Temperature influence on cohort parameters and demographic characteristics of the two cowpea coreids Clavigralla tomentosicollis and C. shadabi

Age-specific life tables of two important pests of cowpea, Vigna unguiculata (L.) Walp., the pod sucking bugs Clavigralla tomentosicollis Stål and C. shadabi Dolling (Heteroptera: Coreidae), were obtained from observations carried out at different temperatures. A biophysical model was found satisfactory to describe the temperature-response of developmental and mortality rates of egg and nymphal stages, with a peak developmental rate around 34°C in both species. The variability in development times was small and the experimental data did not permit any conclusion with regard to the Erlang probability density function. Survival of eggs and nymphs remained high between 20° and 30°C for both species. At temperatures above 34°C, C. tomentosicollis survivorship and fecundity was higher than that of C. shadabi, which in turn laid more eggs at temperatures between 20° and 30°C. Maximum fecundity is estimated to be at 29°C for C. tomentosicollis (99 eggs/female) and 26°C for C. shadabi (261 eggs/female). At 30°C, the intrinsic rate of increase reached a maximum in both species, 0.152 per day for C. tomentosicollis and 0.145 per day for C. shadabi, and remained high for C. tomentosicollis until 36°C. C. tomentosicollis performed significantly better on pigeonpea, Cajanus cajan Millsp., than on cowpea at higher temperatures.     

Comparison of biological and demographic parameters forMononychellus progresivus andOligonychus gossypii on cassava: influence of temperature

The effect of five constant temperatures (16, 22, 26, 31 and 36°C) on biological (survival and duration of developmental stages, fecundity and longevity of females, sex-ratio) and demographic parameters (R _o , G, r _m and λ) of the two main phytophagous mites that attack cassava in Africa,Mononychellus progresivus Doreste andOligonychus gossypii (Zacher), was studied in the laboratory. Experiments were performed simultaneously on the two mite species reared on the same cassava variety (1M20) under controlled conditions: 70±10% r.h. and 12L∶12D. The lower thermal threshold was 13°C forM. progresivus and 11°C forO. gossypii. Both species developed in the range from 22 to 36°C. The shortest development time was obtained at 31°C for both species; it was 7.2 days forM. progresivus and 8.2 days forO. gossypii. Maximum fecundity of both species was recorded at 26°C with 42.1 eggs forM. progresivus and 36.3 eggs forO. gossypii The highest intrinsic rate of increase (r _m ) was obtained at 31°C for both species with 0.289 and 0.214 forM. progresivus andO. gossypii, respectively.     

Bionomics and population growth statistics of apterous virginoparae of woolly apple aphid, Eriosoma lanigerum, at constant temperatures

Development, survival, reproduction and population growth statistics of apterous virginoparae of woolly apple aphid, Eriosoma lanigerum (Hausmann) (Hemiptera: Aphididae) at constant temperatures of 10, 13, 15, 20, 25, 30 and 32°C are reported. The developmental times of all life stages were inversely related to temperature ranging from 10 to 30°C. Span of total development (time from birth to adulthood) decreased from 57.8 days at 10°C to 11.7 days at 30°C and increased to 16.8 days at 32°C. A good linear model fit (R²>0.96) between developmental rate and temperature in the range 10–25°C was observed for all life stages. The lower developmental threshold was estimated at 5.8°C for instar I, 4.8°C for instar II, 4.9° for instar III and 4.4°C for instar IV. The lower temperature threshold for total development was estimated at 5.2°C. The upper developmental limit was found to be 32°C. Mean degree-day accumulations required for completion of instars I, II, III, IV and total development were: 125.6, 51.0, 47.7, 50.7 and 267.6, respectively. Fecundity, larviposition period and adult longevity were reduced with increasing temperature. Net reproductive rate was greatest at 15°C whereas intrinsic rate of increase peaked at 25°C. Optimal performance, as measured by fecundity, survival and intrinsic rate of increase, ocurred in the range 13–25°C.     

