DeMichele Model Research Articles

A Temperature Based Model for Cotton Mealybug to Development, Survival and Population Growth Potential

Aims: Based on the different temperature model, analysis the cotton mealy bug growth, developmental, survival, mortality, and reproduction rate.
 Place and Duration of Study: This secondary data were collected from Central Institute of Cotton Research, Coimbatore.
 Methodology: In this study, we used models like the Sharpe and DeMichele model, the Wang model, the Polynomial model, the Stinner model, and the Gaussian model. To measure the goodness-of-fit criteria, the model performance has been assured using Coefficient of Determination (R2), Alkaline Information Criteria (AIC), Root Mean Squared Error (RMSE), Mean Absolute Percentage Error (MAPE), Mean Absolute error (MAE), Relative Absolute Error (RAE) and Relative Standard Error (RSE).
 Result and Conclusion: From the Sharpe and Demichele and Polynomial models, male have highest R2 and least error values. From the Wang model, nymph 3 has highest R2 and least error values. When compare all models the Polynomial model have highest R2 and least error values. So it is the best fit model compare to all the models.

<p class="Body"><strong>Oviposition model of <em>Amblyseius swirskii</em> Athias-Henriot in prey system (<em>Tetranychus urticae</em> Koch)</strong></p>

In this study, temperature-dependent oviposition model of Amblyseius swirskii Athias-Henriot fed by Tetranychus urticae Koch as prey was developed. In order to obtain data for the model, the longevity, fecundity and survivorship of adult females of A. swirskii were recorded at seven different temperatures (15, 20, 25, 27.5, 30, 32.5 and 35 °C) all at 60±5% RH and a photoperiod of 16:8h (L; D) in growth chamber. The longevity of females decreased with increasing temperature; the maximum at 15°C (84±3.24 days) and the minimum at 32.5°C (22.48±0.31 days). The female adult developmental rates (1/median longevity) was described by Sharpe and DeMichele model (r2=0.99). The highest and the lowest fecundity were observed at 25°C (22.63±0.76 eggs/female) and 15°C (9.4±0.67 eggs/female), respectively. The oviposition model comprised of three functions: temperature-dependent fecundity, age-specific cumulative oviposition rate and age-specific survival rate. The best model of temperature-dependent fecundity was described by a non-linear equation (extreme value function) (r2=0.98). Similarly, the best model of age-specific cumulative oviposition was described by the two-parameter Weibull function (r2=0.94). Eventually, the best model of age-specific survival rate was described by sigmoid function (r2=0.97). Amblyseius swirskii has ability to control pests such as thrips, whiteflies and two-spotted spider mites and can grow even in low temperatures. Therefore, this mite can be active at the beginning of spring season. Temperature-dependent oviposition model of A. swirskii can determine optimal temperature for mass-rearing and predict seasonal population dynamic of this predatory mite in greenhouses. Finally, the greenhouse data can validate this model in future.

Estimation and validation of developmental thresholds and thermal requirements for cotton pink bollworm Pectinophora gossypiella

The developmental thresholds and thermal requirements of pink bollworm were estimated using laboratory data on its development at six constant temperatures from 15 °C to 38 °C. The results were validated using field data on male moth catches in sex pheromone traps baited with gossyplure recorded at Nagpur (Maharashtra) during 2018 for predicting the initiation of moth emergence and completion of generation events. The theoretical lower and upper threshold temperatures estimated using non–linear Sharpe and DeMichele model applied to mean development rates were: 14.17/35.43, 15.18/35.48, 11.00/35.48 and 13.40/35.50 °C, and the thermal requirements estimated as inverse of slope of linear regression were: 72.99, 285.71, 144.92 and 503.62° days for development of eggs, larvae, pupae and egg – adult emergence, respectively. Simulation of life table parameters provided reasonably closer estimates across the tested locations. The estimated lower and upper threshold temperatures accumulated the heat units (489.90–497.90) closer to the laboratory estimates (503.62 DD) and sensibly predicted the developmental events in pink bollworm with ±1.0 day error of margin under field conditions. The estimated thresholds and thermal requirements may help in comprehending seasonal dynamics of pink bollworm in relation to timings of developmental events like beginning and peaks of moth emergence, oviposition and egg hatching. This could facilitate in undertaking timely pest management actions such as insecticidal applications.

