Most Symphyta are phytophagous and lay their eggs in the host plant in contact with the plant tissue. We tested the hypothesis that Diprion pini L. egg hatching and larval survival vary between Scots pine clones with particular foliage characteristics. We also tested the influence of water limitation on hatching rates. Larval survival and hatching rate of D. pini eggs differed significantly among Pinus sylvestris L. genotypes and they were not correlated. We confirmed that the presence of taxifolin, a phenolic compound, and quantity of 3-carene were correlated with low larval survival. Foliage analysis showed an inverse relationship between hatching rate and dry matter content of foliage. The hatching rate on a tree varies, according to needle water content. This suggests that the success of egg development might be important for the population dynamics of D. pini.

Mating disruption treatments for the Chinese tortrix Cydia trasias (Meyrick) with synthetic sex pheromone were tested on a shade-tree, the Chinese scholar-tree (Sophora japonica L.), in Beijing, China, in 1999. Two test sites were treated three times each during the beginning of overwintering flight period, and during the first- and second-generation flight periods. Each tree was treated with six dispensers releasing the C. trasias sex pheromone (0.5 mg load per dispenser). Treatments were evaluated by petiole and seed pod injuries and by captures of males in traps baited with live virgin females or synthetic sex pheromone lures. A 2:3 two-component blend of E8,E10-dodecadien-1-ol (E8,E10–12:OH) and E8,E10-dodecadienyl acetate (E8,E10–12:Ac) was used for mating disruption. At site I, catches of males in female-baited traps were reduced by 100, 99.1, and 98.2% when compared with control plots, and catches in pheromone-baited traps were reduced by 98.2, 95.7, and 93.6%, during the three periods of moth flight, respectively. Also at site I, the tunneled petioles (first- and second-generation larval injury) were reduced by 68.1 and 60.6%, and the bored seed pods (third-generation larval injury) were reduced by 70.0%, for the first, second, and third larval generations, respectively, when compared with control plots. At site II, the bored seed pods in the treated plots were reduced by 89.5%, during the third period of larval injury. We conclude that mating disruption is promising as an effective control against C. trasias on shade-trees planted along streets.

Freeze tolerance and enhanced supercooling ability (freeze avoidance) are distinct adaptations in insects facilitating survival of subfreezing temperatures. It has been suggested that freeze tolerance has advantages over freeze avoidance with respect to certain aspects of insect ecophysiology. Third instars of the gall fly Eurosta solidaginis Fitch were kept either frozen or supercooled at −5°C for 10 wk. Supercooled larvae lost 26% of their wet weight and frozen larvae lost 14% of wet weight, mostly as a result of water loss during the treatments. Moreover, although supercooled larvae lost more water than did frozen larvae, lipid content was stable throughout both treatments. Freeze-treated larvae were 50% more likely than supercool-exposed larvae to survive to pupariation and adult emergence. E. solidaginis larvae survived prolonged freezing better than they endured prolonged supercooling, but it remains to be clarified whether or not this effect can be attributed to differences in water retention.

Larvae of the Carolina sawyer Monochamus carolinensis (Olivier) (Cerambycidae) and bark beetle larvae (Scolytidae) often simultaneously feed in phloem of recently killed pine trees. Our investigations reveal that M. carolinensis larvae may act as facultative intraguild predators of bark beetle larvae. Phloem sandwiches were used in four experiments to examine inter- and intraspecific interactions. We discovered that all sizes of M. carolinensis larvae killed bark beetle larvae. Seventy-six percent of the killed bark beetle larvae were consumed by M. carolinensis, including 58% that were entirely ingested. Cannibalism in M. carolinensis occurred in every experimental trial. Based on this evidence, M. carolinensis, and possibly related cerambycid species associated with bark beetles, are facultative intraguild predators of larvae of other phloem inhabiting species. The consequences of this behavior may have important implications for bark beetle population dynamics.

The development time of different stages of Sesamia nonagrioides Léfèvbre was studied in the laboratory at constant temperatures in the range 10–36°C. The relationship between the developmental rate (1/d) and the temperature (°C) was determined using both linear and nonlinear (Logan type III) models. The fit of the linear regression in the temperature range 15–27.5°C and Logan type III equation was good (R² > 0.97). The lower developmental threshold, calculated using the linear model, was t_b = 12°C. The nonlinear model gave a higher threshold of T_max = 36°C, and an optimal developmental temperature of T_rmax = 30°C. The flights of S. nonagrioides were studied in Lleida, Spain, from 1984 to 1997, and the number of degree-days required for their occurrence was calculated. A relationship between the degree-days required for the first flight calculated by the averaging method and the degree-days required for estimated diapause termination was obtained (R² = 0.84). This relationship allowed the prediction of the first flight occurrence in the field. The degree-days required for the second and third generations were then calculated as 730 and 491, respectively.

