Estimation of time since death is an important variable when investigating legal cases involving decomposing human remains; however it has been sparsely studied in controlled environments. Decomposition rates are largely influenced by external factors with temperature being the most critical factor. The decomposition rates can also be influenced by insect infestation, chemical residues, and burial, yet little research has been conducted to document how various factors alter the rate and process of decomposition. A common occurrence at human remains recovery sites is the deposit of residues from criminal activities such as gunpowder and explosives. This experiment will look at gunpowder residue’s effects on porcine remains and the insect infestation after exposure. This study was conducted in two phases: the 1st experiment being conducted in the late spring and the 2nd in the early fall. For each experiment two carcasses were covered with gunpowder residue while one carcass served as a control (no residue). The physical decomposition processes as well as ambient temperature were documented for each carcass. The results for the study showed variable findings between the control and experimental subjects. The insect infestation of the remains was consistent with the data from previous entomological studies conducted from areas of similar climate and terrain. Factors that may have influenced the results are discussed in reference to the effects of the gunpowder residue on the decomposing remains.

The risk of corn rootworm damage to continuously-grown corn was assessed in 32 fields from seven counties in Virginia in 1993 and 1994, Approximately 28% of the fields examined had economic root damage in corn left untreated with a soil insecticide. In addition, 190/0 of the fields overall had an economic loss in silage due to corn rootworm damage. A second study evaluated the effectiveness of using adult corn rootworm counts on commercial Olson yellow sticky traps and ear-zone regions of corn plants to predict subsequent damage to corn. Regression models for each sampling method were used to calculate economic thresholds of 20 adults per trap per wk for the Olson trap and 0.3 adults per stalk for the ear-zone visual count method. Adult counts on Olson traps obtained in mid-Aug correctly predicted economic damage to com 81 % of the time, and resulted in only one serious error of failing to predict economic damage to corn. A sampling plan for the use of Olson traps is suggested. A third study investigated a possible sexual dimorphism in the elytra coloration pattern of western corn rootworm, and compared the sex ratio of adults captured yellow sticky traps with those obtained by aspiration. Striped and solid variations in elytra pattern were found in both sexes of western corn rootworm; however, 98% of the adults that exhibited the solid elytra pattern were male. The sex ratio of adults varied over time; however, in all cases, sticky traps captured a significantly greater proportion of males compared with aspiration. / Master of Science

Killed Virginia pine, (Pinus virginiana Mill.), held in the vertical position, attracted 99.65 percent of the insects in the families Scolytidae, Cerambycidae, Curculionidae, and Buprestidae. The remaining 0.35 percent were collected from nontreated control trees. The dominant insect species were analyzed regarding seasonal abundance and specificity in selecting suitable host material. / Master of Science

Thesis (MScFor (Forest and Wood Science))--University of Stellenbosch, 2010. / ENGLISH ABSTRACT: The purpose of the study was to investigate the potential tree taxa that could be grown as a source of biomass in the Cape Winelands region. The trials comprises of two different aspects. The first being the estimation of potential volume, density and biomass of a pair of six year-old stands of E. gomphocephala and E. cladocalyx families at two climatically different sites within the study region. The second part of the study was the early growth assessment of alternative taxa that could be planted in the region compared to the regional mainstay E. cladocalyx. The volume of families was estimated using appropriate volume equations and using the form height were none were available. The best volume yield varied from 4.6 to 11.2 m3 ha-1a-1, at the dry and sub-humid sites, respectively. Wood density, estimated from non-destructive samples at both sites, varied from 620 (sub-humid) to 588 kg m-3 (dry site). The estimated biomass production rate of the top producing families yielded 2.7 and 6.9 t ha -1a -1 at the dry and sub-humid sites, respectively. In terms of estimated biomass and survival, E. gomphocephala was more suited to the dry site, while E. cladocalyx displayed superior yield than E. gomphocephala on the sub-humid site, but not significantly so. Early growth assessment of the trial of alternative taxa found that the hybrid E. grandis × camldulensis and E. grandis × urophylla had superior biomass indices, but were more susceptible to infestation by Thaumastocoris peregrinus and Gonipterus scuttelatus. / AFRIKAANSE OPSOMMING: Die doel van hierdie studie was om potensiële boom taksa vir gebruik as ’n bron van biomassa in die Kaapse Wynlandstreek te ondersoek. Die proewe behels twee aspekte: eerstens die beraming van die potensiële volume, digtheid en biomassa van sesjaaroue opstande met families van E. gomphocephala en E. cladocalyx by twee klimatologies verskillende groeiplekke in die studiegebied; tweedens die beoordeling van die vroeë groei van alternatiewe taksa wat in die streek geplant kan word in vergelyking met die streek se historiese staatmaker-spesie E. cladocalyx. Die volume van die families is beraam deur gebruik te maak van toepaslike volumevergelykings, en met behulp van ’n vormfaktor waar vergelykings nie beskikbaar was nie. Die volume aanwas by die droë en sub-humiede groeiplekke was onderskeidelik 4.6 en 11.2 m3 ha-1j-1. Houtdigtheid is beraam deur nie-destruktiewe monsters uit die opstand te neem. Gemiddelde digthede het variëer van 588 (sub-humied) tot 620 kg m-3 (droë groeiplek). Die beraamde biomassaproduksie van die top-families beloop onderskeidelik 2.7 en 6.9 t ha -1j -1 vir die droë en sub-humiede groeiplekke. In terme van beraamde biomassa en oorlewing, is E. gomphocephala meer geskik vir droër groeiplekke , terwyl E. cladocalyx by die sub-humiede groeiplek ’n hoër opbrengs as E. gomphocephala getoon het, hoewel nie betekenisvol nie. Beramings van die vroeë groei by die proef met alternatiewe taksa het getoon dat die basters E. grandis × camldulensis en E. grandis × urophylla hoër biomassa-indekse het, maar meer vatbaar is vir besmetting deur Thaumastocoris peregrinus en Gonipterus scuttelatus. / Centre for Renewable and Sustainable Energy Studies