Agathis bishopi (Nixon) (Hymenoptera: braconidae) its biology and usefulness as a biological control agent for false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: tortricidae), on citrus bishopi (Nixon) (Hymenoptera: braconidae) its biology and usefulness as a biological control agent for false codling moth (FCM), Thaumatotibia leucotreta (Meyrick) (Lepidoptera: tortricidae), on citrus
- Authors: Gendall, Kierryn Leigh
- Date: 2008
- Subjects: Cryptophlebia leucotreta -- Parasites , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Tortricidae , Braconidae , Citrus -- Diseases and pests
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:5635 , http://hdl.handle.net/10962/d1005317 , Cryptophlebia leucotreta -- Parasites , Cryptophlebia leucotreta -- Control , Pests -- Biological control , Tortricidae , Braconidae , Citrus -- Diseases and pests
- Description: The false codling moth, Thaumatotibia leucotreta (Meyrick) (Lepidoptera: Tortricidae), is one of the major pests of citrus in South Africa, the others being mealybug, Mediterranean fruit fly, bollworm and some mites. Due to problems such as the expense of pesticides, insects evolving pesticide resistance (Hogsette 1999), chemical residue on the skin of export fruit and the negative impact of pesticides on the environment, it became necessary to find alternative methods for pest control (Viggiani 2000). Agathis bishopi (Nixon) (Hymenoptera: Braconidae), a larval parasitoid of false codling moth known only from the Sundays River Valley area (Sishuba 2003), offers a means of control for the pest. A total of 11 389 navel oranges were collected from various orchards in the Addo/Kirkwood area, and false codling moth larvae infested 36.09% of the fruit. A single parasitoid species, A. bishopi, was reared from these larvae. In 2006 the highest parasitism rate, 11.43%, was recorded in May and in 2007, the highest parasitism rate, 13.27%, was in April. Agathis bishopi parasitizes larvae in instars 2 and 3, possibly due to the accessibility of these younger instars to the female parasitoid and possibly due to the length of the life cycle of this koinobiont. Second instar hosts yielded the highest number of parasitoids, and there was no emergence of parasitoids from fifth instar larvae. Females of A. bishopi live for 18.5 days (n = 20; S.E. = 3.1) and males for 8.25 days (n = 20; S.E. = 1.23). Females produce an average of 23 offspring in a lifetime, while female false codling moths produce about 800 eggs each. A high number of parasitoids will be required per hectare to reduce the population of false codling moth. Captive rearing of A. bishopi proved difficult due to viral and fungal contamination. Agathis bishopi has potential for use in an integrated pest management programme once the hurdle of mass-rearing has been overcome.
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- Date Issued: 2008
Road culture : an investigation of the road as a means of mental and physical exploration
- Authors: Meistre, Brent Arthur
- Date: 2000
- Subjects: Roads in art , Travel in art , Travel -- Psychological aspects , Travelers -- Psychology
- Language: English
- Type: Thesis , Masters , MFA
- Identifier: vital:2414 , http://hdl.handle.net/10962/d1002210 , Roads in art , Travel in art , Travel -- Psychological aspects , Travelers -- Psychology
- Description: Chapter one considers various manifestations of the concept of ‘journey’ and how they have changed over history. The Odyssean journey that the hero undertakes to reach a point of self-realisation is investigated. This leads to a other discussion of types of journeys such as pilgrimages, as well as ‘wandering’. These are contrasted with the twentieth century perceptions of journey. Questions of travel are then dealt with: how the nature of the traveller's path has changed over the centuries, various points of travel and gender, and how in the last century solitary travel has been transformed into mass tourism. The second chapter deals specifically with the motorcar, the mobility it enables and how it has led to the rise of a roadside culture. Different factors that influenced the rise of the motorcar are looked at. The motorcar as a cell and eroticism and the car are also investigated. The twentieth century city, it's restructuring, as well as the highway systems is discussed. In Chapter Three, the sense of freedom that the motorcar created is considered in particular reference to escape, aimlessness, and road weariness, as well as the landscape as a symbol of freedom. This leads to a discussion on the notion of speed, the sense of power and the romanticisation of death in car crashes. Chapter Four investigates masculinity and the road. The frontier as a place in the psyche of the male is also dealt with. The road as a means of testing and regaining masculinity in the mid-twentieth century is considered. Issues of the male domination of the land and the feminine are discussed, with the chapter ending with a brief examination of the woman as traveller. Lastly the masters’ submission exhibition, entitled RODE is discussed with direct reference to the theories investigated in the previous chapters. Individual works as well as the methodology are looked at closely.
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- Date Issued: 2000