The adult potato tuberworm, Phthorimaea operculella (Zeller), is a primary pest of potato plants. Studies were conducted to assess the possibility of applying sterile insect technique as an alternative control method against this pest. The purpose of this study was to examine the effects of adult age, weight, female mating status, and sex ratio on success and frequency of mating in P. operculella. The relationship between number of matings, fecundity, and fertility of females was also studied. A negative correlation was found between mating success and adult age. Female and male weights had an effect on the number of times individuals mate, but male weight only influenced mating success. Males mated more than once when confined with three virgin females for 24 h. Females did not mate more than once, even when they were confined with three virgin males. Males were more likely to mate with virgin females than with previously mated females. Multiply mated females and those which did not accept a second mating showed higher fecundity and fertility than their counterparts which were not given the opportunity to remate. Our results provide essential information necessary to increase the effectiveness of sterile insect technique as a control method against P. operculella.

A major outbreak of the hemlock looper, Lambdina fiscellaria (Guenée), predicted for 1997 on the Gaspé Peninsula in Quebec, collapsed due to egg parasitism by Telenomus spp. Only 3,857 ha of balsam–spruce forest were defoliated from the forecasted 130,000-ha outbreak area. This represents only 3% of the anticipated outbreak area. We present data that indicate highly efficient natural control by Telenomus spp. The L. fiscellaria population also collapsed due to egg parasitism by Telenomus spp. on Anticosti Island in the same year. In the past, L. fiscellaria egg parasitism has usually been estimated from egg samples collected in the fall or early spring surveys and was based mostly on the eggs’ black coloration. However, our observations indicate that entirely black and opaque eggs result from parasitism by Trichogramma spp., those attacked by Telenomus spp. varying from translucent to dark brown but always showing a single dark spot on the chorion. Moreover, our data on seasonal egg parasitism showed important and rapid increases in parasitism by Telenomus spp. in late spring. Therefore, similar unexplained L. fiscellaria outbreak collapses that occurred in the past might have also been caused by egg parasitism by Telenomus spp. There are several species in the Telenomus complex attacking L. fiscellaria and the most abundant one might be a “keystone species” in the population dynamics of this defoliator. The spring activity of Telenomus spp. may lead to errors when forecasting L. fiscellaria populations based only on fall egg surveys.

The development, survivorship, longevity, reproduction, and life table parameters of the spirea aphid, Aphis spiraecola Patch, were evaluated at 25°C on seven commonly grown plants (Polyscias crispata (Bull) Merrill cultivar chicken-gizzard aralia, P. scutellaria (Burman) Fosberg, Vibernum suspensum Lindley, grapefruit (Citrus paradisi Macfadyen), rough lemon (C. jambhiri Lushington), pineapple orange [C. sinensis (L.) Osbeck variety pineapple orange], orange jessamine [Murraya paniculata (L.) Jack]) in the laboratory. Spirea aphid failed to survive on orange jessamine. The developmental times for the immature stages ranged from 7.9 d on P. scutellaria to 9.9 d on grapefruit or pineapple orange. The immature survival varied from 92.7% on P. scutellaria to 78.8% on pineapple orange. The average number of nymphs reproduced per female were 42.7, 35.7, 28.7, 22.3, 18.0, and 11.7 on P. crispata, P. scutellaria, V. suspensum, grapefruit, rough lemon, and pineapple orange, respectively. Female adults lived an average of 14.1, 15.3, 12.2, 11.0, 12.0, and 9.3 d on these same hosts. The intrinsic rate of increase (r_m) for spirea aphid on P. crispata was highest. Jackknife estimates of r_m varied from 0.308 on P. crispata to 0.177 on pineapple orange. The mean population generation time on these hosts ranged from 11.6 to 13.2 d. It was concluded that the ability of spirea aphid to feed and develop on a wide range of host plants increases its chance to infest citrus and thereby spreading the citrus tristeza virus.

