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Production flow system methodologies, originally developed for use in industrial quality control and electrical engineering problem solving, were adopted for use in describing the partial within-tree population system of Dendroctonus frontalis . The spatial and statistical distribution of D. frontalis life stages were defined by 2 and 3 parameter non-linear mathematical models. By integrating under the curves generated by the models for the various life stages it was possible to quantitatively define within-tree populations of the various life stages. For each year of study, transition probabilities between life stages were calculated using standard production flow system techniques. These transition probabilities were cast into a production flowgraph format. Each of the production flow models was evaluated using an algebraic solution technique and the similarities and differences between populations occuring in the 3 yr of study were contrasted. The production flow system technique was suggested as an alternative to the traditional life table format. Several advantages of the production flow system format over the life table were suggested. The most important advantage was that the variables are tied together mathematically and cast into a formalized engineering methodology.

Probability density functions for the various within-tree developmental life stages ofD. frontalis are derived. The differences between some of these distributions are discussed. The possibility of the existence of a negative feed-back mechanism which enables the beetle to make optimum utilization of the available resources is proposed. In addition, the concept of an optimum location on the infested bole where the environmental (tree) conditions are such that maximum survivorship occurs is advanced.

Regression equations for predicting diameter outside bark (DOBx) and bark thickness (BTx) as functions of height and diameter or bark thickness class were developed from data collected as part of a Dendroctonus frontalis population dynamics study. The 2 equations were combined and integrated over height to provide estimates of the phloem area and bark volume infested by the insect. A graphic analysis using the BTx model showed that eggs/cm3 of bark increase with height, indicating that factors other than BTx control the egg density per unit area. An example is presented showing the use of the phloem area model to estimate the total number of insects inhabiting a tree.

Within-tree larval and progeny adult populations of Dendroctonus frontalis Zimm. attacking loblolly pine, Pinus taeda L., were investigated in order to define the distribution of larvae within sample units (100 cm2 disks of bark) and to describe the functional relationship of both larvae and progeny adults to the infested portion of the tree bole.Larvae and progeny adults were sampled over the infested bole of the 50 trees. Two separate measures of progeny adults were obtained. The first measure was taken just prior to emergence from the tree and the second measure was obtained by rearing the insect until emergence from the sample disks was completed.Larvae were found to be uniformly distributed within the total disk. The functional relationship of the larvae and the two measures of progeny adults to the normalized height on the infested bole was described by the two parameter nonlinear model y = Ax(1−x)eBx.Highest larval density along the infested portion of the tree bole occurred just below the center and tapered abruptly towards the base and gradually towards the top of the tree. The density of progeny adults on the other hand was greatest just above the center portion of the infested bole and tapered abruptly towards the top and gradually towards the base of the tree. Both measures of progeny adults produced curves of virtually the same shape. However, the density of progeny adults was substantially less in the samples which were reared indicating that mortality agents continued to act on the population until emergence from the tree.

Within-tree populations of Dendractonus frontalis Zimmerman were measured in untreated control trees, cacodylic acid-injected trees, and frontalure-baited trees. Effects of the treatments were compared to the controls for the mean density/100 cm2 of attacking adults, eggs, larvae, pupae-callow adults, and brood adults by using a life table format. Mathematical models were employed to describe the within-tree spatial distribution and mean density/100 cm2 of the various life stages. Cacodylic acid treatments, when compared to controls, resulted in reduced attack density, substantially greater mortality between the egg-larva and larva-pupa-callow adult stages, greater total generation mortality, and a much reduced increase ratio for the generation. Treatment effects were most pronounced in the basal portion of the tree. Statistically, the mean densities/100 cm2 of the various life stages measured were significantly different from controls. The mean densities of the various life stages/100 cm2 in trees baited with frontalure were not significantly different from controls. Mortality between life stages, total generation mortality, and the increase ratio for the generation all were essentially identical to controls.

The methodology of a topological mapping procedure for estimating the total number of insects inhabiting a tree trunk is presented. Data necessary for using the procedure are insect densities at measured intervals on the bole. The procedure minimizes errors resulting from smoothing, regression or extrapolation and provides estimates suitable for evaluating bias and variability of other sampling plans.

The within-sample distributions of gallery length (GL) and egg (E) density as well as their functional relationships to the infested bole were studied in an epidemic population of the southern pine beetle in southeast Texas.A least-squares linear regression analysis through the origin showed an average of 1.59 eggs per centimeter of gallery. GL accounted for 81% of the variation in E and thus is useful for estimating egg numbers. The density of attacking adults is unsatisfactory for predicting E.GL and E are uniformly distributed within but not among the 100-cm2 sample disks at a given height. The functional relationship of both variables to the infested bole is adequately described by the model y = (A+Bx)exp(Cln(x−x2)), where y = GL or E per 100 cm2, x = the normalized height on the infested bole, and A, B, and C are parameters to be estimated for each set of data.