Fecundity and Egg Laying in Helicoverpa armigera (Lepidoptera: Noctuidae): Model Development and Field Validation.

Models can be useful to help understand population dynamics of insects under diverse environmental conditions and in developing strategies to better manage pest species. Adult longevity and fecundity of Helicoverpa armigera (Hübner) were evaluated against a wide range of constant temperatures (15, 20, 25, 30, 35, and 37.5°C). The modified Sharpe and DeMichele model described adult aging rate and was used to estimate adult physiological age. Maximum fecundity of H. armigera was 973 eggs per female at 25°C decreasing to 72 eggs per female at 37.5°C. The relationship between adult fecundity and temperature was well described by an extreme value function. Age-specific cumulative oviposition rate and age-specific survival rate were well described by a two-parameter Weibull function and sigmoid function, respectively. An oviposition model was developed using three temperature-dependent components: total fecundity, age-specific oviposition rate, and age-specific survival rate. The oviposition model was validated against independent field data and described the pattern of field occurrence of H. armigera egg numbers very well. Our model will be a useful component for population modeling of H. armigera and can be independently used for the timing of sprays in management programs targeting this key pest species.

상추에서의 싸리수염진딧물(Aulacorthum solani)의 발육과 발육모형

싸리수염진딧물(Aulacorthum solani)의 온도별 발육상을 조사하기 위해 <TEX>$12.5^{\circ}C$</TEX>에서 <TEX>$27.5^{\circ}C$</TEX>까지 <TEX>$2.5^{\circ}C$</TEX> 간격으로 7개 온도에서 조사를 하였으며, 상대습도는 <TEX>$65{\pm}5%$</TEX>, 광주기는 16L:8D 조건으로 처리하였다. 일반적으로 진딧물의 약충 단계는 1령<TEX>${\sim}$</TEX>4령까지로 구분하나 본 연구에서는 1<TEX>${\sim}$</TEX>2령과 3<TEX>${\sim}$</TEX>4령으로 구분하였다. 대부분의 온도에서 사망률은 1<TEX>${\sim}$</TEX>2령과 3<TEX>${\sim}$</TEX>4령 약충이 유사하였으나, <TEX>$27.5^{\circ}C$</TEX>에서는 오히려 3<TEX>${\sim}$</TEX>4령의 사망률이 66.7%로 대부분을 차지하였다. 온도별 발육기간은 <TEX>$12.5^{\circ}C$</TEX>에서 16.9일로 가장 길었고 온도가 상승함에 따라 점차 짧아져 <TEX>$22.5^{\circ}C$</TEX>에서는 6.6일로 가장 짧았으나, <TEX>$25^{\circ}C$</TEX>에서는 오히려 7.4일로 발육 기간이 길어지는 양상을 보였다. 약충의 발육영점온도는 <TEX>$0.08^{\circ}C$</TEX>이고, 유효적산온도는 162.8일도였다. 각 온도별 발육률은 변형된 Sharpe와 DeMichele의 비선형 모형에 잘 적합 되었다. 발육단계별 발육기간을 표준화하여 누적시킨 값을 3개의 변수를 갖는 Weibull function에 적용했을 때 1<TEX>${\sim}$</TEX>2령 < 3<TEX>${\sim}$</TEX>4령 < 전체 약충 순으로 발육기간이 짧아지는 경향을 보여 주었고, <TEX>$r^2$</TEX>는 0.86<TEX>${\sim}$</TEX>0.91로 나타났다. The development of Aulacorthum solani (Kaltenbach) was studied at temperatures ranging from 12.5 to <TEX>$27.5^{\circ}C$</TEX> under <TEX>$65{\pm}5%$</TEX> RH, and a photoperiod of 16:8 (L:D). Mortality of <TEX>$1st{\sim}2nd$</TEX> nymph was higher than that of <TEX>$3rd{\sim}4th$</TEX> nymph at the most temperature ranges whereas at high temperature of <TEX>$27.5^{\circ}C$</TEX>, more <TEX>$3{\sim}4th$</TEX> nymph stage individuals died. The total developmental time ranged from 16.9 days at <TEX>$12.5^{\circ}C$</TEX> to 6.6days at <TEX>$22.5^{\circ}C$</TEX>, suggesting that higher the temperature, faster the development. However, at higher temperature of <TEX>$25^{\circ}C$</TEX> the development took 7.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were <TEX>$0.08^{\circ}C$</TEX> and 162.8 day-degreeslated development. The nonlinear shape of temperature rewas well described by the modified Sharpe and DeMichele model. When the normalized cumulative frequency distributions of developmental times for each life stage were fitted to the three-parameter Weibull function, attendance of shortened developmental times was apparent with in <TEX>$1{\sim}2nd$</TEX> nymph, <TEX>$3{\sim}4th$</TEX> nymph, and total nymph stages in descending order. The coefficient of determination <TEX>$r^2$</TEX> ranged between 0.86 and 0.91.