An important hypothesis concerning the role of aggregation in the antipredator defense of aposematic insects is that a group projects a larger aposematic signal to a predator. The nearly exclusive use of birds as model predators may be leading us to over-emphasize the importance of signal amplification as an explanation for the gregarious behavior of aposematic insects. Ambush (sit-and-wait) predators such as amphibians and praying mantids make predatory decisions relying primarily on prey movement, and secondarily on prey size, with prey color being less important. Therefore, we tested the interaction of aposematic coloration and gregarious behavior in insect defense from frogs. We offered frogs four types of mealworm prey: (1) cryptic and solitary, (2) cryptic and gregarious, (3) aposematic and solitary, and (4) aposematic and gregarious. The frogs ate aposematic and gregarious prey significantly later than they ate cryptic and gregarious prey and cryptic and solitary prey. Our results support the hypothesis that aposematic coloration in gregarious prey, but not in solitary prey, can function to produce a sufficient aposematic signal to delay attack by an ambush predator. This result was not due to predator learning. Hence, the antipredator benefits of aposematic coloration in aggregated prey may function in encounters with a wide range of predators, including frogs.

Development time and percent survival of the silverleaf whitefly, Bemisia argentifolii Bellows & Perring (formerly referred to as B strain of sweetpotato whitefly), were determined at five constant temperatures ranging from 20 to 35°C on two cultivars of cotton, cantaloupe, and pepper (Capsicum sp.). Fecundity was recorded at 30°C during the first 10 d of adulthood. Developmental, survival, and fecundity rates were not significantly different between cultivars within crops of either cotton or cantaloupe, but varied between crops. Development time from egg to adult at 20–32°C ranged from 14.6 ± 0.8 (mean ± SE) to 36.0 ± 1.0 d on cantaloupe and from 16.3 ± 0.7 to 37.9 ± 2.1 d on cotton, respectively. Whiteflies did not develop at 35°C or on pepper at any temperature. Minimum developmental thresholds and degree-days requirements from egg to adult were 11.1°C and 312.5 DD on cotton and 13.2°C and 250.0 DD on cantaloupe, respectively. Immature survival was high (76.5 ± 11.5–100%) on cantaloupe, intermediate (37.3 ± 13.3–64.4 ± 10.2%) on cotton, and very low (0–8.3 ± 8.3%) on pepper from 20–32°C. Fecundity ranged from 153.3 ± 10.8–158.3 ± 9.3 eggs per female on cantaloupe, from 117.0 ± 6.0–117.5 ± 22.1 eggs per female on cotton, and from 2.1 ± 0.7–40.5 ± 5.8 eggs per female on pepper, at 30°C.

A 2-yr study was conducted to evaluate the effect of ethephon (2-chloroethylphosphonic acid) on efficacy of pheromone traps in monitoring fall and spring populations of adult boll weevils. The experimental procedure consisted of a grandlure pheromone strip placed in a boll weevil trap together with a 7.5-ml aqueous solution of ethephon at 0.1, 1, 10, and 100 ppm concentrations. Treatments also included traps with nothing, ethephon alone at each of the four concentrations, and grandlure alone. Traps were monitored twice a week, and ethephon solutions were replenished during each trap inspection. Trap catch was significantly affected by year, season, and treatments. Overall, significantly higher numbers of boll weevils were captured in 1996–1997 compared with 1997–1998. Average numbers of boll weevils captured in fall season were approximately six times higher than the numbers captured in the spring season. Ethephon alone did not elicit a significant attraction to fall or spring populations at any concentration evaluated. However, the combination of ethephon and grandlure pheromone showed a distinct synergistic effect, enhancing the efficacy of pheromone-baited traps in monitoring fall migration of boll weevil populations. Ethephon at 1 and 10 ppm combined with grandlure were most attractive to fall-migrating weevils, capturing 20–35% more weevils than the grandlure alone. The combination of ethephon at 10 ppm and grandlure also had a significant effect on weevil attractancy for spring populations, but the results were not consistent between years. Data from this study clearly suggest that the addition of ethephon to grandlure can significantly improve trap attractancy and will aid in boll weevil monitoring and eradication strategies that aim at attacking the weevils during the fall, with some potential of improved attractancy in monitoring spring populations.