The predatory mite Hypoaspis miles: temperature dependent life table characteristics on a diet of sciarid larvae, Bradysia paupera and B. tritici

Life table characteristics of Hypoaspis miles Berlese (Acarina: Hypoaspidae) fed on a mixture of Bradysia paupera Tuomikoski (Diptera: Sciaridae) and B. tritici Coquillet larvae were investigated in laboratory experiments at 4 temperatures (15, 20, 25, 30 °C) for development time, juvenile mortality, sex ratio, preoviposition period, oviposition period, postoviposition period, age-specific fecundity, and adult longevity. Juvenile development time decreased with increasing temperature from 46 days at 15 °C to 10 days at 30 °C. The lower temperature threshold was 9.9 °C and development required 205 °D. Juvenile mortality decreased from 52% at 15 °C to 3% at 25 °C and then increased to 24% at 30 °C. Preoviposition period varied with temperature from 12 days at 15 °C to 3 days at 25 °C and then increased to about 4 days at 30 °C. Oviposition period decreased with increasing temperature from 58 days at 15 °C to 25 days at 30 °C. The mean number of eggs per female per day increased from 0.4 at 15 °C to 2.3 at 25 °C and decreased to 1.3 at 30 °C. Age-specific fecundity was described by a temperature dependent model from which the maximum daily fecundity rate could be estimated to be attained at 25.6 °C. Female longevity was significantly shorter than for males, and decreased from 90 days at 15 °C to 34 days at 30 °C. Sex ratio was female-biased at all 4 temperatures and increased with temperature up to 25 °C, decreasing at 30 °C. Estimates of net reproductive rate, intrinsic rate of increase, finite rate of increase, mean generation time and doubling time were obtained. The r _m -value increased with temperature from 0.031 day^-1 at 15 °C to 0.133 day^-1 at 25 °C, after which it decreased to 0.112 day^-1 at 30 °C. The study showed that H. miles can develop and reproduce at temperatures between 15 and 30 °C. H. miles and sciarids have approximately the same optimum temperature and thresholds for development and reproduction and H. miles can be used for biological control of sciarids within the temperature range where the pest occurs.     

Life history study of Thrips setosus

Development, reproduction and population growth of Thrips setosus Moulton (Thysanoptera, Thripidae), reared on a leaf of kidney bean, was studied under six different constant temperatures, and the effect on reproduction of short photoperiod during immature stages was examined. Survival rates from hatch to adult were more than 67.5% at temperatures between 17.5 and 27.5 °C, but less than 55% at 30 °C. Developmental rates increased linearly as rearing temperature increased. A total of 181.1 degree-days, above a developmental zero of 12.5 °C, were required to complete development from egg to adult oviposition. These data were related to records of field temperatures in Kurashiki in western Japan, and an estimate produced that, under outdoor conditions, a maximum of between seven and 12 generations could have developed annually between 1990 and 1999. There were no significant differences in mean adult longevity and mean fecundity among three temperatures (20, 22.5 and 25 °C). The intrinsic rate of natural increase (r _m) was 0.1997 at 25 °C. Reproductive diapause was induced by a photoperiod less than 12 h at 20 °C.     

Egg production in response to combined alternative foods by the predator Coccinella transversalis

The peformance of the parasitoid Anagyrus kamali Moursi [Hymenoptera: Encyrtidae], as a function of host density, temperature, and photoperiod was investigated with the objective to optimize a mass-rearing system in the context of a biological control program. The number of hosts parasitized at densities varying from 2–100 hibiscus mealybug (HMB), Maconellicoccus hirsutus Green [Homoptera: Pseudococcidae], corresponded to a type II-III functional response in fixed-time conditions and a type III in variable-time conditions. Twenty-six percent of the oviposited eggs led to progeny emergence with a sex ratio of 0.49±0.102 (M/F), regardless of host density. Fecundity and oviposition period under six abiotic combinations (i.e., two temperatures (26±2 °C and 32±2 °C) and three photoperiods (L0:D24, L12:D12, L24:D0)) were measured. Lifetime fecundity and reproductive life were significantly affected by temperature and photoperiod conditions. Optimum female parasitoid lifetime fecundity was attained at 26±2 °C, L0:D24 with an average of 116.1±17.43 eggs. At 32±2 °C, L24:D0 and L12:D12, an average of 79.4±34.57 and 85.8±35.81 eggs were laid, respectively. Reproductive longevity was maximal at 26±2 °C, L0:D24 with 12±4.85 days of oviposition. Because the parasite A. kamali can be reared optimally without light, this may save tremendous energy costs.     

