Genetic divergence and larval dispersal in two spider crabs (Crustacea: Decapoda)

The spider crabs Inachus dorsettensis (Pennant) and Hyas coarctatus Leach are widespread in subtidal areas of muddy sand or gravel around western Europe. Both species have a life cycle with an obligatory planktonic larval phase of several weeks, which might be expected to cause widespread larval dispersal and consequent genetic homogeneity over considerable distances. However, earlier work on both taxa has indicated differences in growth pattern between populations separated by tens of kilometres. This study was undertaken to determine whether these differences were purely environmental or whether, despite the short distances involved, differences may have a genetic basis. A study of gene frequencies, as indicated by allozymes in samples of adults collected off the Isle of Man (northern Irish Sea), indicates significant genetic differentiation between populations over a geographical distance of only about 40 km in both Inachus dorsettensis ( = 0.086 ± 0.048) and Hyas coarctatus ( = 0.023 ± 0.017). Variability measures differed between species, showing I. dorsettensis to have a mean number of alleles per locus of 2.5–2.6 and a range of gene diversity of 0.216–0.241, while H. coarctatus showed lower values of mean number of alleles (1.9–2.0) and a range of gene diversity from 0.122 to 0.124. Given the high expected larval mobility of the two species the results are most surprising. Possible explanations are discussed in relation to population discontinuities and patterns of larval drift.     

Effect of low rearing temperature on development of Galleria mellonella larvae and their sensitivity to juvenilizing treatment

• 1.1. The development of Gallena mellonella is strongly affected by a low temperature of 18°C (the last instar persists for more than one year, instead of about 9 days at 30°C). At 18°C the last instar Galleria mellonella larvae respond to juvenilizing treatment—chilling stress or juvenile hormone analogue—with a very low percentage or no supernumerary moults, respectively.
• 2.3. Experiments in which larvae subjected to such treatments were transferred from 18°C to 30°C and vice versa showed that for the realization of the larval programme after chilling stress application the higher (30°C) temperature is needed.
• 3.4. In last instar larvae reared at 18°C there coexist very high juvenile hormone titre and high juvenile hormone esterase activity.
• 4.5. This phenomenon which is found in both, chilled and unchilled larvae, is discussed.

     

The influence of temperature on size as an indicator of host quality for the development of a solitary koinobiont parasitoid

The influence of aphid size on the host quality assessment and progeny performance of aphidiine parasitoids was examined using the mealy plum aphid parasitoid, Aphidius transcaspicus Telenga (Hymenoptera: Braconidae) and the black bean aphid, Aphis fabae Scopoli (Homoptera: Aphididae), as a readily acceptable alternate host. Aphid size in relation to stage of development was manipulated by rearing synchronous aphid cohorts at either 15 or 30 °C. At 15 °C, 2nd instar aphids were approximately the same size as 4th instar aphids reared at 30 °C. Cohorts of 30 aphids from each instar, reared at each temperature, were exposed to parasitism by a single parasitoid female for a period of 5 h. Overall susceptibility to parasitism did not vary between aphid cohorts, but the parasitoid response to aphid size differed significantly between rearing temperatures for both progeny sex ratio (parent female assessment of host quality) and larval growth and development (host suitability for parasitoid development). For aphids reared at 15 °C, the proportion of female progeny and emerging adult size for the parasitoid increased linearly with aphid size at the time of attack, while development time remained constant. In contrast, for aphids reared at 30 °C, the proportion of female progeny, emerging adult size, and the development time of the parasitoid all declined with aphid size at the time of attack. The contrasting responses of the parasitoid to host size for aphids reared at the two temperatures suggest that host quality is only indirectly related to aphid size among aphidiine parasitoids. The possible effects of higher temperatures on nutritional stress, obligate endosymbionts, and future growth potential of the aphids are discussed as explanations for the variation in host quality for parasitoid development.     