Interspecific competition was hypothesized to exist as a result of foraging by Monochamus titillator Fabricius in the sub-cortical region of loblolly pines attacked by Dendroctonus frontalis Zimmerman. The existence of the interaction was demonstrated experimentally; first by defining the distributional pattern of D. frontalis progeny adults in samples of bark in which M. titillator foraging was absent. Next, using data in which foraging occurred the observed number of D. frontalis inside the foraged area was compared with the expected number if no foraging were present. The observed and expected values were demonstrated to come from different distributions which substantiated the existence of competition. The specifications for developing mathematical models of the competitive process included consideration of the extent and distribution of M. titillator foraging over the entire bole of the tree and D. frontalis density in the infested portion of the tree bole. The form of the data used in model development was appraised from the standpoint of providing the most realistic account of the process under consideration and the results of the use of unmanipulated data were compared with 2 separate types of manipulations commonly employed in the analysis of bark beetle populations. A series of nonlinear mathematical models based on unmanipulated data was developed which provides the expression of mortality resulting to D. frontalis as a consequence of M. titillator foraging as well as a survivorship model. These models include a definition of the following components: the relationship between the expected number of D. frontalis in the area foraged by M. titillator [E( SPB ¯ 1)] and the normalized tree bole (obtained by dividing the sample height, S.H., by the infested bole height, I.B.H.); the difference between observed number of D. frontalis in the foraged area ( SPB ¯ 1) and E( SPB ¯ 1)=∆( SPB ¯ 1) and S.H./I.B.H.; the relationship between the area foraged by M. titillator A ¯ 1 and S.H./I.B.H.; the relationship between ∆ SPB ¯ 1 and A ¯ 1, which is the mortality expression; and the relationship between ( SPB ¯ 1)/E( SPB ¯ 1) and A ¯ 1, which is the survivorship expression. The object of competition between the 2 species is the limited area of inner-bark necessary for development of both species. The form of the competitive process contains elements of both interference and exploitation.

Equal numbers of male and female rats of the King-Holtzman hybrid breed, divided into two age groups (group A1: 21–30 days old and group A2: 90–100 days old), were exposed to two levels of noise: N0 = 30 db and N1 = 90 db, (ref. 0.002µbar), and three levels of direct electric field intensities: E0 = electric field strength of zero; E1 = 1,600 v/m; and E2 = 16,000 v/m. Time and error scores of 240 rats running a modified Lashley left-right maze with an escape-from-water motive served as criteria. A randomized complete blocks design with replications (2 × 3 × 2 × 2 × 10) was selected for treatment by analysis of variance. The results indicate that (a) adult rats pre-exposed to electric fields showed significantly lower error scores than young rats, regardless of sex or the noise condition; (b) after exposure to electric fields all rats swam faster than their controls; (c) after exposure to noise females showed significantly higher time scores than males under the same conditions, regardless of age; and (d) when subjected to the combined effect of electric fields and noise males showed significantly lower time scores than females under the same conditions, regardless of age.

Aerial estimates of the number of trees comprising infestation spots of Dendroctonus frontalis Zimmerman were compared to the actual number of infested trees as determined by inventory from the ground. The error aerial estimates was found to be related linearly to the size of the infestation. For the data utilized in this study, the estimation error was found to be ca. 150%. Operating characteristics ( OC) curves were constructed to assess the discriminatory power of the aerial estimation technique. These curves further substantiated the inadequacy of characterizing southern pine beetle infestations by aerial surveys alone.

A method for the consideration of learning impacts on economic order quantity is presented for the simple inventory model. The developed techniques can be applied to the analysis of more complex and generalized inventory systems.

An equal number of male and female rats of the King-Holtzman hybrid breed, divided into two age groups (group A1 : 21–30 days old and group A2 : 90–100 days old), were exposed to two levels of noise: N0 = 30 db and N1 = 90 db, (Ref. 0.0002µ bar), and three levels of negative air ions: IO = no measurable ion concentration, I1 = 7 × 106 ions/cm3 and I2 = 7 × 107 ions/cm3. Time and error scores of 240 rats running a modified Lashley left-right maze with an escape-from-water motive served as criteria. A randomized complete blocks design with replications (2×3×2×2×10) was selected for treatment by analysis of variance. The results indicate that (a) the males show significantly lower error score in negatively ionized air; and (b) the females swim significantly faster than males under all investigated conditions with no apparent effect of noise or ions on their performance.

This research was conducted to evaluate the feasibility of utilizing the deviation in auditory flutter fusion as a predictor of induced mental stress resulting from variations in environmental temperature and illumination. Auditory flutter fusion is a sensory effect tantamount to visual flicker fusion in the auditory sense. The experiment involved the performance of a mental‐stress task consisting of solving arithmetic problems. This task, which depends on prior learned information, was selected as the mental task representative of the types performed by office personnel. Six college male students 20–23 years of age were used. Judgments were made of two thresholds (i.e., fusion and flutter) in the prestress and poststress periods. The deviations due to the mental stress induced during the 1‐h stress period were determined. The experiment was conducted under the combined environmental effects of three levels of environmental temperature (60°, 75°, and 90°F) and three levels of illumination (20, 50, and 100...