Influence of root-zone temperature on growth,development and yield of cucumber plants cv. Toska

Summary In a first experiment, cucumber transplants (cucumis sativa L. cv. Toska) were grwon at five root-zone temperatures (RZT) ranging from 12° to 36°C. Maximum shoot growth and total leaf area were obtained at 24° and 30°C (RZT). In a second experiment, cucumber transplants were submitted to five RZT (12, 18, 24, 30 and 36°C) and five night air temperatures (NAT) that were maintained either constant at 9°, 13° and 17°C or splitted (in two halfs) at midnight (17°/12°C, 17°/9°C). Root-zone warming to 24° or 30°C increased cucumber plant growth and leaf development, but did not compensate completely the loss of productivity induced by low NAT. Split-night temperature had greater effects under the lowest NAT (17°/9°C) and at high RZT (24° or 30°C). In a third experiment, soil warming caused large increase in yields when cucumber plants were grown in the spring, but had very little effects in the fall.     

Biological aspects of the geranium mites,Coptophylla caroliniani andAceria mississippiensis (Prostigmata: Eriophyidae)

Aceria mississippiensis andCoptophylla caroliniani (Prostigmata: Eriophyidiae) were found on wild geranium,Geranium carolinianum L., in northern Mississippi. About onehalf of the total developmental time was spent in the egg stage for each species. The developmental threshold forA. mississippiensis was 5.5±1.04°C and 7.3±0.93°C forC. caroliniani. The optimum temperature for each developmental stage was between 25 and 29°C.C. caroliniani failed to develop at 36°C, whereasA. mississippiensis failed at 40°C. Day-degree requirements to complete development were 100.7±3.6 D^o and 154.6±4.1 D^o forC. caroliniani andA. mississippiensis, respectively.Mean female longevity at 20°C was 17.4 (range 12–21) days forC. caroliniani and 16.5 (range 15–19) days forA. mississippiensis. The shortest pre-oviposition period was 2.2 days forC. caroliniani at 20°C and 1.7 days forA. mississippiensis at 25°C, and the length of pre-oviposition period increased with temperature above 25°C for both species.Maximum egg production ofC. caroliniani andA. mississippiensis occurred at 20°C. There were no differences (P0.05) in number of eggs per day at temperatures of 20, 25 and 32°C for each species, but there was a tendency to lay more eggs per day with increasing temperature. The percentages of egg hatch were not significantly different at these temperatures. The sex ratio of laboratory-rearedA. mississippiensis was 1:1.8, whereas field-collectedC. caroliniani showed a ratio of 1:1.     

Temperature and plant nutrient effects on the development, survival and reproduction of Cinara sp. nov., an invasive pest of cypress trees in Africa

