Delia flies (Diptera: Anthomyiidae) are economically important pests in several horticultural crops. The control is commonly relying on chemical insecticides, though there are possibilities with biological control from the natural enemies in the field. An important natural enemy is the parasitic wasp, Trybliographa rapae Westwood (Hymenoptera: Figitidae) that lays eggs in the Delia fly larvae. The parasitoid larva and the host larva have a parallel development until the host dies within its puparium and an adult parasitoid emerges. The aim of this thesis was to understand the attraction to host- and food-associated plant volatiles of T. rapae, in order to enhance the effectiveness of the parasitic wasp as a biological control agent.

The purpose of this paper is to examine what problems Cabbage growers have with the Swede Midge. The last few years the Swede Midge, Contarinia nasturtii, has become a larger problem for Cabbage growers in several countries in Europe as well as in Sweden. In Canada the problems are so severe that the midge is classified as a quarantine pest and therefore certain rules have to be followed. I have collected facts of the biology, host plants and reproduction of the Swede Midge, as well as the growers experiences and the occurrence of the midge in Canada, Europe and Sweden. The Swede Midge is hard to control because of its short life cycle and the larvae are protected between the heartleaves of the plant. When the larva feeds on the growth point the plant becomes distorted, in some cases several heads develop or none at all. When the midge infests spring rape its flower buds become undeveloped and rosette like.

Larvae of Lepidopteran Manduca sexta and Spodoptera littoralis are pests of economical importance in several horticultural and agricultural crops. Knowledge of insect feeding preferences and behavior is crucial in order to find economically and ecologically sustainable solutions to the problems caused by these herbivores. The aim of this thesis was to study the behavior and the induced feeding preferences in larvae of M. sexta and S. littoralis when reared on certain host plants. The hypothesis was that larvae of M. sexta would have an innate preference for plants of the Solanaceae family and therefore discriminate the previously experienced nonhost when faced with the choice between a true host and the previous food source.

The objective of this report is to present a review of the studies which has been carried out up to days date concerning how temperature affects vegetables physiologically when it comes to their health inducing as well as quality reducing features. The essay therefore starts off with defining what is meant by the terms health promoting and quality reducing features. It then moves on to describe how different subspecies of Brassica oleracea, that is to say vegetables such as broccoli, cauliflower, Brussels sprouts and kale, is affected by temperature. B. oleracea was chosen because the species contains several commercially interesting subspecies and therefore provides a broad field even though only one species is assessed.

The purpose of this report is to examine the possibilities to decrease the number of insects and other pathogens in a crop of pak choi (Brassica rapa), grown with different types of cover and living mulches. Included in the report is a study of literature where amongst others, a summary on the vegetable pak choi and theories of living mulches and different kind of covers are to be found. To examine the amount of predators in the field, traps were used. During the autumn 2002 the tests were conducted in Alnarp. The pak choi and the living mulches were planted/sawn at the same time, the different covers were also applied at this time. The total experiment was divided into six different treatments (plus control) of which three were with covers and three were with living mulches. Once a week the number of leaves, the height and damages were read on ten of the plants from each parcel.

This study was made to compare and distinguish any differences in olfactory recognition and host plant adaptation between two strains of cotton leaf worm, Spodoptera littoralis. The populations used were established in Egypt and Benin, Africa. The documentation consisted of information about (1) each of the strains development through the larval stage up to pupation on diets of cotton, clover and cowpea. (2) Their oviposition preferences as adults between cotton, clover, cowpea, maize and Cabbage. (3) Electroantennographic recordings to quantify any possible responses to plant volatiles. Throughout the diet experiments the larvae from the Benin strain showed significantly a better development between artificial, clover, cowpea and cotton respectively, while the Egypt strain had significance between artificial, cotton and cowpea/clover as diet. Also noted was how the strains substantial development of weight differentiated if fed the cotton diet, followed by the cowpea diet showing that the Benin strain would develop a higher body mass on a cotton diet as well as on a cowpea diet. This trend was however switched once the pupal stage was reached, where the Egyptian strain contained a significantly greater body mass than the Benin strain on the artificial and the Benin strain a greater on cowpea, which suggests that in the end, the Benin strain develops significantly better on cowpea while the Egypt strain develops better on an artificial diet. During the oviposition experiment that both stains showed a clear difference in hierarchy of host plants considered suitable for oviposition, where the Egyptian strain is significantly more attracted to clover than the Benin strain. Also showed with electroantennographic recordings and significant values was the higher sensitivity the Egypt strain had towards (E)2-hexenal, (E/Z)-b-ocimene, (Z)-3-hexenyl acetate, Nonanal, (-)-linalool and ?-myrcene when compared to the responses from the Benin strain..

The price trend on rapeseed the latest years has led to an increasing interest to grow the crop among many farmers in Sweden. The price trend has resulted in more than a doubling of the oilseed area since the early 2000s. For many farmers it is an advantage to increase cultivation of rapeseed because of the high proportion of cereals in the crop rotation on many farms, but it is not just benefits. The risk of the fields being infected by clubroot increases within frequent rapeseed cultivation and it often leads to subtantial economic losses. Clubroot is caused by Plasmodiophora brassicae that is a soilborne pathogen in genus Protozoa and its resting spores can be found in the soil for up to 18 years.

The open air museum of Disagården is situated in the Old Uppsala parish, Uppsala municipality, are projected to portray a double row village, before the land enclosure, on the Uppsala plain during the 1860s and 1870s. Disagården operates under the County Museum of Uppland and serves as an exhibit of Uppland's farming culture during the late 19th century. However, an open-air museum is a complex institution where many interests are linked together. Disagården aims to simultaneously portray an historical environment while offering broad public appeal. The Disagården open air museum was inaugurated in 1931 and consists of relocated buildings that together form three farm complexes "Gränbygården", "Skuttungegården" and "Bärbygården". The thesis explores how the close surroundings of a typical farm in Uppland looked during the 1860s and 1870s. This historical depiction has then been applied to Disagården in a development suggestion creating a foundation from which Disagården can structure the close cultivation of the different farms. The basis of the development program has primarily been compiled through archival and literary studies but also through on-site visits and interviews. How did the concept of open air museums start and what were the ideas behind the concept? Which external influences affected the situating of cultivations and buildings? Which crops and species were present on the farms in Uppland during the specified time period? What was the relation of the different structures to each other? Which organizations had influences on the farmer's household of the Uppland plain? The thesis attempts to clarify the answers to these questions. The influences affecting on the farmer's household in Uppland were probably numerous.

Summary The estate of Johannishus is situated in the south of Sweden and in the province of Blekinge, about 8 kilometres from the city of Ronneby. The main building together with the park represents the province´s only example of a well preserved estate environment from the early 1800th Century, and was declared as a historic monument in 1982 because of its unique role in the province. Johannishus Park has during 300 years developed in close relation to the main building, the landscape and the surrounding infrastructure. Each century and owner has had an influence on the park, which has resulted in an interesting visible cross-section of 300 years of Swedish garden history. Most noticeable today are the traces from late 19th Century, but in its oldest parts the park contains structures from the early 18th Century.