The influence of temperature and salinity on the duration of embryonic development,fecundity and growth of the amphipod Echinogammarus marinus Leach (Gammaridae)

The effects of salinity and temperature on the duration of embryonic development, fecundity and growth of the amphipod Echinogammarus marinus Leach from the Mondego estuary (Portugal) were studied in laboratory experiments. Combinations of three temperatures (10, 15 and 20 °C) and four salinities (10, 15, 20 and 25 ‰) were used. The duration of embryonic development was 33 ± 0.7 d (mean ± S.E.) at 10 °C, 32 ± 0.5 d at 15 °C, and 17 ± 0.3 d at 20 °C. Analysis of variance demonstrated that the duration of E. marinus embryonic development, reared under different combinations of salinity and temperature, was significantly affected only by temperature (P < 0.001). A positive correlation between the number of newborn juveniles and the size of E. marinus females (as head length) was observed. The number of juveniles released per female was higher at 10 °C and lower at 20 °C. Analysis of variance showed that only temperature significantly affected the number of juveniles released per female (P < 0.001). Experimental data were used to calibrate the von Bertalanffy growth model. Results showed that growth was continuous throughout life under all laboratory conditions. Intrinsic growth rates were higher at 20 °C and lower at 10 °C. Analysis of covariance applied over the initial 90 d after hatching showed significant differences between growth rates of E. marinus under different salinity and temperature conditions. Extrapolation of laboratory data to the field scenario suggests that E. marinus in the Mondego estuary have a multivoltine life cycle.     

Effects of temperature on growth and efficiency of food utilization in fifth-instar caterpillars of the tobacco hornworm, Manduca sexta

Fifth-instar larvae of Manduca sexta were reared from hatching on artificial diet at 15, 20, 25, 30 and 35°C. Total development time decreased with increasing temperature. Very few larvae (12%) survived at 15°C, so this temperature was not considered further. There was some mortality at 30°C (11%), and at 35°C (50%).The absolute rate of growth in the fifth instar was faster at 25 than at 20°C, but was similar at 25, 30 and 35°C. This was true both for caterpillars that were chronically exposed to experimental temperatures (i.e. since hatching) and for those acutely exposed (i.e. reared up to fifth instar at 25°C).There was a progressive decrease with higher rearing temperatures in both the initial and final sizes of chronically exposed fifth-instar larvae. Acutely exposed caterpillars matched for initial size showed smaller temperature related differences in final size. Because of these size differences there were differences in relative growth rate which did not reflect true differences in absolute growth rate.Total food consumed by chronically exposed caterpillars was greatest at the lowest temperature (20°C), and decreased progressively with increasing temperature. The absolute rate of food consumption increased from 20 to 25°C, but did not vary significantly between 25 and 35°C. Differences in the sizes of the insects at the different temperatures meant that there were differences among relative measures of consumption that did not reflect absolute food consumption.For chronically exposed caterpillars, none of the three usual indices of food conversion efficiency (AD, ECI and ECD) varied significantly with temperature between 20 and 35°C. This implies that the effects of temperature on metabolic costs are closely matched to food consumption.Oxygen consumption increased with temperature between 20 and 25°C but was temperature compensated between 25 and 35°C.These findings are discussed in terms of their implications for the optimal temperature for growth in Manduca.     

Effects of brief exposures to low temperature on the development, longevity and fecundity of the grain aphid Sitobion auenae (Hemiptera: Aphididae)

First instar nymphs and adults of the grain aphid Sirobion auenae that had been reared at 10°C and 20°C over a number of generations, were cooled to -5°C and -10°C for 1 h and 6 h and returned to 20°C to assess the effects of brief exposures to low temperatures (cold-pulses) on their survival. rate of development, longevity and fecundity. A strong acclimation response was observed in first instar nymphs, with significantly less mortality in groups reared to 10°C compared to 20°C. Mean development time from first instar to adult was not significantly affected by low temperature exposure at the first nymphal stage. Longevity in all groups cooled as first instars was reduced by the sub-zero cold-pulses, and was also dependent on temperature and exposure time. Acclimated aphids survived longer than non-acclimated individuals. Reproductive rate, in terms of the number of nymphs born per aphid per day, was unaffected by cold stress applied at the first instar stage. Total fecundity was however reduced, being a function of the number and longevity of the survivors. Adult aphids were less cold hardy than nymphs; mortality was higher at -10°C than -5°C increasing with duration of exposure from 1 h to 6 h. Mean fecundity was reduced significantly in aphids cooled at the adult stage, the number of aphids born per day decreasing as the exposure period of the cold-pulse increased, suggesting that low temperature had affected embryogenesis. All the nymphs born to adults surviving exposure to -5°C for 6 h died within 48 h of birth, indicating that low temperature has a pre-natal effect on mortality.     