Cinara sp. nov., previously identified as Cinara cupressi (Buckton) (Homoptera: Aphididae), is an important alien aphid pest of cypresses and junipers, and invaded Africa in the late 1980s. The work reported here was carried out as part of a larger programme aimed at the classical biological control of the aphid in Africa. Basic life history attributes including life table statistics of the aphid were quantified in order to facilitate the development of efficient aphid culturing methods and essential baseline information necessary for the culturing of potential parasitoid biological agents prior to selection for introduction to Africa. Developmental rates and fecundity were studied under four constant temperatures (10 °C, 15 °C, 20 °C, and 25 °C). The effects of several plant nutrients (nitrogen, potassium and phosphorus) supplied at different dose levels on life history attributes of Cinara sp. nov. were also studied.Unlike most other aphids, the apterous morph of Cinara sp. nov. developed through only three instars, and the alate four instars. The aphid is highly aggregative and exploits a wide range of feeding sites from young green branches to woody stems. The developmental period of Cinara sp. nov. ranged from 9.3 days at 25 °C to 22.3 days at 10 °C and the developmental threshold was 0.61 °C. Reproduction was delayed, because of the longer duration of development, and nymph production decreased with decreasing temperature. The intrinsic rate of increase ranged between 0.117 at 25 °C and 0.060 at 10 °C. Aphid size increased significantly as temperature was lowered. Wing formation was not induced when apterae were reared for up to three generations at each constant temperature but continuous crowding in the supply cultures held at 21 °C resulted in a high number of alates being formed. No appreciable effects of the different plant nutrients, supplied either singly or in combination, on the duration of instars or overall survival could be detected.     

Costs and benefits of acclimation to elevated temperature in Trichogramma carverae

The consequences of acclimation for survival and other fitness components in the parasitoid wasp, Trichogramma carverae (Oatman and Pinto), were examined. Heat hardening adult wasps at 33 °C or 35 °C for one to two h increased survivorship at 40 °C. This benefit was apparent for several hours after heat-hardening and occurred in both males and females. Heat hardening at 33 °C during development also resulted in significant increases in survivorship of adults after exposure to 40 °C. However, this developmental hardening reduced longevity of adult male and female wasps and also reduced parastism rate. This suggests costs and benefits of exposure to non-lethal temperature increases. Acclimating wasps by rearing them under constant temperatures (14, 25 or 30 °C) influenced parasitism rates at these temperatures at the adult stage; only females reared at 14 °C parasitised eggs at 14 °C, while parasitism at 25 °C and 30 °C was not significantly influenced by rearing temperature. Acclimation may be useful for increasing the survival or fecundity of mass-reared Trichogramma in inundative releases, but any benefits could be offset by fitness costs of the acclimation process.     

Xylanases of thermophilic bacteria from Icelandic hot springs

Thermophilic, aerobic bacteria isolated from Icelandic hot springs were screened for xylanase activity. Of 97 strains tested, 14 were found to be xylanase positive. Xylanase activities up to 12 nkat/ml were produced by these strains in shake flasks on xylan medium. The xylanases of the two strains producing the highest activities (ITI 36 and ITI 283) were similar with respect to temperature and pH optima (80°C and pH 8.0). Xylanase production of strain ITI 36 was found to be induced by xylan and xylose. Xylanase activity of 24 nkat/ml was obtained with this strain in a laboratory-scale-fermentor cultivation on xylose medium. -Xylosidase activity was also detected in the culture filtrate. The thermal half-life of ITI 36 xylanase was 24 h at 70°C. The highest production of sugars from hydrolysis of beech xylan was obtained at 70°C, although xylan depolymerization was detected even up to 90°C. Correspondence to: M. Rättö     

Effect of three diaspididae prey species on development and fecundity of the ladybeetle Chilocorus bipustulatus in the laboratory

The purpose of this investigation was to determine the most suitable prey for the development and fecundity of the predatory coccinellid, Chilocorus bipustulatus (L.) on three different diaspidid species: Aspidiotus nerii Bouché, Aonidiella aurantii (Maskell), and Pseudaulacaspis pentagona (Targioni-Tozzetti). Life tables were constructed at constant 25°C and the developmental time, longevity, fecundity, and the sex ratio were determined. Individuals fed with A. nerii displayed the shortest larval and pupal developmental time (26.0 days), lowest immature mortality rate (16.6%), highest net reproduction rate (264.7 females/ female), shortest generation time (72.9 days), and the highest intrinsic rate of increase (0.077 females/female/day). The results showed that under laboratory conditions C. bipustulatus developed best on A. nerii.     

