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.

The development, reproduction and longevity of corn aphids Rhopalosiphum padi (L.), Sitobion avenae (Fabricius) and Metopolophium dirhodum (Walker) were studied at 18, 22, 25, 27.5 and 30°C. Only nymphs of R. padi survived at 30°C, but the adult reproductive capacity was very low. Rhopalosiphum padi performed better than M. dirhodum at all temperatures tested, and better than S.avenae over the range of 22–27.5°C. The better performance of R. padi was due to a lower nymphal mortality, lower developmental and prereproductive times and a higher intrinsic rate of increase (r_m). Sitobion avenae had a higher r_m than M. dirhodum at all temperatures. The most suitable temperature for population development was ≈28.5°C for R. padi, 26.5°C for S. avenae and 24.5°C for M. dirhodum, suggesting the ability of aphid populations to adapt to high temperatures in the Iberian peninsula. The role of temperature as a key factor in determining aphid population dynamics in the northeastern Iberian peninsula is discussed.

The development, survivorship, and fecundity of the potato psyllid, Bactericera cockerelli (Sulc), fed on eggplant (Solanum melongena L., variety Special Hibush) and bell pepper (Capsicum annuum L., variety Capsitrano) were studied in the laboratory at 26.7 ± 2°C, 70 ± 5% RH, and at a photoperiod of 14:10 (L:D) h. Immature B. cockerelli developed faster (24.1 d) when fed on eggplant than on bell pepper (26.2 d). Survival rates of immature stages from egg to adult emergence were higher on eggplant (50.2%) than on bell pepper (34.6%). The longevity of B. cockerelli female adults fed on bell pepper was similar to that of females fed on eggplant (62.2 versus 55.0 d), but the male adults fed on eggplant lived shorter lives (39.4 d) than those fed on bell pepper (53.9 d). However, the preoviposition and oviposition periods, fecundity, and sex ratio of B. cockerelli fed on eggplant were not different from those fed on bell pepper. The r_m value and the finite rate of increase (λ) of B. cockerelli were higher on eggplant (0.1099 and 1.116, respectively) than on bell pepper (0.0884 and 1.0924, respectively). Mean generation time and doubling time of B. cockerelli were shorter on eggplant (40.4 and 6.3 d, respectively) than on bell pepper (46.1 and 7.8 d, respectively). In contrast, lifetime fecundity of B. cockerelli was greater on bell pepper (227.3 offspring) than on eggplant (186.5 offspring). Based on these life history parameters, we concluded that B. cockerelli performed better on eggplant than on bell pepper.

A computer model for simulating population dynamics of Lyctocoris campestris (F.), a predator of stored-product insects, was developed using data from the literature and newly collected data for adult longevity and fecundity. Immature development time and survival, adult longevity, fecundity, and cannibalism were simulated. The model was validated at ambient environmental conditions during three seasons in Wisconsin. The model accurately simulated development of the predator feeding on larvae of the Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), in the validation studies. The model will be useful in optimizing mass-rearing and augmentative releases of this predator for biological control of stored-product insect pests.

Gypsy moth females that survived inoculation with Lymantria dispar (L.) nucleopolyhedrovirus (LdNPV) as fifth instars were smaller as pupae and laid fewer eggs as adults. Treatment with both wild type virus containing the egt gene and a genetically manipulated, egt- virus, lacking this gene, reduced pupal mass to a similar degree. Sublethal infection with wild type virus reduced the masses of surviving pupae at 20, 25, and 28°C. A relationship between virus dose (5,000, 50,000 and 500,000 occlusion bodies per larva), mass of pupae, and egg mass size only occurred in one experiment in which larvae were reared at 25°C and inoculated 5 d after molt to the fifth instar. Vertical transmission of overt infection occurred in two of 13 egg masses (15%) produced by females inoculated with virus as larvae. The five larvae infected with virus were ≈0.5% of the larvae tested. Whether sublethal effects of LdNPV infection occur in field populations of gypsy moth remains to be tested.

The influence of temperature on oviposition behavior, adult longevity, and fecundity on two Norwegian populations of the codling moth, Cydia pomonella (L.), was investigated within the range of 12.3–25°C. In addition, lower threshold temperatures (T₀) and degree-day (DD) requirements for three egg developmental stages are given. The results showed that the Norwegian populations of C. pomonella lay eggs at lower temperatures than reported previously from other countries. Eggs were deposited in ≈40% of the containers at an average temperature of 12.3°C. However, below 15°C, <40% of the population deposited eggs that developed to the black head stage. Preoviposition period was highly affected by temperature, and it was the only response for which population (West versus East) had a significant effect. At lower temperatures (≤15°C), the preoviposition period was markedly prolonged in both populations. The western population required ≈20 DDs more than the eastern population at a base temperature of 11°C, but these results remain to be validated with field data. Temperature had no significant effect on the realized fecundity per ovipositing female or the fertility of these eggs, and both responses were highly variable at all temperatures investigated. Mean fecundity was 11 eggs per female. All estimates of T₀ for the egg developmental stages were below 10°C, which suggests that the base temperature for egg development for the Norwegian populations of the codling moth is 1 or 2 degrees lower than 10°C.