Effect of photoperiod and temperature on ovarian development in Culex pipiens pipiens

Culex pipiens pipiens is one member of the C. pipiens complex which diapauses as an adult. Experiments show that photoperiod and temperature both affect the development of the ovarian follicles. Females reared at a 15 hr photophase and 22°C show an increase in follicle size over the first 8 days after emergence. Females reared at 10 hr and 22°C do not show an increase in follicle size. Follicle size does not gradually increase as photophase is lengthened. Rather, at photophases between 9 and 12 hr the follicles remain small and at photophases of 13 hr or more, the increase is seen. An increase in temperature tends to increase follicle size regardless of the photophase. However, a strong interaction between photophase and temperature is evident.No evidence exists for a single ‘critical stage’. Instead, the final follicle size is dependent, in a complex manner, upon the photophase experienced by all the stages. The final size is not a result of a cumulative effect.Photoperiod, independent of temperature, shows a marked effect on blood feeding. Females reared at 15 hr feed much more readily than those reared at 10 hr. Those 10 hr females that feed show no signs of gonotrophic dissociation.     

Influence of temperature on the biological parameters of the anholocyclic species Cinara tujafilina (Hemiptera: Aphidoidea)

Aphids are a good model to study insect reaction to habitat change. Temperature is one of the main factors that influences insects. This paper examines the influence of temperature on developmental stages, fecundity, survival rate and demographic parameters of Cinara tujafilina (Hemiptera: Aphidoidea, Lachnidae), connected with decorative plants of the Cupressaceae family. C. tujafilina was reared in a laboratory on T. orientalis at five constant temperatures of 10, 15, 20, 25 and 28°C, 70% humidity and 14L:10D. The pre-reproduction stage varied from 7 at 25°C to 19 days at 10°C. Developmental threshold was assigned at 3.5°C. The longest reproduction stage for the aphids developing was recorded at 25°C, namely 33 days, while the shortest, at the temperature of 10°C, lasted 8 days. At 25°C this species is characterised by the shortest pre-reproduction stage, the highest fecundity, the highest survival rate and the highest demographic parameters, particularly r_m (0.17). The results suggest that the optimal temperature for the species is 25°C, and indicate that climatic change will favourably influence its development and increase its role as a pest of decorative plants.     

Alterations in the production of hemocytes due to a neoplastic mutation of Drosophila melanogaster

The hemocytes of a genetically induced, temperature-sensitive lethal mutation of Drosophila, Tum¹, were examined both quantitatively and qualitatively during the third larval instar. At the tumor-permissive temperature, 29°C, there was a fourfold increase in the concentration of circulating hemocytes in mutant larvae as compared to control. Additionally, the relative frequency of lamellocytes was 30 times greater in Tum¹ larvae than Basc in the early third instar. However, the severity of this abnormality gradually diminished as Tum¹ approached pupariation; though high frequencies of lamellocytes were always present. At the tumor-restrictive temperature (15°C) the concentration of circulating hemocytes was over twice that found at 29°C for Tum¹ larvae, and did not change during the course of third instar. However, in contrast to 29°C there was no abnormal increase in the frequency of lamellocytes at the tumor-restrictive temperature. Control larvae had equivalent concentrations of hemocytes at both temperatures. In one of two temperature shift experiments, Tum¹ larvae shifted from 15° to 29°C at the beginning of third instar expressed the abnormal hemocyte concentration and differentiation associated with larvae raised continuously at 29°C. In addition, Tum¹ larvae shifted from 29° to 15°C expressed reduced abnormalities of hemocyte differentiation, e.g., with fewer lamellocytes in circulation. The possibility of a temperature-sensitive period for the activation of the Tum¹ gene is discussed.     

Hot and salty: the temperature and salinity preferences of a temperate estuarine shrimp larva, Upogebia pusilla (Decapoda: Thalassinidea)

At a time when global climate changes are forcing life to adapt to a warming and salinity-changing environment, it is essential to understand how future changes in ocean chemistry will affect species. This study evaluates the combined effects of temperature and salinity on survival and development of Upogebia pusilla larvae. Combinations were made from three temperatures (18, 23, and 28°C) and three salinities (15, 25, and 35). Survival, larval duration and megalopa size were compared between treatments. U. pusilla larvae developed optimally in the highest salinity (35) and higher temperatures (23–28°C). Low salinities and temperatures did not support larval survival and development, with salinity being the main restricting factor for survival, while temperature affected mainly the duration of the larval stages. Larvae at higher temperatures (23–28°C) presented a higher development rate but no differences were found in megalopa size.     