Temperature,time, and the influence of volatiles on phialospore germination in Verticillium malthousei Ware

Phialospores of Verticillium malthousei Ware were atomized onto acclimatized water agar and incubated for 3, 6, 9, 12, and 24 hr at 12 to 36 °C at 6 °C intervals. Germination occurred at all temperatures exclusive of 36 °C with maximum germination (90–98 %) occurring in 24 hr at 12 °C, 12 hr at 18 °C, 9 hr at 24° and 30 °C. Volatiles from: 1) horse manure compost colonized by Agaricus bisporus; 2) mycelium impregnated casing (soil); or 3) casing supporting mature and immature mushrooms had no statistically significant effect on spore germination of V. malthousei when measured after 12 hr at 24 °C. However, a tendency towards inhibition after 6 and 12 hr at 24° and 12 °C, respectively, suggests the inhibition is temperature and time dependent. This dependency was noted with two substrates, colonized compost and casing which supported sporocarps.The statistical and programming assistance of Dr. J. A. Ayers, Department of Plant Pathology, Dr. R. Craig, Department of Horticulture, and Ms. Isabel M. Hoover, Agricultural Statistic Laboratory, The Pennsylvania State University is gratefully acknowledged.Contribution No. 759 from the Department of Plant Pathology, The Pennsylvania Agriculture Experiment Station. Authorized for publication as Journal Series Paper No. 455.0 on October 8, 1973.     

Relationships between temperature, development and survival of different life stages of the tomato fruit fly, Neoceratitis cyanescens

The development and survival of female Neoceratitis cyanescens (Bezzi) (Diptera: Tephritidae) from egg to complete ovarian maturation were studied in the laboratory at five different constant temperatures: 15, 20, 25, 30, and 35 °C. The aim of this study was to get information on the influence of temperature on pre-mature stages, as a prerequisite to optimise rearing procedures and to understand temporal and geographical patterns of fruit fly occurrence. The developmental rate of the different life stages increased linearly with increasing temperatures up to 30 °C. The fastest development of pre-mature stages was recorded at 30 °C (22±1 days) and the slowest at 15 °C (98±3 days). The day-degrees requirements (K) to complete total development were 432.6 day-degrees. Lower temperature thresholds were 11.4, 11.9, 10.0, and 11.1 °C for egg, larval, pupal stages and ovarian maturation, respectively. The number of adults obtained from an initial batch of 100 eggs reached a maximum (64) at 25 °C. At 35 °C, no adults emerged. Larval developmental time was significantly shorter in green tomato fruits than in potato tubers at 15, 20, and 25 °C. Mortality rate of larvae was higher in green tomato fruits than in potato tubers at 25 and 30 °C.     

Biology, life table and host specificity of the mushroom pest, Brennandania lambi (Acari: Pygmephoroidea)

Biology and life table parameters of Brennandania lambi (Krczal) were studied at different temperatures while feeding on white mushroom (Agaricus bisporus) mycelium cultured on mushroom compost. The duration of egg and larva development, preoviposition and oviposition period, female longevity, and the time to 50% mortality declined as temperature increased from 16 to 28°C. The threshold temperature of development (female) was 9°C and the thermal constant for completion of development (female) was 195 day-degrees. At 16, 20, 24 and 28°C, the total fecundity (eggs/female) was 71, 67, 66 and 57, respectively and the daily fecundity rate (eggs/female/day) was 5.6, 8.7, 8.7 and 9.1, respectively. The sex ratio (female/male) ranged from 1.9 to 2.1 at 16–28°C. At 16, 20, 24 and 28°C, the intrinsic rate of natural increase (r _m) was 0.11, 0.18, 0.22 and 0.27, respectively, and the population doubling time was 6.1, 3.9, 3.2 and 2.5 days, respectively. All life stages of the mite died when exposed to 35°C constant temperature for 24h, or to 32°C constant temperature for 12 days or to 31–35°C (average 32.9°C) ambient temperature for 4 days. Brennandania lambi completed development only when fed on Ag. bisporus mycelium growing on mushroom compost. It could not survive on mushroom mycelia of Auricularia auricula, Au. polytricha, Ganoderma lucidum, Hericium erinaceus, Lentinus edodes, Pleurotus ostreatus, P. sajor-caju and Tremella fuciformis.     