A gas chromatograph-electron capture detection method for analysis of permethrin (cis- and trans-isomers) and esfenvalerate on the surface of almond twigs is described. Permethrin and esfenvalerate were extracted from the substrate with a hexane sonication, Florisil solid phase extraction cleanup, and quantification by gas-liquid chromatography with electron capture detector with a megabore capillary column. The mean recoveries for all three analytes were 87% with a coefficient of variation <13% at fortification levels ranging from 50 to 1,000 ng for each analyte. The limit of detection was 14, 13, and 4 ng for cis-permethrin, trans-permethrin and esfenvalerate respectively for almond twigs. Field collected twig samples taken 7 mo after pesticide application were found to contain measurable bark surface residues. Bioassays using those twigs indicated significant mortality to the beneficial mite, Galendromus occidentalis Nesbitt.

The early soybean production system (ESPS) in the southern region of the United States is being promoted as a cropping practice that reduces the risk of drought stress to the crop. This ESPS involves planting an early-maturing soybean cultivar, ≈4–6 wk before planting the conventional later-maturing soybean cultivars. A field study was conducted in Georgia soybeans in 1997–1999 to compare arthropod pest seasonal abundance, insect-induced defoliation, and yields between ESPS and conventionally planted soybeans. The conventional soybean production system had higher populations of late season defoliators, including the velvetbean caterpillar, Anticarsia gemmatalis Hübner, and the soybean looper, Pseudoplusia includens (Walker). The percentage defoliation was higher in the conventional system than in the ESPS all three years. The threecornered alfalfa hopper, Spissistilus festinus (Say), was more abundant in the ESPS in early season, but similar population densities were observed in July–August in both ESPS and conventional soybeans, then the highest seasonal population peaks occurred in the conventional soybeans in September, after the ESPS was harvested. Stink bugs, primarily the southern green stink bug, Nezara viridula (L.), also were more numerous in the ESPS during midseason. However, stink bugs moved to the conventional soybeans in September and peaked at densities much higher than in the ESPS. Yields in the ESPS plots were equal to or exceeded the yields in the conventional soybean plots in all three years of this study. Adoption of ESPS in the southern region should have a positive economical and environmental impact on soybean integrated pest management because this system escapes serious crop injury from some annual insect pests.

The eastern cherry fruit fly, Rhagoletis cingulata (Loew), and black cherry fruit fly, R. fausta (Osten Sacken), are the most important insect pests of cherries Prunus spp. in the eastern and midwestern United States. In 1998, we studied the responses of cherry fruit fly species using the recommended V-shaped Pherocon AM board. Significantly more R. cingulata flies were caught on boards with aqueous solutions of ammonium baits compared with boards that had solid ammonium baits mixed into the Tangle-Trap. Captures of R. fausta flies were low in 1998 and the weekly trapping data never exceeded a total of five adults. In 1999, several commercial traps were evaluated including the unbaited, three-dimensional Rebell trap and different types of ammonium baited spheres and boards including a 9-cm-diameter red sphere, a modified version of the Ladd trap (L & S trap), and the Pherocon AM yellow board in the vertical and V-shaped orientations. There were significantly more R. fausta flies caught on unbaited Rebell traps compared with any other commercial traps studied. Red sphere treatments (regardless of baiting system) consistently captured significantly fewer R. fausta flies than any other treatment evaluated. For R. cingulata, total captures on unbaited Rebell traps were not significantly different from other commercial traps including the 9-cm-diameter red spheres baited with ammonium acetate mixed into the Tangle-Trap, L & S traps, and the baited Pherocon AM yellow boards deployed in a vertical orientation. The study demonstrated that the unbaited Rebell trap was the most effective and selective device evaluated for monitoring R. fausta and R. cingulata flies. In addition, red sphere (9-cm-diameter) traps were found ineffective for use in R. fausta monitoring programs.

