The navel orangeworm, Amyelois transitella (Pyralidae) (Walker), is the most damaging Lepidoptera larva found on pistachio nuts (Pistacia vera L., Anacardiaceae). Pistachios have only relatively recently been planted in South Africa at Green Valley Nuts, a division of the Industrial Development Corporation, near Prieska in the Northern Cape Province. The navel orangeworm causes direct damage to pistachio nut clusters by feeding on individual nut kernels and contaminating nuts with their faecal excretions. In the process the quality of the nuts is reduced and the nuts are rendered more susceptible to fungal infection. After harvest, navel orangeworm larvae overwinter inside fallen nuts on the orchard floor, as well as inside nuts left behind on trees. The prevalence of navel orangeworm in mummy nuts was studied from May to September in 2008 and 2009 at Green Valley Nuts. The potential survival of the larvae in these nuts was estimated from nuts sampled under trees of three different pistachio cultivars (Ariyeh, Sirora and Shufra). Orchard row management practices were investigated to determine the effect of cover crops, mulch and hydro-cooling on navel orangeworm survival. This was done by monitoring emergence cages and light traps for the presence of navel orangeworm adults emerging from mummy nuts. In both years, navel orangeworm was noted overwintering in mummy nuts. The highest occurrence of navel orangeworm over the two year study period was recorded in nuts from Sirora, a cultivar planted in an orchard lacking inter-tree row cover crops, mulch and hydro cooling. The results support the assumption that these orchard row management practices have a suppressing effect on navel orangeworm development, causing high mortality rates due to mummy nut decomposition. Research was also conducted to observe the life cycle and behaviour of the pest under laboratory conditions. The complete life cycle duration of the navel orangeworm ranged from 50 to 84 days. A single life cycle which gave rise to a next generation was successfully tracked.

The first insects attracted to a decomposing body are usually representatives of the Diptera, in particular members of the families Calliphoridae (blow flies) and Sarcophagidae (flesh flies). These flies will deposit their eggs (or often larvae in the case of sarcophagids) on the body, within a few hours after death, depending on environmental conditions. The immature stages will complete their developmental cycle on and around the body. As a consequence, these insects are of great importance in forensic entomology; the main area of application being the determination of the postmortem interval (PMI). One of the key pieces of information needed to calculate the PMI is the correct species identification of the immature stages. The aim of this study was to provide diagnostic descriptions for the immature stages of forensically important calliphorids and sarcophagids in central South Africa. Forensically important calliphorids prevalent in this region are Lucilia cuprina (Wiedemann), Lucilia sericata (Meigen), Chrysomya chloropyga (Wiedemann), Chrysomya marginalis (Wiedemann), Chrysomya albiceps (Wiedemann) and Calliphora vicina Robineau-Desvoidy. The sarcophagid prevalent in the region is Sarcophaga cruentata Meigen. A range of characteristics was evaluated by means of light and scanning electron microscopy and the most pertinent of these were identified for diagnostic purposes. The eggs were evaluated in terms of nine characteristics; six of which were of no diagnostic use, while three could be used to identify some of the species. The eggs of C. chloropyga and C. albiceps were indistinguishable from each other. Twelve features were identified for their possible diagnostic value in larvae. In first instar larvae five of these characteristics were of no diagnostic value, while six were useful to identify some of the species. All species could, however, be identified with the aid of the cephalopharyngeal skeleton. For second instar larvae, four of the characteristics were of no diagnostic use, but seven were useful to identify some of the species. All the species could be identified using the cephalopharyngeal skeleton. In the third instar larvae four characteristics were of no diagnostic use, but by using three other characteristics some of the species could be identified. All the species could be identified by means of five morphological characteristics (labrum, cephalopharyngeal skeleton, posterior spiracles, spiracular plate and anal area). Seven characteristics were identified for their possible diagnostic values in puparia. Five of these characteristics were useful to identify some of the species, but all the species could be identified with the aid of two of the characteristics (frontal field and bubble membrane). The ultimate aim of the study was to construct keys for use during the identification of specimens found at the crime scene. The keys that were constructed not only mapped out the pertinent diagnostic characteristics, but also considered what characteristics could be combined when a specimen was viewed from a specific angle. Since specimens often reach the forensic laboratory in less than optimal condition, it is essential that a wide range of characteristics and keys be available during identification. This will also enable the forensic entomologist to give priority to specimen preparation and the method of observation when rapid analysis is needed or where very few good specimens are available for identification. With these tools (descriptive diagnostic characteristics and keys) the identification of immature stages of calliphorids and sarcophagids found at the crime scene should be an uncomplicated exercise.