The effect of temperature upon Tipula iridescent virus infection in Tipula oleracea

The mean incubation period (time from inoculation with virus to first appearance of iridescence) was used as an indication of the rate of replication of Tipula iridescent virus (TIV) in Tipula oleracea larvae. The mean incubation period and survival time (time from inoculation with virus to death) were compared with the mean instar duration at a series of temperatures. In most stages of the insect the optimum temperature for the replication of TIV and the temperature for the shortest mean survival time coincided with the peak temperature (the temperature for the fastest development of the insect stage). The peak temperature for T. oleracea does not appear to be the same for each stage, and the optimum temperature for TIV replication appears to be closely linked to the peak temperature of the infected stage. The optimum temperature (the temperature at which most individuals survived from hatching to the adult stage) of the insect was 20°C. Tipula iridescent virus replicated in T. oleracea larvae and pupae at 3° and 27°C, which are near the temperature limits for the insect. Incubation periods and survival times in TIV-inoculated larvae incubated in the field were much longer in winter than in summer.     

Effects of previous diet and frequency of feeding on development of larval damselflies

SUMMARY. 1. Food availability during instar F-3 affected duration of instar F-3 of larval Ischnura vertiealis (Say) maintained in the laboratory but did not affect the increase in head width at the moult to instar F-2.
2. Food availability during instar F-2 altered both duration in instar F-2 and weight per unit head width of newly moulted F-l larvae, but not the increase in head width at the moult to instar F-1.
3. Food availability during instar F-3 had no effect on instar duration, weight per unit head width, or increase in head width of F-2 larvae at the moult to instar F-l.
4. Survival of larval Coenagrion resolution (Hagen) reared in the laboratory was dependent on mean number of Daphnia offered per day. In addition, larvae fed less frequently, but on the same mean number of Daphnia per day. had lower survival rates than larvae fed more frequently.     

Effect of Temperature on Development and Fecundity of the Predaceous Plant Bug <Emphasis Type="Italic">Deraeocoris brevis</Emphasis> Reared on <Emphasis Type="Italic">Ephestia kuehniella</Emphasis> Eggs

Temperature-dependent development and oviposition component models were developed for Deraeocoris brevis (Uhler) (Hemiptera: Miridae). Egg development times decreased with increasing temperature and ranged from 35.8 d at 15 °C to 6.7 d at 32 °C. Total development times of nymphs reared on frozen Ephestia kuehniella (Zeller) (Lepidoptera: Pyralidae) eggs decreased from an estimated 55.6 d at 15 °C to 9.2 d at 32 °C and 10.0 d at 34.6 °C. By fitting linear models to the data the lower developmental threshold temperatures for eggs, small nymphs (1st to 3rd instar), large nymphs (4th to 5th instar), and all nymphs combined were calculated as 10.5, 12.5, 11.8, and 11.9 °C, respectively. The thermal constants were 144.1, 90.3, 95.0, and 190.8 degree-days for each of the above stages. The non-linear model was based on a Gaussian equation, which fit the relationship between development rate and temperature well for all stages. The Weibull function provided a good fit for the distribution of development times of each stage. Adult longevity decreased with increasing temperature and ranged from 52.9 d at 21.7 to 16.8 d at 32.0 °C. D. brevis had a maximum fecundity of 471 eggs per female at 24 °C, which declined to 191 eggs per female at 32 °C. Also, three temperature-dependent components for an oviposition model of D. brevis were developed including models for total fecundity, age-specific cumulative oviposition rate, and age-specific survival rate.     

Larval development of Diploptera punctata reared alone and in groups

Larvae of the cockroach Diploptera punctata were reared in isolation, in pairs, or in groups of 8–10. Duration of larval development, age at each ecdysis, weights at birth and ecdyses, and adult head-capsule width were measured. Duration of larval development was longer and adult size was larger in isolated animals than in animals reared in pairs and groups. The effect of isolation on development was more pronounced in males. All females had 4 larval instars, whereas males had 3 or 4 instars. The proportion of males with 4 larval instars was higher among animals reared in isolation. There was no difference in the duration of larval development or adult size between pair- and group-reared animals. The sex of animals in the group did not affect adult size or the duration of larval development. Males which underwent 3 or 4 larval instars had different schedules of moulting. Rates of growth of males of both instar types reared in isolation and pairs were similar. Greater adult weight of isolated animals and 4-instar-type males was a result of their longer duration of larval development. Both a higher rate of growth and longer duration of larval development contribute to the larger adult size of females than males.     

