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[Summary]: The larvae of Anomala opacicollis (Pér), of Melolonthid and of other Rutelid species, attack tobacco in Southern Rhodesia, and are more commonly called "whitegrubs". Whitegrubs are widespread in the sandveld areas where tobacco is grown and, at the Trelawney Station of the Tobacco Research Board of Southern Rhodesia, where this work was done, A. opacicollis was the predominant species. An account o£ the one year life cycle is given. The adults eat the leaves of various indigenous trees and an account of an experiment on the food preferences of A. opacicollis adults is given, and the main food sources in the Trelawney area are listed. An experiment is described which shows that the beetles prefer to lay their eggs in the veld or in manured broken land rather than in normal ploughed lands. The larvae are erratically distributed in lands and experiments on larval movement suggest that this is mainly due to concentration of the larvae at discrete concentrations of organic matter in the soil. The temperature and moisture condition of the top 3" of soil are found to be those which attact the larvae. It is suggested that tho larvae prefer and move to soil which contains the lowest amount of moisture which keeps the soil air spaces saturated. lt appears that the preferred temperature decreases with increasing soil moisture content and it is suggested that this is due to the respiratory requirements of the larvae. Soil pH, compaction and fertiliser content and the presence of plants do not appear to influence larval movements. A theory is developed concerning the mechanism of movements in the soil and it is suggested that, in the absence of a continuous gradient, the speed but not the direction of movement is influenced by conditions to which the larvae are sensitive. Evidence in support of thie theory is given. Studies on the survival of larvae at different soil moisture contents and temperatures show that conditions in the top 3" of soil are not likely to be lethal in spite of the high temperatures and low moisture contents found there. The relation of whitegrub behaviour to agricultural problems is discussed. Other workers published evidence indicating that early ploughed lands were attractive to whitegrubs; this is shown not to be the case and the previous evidence is re-interpreted. Such lands tend to contain concentrations of whitegrubs round the borders. The reason for this is discussed and it is suggested that lands should be ploughed early to confine whitegrub infestations in this manner. Soils low in fertility through repeated cultivation are commonly believed to contain more whitegrubs than virgin soil. However, behaviour studies suggest that it is the activity and not the size of the population which is affected by soil fertility. The time at which tobacco is planted is known to determine the extent of subsequent whitegrub damage. The reason for this is to be found in the life cycle of whitegrubs and the results of an experiment on time of planting in relation to whitegrub damage are given. Some insecticides are shown to be more repellant than others to A. opacicollis larvae and the influence of this fact on the assessment of soil insecticide effectiveness in the field is discussed. Reference is made to a method developed by the writer for the determination of insecticide effectiveness under the conditions of erratic whitegrub distribution which normally occur.

The survey of the diversity of coprophagous beetles (Scarabaeidae, Geotrupidae, and Hydrophilidae families) and their soil activity took place at two sites in a cattle pasture in southern Bohemia (site A: 49°29'31.720"N, 14°23'44.310"E; site B: 49°29'23.257"N, 14°23'35.964"E; 575 m a. s. l.). Baited pitfall traps with fresh cow dung (1.5 l per trap) were used to capture the beetles. During the survey of the diversity of coprophagous beetle community, a total of 29 species of beetles numbering 1,189 specimens were captured from May to September 2013. Of these, the most numerous were the beetles of the genus Aphodius, who made up 79 % of the total number of captured specimens. In terms of biomass, Geotrupes spiniger (Marsham, 1802) was significant, in that it made up 24 % of the total biomass of all of the captured beetles. This species contributes most to the decomposition of dung in the pasture. The family with the least number of specimens was Hydrophilidae. Beetles from this family made up 19 % of total number. Measurement of soil activity took place repeatedly over the course of 3 weeks, always after one-week measurement of diversity. The most numerous species (A. fimetarius, A. rufus and A. fossor) showed a linear dependence of the abundances in soil-activity traps on the abundances in diversity traps from the precedent capture period. A. sticticus was one of the most numerous species during surveys of diversity (10 %). This species, belonging to the dwellers group, was not recorded in soil-activity traps, however. Large tunnellers were represented mainly by G. spiniger in traps, for which the linear dependence was not possible to confirm.