Geographical variation in insect developmental period: effect of host plant phenology on the life cycle of the bruchid seed feeder shape Kytorhinus sharpianus

The voltinism of the bruchid Kytorhinus sharpianus Bridwell (Coleoptera: Bruchidae) and the phenology of its host plant Sophora flavescens Aiton (Leguminosae) were observed at four latitudes: Aomori (40°46' N), Obanazawa (38°37' N), Kujiranami (37°21' N) and Mitsuma (36°05' N) in northeastern Honshu (Japan). Kytorhinus sharpianus life cycle ranged from bivoltine and partially trivoltine in the south to univoltine and partially bivoltine in the north. Sophora flavescens started growing later in spring at higher latitudes. However, the relative growth rate was higher in the north (Aomori) than in the south (Mitsuma). In parallel with this, the first-generation of adult K. sharpianus appeared later at higher latitudes. When the four local populations were reared at 24 °C, L16:D8 and 65% r.h., males developed faster than females. The mean developmental time showed a saw-toothed latitudinal cline. The reversion in the latitudinal trend of variation corresponded to the change in the major type of life cycles from univoltine to bivoltine. Two heat units throughout the year and post-fruiting period were calculated as the sums of degree-days above the developmental threshold (12 °C) of K. sharpianus. Both heat units decreased in parallel with each other with increasing latitude. The greater growth rate of hosts in the northern population compensated for the smaller heat units. In addition, when the heat units were divided by the degree-days needed to complete development, the numerical value was the approximate number of generations observed in each locality.     

Life history divergence of sympatric diploid and polyploid populations of brine shrimp Artemia parthenogenetica

In order to study how polyploidy affects life history patterns in animals, we have examined sympatric diploid and polyploid brine shrimp (Artemia parthenogenetica) from China, Italy and Spain under laboratory conditions. At optimal temperature and salinity (25°C and 90 ppt), diploids from the three populations had much higher intrinsic rates of increase, higher fecundity, faster developmental rates, and larger brood sizes than their sympatric polyploids. The Chinese and Italian populations were selected for further analysis to determine the life history responses of diploids and polyploids to temperature and salinity changes. Under intermediate and high salinities, Chinese and Italian polyploids produced most of their offspring as dormant cysts while their sympatric diploids produced most of their offspring as nauplii. This relationship is reversed in the Spanish diploid-polyploid complex. For the Chinese population at 25° C, pentaploid clones had higher developmental rates than diploid clones at 35 ppt; at 90 ppt, diploid clones had higher developmental rates than the pentaploids. Italian diploids and tetraploids had different responses to variation in both temperature (25° C and 31° C) and salinity (30 ppt and 180 ppt). Our results demonstrate that relative fitness of the two cytotypes is a function of environmental conditions and that sympatric diploids and polyploids respond differently to environmental changes. Chinese and Italian polyploids are expected to have lower fitness than their sympatric diploids when the physical environment is not stressful and when intraspecific competition is important. However, polyploids may have advantages over sympatric diploids in stressful habitats or when they encounter short-term lethal temperatures. These results suggest that polyploid Artemia have evolved a suite of life-history characteristics adapting them to environments that contrast to those of their sympatric diploids.     

Effects of alternating temperatures onAcarus siro L. (Acari: Acaridae)

Fecundity, longevity and survival to adulthood ofAcarus siro (L.) at constant and alternating temperatures were compared. Both fecundity and longevity were affected by alternating temperatures but the effect of the frequency of alternations was not significant. Significantly higher fecundity and longer life spans were recorded at constant temperatures of 14 and 21°C than at 28°C or at alternating temperature regimes. Alternating temperature regimes in comparison to constant regimes did not significantly change the number of males and females surviving to adulthood or the sex ratio. However, the lowest number of adults surviving was recorded when temperatures were changed every 12 h and the highest at a constant temperature of 14°C.     