Temperature-dependent development rates of Bracon vulgaris, a parasitoid of boll weevil

The duration of development of Bracon vulgaris Ashmead, parasitoid of the boll weevil Anthonomus grandis Boheman, was determined at nine constant temperatures between 18°C and 38°C. Nonlinear regression analysis was used to test the fit of temperature-dependent development rates to the Sharpe and DeMichele and Lactin et al. models. At the highest tested temperature (38°C) all the parasitoid eggs died before hatching and no evidence of development was observed. The high values of R 2 for the models of Sharpe and DeMichele (0.8432 to 0.9834), and Lactin et al. (0.9071 to 0.9795) indicated that these models are suitable to estimate the development rate of B. vulgaris as a function of temperature. B. vulgaris showed tolerance to high temperature which is represented by the high value of H H (change in enthalpy associated with high-temperature inactivation of the enzyme) for the prepupa stage of this insect obtained with the Sharpe and DeMichele model. According to that model, B. vulgaris exhibits thermal stress at 35.7°C, which indicates that maximum thermal stress estimated by this model was close to the real one.

보리두갈래진딧물 [Schizaphis graminum (Rondani)]의 온도발육과 발육모형

The development of Schizaphis graminum (Rondani) was studied at various constant temperatures ranging from 15 to , with RH, and a photoperiod of 16L:8D. Mortality of the stage nymphs were similar at most temperature ranges while at high temperature of , more stage individuals died. The total developmental time ranged from 13.8 days at to 4.9 days at suggesting that the higher the temperature, the faster the development. However, at higher end temperature of the development took 6.4 days. The lower developmental threshold temperature and effective accumulative temperatures for the total immature stage were and 105.9 day-degrees, respectively and the nonlinear shape of temperature related development was well described by the modified Sharpe and DeMichele model. The normalized cumulative frequency distributions of developmental period for each life stage were fitted to the three-parameter Weibull function. The attendance of shortened developmental times was apparent with nymph, and total nymph stages in descending order. The coefficient of determination ranged between 0.80 and 0.87.