Intercropping with poor and nonhosts was tested as means to reduce densities of whitefly eggs and nymphs on common bean (Phaseolus vulgaris L.) in central Guatemala during dry and rainy seasons. Row and mixed intercrop field designs were used, with pesticides evaluated on a subplot level in the row-intercrop test. Tomato (Lycopersicon esculentum Mill.) was also evaluated in the mixed-intercrop test. Intercropping failed to reduce whitefly densities, although interpretation of data was difficult because of high variability among samples and reduced crop quality in some intercrop and pesticide treatments. Imidacloprid effectively reduced whitefly densities, but imidacloprid combined with intercropping offered no advantage over imidacloprid in monoculture. Laundry detergent and vegetable oil were tested as less-toxic inexpensive alternatives to pesticides under monocropped and intercropped conditions during the dry season, but failed to provide protection against whiteflies or other sucking insects. Trialeurodes vaporariorum Westwood was the predominant whitefly species in the area. Bemisia tabaci (Gennadius) on bean comprised ≈10% of the total whitefly population at the end of the dry season, 46% in the middle of the rainy season, when overall populations were lowest, and 1.15% toward the end of the rainy season. Encarsia pergandiella Howard was the predominant whitefly parasitoid throughout the study, and the only parasitoid reared from whitefly nymphs on bean in the dry season. Members of the Encarsia meritoria species complex and Amitus fuscipennis MacGown & Nebeker were recovered from tomato during the rainy season. Parasitoid diversity increased in the rainy season on tomato intercropped with roselle (Hibiscus sabdariffa L.) and corn (Zea mays L.) compared with tomato grown in monoculture. Intercropping with poor and nonhosts did not reduce whitefly densities on bean in an economically significant manner under high, intermediate, or low whitefly populations levels in either the dry or rainy season.

Mi is a dominant locus in tomato that confers resistance to both root knot nematodes, Meloidogyne spp., and potato aphids, Macrosiphum euphorbiae (Thomas). The goal of this study was to investigate the breadth of Mi-mediated aphid resistance. To examine variability in potato aphid response, the effect of Mi on seven isolates of the potato aphid from California, New Jersey, North Carolina, France, and The Netherlands was measured in greenhouse bioassays. Assays were also performed to determine if Mi impacted another aphid species that attacks tomato, Myzus persicae (Sulzer). Tomato varieties carrying Mi had a profound negative impact on the potato aphid isolates from France and The Netherlands. In contrast, other potato aphid isolates from New Jersey, North Carolina, and California proved to be virulent, or capable of overcoming Mi. Mi-mediated resistance also did not extend to the green peach aphid isolates tested. These results demonstrate that Mi-mediated aphid resistance is isolate-specific, and it may not extend to all aphid species. Our data also show that virulent potato aphids are geographically widespread, and, unlike virulent nematode isolates, are relatively common. Virulence is persistent and is maintained even in the absence of selection pressure by Mi. The response of a particular aphid isolate to Mi could not be predicted on the basis of aphid color, because both avirulent and virulent isolates were found within the pink and green biotypes of the potato aphid.

This field survey, the second noting the occurrence and diversity of filth fly pupal parasitoid fauna in Hungary, was performed on beef and dairy feedlots and swine facilities in the southern and eastern parts of the country. The filth flies Musca domestica L. and Stomoxys calcitrans (L.) were the two most commonly parasitized hosts. The three species of Spalangia recovered, in decreasing order of abundance, were S. cameroni Perkins, S. nigroaenea Curtis, and S. endius Walker. Pachycrepoideus vindemiae Rondani, Trichomalopsis sp., two apparently undetermined Diapriidae spp. and one apparently undetermined Brachycera sp. are believed to be new country records.

The population dynamics of the bollworm, Helicoverpa zea (Boddie), and its associated natural enemies were studied in insecticide-free, commercial, short-season cotton fields from 1991 to 1995 in the southern Blacklands of Texas. Bollworm had one discernable generation per season in cotton. Partial ecological life tables constructed for each annual generation indicated that 71–95% mortality could be consistently expected in the egg and first-instar life stages. Intrageneration mortality ranged from 93 to 99%. Unexplained mortality was the leading cause of mortality in 1991–1993, but not in 1994 and 1995 when predation due to Orius spp. was partitioned. Unexplained mortality included abiotic as well as biotic factors. Parasite activity was consistently low. Egg parasitization by Trichogramma spp. averaged 3.4%. Larval parasitization rarely exceeded 5% and no larval parasitization was found in 1993. Microplitis croceipes (Cresson) was the most common larval parasite collected. Predation of bollworm eggs by Orius insidiosus (Say), the numerically dominant predator in the system, was estimated using ELISA in 1994 and 1995. O. insidiosus was the most important mortality factor when measured consuming 84 and 71% of the eggs in 1994 and 1995, respectively.