Conflict between livestock farmers and predators has been an ongoing battle since the breeding of domestic animals were first attempted by man. Insufficient data on the dynamics of predators, especially in regions outside formal protected areas where they are perceived as problem animals, make control methods almost impossible. Due to complaints of predation by cattle farmers in the unspoiled Roodewalshoek Conservancy, the dynamics of livestock predation was investigated. Specific emphasis was placed on the relationship between the ecological traits of leopard, brown hyaena and natural prey species and the consequences thereof on livestock losses. Investigations were carried out by means of motion-sensing camera traps, combined with seasonal field observations of all physical signs of animals. The presence of recorded prey species showed a monthly variation, with some prey species present all year round while others showed definite periods of occurrence. Rainfall seemed to have some influence on the occurrence of such species. Most small potential prey species was observed continuously during the winter months and only sporadically during the summer. Medium sized potential prey species that occurred on a constant basis throughout the year in the study area included bushbuck, Chacma baboons and common grey duikers. Sporadic occurrence of impala and mountain reedbuck were encountered mostly during the mid-summer months, especially during December. All species classified as large prey were continuously present throughout the year, except for the aardvark which showed a sporadic presence and were mostly observed during mid-summer. Large predators were continually observed in the conservancy except in late summer during the month of January and reached highest numbers during early autumn, mid-winter and in the height of summer. All the other predators, including small and medium-sized predators, were present on a frequent basis except during late summer and only reached a high in mid-winter and early spring. It was also evident that, when the presence of large predators in the study area increased, the presence of other predators diminished. The majority of calves (59%) were killed by predators during the wet summer months, while only 41% of calves were predated upon during winter months with low precipitation. Lunar cycles seem to play a distinctive role in livestock predation with almost two thirds of calves lost to predators when moonlight intensity was low. Even though sufficient occurrences of natural prey could be found in the Roodewalshoek Conservancy, predation on livestock persists during the calving season. Regarding the key predator of livestock in the conservancy, both leopards and brown hyaenas were almost equally accountable and displayed alternating periods of calf predation. Instances of predation where the problem animal could be identified, implicated brown hyaenas in 48% and leopards in 52% of livestock losses. During times when brown hyaenas were responsible for the most calf losses, predation caused by leopards was low. High incidences of leopard predation consequently resulted in lowered brown hyaena predation. This could be due to inter-predator competition for shared resources. The behaviour of surplus-killing by both predator species is indicative of the ability to fully exploit all the available resources in their area. The relatively large number of livestock lost to predation each year may be due to a combination of several factors. These include the lack of predator control in adjacent game farms and other protected areas, continuous presence of livestock, leopards and brown hyaenas as well as the open, unattended system in which livestock is kept in the Roodewalshoek Conservancy.

