Assessing new chemical control options for the carrot weevil ( Listronotus oregonensis ) and carrot rust fly ( Psila rosae ) in Ontario

AbstractA survey of the insect pests of carrots was conducted in the organic soils of southwestern Quebec with a view to establishing the presence of the carrot weevil, Listronotus oregonensis (Lec.), in this province as well as to confirm the importance of other pests damaging carrot crops. Four different methods were used to capture adults, and the root sampling method was used for establishing larval populations.The carrot weevil was captured by light trap for the first time in Quebec on 1 June 1967, but was neither recognized nor identified until June 1970 when a few specimens were obtained again by light trap set at Ste. Clotilde and by colour traps placed in the experimental fields used for the survey in 1970. Damage caused by this new pest on carrots ranged from 2.0% to 22.0% root injuries throughout the carrot growing areas of the organic soil regions of Sherrington, St. Michel, and Ste. Clotilde representing several thousands of acres. The carrot rust fly, Psila rosae (F.), was the only other carrot pest captured, but has been found to be of no importance in these areas.

Download Full-text

Population variability of a native and an introduced herbivore of carrots (Apiaceae)

The Canadian Entomologist ◽

10.4039/tce.2017.31 ◽

2017 ◽

Vol 149 (5) ◽

pp. 592-599 ◽

Cited By ~ 5

Author(s):

Robert J. Lamb ◽

Guy Boivin

Keyword(s):

Introduced Species ◽

Native Species ◽

First Generation ◽

Population Variability ◽

Psila Rosae ◽

Native Populations ◽

Listronotus Oregonensis ◽

Carrot Weevil ◽

Trap Catches

AbstractLong-term, twice weekly, trap catches of the native carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), and the introduced carrot rust fly, Psila rosae (Fabricius) (Diptera: Psilidae), were used to test the hypothesis that native populations fluctuate less from year-to-year than those of introduced species, because the native species has had more time to adapt to temporal variability in its habitat than an introduced species. Variability in annual abundance was estimated for 33 years, and for 11-year or 16–17-year subsets of the 33-year time series. Temporal population variability was quantified as PV, a proportion between 0 and 1. The native carrot weevil had a PV of 0.39, less than that of the introduced carrot rust fly with a PV of 0.67, supporting the hypothesis. Generation 1 for both species showed a decline in PV over three decades consistent with the hypothesis that adaptation to variability in the habitat leads to lower PV. Over 33 years, the carrot weevil developed a second generation with a PV of 0.70, higher than that of the first generation, which is consistent with the hypothesis that adaptation is required to stabilise population dynamics in a new habitat, in this case a new temporally defined habitat.

Download Full-text

Degree-day models to predict carrot weevil (Coleoptera: Curculionidae) emergence and oviposition in Nova Scotia, Canada

The Canadian Entomologist ◽

10.4039/tce.2020.19 ◽

2020 ◽

Vol 152 (3) ◽

pp. 374-388

Author(s):

Suzanne Blatt ◽

Deney Augustine Joseph ◽

G. Christopher Cutler ◽

A. Randall Olson ◽

Scott White

Keyword(s):

Nova Scotia ◽

Adult Emergence ◽

Hill Equation ◽

Base Temperature ◽

Degree Days ◽

Eastern Canada ◽

Leaf Stage ◽

True Leaf ◽

Listronotus Oregonensis ◽

Carrot Weevil

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.

Download Full-text

THE LIFE HISTORY OF THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (COLEOPTERA: CURCULIONIDAE) UNDER CONTROLLED CONDITIONS

The Canadian Entomologist ◽

10.4039/ent108931-9 ◽

1976 ◽

Vol 108 (9) ◽

pp. 931-934 ◽

Cited By ~ 17

Author(s):

P. Martel ◽

H. J. Svec ◽

C. R. Harris

Keyword(s):

Life History ◽

Life Cycle ◽

Larval Stage ◽

Egg Production ◽

Laboratory Studies ◽

Preoviposition Period ◽

Complete Life Cycle ◽

History Of ◽

Listronotus Oregonensis ◽

Carrot Weevil

AbstractLaboratory studies on the biology of the carrot weevil, Listronotus oregonensis (LeConte), were performed at 21° and 27 °C. At 21 °C females laid eggs for 88 days on carrot slices and 94 days on foliage. Egg production per female averaged 156 and 175 on slices and leaves respectively. Eggs hatched after 8.3 days incubation and the larval stage comprising four instars was completed in 19.1 days. The prepupal and pupal stages lasted 3.7 and 9.4 days respectively. The complete life cycle including an average preoviposition period of 17 days was 57.6 days. Development was more rapid at 27 °C, with the complete life cycle taking only 37 days.

