrot weevil emergence and oviposition were monitored in commercial carrot fields in Nova Scotia. Cumulative degree days were calculated using a base temperature of 7 °C (DD7), and models were developed to predict cumulative emergence and oviposition using nonlinear regression. Cumulative emergence and oviposition were adequately explained as functions of DD7 by a three-parameter sigmoidal Hill equation. Our emergence model predicted initial and peak adult emergence at 35 and 387 DD7, respectively, with oviposition on carrot baits occurring as early as 42 DD7. Models were then validated to evaluate how well they performed. Oviposition on carrot plants began at the fourth true-leaf stage (342 DD7) and continued until eleventh true-leaf stage. Growers using these models can identify their window of opportunity to manage their carrot weevil populations targeting the majority of emerged adults before oviposition begins in the field.


2011 ◽  
Vol 125 (1) ◽  
pp. 58 ◽  
Author(s):  
Jean-David Moore ◽  
John Gilhen

Three colour morphs of the Eastern Red-backed Salamander, Plethodon cinereus, are known in eastern Canada: red-backed, lead-backed, and erythristic. Anomalies, including two albino and four leucistic individuals, are also known from eastern Canada. We report the first salamander individuals exhibiting amelanism, which is a lack of black skin pigment, but with black eyes, one from Quebec and one from Nova Scotia, Canada.


2013 ◽  
Vol 126 (4) ◽  
pp. 328
Author(s):  
Eric L. Mills

Based on several lines of evidence, a specimen of an adult white-morph Reddish Egret (Egretta rufescens) now on display in the Macdonald Museum of the Annapolis Valley Historical Society in Middleton, Nova Scotia, probably originated from the 19th-century Nova Scotian bird collections of Thomas McCulloch senior (1776–1843) and his son Thomas (1809–1865), likely between 1838 and 1865. The only other records of this species in Canada are sightings in Nova Scotia in 1965 and 1966. This may therefore be the first specimen evidence of the species in Nova Scotia and Canada. Historical evidence links the specimen with the McCulloch collection of birds, part of which has survived at Dalhousie University.


1937 ◽  
Vol 69 (7) ◽  
pp. 145-146
Author(s):  
F. C. Gilliatt

Eulia mariana Fern. was identified in Annapolis Valley orchards about twelve years ago and since has become one of the major orchard pests. Although outbreaks continue to occur, fruit growers should fully appreciate the value of natural control, which in one form or another is always assisting in keeping this insect in check. The various natural control factors may be recorded as follows:(1) Mortality of pupae. (2) Parasites of larvae and pupae. (3) Parasites of eggs. (4) Predators.


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