A diverse and abundant nematode fauna is known to exist in South Africa with plant parasitic nematodes being the most representative. Seven genera belonging to the family Belonolaimidae Whitehead, 1960 are known to occur in South Africa, including Histotylenchus Siddiqi, 1971, a small genus only found in Africa and India. Nematodes belonging to the family Belonolaimidae are obligatory, primarily migratory ectoparasites of roots. These nematodes are found in cultivated soils and natural veld and are usually seen as mild plant parasites. Histotylenchus is represented by three species from South Africa, namely Histotylenchus hedys Kleynhans, 1975, Histotylenchus histoides Siddiqi, 1971 and Histotylenchus mohalei Kleynhans, 1992. Diagnostic characters of Histotylenchus include a lip region confluent with body contour or offset, asymmetrical stylet conus with an angular lumen, a large metacorpus valve, genital tracts about equal, lateral fields with four lines usually areolated, spicules tapering distally with distinct vela and gubernaculum proximally recurved with titillae. The aim of this study was to review all existing literature concerning the genus Histotylenchus in Africa, and to examine and describe the species from this genus collected in South Africa, which are deposited in the National Collection of Nematodes, Biosystematics Programme, Agricultural Research Council, Plant Protection Research Institute, Pretoria, South Africa. Results showed that a total of 44% of the fixed material examined was not suitable for this morphological study as a result of the separation of the cuticle from the body. This phenomenon is reported from this genus for the first time. Histotylenchus hedys and Histotylenchus mohalei were re-described from material of the National Collection of Nematodes, while Histotylenchus histoides was re-described from type material of the Rothamsted Nematode Collection housed at the Food and Environment Research Agency (Fera), York, United Kingdom; and CABI Bioscience, Egham, United Kingdom. A new species, Histotylenchus niveus sp. n., was described from material collected in the Witsand Nature Reserve, Northern Cape, South Africa. Additionally, two species Histotylenchus sp. 1 and Histotylenchus sp. 2 were described during this study and could possibly be new to science. However, additional material needs to be collected to verify these results. The present study revealed that further research into the genus is necessary, especially since the current information is limited and incomplete.

In the Qwa-Qwa and Thaba Nâchu regions of the Free State Province, South Africa, resource limited farmers that produce wheat are mainly situated in temporary crop environments. They are drastically affected by crop losses that occur during years of serious Russian wheat aphid (Diuraphis noxia) (Kurdjumov) and oat aphid (Rhopalosiphum padi) (Linnaeus) infestations. Therefore the main objective of this study was to identify simple alternate control methods to be used by small-scale farmers for the control of these aphids. The focus was on minimizing the numbers of the immigrating individuals. That must happen before they arrive in the crop habitat and decrease the possibility of the pest population reaching damaging levels when the crop is still in its susceptible phase for insect damage. Plant derived semiochemicals, which could modify insect behaviour, were considered as an option to be used since this could be extracted from plants, and were demonstrated to be successful in other countries. These semiochemicals are also known to attract natural enemies of these insects. It was therefore decided to test two types of extracts (an aqueous and a light mineral oil) which could be easily prepared from four plant species, namely Wild wormwood Artemisia afra (Jacq. ex Willd.), Big thorn apple Datura stramonium (Linnaeus), Khaki bush Tagetes minuta (Linnaeus) and Wild garlic Tulbachia violacea (Harv.). The plants were chosen due to their availability in the wheat production regions and their possible insect repelling properties known from other species in the same genera. The behavioural response of alate aphids D. noxia and R. padi and two parasitoids, Aphelinus hordei (Kurdjumov) and Diaeretiella rapae (McIntosh) to these extracts was tested in olfactometer trials in the laboratory. The aphid D. noxia showed the highest repellence to the aqueous extract of A. afra and the oil extract of T. violacea. Aphid R. padi was also best repelled by the aqueous extract of A. afra and the oil extract of D. stramonium. The parasitoid A. hordei was strongly attracted to the aqueous extracts of A. afra and T. minuta. Diaeretiella rapae on the other hand, was also highly attracted to the aqueous extract of T. minuta, but T. violacea oil extract had a very strong effect on the parasitoid and would be recommended to farmers. Artemisia afra and T. violacea are perennials and available as green material for extraction purposes in the winter when wheat is planted. The other two plants are annuals and not available in winter. The A. afra aqueous extract will repel both aphid species when sprayed early in the wheat growing season when wheat is still small and aphids are flying into the wheat. This extract will also attract A. hordei and this could enhance the biological control of D. noxia. The T. violacea oil extract could also be used to repel D. noxia. It could also be used to attract the parasitoid D. rapae later in the season and enhance the biological control of both aphid species. Thus there are potential alternate simple aphid control methods available for small-scale farmers. These methods should be refined and farmers trained to use them effectively.

