Observations on the Biological Control Agents of the American Plum Borer (Lepidoptera: Pyralidae) In Michigan Cherry and Plum Orchards

The American plum borer, Euzophera semifuneralis (Walker) (Lepidoptera: Pyralidae), is an important pest in orchards, yet little is known regarding its biological control. We performed a comprehensive survey of the natural enemy complex contributing to American plum borer control in Michigan plum and cherry orchards, while also exploring the relationship between pest infestation and tree wounding from mechanical harvesting. We scouted 30 orchards with varying degrees of tree wounding to document extent of infestations of American plum borer and another pest, the lesser peach borer, Synanthedon pictipes (Grote and Robinson) (Lepidoptera: Sessiidae). We simultaneously recorded biological control agents, including the presence of a Hirsutella fungal pathogen. Live American plum borer larvae and pupae were collected for rearing and identifying hymenopteran parasitoids. American plum borer infestations were highest in orchards with high levels of tree wounding, or in orchards that used minimum pesticides or were abandoned. Numerous organisms were documented as biological control agents including various species of birds, spiders, beetles, and ants. Ichneumon wasps were the dominant parasitoids, of which Venturia nigricoxalis (Cushman) (Hymenoptera: Ichneumonidae) was the most common. Liotryphon variatipes (Provancher) (Hymenoptera: Ichneumonidae) was com- monly reared from a closely associated sessiid pest, but not from American plum borer. Hirsutella was commonly found and had a density-dependent relation- ship with American plum borer infestations. Our information gathered on the natural enemy complex of E. semifuneralis includes many new host associations and can serve as a starting point for developing biological control programs for fruit orchards in the Great Lakes region

Thermal contraints on high-pressure granulite metamorphism of supracrustal rocks

The circumstances leading to the formation and exposure at the Earth's surface of supracrustal granulites are examined. These are defined as sediments, volcanics, and other rock units which originally formed at the surface of the Earth, were metamorphosed to high-pressure granulite facies (T = 700-900 C, P = 5-10 kbar), and reexposed at the Earth's surface, in many cases underlain by normal thicknesses of continental crust (30-40 km). Five possible heating mechanisms to account for granulite metamorphism of supracrustal rocks are discussed: magnetic heating, thermal relaxation of perturbed temperature profiles following underthrusting of the continental crust, thermal relaxation after underthrusting of thin slivers of supracrustal rocks below continental crust of normal thickness, major preheating of the upper plate, and shear heating caused by frictional stress along the thrust plane

Psychological types of female primary school teachers in Anglican state-maintained schools in England and Wales : implications for continuing professional development

A sample of 221 female primary school teachers in Anglican state-maintained schools in England and Wales completed the Francis Psychological Type Scales (FPTS). The data demonstrated clear preferences for Extraversion (E) over Introversion (I), for Sensing (S) over Intuition (N), for Feeling (F) over Thinking (T) and for Judging (J) over Perceiving (P). The two predominant types among female primary school teachers were ESFJ (27.6%) and ISFJ (18.6%). These findings confirm earlier research among trainee female primary school teachers and help to clarify the main strengths and potential challenges facing primary schools in light of knowledge about the key psychological preferences of those who shape the classroom environment. These findings also generate new insights into teacher retention and career paths in primary schools

Resolved rate and torque control schemes for large scale space based kinematically redundant manipulators

Resolved rate control of kinematically redundant ground based manipulators is a challenging problem. The structural, actuator, and control loop frequency characteristics of industrial grade robots generally allow operation with resolved rate control; a rate command is achievable with good accuracy. However, space based manipulators are different, typically have less structural stiffness, more motor and joint friction, and lower control loop cycle frequencies. These undesirable characteristics present a considerable Point of Resolution (POR) control problem for space based, kinematically redundant manipulators for the following reason: a kinematically redundant manipulator requires an arbitrary constraint to solve for the joint rate commands. A space manipulator will not respond to joint rate commands because of these characteristics. A space based manipulator simulation, including free end rigid body dynamics, motor dynamics, motor striction/friction, gearbox backlash, joint striction/friction, and Space Station Remote Manipulator System type configuration parameters, is used to evaluate the performance of a documented resolved rate control law. Alternate schemes which include torque control are also evaluated