The effect of temperature on the growth,development and survival of Macropetasma africanus (Balss) (Penaeoidea:Penaeidae) larvae reared in the laboratory

Macropetasma africanus (Balss) has been successfully spawned and its larvae reared under controlled laboratory conditions. The relationship between egg number (E) and female total length (L) was E = 18.59 L^2.11. An experiment was designed to test the effect of temperature on larval development, survival and growth. Temperature effected larval development time, from 13–15 days at 25°C, to 25 days at 15°C (nauplius 1 to post-larva). Mortality was low for the naupliar stages at 25, 22 and 18°C, while at 15°C only 52% of the larvae reached nauplius 6. Mortality was highest from nauplius 6 to protozoea 1 (17, 21, and 18% at 25, 22, and 18°C, respectively), but decreased considerably for all temperatures once the mysis stage was reached. Overall survival rates from nauplius 1 to post-larva decreased with decreasing temperature (65, 54, 48, and 39% at 25, 22, 18, and 15°C respectively). Temperature also significantly affected larval growth. At 25°C mean total length was significantly (P < 0.05) larger than at 15°C (protozoea 2 to post-larva), while from protozoea 3 to post-larva total length differences were significantly different (P < 0.05) between 18 and 25°C. M. africanus has a major spawning peak in summer, suggesting that there may be a selective advantage to reproducing during the warmer months.     

The specific response of gypsy moth A1 neurosecretory neurons to different environmental stressors

Changes in the number and morphometric parameters of A1 neurosecretory neurons (nsn) were analyzed in Lymantria dispar 4^th instar caterpillars, exposed for 3 days to different stressors: cadmium, high temperature and tannic acid. The relative cytoplasm density of A1 nsn was also estimated. Caterpillars reared on a diet supplemented with cadmium exhibited increased size of A1 nuclei (10 and 250 μg Cd per g of dry food weight), increased number of nucleolii in nuclei and raised relative cytoplasm density in all experimental groups. Cadmium obviously induces intensive synthetic activity in A1 nsn. The second stressor was high environmental temperature of 35°C. Decrease of all analyzed morphometric parameters suggests that acute exposure of 4^th instar caterpillars to 35°C, as well as 12 h recovery at optimal temperature of 23°C, reduced the activity of A1 nsn. Tannic acid was added to the artificial diet in the following concentrations: 1%, 2.5% and 5%. All estimated morphological parameters did not change after addition 1 and 2.5% of tannic acid. After addition of 5% of tannic acid, the activity of A1 nsn declined.     

Temperature effects on embryonic development of Paratlanticus ussuriensis (Orthoptera: Tettigoniidae) in relation to its prolonged diapause

Paratlanticus ussuriensis eggs overwinter by entering diapause, which can be prolonged to more than 1 year depending on environmental conditions. To determine temperature effects on diapause duration of P. ussuriensis eggs, the rates of embryonic development and hatching were compared at various temperatures conditions by measuring embryonic stages and egg weights. Most eggs stayed in a very young stage (blastoderm formation, stage 4) when reared at 15 and 20 °C, 10–30% eggs developed into middle or late stages when reared at 25 °C, and most embryos developed fully (stage 23/24) when reared at 30 °C. Egg weight at 30 °C was 1.5 times higher than those reared at 20 °C. Chilling induced hatching in embryos at stage 23/24. Chilling caused stage 4 embryos to develop into stage 24, but they failed to hatch in response to a second warm period. Thus, P. ussuriensis eggs can overwinter either as young embryos (initial diapause) or as fully-developed embryos (final diapause). Eggs that experience an initial diapause overwinter again the second year in a final stage diapause. The post-diapause period was shorter when embryos overwintered in a final stage diapause. The hatching rate was highest in a temperature range of 7.5–15 °C. Our results suggest that temperature is an important environmental factor for the control of prolonged diapause in P. ussuriensis and initial diapause plays an important role in the control of its life cycle.     