The larvae of some insects arrange themselves in a tight, orderly circle at rest; a behaviour that Vasconcellos-Neto and Jolivet (1988b) first called "cycloalexy". The word was defined by Jolivet and collaborators in 1990 as a defensive behaviour adopted by insect larvae that form a tight circle with the best defended extremity at the periphery, either heads or abdomens. The formation is also associated with coordinated movements to repel threats. The term has steadily gained acceptance and expanded to include insect nymphs, adult insects and even vertebrates. We review reports of cycloalexy and find the behaviour is less common than suggested. Convincing examples are found only in sawflies, leaf beetles, caterpillars, one weevil and one midge species. We question reports of cycloalexy in penguins, an amphipod crustacean, nymphs of Hemiptera and larvae of Hymenoptera and Neuroptera. We argue that analogous behaviours in mammals are reactive rather than preventive and, hence, not cycloalexic. A molecular phylogeny was reconstructed to evaluate the relationships of 70 species of Neotropical Chrysomelinae and the evolution of cycloalexy. We sequenced five gene segments: nuclear protein-coding CAD and 28S rDNA, mitochondrial 12S rDNA and protein-coding COI and COII. The phylogeny was inferred using Bayesian and Maximum Likelihood (ML) methods and ancestral larval behaviour was reconstructed with ML and Maximum Parsimony methods. The ancestral behaviour reconstructions show five independent evolutionary origins of larval gregariousness in Neotropical chrysomeline beetles, two with maternal care and circular grouping of larvae and one accompanied by cycloalexy. Further, our phylogeny clarifies relationships within Chrysomelinae, and shows a revision is needed: the genus Stilodes is paraphyletic with Zygogramma, Platyphora is polyphyletic and divided into two clades; one with Doryphora nested within and the other with Proseicela. / Les larves de certains insectes forment un cercle serré et ordonné au repos, un comportement appelé « cycloalexie » pour la première fois par Vasconcellos-Neto et Jolivet) (1988b). Le mot a été défini par Jolivet et collaborateurs en 1990 comme étant un comportement défensif de larves d'insectes qui forment un cercle serré, avec l'extrémité la mieux défendue à la périphérie. soit leurs têtes ou leurs abdomens. La formation est aussi associée à des mouvements coordonnés du groupe pour repousser les menaces. Le terme a progressivement gagné en acceptation et s'est élargi pour inclure des nymphes d'insectes, des insectes adultes et même des vertébrés. Nous faisons la revue des rapports de cycloalexie et trouvons que le comportement est moins rependu que suggéré. Les exemples convaincants ne se retrouvent que chez les mouches à scie, les chrysomèles, les chenilles, une espèce de charançon et une de moucheron. Nous questionnons les rapports de cycloalexie chez les manchots, un crustacé amphipode, des nymphes d'hémiptères et des larves d'hyménoptères et de névroptères. Nous suggérons que les comportements analogues chez les mammifères sont réactifs plutôt que préventifs, et donc pas cycloalexiques. Une phylogénie moléculaire a été reconstruite pour évaluer les relations de 70 espèces de Chrysomelinae néotropicales et l'évolution de la cycloalexie. Nous avons séquencé des segments de cinq gènes : les gènes nucléaires CAD codant et 28S ribosomal, et les gènes mitochondriaux 12S ribosomal et COI et COII codants. La phylogénie a été inférée en utilisant des méthodes bayésienne et de Maximum de Vraisemblance (MV), le comportement ancestral des larves a été reconstruit à l'aide de méthodes de MV et de Maximum de Parcimonie. La reconstruction du comportement ancestral montre cinq origines évolutives indépendantes du grégarisme des larves chez les chrysomèles Néotropicales, deux avec soins maternels et regroupement circulaire des larves et une accompagnée de cycloalexie. De plus, notre phylogénie clarifie les relations à l'intérieur des Chrysomelinae, et montre qu'une révision est nécessaire : Stilodes est paraphylétique avec Zygogramma, Platyphora est polyphylétique et divisé en deux clades; l'un avec Doryphora imbriqué dedans et l'autre avec Proseicela.

