Diachasma alloeum (Muesebeck) is a braconid parasitoid of Rhagoletis mendax Curran and Rhagoletis pomonella (Walsh). Laboratory choice tests using a Y-tube olfactometer compared behavioral responses of D. alloeum to various olfactory stimuli. More than 25% of naïve D. alloeum females, never having experienced R. mendax or blueberries, were ‘innately’ attracted to volatiles emitted from uninfest...

We test the common assumption that organic carbon (OC) storage occurs on sand-sized soil particles only after the OC storage capacity on silt- and clay-sized particles is saturated. Soil samples from a Brookston clay loam in Southwestern Ontario were analysed for the OC concentrations in bulk soil, and on the clay (<2 μm), silt (2-53 μm) and sand (53-2000 μm) particle size fractions. The OC con...

Sand compaction piles are used in practice for ground improvement of soft subsoil in order to accelerate consolidation, reduce compressibility, and increase strength. The current design procedure of sand compaction piles is based on simple empirical calculations, which does not take full account of the sand pile behaviour. This research project investigates the behaviour of a base reinforced em...

The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae) is a major pest of pepper (Capsicum spp.; Solanales: Solanaceae) in the southern United States, Mexico, Central America and the Caribbean. Feeding and oviposition cause flower and fruit abscission and internal fruit damage resulting in serious yield losses. Females lay eggs in flower buds and small fruits, shielding larvae f...

Description of Materials Soil profiles developed from Dwyka tillite consist of a fine sandy loam overlying a gravel and rubble layer and succeeded by a zone of clay illuviation. Below this, the disintergrating tillite may proceed to depths of two hundred feet under favourable circumstances. This material in its most weathered aspect consists of a "soapy" orangy yellow fine silty clay of the fol...

Population increase of Pratylenchus hexincisus on corn was tested over 3 months at 15, 20, 25, and 30 C in Marshall silt loam, Clarion silt loam, Buckner coarse sand, and Haig silty clay loam soils. The optimum temperature for increase was 30 C in all soils. The nematode population was significantly larger in Buckner coarse sand than in other soil types at 50 C. The recovered P. hexincisus popu...

In order to determine the boron isotopic fractionation factor between boron adsorbed onto kaolin clay and boron in solution (S), as a first attempt, a break-through column chromatography at a high pressure (12.0 MPa) was performed. A boric acid standard solution (9.25 mmol/l, NIST SRM 951) was fed into a stainless steel column packed with boron-free kaolin clay with the flow rate of 0.8 ml/h. T...

The vertical migration of N. carpocapsae infective juveniles applied to the soil surface or introduced 14 cm below the soil surface was studied in four different soil types (pure silica sand, coarse sandy loam, silty clay loam, and clay). The percentage of juveniles able to migrate and infect wax moth pupae placed in the soil decreased as the percentage of clay and silt increased. Most nematode...