Simulation Modeling of Twospotted Spider Mite Population Dynamics in Apple and Pear Orchards in Korea

Reliable prediction of pest population density plays a critical role in decision making for pest management. For this purpose, a stage-structured simulation model was constructed to predict the population dynamics of twospotted spider mite, Tetranychus urticae Koch in apple and pear orchards. Three external factors influential to spider mite population dynamics in Korean orchard systems are temperature, acaricide and precipitation. Temperature-dependent developmental parameters were mostly derived from experimental measures with a Korean strain of T. urticae. Immature development and adult longevity were fitted to the poikilotherm rate function (modified Sharpe and De-Michele model) with daily mean temperature while its variation and age-specific-oviposition, and -mortality were described by a three-parameter Weibull function relative to physiological age. Acaricidal effect and precipitation effect on T. urticae were expressed as exponential decay. Sensitivity tests and validation process provided good correlations to observed data from apple and pear orchards in a shorter period, but a little deviation in a longer period. Further improvement and implication of simulation model in integrated mite management are discussed.

A Temperature-Based Simulation Model for the Potato Tuberworm,Phthorimaea operculellaZeller (Lepidoptera; Gelechiidae)

The potato tuberworm, Phthorimaea operculella Zeller, is a serious pest of the potato, Solanum tuberosum L., in subtropical and tropical production systems around the world. Knowledge of the temperature-dependent population growth potential is crucial for understanding population dynamics and implementing pest control strategies in different agro-ecological zones. The development, mortality of immature life stages, and reproduction of P. operculella were studied at constant temperatures ranging from 10 to 32°C. The theoretical developmental thresholds were 11, 13.5, and 11.8°C, and required incubation times were 65.3, 165.1, and 107.6 degree-days (DD) for the egg, larval, and pupal stages, respectively. The nonlinear shape of the temperature–development curve at low temperatures was well described by the modified four-parameter Sharpe & DeMichele model. The log-normal function was fitted to the normalized cumulative frequency distributions of developmental times for each life stage. Temperature effects on immature mortality were described by polynomial regressions. The optimal temperature for survival was within the range of 20–30°C. Temperature effects on adult senescence were described by the modified Sharpe & DeMichele model. A polynomial function was fitted to total fecundity and temperature. Fecundity was highest around 21°C. Age-related cumulative proportions of fecundity were well described by a Gamma function. Most eggs were laid within the first quarter of the female life span. The established functions were used to build a P. operculella population model, and life table parameters were simulated over a range of temperatures. Calculations gave good predictions when compared with published data. Populations increase within a temperature range of 10–35°C, with an optimum at 28–30°C.

Comparison of three models predicting developmental milestones given environmental and individual variation

In all organisms, phenotypic variability is an evolutionary stipulation. Because the development of poikilothermic organisms depends directly on the temperature of their habitat, environmental variability is also an integral factor in models of their phenology. In this paper we present two existing phenology models, the distributed delay model and the Sharpe and DeMichele model, and develop an alternate approach, called the Extended von Foerster model, based on the age-structured McKendrick–von Foerster partial differential model. We compare the models theoretically by examining the biological assumptions made in the basic derivation of each approach. In particular, we focus on each model’s ability to incorporate variability among individuals as well as variability in the environment. When compared against constant temperature mountain pine beetle ( Dendroctonus ponderosae Hopkins) laboratory developmental data, the Extended von Foerster model exhibits the highest correlation between theory and observation.

Estimative of Podisus nigrispinus (Dallas) (Heteroptera: Pentatomidae) development time with non linear models

The objective of this study was to evaluate the precision of the non linear models of Davidson (1942, 1944), Stinner et al. (1974), Sharpe & DeMichele (1977), and Lactin et al. (1995) to describe relationship between developmental rate of different stages of Podisus nigrispinus (Dallas) and temperature. Lower values of R2 for the models of Davidson (0.1593 to 0.2672, and 0.1406 to 0.2804 for males and females, respectively) and of Stinner et al. (0.2136 to 0.6389, and 0.1417 to 0.3045 for males and females, respectively) showed that these models were not adequate to estimate developmental rate of P. nigrispinus as function of temperature. However, high values of R2 for the models of Sharpe & DeMichele (0.9226 to 0.9893, and 0.8818 to 0.9914 for males and females, respectively), and of Lactin et al. (0.9485 to 0.9997, and 0.8961 to 0.9997 for males and females, respectively) showed that these models are suitable to estimate developmental rate of P. nigrispinus as function of temperature. Females of P. nigrispinus showed high tolerance to high temperature which is represented by high values of HH for immature stage of this insect obtained with the Sharpe & DeMichele model. According to this model females of P. nigrispinus present thermal stress at 33.3oC, which indicates that maximum thermal estimated by this model was close to the real one.