Download Full-text

RELATIONSHIP BETWEEN TEMPERATURE AND DEVELOPMENT OF THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (LeCONTE) (COLEOPTERA: CURCULIONIDAE), IN THE LABORATORY

The Canadian Entomologist ◽

10.4039/ent1181287-12 ◽

1986 ◽

Vol 118 (12) ◽

pp. 1287-1290 ◽

Cited By ~ 5

Author(s):

A.B. Stevenson

Keyword(s):

Polynomial Function ◽

Rate Of Development ◽

Complete Development ◽

Cubic Polynomial ◽

Listronotus Oregonensis ◽

Excellent Description ◽

Carrot Weevil ◽

The Relationship

AbstractRates of development of selected stages and complete development of the carrot weevil, Listronotus oregonensis (LeConte), were determined in the laboratory at controlled temperatures ranging from 17.5 to 30°C. Within that range of temperature, rates of development increased with temperature. Fitting the data to a cubic polynomial function provided an excellent description of the relationship between temperature and rate of development for all stages as shown by R2 values of at least 0.98.

Download Full-text

A COMPARISON OF THREE METHODS OF MONITORING THE CARROT WEEVIL, LISTRONOTUS OREGONENSIS (LECONTE) (COLEOPTERA: CURCULIONIDAE)

The Canadian Entomologist ◽

10.4039/ent129187-1 ◽

1997 ◽

Vol 129 (1) ◽

pp. 187-194 ◽

Cited By ~ 2

Author(s):

A.B. Stevenson ◽

E.S. Barszcz

Keyword(s):

Seasonal Pattern ◽

Seasonal Activity ◽

Carrot Root ◽

Control Programs ◽

Linear Relationships ◽

Listronotus Oregonensis ◽

Carrot Weevil

AbstractThe carrot weevil, Listronotus oregonensis (LeConte), was monitored at 11 research or commercial carrot plantings at Holland Marsh, Kettleby, Ontario, using three methods, i.e. wooden plate (Boivin) traps to capture adults, carrot root sections placed in the soil to detect oviposition, and recording the numbers of adults present on carrot root sections. All three methods provided similar records of the seasonal pattern of adult activity. At most sites, thresholds used to determine the need for insecticide applications were reached or exceeded soon after the beginning of monitoring.There were significant linear relationships among the seasonal activity parameters generated by the three methods and between those parameters and percentage injury at harvest. Control programs that would have resulted from the use of each method are discussed.

Download Full-text

Apple powdery mildew caused by Podosphaera leucotricha: some aspects of disease management

International Journal of Horticultural Science ◽

10.31421/ijhs/20/1-2/1113 ◽

2014 ◽

Vol 20 (1-2) ◽

Cited By ~ 2

Author(s):

I. J. Holb

Keyword(s):

Biological Control ◽

Disease Management ◽

Powdery Mildew ◽

Chemical Control ◽

Apple Cultivar ◽

Apple Orchards ◽

Cultivar Resistance ◽

Podosphaera Leucotricha ◽

Control Options ◽

Apple Cultivars

Apple powdery mildew (Podoshphaera leucorticha) occurs wherever apples are grown. One of the most important fungal disease of apple which causing severe econimic loss on susceptible apple cultivars. This review focuses on the control of apple powdery mildew. The first part of the study provides details of novel aspects of non-chemical control approaches, including agronomic measures, mechanical and biological control options as well as essential features of apple cultivar resistance. After this, developments in chemical control options are described sperately for integrated and organic apple orchards.

Download Full-text

Floating Rowcovers Improve Germination and Reduce Carrot Weevil Infestations in Carrot

HortScience ◽

10.21273/hortsci.43.5.1619 ◽

2008 ◽

Vol 43 (5) ◽

pp. 1619-1622 ◽

Cited By ~ 12

Author(s):

Djamila Rekika ◽

Katrine A. Stewart ◽

Guy Boivin ◽

Sylvie Jenni

Keyword(s):

Early Development ◽

Daucus Carota ◽

Insect Control ◽

Harvest Time ◽

Emergence Time ◽

Fresh Weight ◽

Listronotus Oregonensis ◽

Carrot Weevil ◽

Leaves And Roots ◽

Weevil Infestation

A lightweight agrotextile floating rowcover (10 g·m−2) designed for insect control was evaluated for its potential to reduce carrot weevil [Listronotus oregonensis (Le conte)] damage and to improve germination and carrot (Daucus carota L.) yield. The floating rowcover had no effect on total emergence and spread on emergence time but decreased emergence time by 0.5 day. Although floating rowcovers generally increased fresh weight of carrot leaves and roots during early development, no effect was detected late in the season and at harvest time. Carrot weevil damage of uncovered plants was 0.4 tunnels per root in 2006 and 2.0 tunnels per root in 2005. In both years, covering carrots with a floating rowcover for a period of 35 days after sowing reduced carrot weevil damage by 65% to 75%. In most years with low or medium carrot weevil infestation, the use of a rowcover could eliminate the use of insecticide to control this pest.

Download Full-text