Biology of Ixodes Rubicundus Ticks under Laboratory Conditions: Observations on Oviposition and Egg Development

Observations on oviposition and egg development of Ixodes rubicundus were made under laboratory conditions. Engorged females were exposed to temperatures in the range 10–25°C and relative humidities (RHs) of 33 and 93%. The pre-oviposition period, oviposition period, incubation period, conversion efficiency index (CEI) values and fecundity were determined. The mean pre-oviposition period varied from 13.3 days (temperature 25°C and RH 33%) to 68.3 days (temperature 10°C and RH 93%). Oviposition extended from a mean of 39 days (temperature 25°C and RH 93%) to 201.7 days (temperature 10°C and RH 93%). The developmental zero temperature for the pre-oviposition period was 9.2°C. The mean total number of eggs produced by engorged I. rubicundus females varied from 2045.7 (temperature 10°C and RH 93%) to 3777.7 (temperature 20°C and RH 93%). Both female mass and RH significantly (p < 0.01) influenced the number of eggs produced. CEI values varied between 43.1–54.4% (RH 93%) and 34.1–42.5% (RH 33%). At 93% RH females produced between 14.2 and 17.7 eggs per mg body mass compared to the 13.2–14.6 eggs per mg body mass at 33% RH. The shortest mean incubation period recorded was 164.3 days (temperature 25°C and RH 93%). The developmental zero temperature for incubation was 6.5°C. Both the pre-oviposition and oviposition periods of I. rubicundus are more extended compared to other species of the genus. Ixodes rubicundus produces a large number of small eggs compared to other prostriate ticks.     

Interactions between size and temperature influence fecundity and longevity of a tortricid moth,Zeiraphera canadensis

Females of Zeiraphera canadensis Mut. & Free., the spruce bud moth, were reared in the laboratory at constant and alternating temperatures, and in an outdoor insectary, to (1) determine the effects of temperature, age and size on several reproductive parameters and, (2) to test the hypothesis that body size-temperature interactions influence longevity and realized fecundity. Egg maturation was linearly related to age and large moths developed eggs at a higher rate than small ones. Mcan lifetime oviposition rate reached a maximum and remained stable at temperatures 20° C while the mean lifetime rate of egg maturation increased linearly with temperature, indicating that higher temperatures adversely affect oviposition. The production of nonviable eggs increased with age but also with temperature, suggesting high temperature (25° C) reduces egg quality and/or hinders fertilization. The realized fecundity and longevity of females reared under an alternating temperature regime (mean 20° C) was significantly less than that of females reared at constant 20° C. Similar realized fecundity, longevity and mean lifetime oviposition rates for females reared at temperatures alternating between 10 and 25° C (mean 20° C) and those at constant 25° C reflected the inability of females to recover from elevated diurnal temperatures. Longevity was positively related to female body size at constant 15 and 20° C but the relationships were negative for moths exposed to diurnal temperatures equal to or exceeding 25° C. Due to the reduced longevity of large moths at high temperatures, linear regressions between size and realized fecundity were only significant at constant temperatures 20° C. At higher temperatures, the size-fecundity relationship became curvilinear as a result of the diminished reproductive output of large individuals. Reduced fecundity and longevity of large females at high temperatures may have been due to elevated internal temperatures of large-bodied moths. Large females in a controlled-environment chamber maintained at 25° C developed an internal temperature excess (i.e. temperature above ambient) of nearly 2° C while small-bodied females exceeded ambient by only 0.3° C. However, when held at 20° C, the temperature excess of large-bodied moths was much less than 1° C and small-bodied females did not differ from ambient. Such interactions between temperature and body size suggest that there should be stabilizing selection toward moderate-sized individuals and may explain the absence of size-related effects on fecundity and longevity previously reported for several other lepidopterans.