Oviposition model of Carposina sasakii (Lepidoptera: Carposinidae)

Adult longevity, survival, and fecundity of Carposina sasakii Matsumura were investigated at 15, 18, 20, 25, 30, and 35 °C, and an oviposition model was developed. The temperature affected adult longevity, survival, and fecundity. Overall, the longevity decreased as the temperature increased and the female adult developmental rates (1/median longevity) were well described by the modified Sharpe and DeMichele model in the rage of 15–35 °C, and were used to calculate the adult physiological age. Total fecundity was the highest at 20 °C, and then declined steadily thereafter. The relationship between total fecundity and temperature was well described by a nonlinear equation. The cumulative age-specific oviposition rate was well described by the two-parameter Weibull function. The overall adult survival exhibited a reverse logistic curve. Three temperature-dependent components, total fecundity, age-specific oviposition rate, and age-specific survival rate, were incorporated into the oviposition model. Oviposition model simulation well described the field occurrence patterns of C. sasakii egg population.

Parameter Estimation for Temperature-Dependent Development Model of Tetranychus urticae Koch: Immature Development

For construction of a mathematical population dynamic model of Tetranychus urticae Koch, parameters of temperature-dependent development were estimated. The immature development of T. urticae was studied under 6 constant temperatures ranging from 16 to 33°C, 60–70% R.H., and a photoperiod of 16:8 (L: D) h to estimate the parameters for a poikilotherm rate model. The effect of temperature on immature development was significant; total immature develop ment required 7–26 days depending on temperatures. The curvilinear shapes of development rate were described well by the modified Sharpe and DeMichele model (poikilotherm rate model). The variation of development completion times was well fitted to the three-parameter Weibull function. The lower threshold for immature development was determined to be 12.1°C. The sex ratio, proportion of females, was estimated to be 0.75. Deviation of developmental parameters from the literature-based data, and the use of parameters for population modeling were further discussed.

Temperature-Dependent Development ofCarposina sasakii(Lepidoptera: Carposinidae) and Its Stage Emergence Models

Temperature-dependent development of Carposina sasakii Matsumura was studied, and its stage emergence models were developed. The development times of C. sasakii decreased with increasing temperature up to 32°C in eggs, up to 28°C in larvae, and up to 30°C in pupae. The estimated low-threshold temperatures were 11.0, 9.4, and 10.3°C for eggs, larvae, and pupae, respectively. Thermal constants of eggs, larvae, and pupae were 104.2, 270.3, and 188.7 degree-days, respectively. The stage emergence models of C. sasakii, which simulate the proportion of individuals shifted from a stage to the next stage, were constructed using the modified Sharpe and DeMichele model and the two-parameter Weibull function. In field validation, a degree-day model for the prediction of egg hatch time showed the bias of <1 d between prediction and observation. The stage emergence models predicted the patterns of C. sasakii stage emergences in the field. Also, the established stage emergence models should be useful in building a C. sasakii population model that will describe its seasonal occurrence pattern and population dynamics under various orchard systems.