GH–IGF system regulation of attenuated muscle growth and lipolysis in Atlantic salmon reared at elevated sea temperatures

Growth regulation in adult Atlantic salmon (1.6 kg) was investigated during 45 days in seawater at 13, 15, 17, and 19 °C. We focused on feed intake, nutrient uptake, nutrient utilization, and endocrine regulation through growth hormone (GH), insulin-like growth factors (IGF), and IGF-binding proteins (IGFBP). During prolonged thermal exposure, salmon reduced feed intake and growth. Feed utilization was reduced at 19 °C after 45 days compared with fish at lower temperatures, and body lipid storage was depleted with increasing water temperature. Although plasma IGF-1 concentrations did not change, 32-Da and 43-kDa IGFBP increased in fish reared at ≤17 °C, and dropped in fish reared at 19 °C. Muscle igf1 mRNA levels were reduced at 15 and 45 days in fish reared at 15, 17, and 19 °C. Muscle igf2 mRNA levels did not change after 15 days in response to increasing temperature, but were reduced after 45 days. Although liver igf2 mRNA levels were reduced with increasing temperatures after 15 and 45 days, temperature had no effect on igf1 mRNA levels. The liver igfbp2b mRNA level, which corresponds to circulating 43-kDa IGFBP, exhibited similar responses after 45 days. IGFBP of 23 kDa was only detected in plasma in fish reared at 17 °C, and up-regulation of the corresponding igfbp1b gene indicated a time-dependent catabolic response, which was not observed in fish reared at 19 °C. However, higher muscle ghr mRNA levels were detected in fish at 17 and 19 °C than in fish at lower temperatures, indicating lipolytic regulation in muscle. These results show that the reduction of muscle growth in large salmon is mediated by decreased igf1 and igf2 mRNA levels in addition to GH-associated lipolytic action to cope with prolonged thermal exposure. Accordingly, 13 °C appears to be a more optimal temperature for the growth of adult Atlantic salmon at sea.     

Preimaginal development,adult longevity and fecundity ofEncarsia inaron (Hym.: Aphelinidae) parasitizingSiphoninus phillyreae (Hom.: Aleyrodidae) in California

A laboratory study of preimaginal development, adult longevity and fecundity ofEncarsia inaron (Walker) was conducted. Preimaginal developmental times varied with temperature, from 55–60 d at 15±1°C to 14–17 d at 30±1°C. No development took place at 10°C, which was approximately the developmental minimum estimated from regression analysis of developmental rates vs. temperature in the range 15–30°C. Development was slowed and survival was reduced at 32°C. Females lived an average of 18.6 days and laid a average of 159 eggs/female at 25°C. At 25°C, average preimaginal survival was 59.3%, and the sex ratio was 73.5% female. The net reproductive rate (R₀) forE. inaron calculated from these studies was 69.3, while the intrinsic rate of natural increase was 0.1686 individuals per individual per day. Oviposition was concentrated slightly in third instar nymphs of the host.     

Low temperature storage effects on two olive fruit fly parasitoids

Effects of cold storage temperatures and storage duration were evaluated for Psyttalia humilis (Silvestri) from Namibia and Psyttalia ponerophaga (Silvestri) from Pakistan, braconid parasitoids of Bactrocera oleae (Rossi) imported to California, USA. Immature stages of P. humilis were exposed to 4, 6, 8, 10, or 12 °C for 1, 2 or 4 months (pupa only at 4 and 12 °C) and then held at 24 °C for adult emergence. Less than 5 % of parasitoids in the 4–8 °C treatments survived, regardless of storage duration. At the 10 °C treatment, adult survival decreased with increased storage duration, but increased with advancing developmental stages. Survival was not affected at the 12 °C treatment. Adult P. humilis were exposed to 6, 8, 10 °C for short periods (1, 2, 4, or 6 weeks) or ambient winter conditions in Parlier, California, USA (about 9 °C). Regardless of storage temperature, P. humilis reproduction was reduced after storage of four and six weeks. Similarly, after 4 months at ambient winter temperatures, P. humilis reproduction was reduced. Psyttalia ponerophaga pupae stored at 6 °C for 41–97 days had decreased survival and increased developmental time. Survival of P. ponerophaga pupae ranged from 13.9–52.1 %, whereas under similar storage conditions survival of P. humilis was <0.7 %, suggesting P. ponerophaga is more cold tolerant than P. humilis.