The effect of the pasture management on dung beetle communities was studied on three sites in Šumava Mts. (South and West Bohemia). The intensity of pasturing was different: 78 cattle on the first, 106 on the second and 162 on the third pasture. The beetles were collected using pitfall traps baited by 1.5 litres of fresh cattle dung. The traps were located on each pasture. Altogether 3 traps were used per each pasture. The pitfall traps were exposed in the pasture for 7 days in monthly repetitions from April to October 2008. Totally 8725 specimen and 33 species of beetles were collected. These species belong to families Scarabaeidae,Geotrupidae and Hydrophilidae. The number of species and individuals was evaluated for each pasture, as well as seasonal dynamics and biomass distribution. The results indicate that the more intensive pasturing has the positive effect on the activity of some groups of coprophagous beetles.Other effects of the different pasture management on the beetles were not documented.

Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-09-11T17:13:00Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ComposicaoScarabaeidaeColeoptera.pdf: 2326047 bytes, checksum: 5cad10732af747a3b97ffa481cd2b538 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-09-27T13:35:22Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ComposicaoScarabaeidaeColeoptera.pdf: 2326047 bytes, checksum: 5cad10732af747a3b97ffa481cd2b538 (MD5) / Made available in DSpace on 2013-09-27T13:35:22Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ComposicaoScarabaeidaeColeoptera.pdf: 2326047 bytes, checksum: 5cad10732af747a3b97ffa481cd2b538 (MD5) Previous issue date: 2006 / Este trabalho teve como objetivo investigar o efeito do tamanho das ilhas de floresta, de suas distâncias para a floresta contínua (isolamento) e para as estradas adjacentes sobre a comunidade de Scarabaeidae coprófagos. Amostras foram coletadas em 24 ilhas de floresta semidecídua, entre 0,5 e 360 ha, em uma matriz de savana amazônica e em oito locais em mata contínua predominantemente secundária, semidecídua, na região de Alter do Chão, Santarém, Pará. Os Scarabaeidae foram coletados com armadilhas do tipo pitfall com isca (fezes humanas) em dois períodos sazonais (seca e chuva). Para cada ponto de coleta foram instaladas 10 armadilhas distribuídas em dois transectos de 250 m, distantes 100 m entre si. Em cada transecto foram colocadas 5 armadilhas distantes 50 m entre si. Para cada local de coleta, foi registrado o DAP de todos os caules com diâmetro igual ou superior a 5 cm, em quatro transectos de 250 x 2 m, sendo estes dados utilizados para derivar os índices da estrutura da vegetação (diâmetro médio e número de indivíduos). A área, perímetro e as distâncias das ilhas para a floresta contínua foram calculadas utilizando-se respectivamente as extensões “X-Tools” e “Nearest Features v3.6d” para ArcView, sobre o mapa da área digitalizado a partir de uma imagem de Landsat TM de 1996. Os exemplares coletados foram identificados com a ajuda de bibliografia especializada e de especialistas. Para a caracterização da fauna, as espécies encontradas foram comparadas com uma lista de espécies gerada a partir de publicações para o Cerrado, Amazônia e ecótonos de transição (floresta–cerrado) brasileiros. Para avaliar a robustez da amostragem, foram empregadas curvas de rarefação e obtidas estimativas de riqueza empregando-se diversos estimadores. Para a análise dos padrões das comunidades, foi utilizada uma análise HNMDS (Semi-strong Hibrid Multidimensional Scaling) utilizandose a distância de Bray-Curtis. Foram encontrados 18 gêneros e 36 espécies pertencentes aos biomas do Cerrado e da Amazônia, mas não foi possível ter uma noção completa da parcela de cada bioma representada neste ecótono de transição savana-floresta, uma vez que as amostras não foram suficientes para o levantamento exaustivo da riqueza de Scarabaeidae. A ordenação mostrou uma tendência de agrupamento das florestas contínuas e de separação destas das ilhas de floresta. Apesar de o levantamento ter registrado um maior número de espécies nas ilhas de floresta que nas áreas de floresta contínua, as comunidades apresentaram um forte padrão hierárquico [P (T< 14,87°)<0,001], indicando que nas ilhas estão persistindo apenas uma parcela do total de espécies da região. Não foi encontrada uma relação entre a composição de Scarabaeidae e o tamanho e a forma das ilhas de floresta. Mas foi encontrada uma relação significativa entre a composição (eixo 1) e o isolamento (F=5,363, P=0,031) e a