Temperature Effects on Development, Fecundity, and Life Table Parameters of &lt;I&gt;Amblyseius womersleyi&lt;/I&gt; (Acari: Phytoseiidae)

Abstract The development, reproduction, and life table of Amblyseius womersleyi (Schicha) were studied at temperatures ranging from 16 to 38°C, 60–70% RH, and a photoperiod of 16:8 (L:D) h. Mortality of A. womersleyi was high in the early developmental stages, and this trend was especially apparent at low temperatures. The developmental threshold for all immature stages was 11.6°C. The total preimaginal developmental time ranged from 48.3 to 316.0 h. The optimal temperature for development was 33°C. The nonlinear shape of temperature development was well described by the modified Sharpe and DeMichele model. The normalized cumulative frequency distributions of developmental times for each life stage were fitted to the three-parameter Weibull function. The 50% adult survivorship occurred at 15-21 d at ≤24°C, and on 7–9 d at ≥29°C. The mean daily fecundity ranged from 0.325 to 2.963 eggs and was fitted by a third-order polynomial equation. The intrinsic rate of increase (rm) ranged from 0.053 to 0.402, and w...

Temperature-Dependent Model for Simulating Development of the Larval Stages of Baris coerulescens (Coleoptera: Curculionidae) on Winter Oilseed Rape

Baris coerulescens Scopoli is a weevil attacking the tap root of winter oilseed rape. Experiments at 6 constant temperatures (10, 15, 21, 25, 30, 35°C) provided mean development rates for each temperature and larval stage as well as distributions of development times. We estimated the 4 parameters of the Sharpe and DeMichele model with high-temperature inhibition and the 3 parameters of a Weibull function describing variability of development times. To validate the model, field data were collected during a 4-yr study. Plants were dissected, and all the egg and 4 instars per plant were counted throughout the development period; these numbers were transformed to proportions for each date. The model was run using a combination of air and soil temperatures, and egg cohorts were defined according to a plant infestation model. Simulation results described field results well, with discrepancies of <15%. We discuss conditions necessary for early development of the pest and potential yield losses.

Comparison of Different Models for Predicting Development Time of the European Corn Borer (Lepidoptera: Pyralidae)

Nine nonlinear models (degree-day with a 10°C base, degree-day model, polynomial, normal distribution, Stinner model, Sharpe and DeMichele model, Logan model with or without a base, Hilbert and Logan model) were tested to describe the relationship between development rate and temperature for the European com borer, Ostrinia nubilalis Hübner. These models were calibrated with laboratory experiments based on destructive sampling under sinusoidal temperatures from 9 to 42°C. They were then evaluated and compared with field experiments, at temperatures from 4 to 37°C, carried out as artificial infestations in various areas. Laboratory development models with the smallest time shifts between predicted and observed molts were the Sharpe and DeMichele model, polynomial model, normal distribution, and Stinner model. A classification with an adjusted coefficient of determination (taking into account the number of parameters in the model) slightly modified the results and the best models were the polynomial and the normal distribution, followed by the Stinner model and the degree-day model with a 10°C base. The classification was almost reversed under field conditions. Large shifts occurred in all models in some experiments, thereby demonstrating that temperature was not the only factor involved. Models showing the smallest shifts under field conditions were the degree-day model and the Logan model. The experiments that showed the greater shifts corresponded to infestations on early or on late phenological stages of corn. Results confirmed that the experimental design and calibration method were adequate. The laboratory experiments provided a means of calibrating the models and of predicting results under field conditions from laboratory experiments. Future studies will focus on a precise quantitative analysis of factors affecting development other than temperature, notably infestation date, climatic factors, and phenological stage of corn.

Temperature-dependent development and survival of the lesser mealworm, Alphitobius diaperinus.