Integrated pest management (IPM) uses multiple approaches to keep pest levels below economic injury levels. Integrated pest management combines preventative methods such as biocontrol with curative methods; this synthesis requires an understanding of the ecology of natural enemies in the agroecosystem. Arthropod natural enemy communities in apple orchards are diverse, and spiders (Araneae) are particularly abundant and species rich. Orchard arthropods are affected by multiple factors, both external (e.g. immigration) and internal (e.g. pesticides) to the orchard environment. In this thesis I explored the influence of these factors on natural enemy communities in apple orchards. I investigated which natural habitats adjacent to orchards are potential sources of spiders, and the influence of distance from a source habitat on the composition of colonizing spider assemblages. I tested how kaolin clay, a pest management technique, affects orchard generalist predator communities and the parasitoids of a pest species and prey item of spiders, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae). I also examined how applications of kaolin to apple foliage affect the behaviour of C. rosaceana larvae and whether this alters the predation on larvae by spiders. Comparisons of spider assemblages in natural habitats adjacent to apple orchards in southern Québec indicated that deciduous forest had spider assemblages similar in to those in the orchard foliage. The composition of the spiders that colonized the apple orchards changed over a small spatial scale (10-50 m). The relative abundance of individuals among spider species in older orchards was more evenly distributed than in assemblages of recently colonized spiders, suggesting that local dynamics also shape the composition of the spider assemblages over time. Kaolin on apple leaves changed C. rosaceana larval behaviour: third and fourth instar larvae and neonates took longer to build leaf shelters, and ne / La lutte intégrée combine plusieurs méthodes de lutte pour maintenir les populations de ravageurs sous des seuils d'intervention. Ces méthodes incluent des mesures préventives, comme l'augmention des agents de lutte biologique, et des mesures curatives. Cette synthèse nécessite des connaissances sur l'écologie des vergers et ses espèces. Les communautés d'espèces utiles dans les vergers sont diverses, et les assemblages d'araignées (Araneae) sont notamment abondants et riches en espèces. Plusieurs facteurs affectent les organismes dans les vergers, incluant les facteurs externes (ex. immigration) et internes (ex. l'application d'insecticides). Dans cette thèse, j'ai étudié l'influence de ces facteurs sur les communautés d'araignées et d'autres espèces utiles. J'ai déterminé quels habitats adjacents au verger ont le potentiel d'être des sources d'araignées, et comment la distance de la source change les dynamiques de colonisation des vergers par les araignées. J'ai déterminé les effets du kaolin (un pesticide à base d'argile) sur les assemblages de prédateurs arthropodes et parasites du ravageur Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae) dans les vergers. Les forêts adjacentes au verger ont des assemblages d'araignées similaires à ceux des vergers, vraisemblablement parce que leur structure végétale et leur niveau de dérangement temporel sont semblables. La composition des assemblages d'araignées change à petite échelle spatiale (10-50 m). La répartition des individus parmi les espèces des assemblages d'araignées dans les vergers établis était plus homogène que celle des vergers récemment colonisés. Ceci suggère que les dynamiques locales façonnent aussi la composition des assemblages d'araignées. Le kaolin a changé le comportement des larves de C. rosaceana: les larves ont requis plus de temps pour se faire un abri sur les tiges traitées avec le kaolin. Les larves néonates se sont dispe

No description available.