composição (eixo 1) e o número de árvores (DAP > 5 cm) (F=6,103, P=0,012, corrigido por Bonferroni). O número de árvores de cada local de amostragem foi relacionado com a proximidade de estradas (0,658), o que reforça a idéia de que as estradas estão contribuindo para mudanças na estrutura da vegetação, que por sua vez tem um efeito sobre a fauna de Scarabaeidae. / This work had as objective to investigate the effect of the size of the forest islands, of its distances for the continuous forest (isolation) and for the adjacent roads on the coprófagos community of Scarabaeidae. Samples had been collected in 24 islands of semideciduous forest, between 0,5 and 360 ha, in an Amazonian savanna matrix and eight places in predominantly secondary, semideciduous continuous forest, in the region of Alter do Chão, Santarém, Pará. The Scarabaeidae had been collected with pitfall traps with bait (human dung) in two seasonal periods (dries and rain). For each point of collection 10 traps had been installed in two 250 m transects, distant 100 m between itself. 5 traps in each transect that had been placed 50 m apart. For each place of collect was registered the DAP (Height Brest Tree Diameter), of all trees with equal or superior diameter of the 5 cm, in four 250 transectos of 2 x m, being these used data to derive the indices from the structure of the vegetation (average diameter and number of individuals). The area, perimeter and the distances of the islands for the continue forest had been calculated using respectively the extensions "X-Tools" and "Nearest Features v3.6d" for ArcView, on the map of the area digitalized from an image of Landsat TM of 1996. The collected units had been identified with the aid of specialized bibliography and specialists. For the characterization of the fauna, the joined species had been compared with a list of species generated from publications for the Cerado, Amazonia and Brazilian ecotone (cerrado-floresta). To evaluate the robustness of the sampling, curves of rarefação had been used and gotten estimates of wealth using itself diverse estimators. For the analysis of the standards of the communities, an analysis HNMDS (Semi-strong Hibrid Multidimensional Scaling) using itself in the distance of Bray-Curtis was used. 18 pertaining sorts and 36 species to biomas of the Cerrado and Amazonia had been found, but was not possible to have a complete notion of the parcel of each biome represented in this ecotone of transition savanna-forest, once that the samples had not been enough for the exhausting survey of the wealth of Scarabaeidae. The ordinance showed a trend of grouping of the continuous forests and separation of these of the forest islands. Although the survey to have registered a bigger number of species in the forest islands that in the areas of continuous forest, the communities had presented a strong hierarchic standard [ P (T< 14,87°)<0,001 ], indicating that in the islands they are persisting only one parcel of the total of species of the region. A relation was not found enters the composition of Scarabaeidae and the size and the form of the forest islands. But a significant relation between the composition (axle 1) and the isolation (F=5,363, P=0,031) and the composition (axle 1) and the number of trees was found (DAP > 5 cm) (F=6,103, P=0,012, corrected for Bonferroni). The number of trees of each place of sampling was related with the proximity of roads (0,658), what it strengthens the idea of that the roads are contributing for changes in the structure of the vegetation, that in turn has a effect on the fauna of Scarabaeidae.

Fourteen spore-forming bacterial strains were isolated and screened for entomopathogenic activity. Five displayed toxicity towards the common mealworm, Tenebrio molitor L., (Coleoptera: Tenebrionidae). The majority of the isolates were obtained from insect larvae and insect rich environments. The three bacterial species identified were Bacillus thuringiensis Berliner, Brevibacillus laterosporus Laubach and Bacillus cereus Frankland and Frankland. Bioassays were conducted using T. molitor larvae. The one isolate of B. cereus required the highest concentration of bacterial cells to achieve its LC50, whereas one of the isolates of B. laterosporus required the lowest cell concentration to achieve its LC50. Dose response curves were generated for the five best isolates, which showed that the isolate of B. laterosporus (NDR2) was substantially more toxic than the other isolates. / Thesis (Ph.D.) - University of KwaZulu-Natal, Pietermaritzburg, 2009.