The red imported fire ant, Solenopsis invicta Buren, is an important predator in some cropping systems in the United States, particularly sugarcane and cotton, where it preys on key pests such as the sugarcane borer, Diatraea saccharalis (F.), and beet armyworm, Spodoptera exigua (Hübner). A study was undertaken to characterize the prey items collected by foraging S. invicta in an Oklahoma peanut field. From June to September 1999, 19 h of collecting yielded 1,276 foraged items. The largest percentage of foraged items (>20%) (other than unidentifiable fragments [39%]) were lepidopteran larvae, of which 87% were Stegasta bosqueella Chambers, the rednecked peanutworm. Overall, S. invicta collected approximately seven times more pest arthropods than beneficial arthropods. Forager success rates were ≈3.8 times higher for solids than liquids. Refuse piles in the field contained a large percentage of Coleoptera (≈26%) and did not mirror foraged material collections. Percent damaged pods on plants growing within S. invicta mounds was significantly (approximately three times) lower than on plants not within mounds. Additional data are presented on forager success rates and foraging/temperature relations.

Laboratory studies were conducted to determine the effects of parasitoid age and number of hosts available on selected attributes of parasitoid reproduction. Newly emerged mated females of the gregarious parasitoid Allorhogas pyralophagus Marsh were divided into groups ranging in age from 5 to 12 d. For each age class, individual females were exposed to one, two, four, and eight hosts of the Mexican rice borer, Eoreuma loftini (Dyar), over a 24-h period. For each age class, number of eggs laid and hosts attacked were fitted to nonlinear oviposition models and type II functional response curves, respectively. Numbers of eggs laid per female per day were highest at ≈20 eggs per day in 6-d-old females, declining to ≈5 per day in 12-d-old females. The functional response curves showed declining attack rates with time, from ≈2.0 hosts per day in 5-d-old females, to ≈1.0 in 12-d-old parasitoids. Percentage of progeny emergence was not affected by either parasitoid age or number of hosts available. Percentage of female progeny also was not affected by parasitoid age, remaining female-biased.

Mortality and sublethal effects of different doses of the multicapsid nucleopolyhedrovirus that infects the spruce budworm, Choristoneura fumiferana (Clemens), on the western spruce budworm, Choristoneura occidentalis Freeman, were investigated. C. fumiferana multicapsid nucleopolyhedrovirus (CfMNPV) is known to be more highly virulent to C. occidentalis than to its own host. Larval and pupal mortality were dose-dependent regardless of the age of the larvae challenged. Larval mortality was higher when younger larvae were challenged, whereas pupal mortality among the survivors was higher when older larvae were challenged. Older larvae were less susceptible to CfMNPV than younger larvae treated with the same virus concentration. Sublethal effects were also greater in the insects treated as older larvae. Sublethal effects of CfMNPV on C. occidentalis infected as sixth instars included prolonged developmental time of males to pupation, decreased male pupal weight, decreased longevity of both male and female adults, and a reduced proportion of females among the survivors, even though proportionally more males than females died in the pupal stage. Some of these changes were significant and were age, dose and sex-dependent. Sublethal effects of CfMNPV on survivors challenged as fourth instars were significant in reducing the proportion of females at the highest virus concentration. Fecundity and hatching success of C. occidentalis was not affected by CfMNPV treatment. These findings suggest that CfMNPV should be applied to fourth instars in the field to achieve high larval mortality. Implications of both the combined larval and pupal mortality and sublethal effects of viral application on the population dynamics of C. occidentalis are discussed and compared with previously reported results on other insects.

The effect of temperature on various life history parameters of Muscidifurax zaraptor Kogan & Legner was determined to develop functions that could be used for improving models of biological control, as well as to compare its response to temperature with other pteromalid species that occur in Alberta. Immature development was influenced by temperature and sex. Male development averaged 90% of the female developmental time. Immature development was >115 d at 15°C, and declined to ≈13 d at 30°C. Relative survival of immatures was lowest at 15 and 33°C, and highest near 25°C. The sex ratio of emerging parasitoids averaged 64% female for wasps reared on pupae of Stomoxys calcitrans (L.) and Musca domestica (L.). Female longevity was highest at 20°C, and decreased with both increasing and decreasing temperatures. Time to 50% progeny production decreased with increasing temperatures. Lifetime progeny production was lowest at 15 and 33°C, and highest at 25°C. The net reproductive rate and intrinsic rate of increase were also lowest at 15 and 33°C, whereas mean generation time declined with increasing temperature. Generation time of M. zaraptor was considerably longer at low temperatures compared with M. raptor and T. sarcophagae. This may explain why the seasonal activity of M. zaraptor in Alberta is restricted to late July and early August, and also suggests that M. zaraptor may not be as effective for early season releases in Alberta compared with other pteromalid species.