The effects of biotic and abiotic characteristics on Schizophora (Diptera) assemblages in six temperate eastern Nearctic bogs were examined. The main objectives were to investigate the impact of bog size, vegetation structure and surrounding land use on Schizophora diversity and species composition. More than 380 species of Schizophora were collected, indicating that these bogs support a diverse Diptera community. Vegetation structure and land use within a 1500 m radius around the sampling location significantly influenced the species compositions and explained the diversity patterns found at the sites. Bog size did not have a significant impact on species richness, possibly due to the flow of non-bog restricted species from the surrounding landscape. From these results, it was concluded that conservation strategies in eastern Nearctic bogs should promote intermediate levels of agriculture and forested landscape up to 1500 m around a bog in order to support healthy ecosystems with high Schizophora diversity. / Les effets de plusieurs facteurs biotiques et abiotiques sur les assemblages de Schizophora (Diptera) de six tourbières situées dans la zone tempérée de l'est de la région néarctique ont été examinés. Les objectifs généraux de ce projet étaient d'étudier les impacts de la superficie des tourbières, la structure de la végétation ainsi que l'utilisation des terres avoisinantes sur la composition et la diversité des assemblages de mouches schizophores. Plus que 380 espèces de Schizophora ont été échantillonnées, indiquant que ces tourbières supportent une communauté de diptères diverse. La structure de végétation a chaque site et l'utilisation des terres environnantes jusqu'à 1500 m des sites d'échantillonnage ont significativement influencé la composition des espèces et expliqué les patrons de diversité inhérent aux sites. La superficie des tourbières n'a pas eu d'impact significatif sur le nombre d'espèces, possiblement en raison du mouvement des espèces du paysage environnant qui ne sont pas restreintes aux tourbières. Ces résultats indiquent que les stratégies de conservation dans les tourbières de l'est de la région néarctique devraient promouvoir le maintient d'un niveau intermédiaire d'intensité agricole ainsi que des terres boisées dans un rayon allant jusqu'à 1500 m autour des tourbières pour maintenir des écosystèmes sains supportant une importante diversité de mouches schizophores.

<p> Mealybugs (Hemiptera: Sternorrhycha: Pseudococcidae) are important agricultural pest that affect hundreds of plants species of economic importance. This taxonomic study of Puerto Rico's pseudococcids contains a list of the actual pseudococcids including their descriptions, biology and hostages range of each species. This study also develops a taxonomickey and reference collection of pseudococcids of Puerto Rico including the species of most economic importance and those of recent introduction. For the Puerto Rico's pseudococcids were reviewed the works of Wolcott (1948), Martorell (1976), Nakahara and Miller (1981), Williams and Granara de Willink (1992), Gimpel and Miller (1996), Granara de Willink (2009), USDA/APHIS/PPQ (1989 - 2013). It was obtained a list of 47 species in 20 genus of Pseudococcidae of Puerto Rico. The taxonomy and classification of the mealybugs it is based in the morphology of females. There have been phylogenetic studies in which it is pretended to establish their principal clades as those of Downie and Gullan (2004) and Hardy et al (2008) which recovered two primary clades of Pseudococcidae, to which they applied the names of subfamilies, Phenacoccinae and Pseudococcinae. Applying Hardy et al (2008) classification to the species of Puerto Rico there was left 19 genus and 46 species as Hardy excluded the genus Puto from Pseudococcidae and put it in Putoidae. From 2008 to 2010, 72 field samples were collected, which are parts of vegetable crops and unknown ornamental plants were found affected by Pseudococcidae. The sampling is centered in 20 towns of Puerto Rico. There were identified 15 species that do harm to crops. This works has shown the need to generate more information about Pseudococcidae in Puerto Rico. To the effect of this study of mealybugs it were reported 14 species of pseudococcids. To present time there have reported 47 species of which one of them is another family Putoidae.</p>