CONTENTS. 



Introduction, by Stephen A. Forbes 311 



PART ONE: PREDICTION PROCEDURE 



The problem of predicting the appearance of the codling moth...... 315 



Measurement of development 317 



Definition of the unit of development 318 



Procedure for predicting the time of emergence of moths 319 



The use of temperature data alone 324 



An example of estimation of seasonal progress 325 



Abundance of late-pupating larvae in spring 326 



Abundance of hibernated larvae as affected by weather of preceding 

 autumn and winter 327 



PART TWO: A BASIS FOR THE MEASUREMENT OF DEVELOPMENT 



Former methods of estimating progress in lite-history stages 328 



Conditions affecting the rate of development 329 



Methods of measurement of factors 330 



Definitions of terms 330 



Graphic representation of velocity 333 



Order of experimentation 337 



Interpretation of experimental data 337 



Calculation of standard time 338 



Effects of conditions other than temperature and humidity 350 



Modification of normal developmental totals 356 



PART THREE: METHODS OF EXPERIMENTATION AND CALCULA- 

 TION 



Theory of thresholds and rates of development 357 



Velocity curves 358 



Evidences of the nature of the velocity curve 359 



Evidences of a constant total in metabolism . 361 



Purpose of the present investigation 362 



(A) General results on pupae 363 



Mortality and failure to pupate 374 



Calculation of thresholds and velocities 381 



Preparation of the equal-velocity chart 387 



Final correction of the equal-velocity chart 391 



(B) Adult moths 401 



( C ) Eggs and larvae 401 



Incubation period 401 



Time from hatching to leaving the apple 403 



Hibernated larvae 405 



Prediction of first pupation 417 



