Thesis (M.S.)--University of Wisconsin--Madison. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 214-221).

Thesis (Ph. D.)--University of Wisconsin--Madison, 1971. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1975. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Bibliography: leaves 175-182.

Thesis (M.S.)--University of Wisconsin--Madison, 1983. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 203-236).

The antennae of the ambrosia beetle Trypodendron lineatum (Olivier) were examined with the light and electron microscopes to determine the types, distribution, and structure of sense organs found thereon. At least six types of sense organs were found, with an additional seventh cuticular structure, the hypodermal gland pore, which is thought to be non-sensory. The sensilla are sensilla chaetica, three types of sensillum tri-choideum, sensilla basiconica, and sensilla campaniformia. Distribution maps of the various sensillum types and the gland pores are presented, for one each of female and male left antenna. Sensilla chaetica, evenly distributed over all parts of the antennae, as well as the rest of the body, consist of a long thick-walled hair 20 to 140 micra long which articulates in a socket composed of a hair root, socket lining, and spongy cylinder. A single bipolar neuron terminates in a scolo-pale attached at one side of the hair base. Sensilla trichoidea, Type I, situated at the base of the scape and the base of the first funicular segment, are short thin hairs articulating in a socket. Their fine structure and innervation are not known. Sensilla trichoidea, Type II, found on the distal periphery of the club only, consist of sharply pointed smooth hairs 18 to 25 micra long, the hair wall being thin and perforated. The hair is solidly joined to the body cuticle. The sensillum has two bipolar neurons, the dendrites of which extend, with slight branching, to the distal limits of the hair lumen. No dendritic endings could be demonstrated at the hair perforations. Sensilla trichoidea, Type III, are evenly distributed over the distal half of the anterior club surface. The hair is 26 to 36 micra long, blunt-tipped, and curved in reverse, with the result that the hairs protrude at right angles to the club surface and beyond all other vestiture. The hair articulates in a socket, and has a double lumen. The dendrites of four to seven bipolar neurons extend through the eccentric small lumen to the hair tip, where, presumably, they are open to the air. Sensilla basiconica cover both club surfaces. At least two types exist, one group being short pegs 6 to 8 micra long, and another group being longer pegs or hairs llj to 18 micra long. The long sensilla basiconica have a thin perforated hair wall, the openings being slit-shaped (700Å by 100 to 200Å). The two nerve cells of this sensillura send two distal processes into the hair where subsequent repeated branching occurs. The relationship of the dendrite branches to the hair perforations is not clear. Sensilla campaniformia are found in small numbers on all parts of the antennae, as well as other parts of the body. They consist of a short thin canal leading from the outside, to a sub-surface dome 3 micra in diameter, in the centre of which lies the nerve ending similar in appearance to the scolo-pale and nerve of the sensillum chaeticum. Also, a cross section of the antennal nerve in the proximal portion of the scape revealed about 2100 axons. A count of the sensilla, corrected for the number of sense cells present per sensillum, gave expected axon numbers of 1845 and 1921 for female and male antennae, respectively, with Johnston's organ not accounted for. Since more axons than expected are present, axon fusion is considered unlikely. This sudy may serve as the basis for further electrophysiological work to determine the functions of the various sense organs. / Science, Faculty of / Zoology, Department of / Graduate

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1969. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Wisconsin--Madison, 1968. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

The behaviour of the ambrosia beetle Trypodendron llneatum (Olivier) has been considered in respect to illumination, body moisture and host factors. The investigation was designed to study potential uses of this insect as a test instrument for chemical studies of host wood attractants. A preliminary study of host attractants was also conducted using a newly-proposed bioassay technique. Monochromatic light at the wavelength 543 millimicrons was found to be the sole peak of stimulation to this insect in the visible spectrum. Beetles displayed a positive photic response by walking toward the source of light. A decrease in sensitivity occurred on either side of this peak, and in the longer wavelengths the sensitivity to light diminished at 735 millimicrons. Evidence to date indicated a second peak of sensitivity in the ultraviolet region of the spectrum; the latter appearing to be much greater than the peak in the visible spectrum. The intensity of any wavelength was also found to be a limiting factor in affecting beetle response, although in the longer wavelengths the sensitivity appeared to be a function of wavelength alone. Monochromatic light as a standard has been proposed for future bioassay techniques to act in opposition to odour stimuli. Red illumination was found to be effective in simulating darkness to T. lineatum. ‘Green’ unattractive sapwood shavings of Douglas-fir after placement under oxygen deficient conditions became attractive to T. lineatum. Maximum attractiveness was indicated in wood placed under anaerobiosis for 20 to 26 hours. Beyond 30 hours, little sign of attractants was noted. Control wood series did not undergo any transition, this leading to the conclusion that a significant change occurred in wood as a result of the anaerobic treatment. The implications of this result have been discussed. The successful use of wood shavings has made possible further studies on the nature of origin of attractants. The use of the anemotactic behaviour of beetles of both sexes to an airstream carrying host odour was found to be a highly efficient technique of analysis. The role of greater quantities of light in attracting insects away from a source of olfactory stimulation became increasingly apparent from this study. Moisture loss of the insect apparently did not alter their response to white light. / Science, Faculty of / Zoology, Department of / Graduate

Gnathotrichus retusus is primarily univoltine with a minor fraction of the population taking more than one year to complete the life cycle. From the spring to the summer, the development of brood from egg to adult took about 40 days or more in Douglas-fir logs. Brood production was significantly related to the gallery length. Boring activities were not consistently related with temperature, shifting from shallow sapwood to deep sapwood over time. Fungal staining was usually limited to the wood near the gallery entrance, and became darker in colour over time beginning in June. Abandonment of some galleries mainly occurred in June and July by females, and was probably induced by high temperatures. G. retusus preferred Douglas-fir stumps to western hemlock stumps, but both host tree species were equally suitable for G. retusus brood development. Significant differences were found among individual Douglas-fir and western hemlock stumps in attack density and brood production. Within a stump, attack density and brood production for Douglas-fir, and attack density for western hemlock increased from the stump top to the bottom. G. retusus emergence from Douglas-fir and western hemlock stumps and G. retusus and G. sulcat us flights began in late April when the daily maximum temperature reached 13.5°C, and peaked in late May. Brood emergence of G. retusus ceased, with rare exception, in late June. G. retusus had only one big peak flight while G. sulcatus had a small second peak flight in late July. Seasonal flights ceased in October when weekly mean maximum temperatures dropped below 15°C. Brood emergence, seasonal flights, and the sex ratios of brood ready to emerge and captured flying beetles were positively correlated with maximum temperature. G. retusus had a bimodal diurnal flight rhythm: a very small morning flight and a much larger dusk flight. Light intensity seemed to be a major stimulus in initiating the flight. However, diurnal flight might also be influenced by both temperature and relative humidity. Both G. retusus and G. sulcatus of both sexes responded significantly to ethanol or their own aggregation pheromones, (+)-sulcatol and (±)-sulcatol respectively, and ethanol was a synergist of (+)-sulcatol for G. retusus of both sexes. Alpha-pinene was neither a primary host attractant nor a synergist of aggregation pheromones. The sex ratios (female/male) of both species increased significantly from less than one for host chemicals alone to above one for treatments including aggregation pheromones. The sex ratio of G. sulcatus increased with increases in release rates of (±)-sulcatol. / Forestry, Faculty of / Graduate