In the KwaZulu-Natal (KZN) Midlands North region of South Africa, the importance and increased prevalence of endemic scarabaeids, particularly Hypopholis sommeri Burmeister and Schizonycha affinis Boheman (Coleoptera: Melolonthinae), as soil pests of sugarcane, and a need for their control was established. The development of a mycoinsecticide offers an environmentally friendly alternative to chemical insecticides. The identification of a diversity of white grub species, in two Scarabaeidae subfamilies, representing seven genera were collected in sugarcane as a pest complex. Hypopholis sommeri and S. affinis were the most prevalent species. The increased seasonal abundances, diversity and highly aggregated nature of these scarabaeid species in summer months, suggested that targeting and control strategies for these pests should be considered in this season. Increased rainfall, relative humidity and soil temperatures were linked to the increased occurrence of scarab adults and neonate grubs. Beauveria brongniartii (Saccardo) Petch epizootics were recorded at two sites in the KZN Midlands North on H. sommeri. Seventeen different fluorescently-labelled microsatellite PCR primers were used to target 78 isolates of Beauveria sp. DNA. Microsatellite data resolved two distinct clusters of Beauveria isolates which represented the Beauveria bassiana senso stricto (Balsamo) Vuillemin and B. brongniartii species groups. These groupings were supported by two gene regions, the nuclear ribosomal Internal Transcribed Spacer (ITS) and the nuclear B locus (Bloc) gene of which 23 exemplar Beauveria isolates were represented and sequenced. When microsatellite data were analysed, 26 haplotypes among 58 isolates of B. brongniartii were distinguished. Relatively low levels of genetic diversity were detected in B. brongniartii and isolates were shown to be closely related. There was no genetic differentiation between the two sites, Harden Heights and Canema in the KZN Midlands North. High gene flow from swarming H. sommeri beetles is the proposed mechanism for this lack of genetic differentiation between populations. Microsatellite analyses also showed that B. brongniartii conidia were being cycled from arboreal to subterranean habitats in the environment by H. sommeri beetles. This was the first record of this species of fungus causing epizootics on the larvae and adults of H. sommeri in South Africa. The virulence of 21 isolates of Beauveria brongniartii and two isolates of B. bassiana were evaluated against the adults and larvae of S. affinis and the adults of H. sommeri and Tenebrio molitor Linnaeus (Coleoptera: Tenebrionidae). Despite being closely-related, B. brongniartii isolates varied significantly in their virulence towards different hosts and highlighted the host specific nature of B. brongniartii towards S. affinis when compared to B. bassiana. Adults of S. affinis were significantly more susceptible to B. brongniartii isolates than the second (L2) or third instar (L3) grubs. The median lethal time (LT₅₀) of the most virulent B. brongniartii isolate (C13) against S. affinis adults was 7.8 days and probit analysis estimated a median lethal concentration (LC₅₀) of 4.4×10⁷ conidia/ml⁻¹. When L2 grubs were treated with a concentration of 1.0×10⁸ conidia/ml⁻¹, B. brongniartii isolates HHWG1, HHB39A and C17 caused mortality in L2 grubs within 18.4-19.8 days (LT₅₀). Beauveria brongniartii isolate HHWG1 was tested against the L3 grubs of S. affinis at four different concentrations. At the lowest concentration (1×10⁶ conidia/ml⁻¹), the LT₅₀ was 25.8 days, and at the highest concentration (1×10⁹ conidia/ml⁻¹) the LT₅₀ dropped to 15.1 days. The persistence of B. bassiana isolate 4222 formulated on rice and wheat bran and buried at eight field sites in the KZN Midlands North was evaluated by plating out a suspension of treated soil onto a selective medium. All eight field sites showed a significant decline in B. bassiana CFUs per gram of soil over time, with few conidia still present in the samples after a year. Greater declines in CFUs were observed at some sites but there were no significant differences observed in the persistence of conidia formulated on rice or wheat bran as carriers. Overall, poor persistence of B. bassiana isolate 4222 was attributed to suboptimum temperatures, rainfall, which rapidly degraded the nutritive carriers, attenuated fungal genotype and the action of antagonistic soil microbes. Growers’ perceptions of white grubs as pests and the feasibility of a mycoinsecticide market were evaluated by means of a semi-structured questionnaire. The study showed that the reduced feasibility of application, general lack of potential demand for a product, high cost factors and most importantly, the lack of pest perception, were factors which would negatively affect the adoption of a granular mycoinsecticide. Growers however exhibited a positive attitude towards mycoinsecticides, and showed all the relevant attributes for successful technology adoption. It is recommended that because B. brongniartii epizootics were recorded on target pests which indicated good host specificity, dispersal ability and persistence of the fungus in the intended environment of application; that a mycoinsecticide based on this fungal species be developed. What will likely increase adoption and success of a mycoinsecticide is collaboration between various industries partners to increases market potential in other crops such as Acacia mearnsii De Wild (Fabales: Fabaceae).