Development, growth and survival of the lesser mealworm, Alphitobius diaperinus (Panzer), were determined at six constant temperatures. No egg hatch or larval development occurred at 17 degrees C. At temperatures of 20, 25, 30, 35 and 38 degrees C the median development times (days), respectively, were for eggs (13.4, 6.0, 4.4, 2.6 and 2.6), larvae (133.0, 46.0, 26.2, 22.4 and 23.9), pupae (17.0, 8.0, 5.5, 4.0 and 4.1), and from oviposition to adult emergence (164.4, 60.2, 37.9, 29.0 and 30.8). The Sharpe & DeMichele (1977) model was used to describe the temperature-dependent development. The mean egg survival (hatching) ranged from 61% to 86%, with lowest hatch at 20 degrees C. Survival of the larvae and pupae ranged from 32% to 73% and from 85% to 95%, respectively, with lowest survival at 20 degrees C. Pupae had significantly lower weights at 35 degrees C and adults at 38 degrees C than at the other temperatures. Female pupae (20 mg) and female adults (16 mg) were significantly heavier than male pupae (17 mg) and male adults (13 mg). Adults (0.5-9 months old) laid 4-7 eggs per female per day at 25 degrees C.

Temperature-Dependent Development of the Fungal Pathogen Lagenidium giganteum (Oomycetes: Lagenidiales) in Larvae of Culex quinquefasciatus (Diptera: Culicidae)

The rates of development of Lagenidium giganteum were determined in the four larval instars of Culex quinquefasciatus Say held at 15, 20, 25, 27, 30, and 34 degrees C. The fastest development was in second instars held at 34 degrees; vesicles and oospores occurred in 50% of the larvae (the median development time) 19.7 and 25.0 h, respectively, after infection. The greatest median time to the formation of vesicles was in third instars at 15 degrees C (185.6 h) and for oospores was in second instars at 15 degrees C (152.3 h). The fungus did not form oospores in fourth instars at 15 degrees C. The median developmental rates of vesicles and oospores in each instar were fit to the Sharpe & DeMichele model, which may be used to predict the effects of different temperatures on the in-vivo developmental rate of the fungus.

Development and Mortality of Ips calligraphus (Coleoptera: Scolytidae) at Constant Temperatures

We describe effects of constant temperature, beetle density, and time of oviposition on aspects of development, mortality, sex ratio, and size of Ips calligraphus (Germar). Emphasis is placed on individual life stages. Relationships of median development times to constant temperatures were similar for eggs, larvae, and pupae in the 12.5–37.5°C range. These relationships appeared as backward J-shaped curves. Reciprocal development times versus temperatures for these life stages were described by the six-parameter rate function of Sharpe & DeMichele (1977, J. Theor. Biol. 64: 649–670). Development times and foraging distances of larvae increased with each instar. The third instar required 61% of total larval time and excavated 73% of the total larval gallery. Optimum development temperature of teneral adults was not identified, indicating greater tolerance to high temperatures of this stage compared with the others. The four-parameter Sharpe & DeMichele (1977) model (without high-temperature inhibition) described teneral adult rate as a function of temperature. Timing of oviposition influenced development time of larvae (increased development time with late oviposition) and teneral adults (decreased), but not development times of eggs or pupae. Reversed patterns of longer development times for larvae and shorter times for teneral adults canceled any effects of sequential oviposition on length of life cycle. Distributions of development times were generally skewed toward the longer times, and variation around mean time tended to increase with successive life stage. A single, temperature-independent distribution of normalized development times is presented for each life stage and is described by a three-parameter cumulative Weibull function. Stage-specific mortality (resulting from unknown causes) formed partial or full U-shaped patterns when plotted against temperature. Density-dependent mortality resulting from cannibalism is discussed, with a Weibull function describing influence of egg density on probability of being cannibalized. Timing of oviposition influenced percentage of mortality of all life stages, primarily due to increased cannibalism of later-developing brood. An overall sex ratio of 1:1 was observed, but proportion of males to total I. calligraphus increased from 0.374 in the first quarter of the emergence period to 0.569 in the fourth quarter. Beetles reared at 15–25°C were somewhat larger than those reared at 30–35°C. Generally, males were slightly larger than females when size was examined relative to time of emergence. An inverse relationship of beetle size to time of emergence was observed for each sex.