Adult parasitoids frequently require access to food and adequate microclimates to maximize host location and parasitization. Realized levels of parasitism in the field can be significantly influenced by the quantity and distribution of extra-host resources. Previous studies have demonstrated a significant effect of landscape structure on parasitism of the armyworm Pseudaletia unipuncta (Haworth) (Lepidoptera: Noctuidae). As a possible mechanism underlying this pattern, we investigated the effect of carbohydrate food sources on the longevity and fecundity of armyworm parasitoids under laboratory conditions of varying temperature, host availability, and mating status. Glyptapanteles militaris (Walsh) (Hymenoptera: Braconidae) adults lived significantly longer when provided with honey as food and when reared at 20°C versus 25°C. Meteorus communis (Cresson) (Hymenoptera: Braconidae) adults also lived significantly longer when provided with honey, although longevity was reduced when females were provided hosts. Honey-fed females of M. communis parasitized significantly more hosts because of their increased longevity, but did not differ in daily oviposition from females provided only water. Mating significantly increased parasitism by honey-fed M. communis, but not those provided water alone. These results indicate that the presence of both carbohydrate resources and moderated microclimates may significantly increase the life span and parasitism of these parasitoids. However, the greater longevity and lower daily rate of oviposition of M. communis suggest that food and microclimate resources are more critical for this species than for the shorter lived, gregarious G. militaris. These findings contribute to our understanding of how these two parasitoids respond to landscape complexity.

Because mating may be costly, sexually active males or females are predicted to be in relatively good physiological condition and may preferentially direct their mating behavior toward relatively high-quality mates. We tested this hypothesis in Japanese beetles (Popillia japonica Newman), a pest species in which males and females may be either isolated or in aggregations while feeding on host plants. We examined male size and lipid content and female size and egg load with respect to both their pairing status and whether they were isolated or in aggregations. Males that were paired had the highest lipid levels, and single, isolated males had the lowest. Paired females had the highest egg loads and single, isolated females had the lowest. Neither male nor female size was related to pairing status. Females captured during the times of relatively high pairing frequency (i.e., morning and evening) had higher egg loads than females captured at times of lower pairing frequency (i.e., afternoon). These results suggest that mating and aggregative behaviors in Japanese beetles are dependent on the physiological status of males and the reproductive condition of females.

We investigated effects of temperature, at 70% RH, on the reproductive parameters of the parthenogenetic psocid Lepinotus reticulatus Enderlein (Psocoptera: Trogiidae). The lowest fecundity (21) was at 35°C and the highest (41) at 27.5°C. At 22.5, 25, and 27.5°C, peak oviposition rates (eggs/female/week) occurred in week 3 and were 4.7, 6.6, and 7.8, respectively; also 51, 57, and 62%, respectively, of all eggs were laid in the first 4 wk. At 30, 32.5, and 35°C, peak oviposition rates occurred in week 2 and were 8.2, 9.0, and 7.4, respectively; 80, 85, and 98%, respectively, of all eggs were laid in the first 4 wk. The longest preoviposition period (4.4 d) was at 22.5 and 25°C, and the longest postoviposition period (13.1 d) was at 22.5°C. Oviposition period and longevity decreased with increasing temperature; at 22.5°C, these parameters were 66 and 83 d, respectively, and at 35°C, they were 18 and 24 d, respectively. Mean weekly oviposition rate increased with temperature and was highest at 32.5°C (5.8 eggs/female/week). At 22.5, 25, 27.5, 30, 32.5, and 35°C, it took 29, 20, 12, 11, 8, and 6 wk, respectively, for all females to die. Intrinsic rate of population increase increased with temperature until 32.5°C (0.128) and then declined. We have developed temperature-dependent equations for preoviposition period, postoviposition period, oviposition period, oviposition rate, and longevity. Reproductive parameters affect population dynamics, and information on these parameters can be used in simulation models to predict L. reticulatus population dynamics to aid in developing effective management strategies.

Development of green peach aphid, Myzus persicae (Sulzer), was modeled under high and fluctuating temperatures to determine what effects an increase in mean summer temperatures of 2.5–3.5°C would have on green peach aphid populations in Minnesota and North Dakota. Green peach aphid developed faster and had greater fecundity under fluctuating conditions. The constant temperature model failed to predict observed development under fluctuating temperatures (R² = 0.01). Optimal temperature for green peach aphid population growth was 26.7°C. The lower and upper developmental thresholds were 6.5 and 37.3°C, respectively. Under optimal conditions, intrinsic rate of increase was 0.356, and population doubling time was 1.95 d. At optimal fluctuating temperature conditions, one female aphid produced 12.2 progeny each week while under the most favorable constant temperature conditions; each female aphid produced only 5.9 progeny. Green peach aphid was able to survive 1 h each day above its calculated lethal death point of 38.5°C. It seems that, in midwestern North America, green peach aphid would benefit from an increase in mean summer temperature (20°C) of 2.5–3.5°C.

The toxicity of spinosad and methoxyfenozide against neonates and fourth instars of Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) was tested under laboratory conditions. According to LC₅₀ values, no significant differences were observed between spinosad (0.50 mg [AI];/kg diet) and methoxyfenozide (0.54 mg [AI]; /kg diet) after 48 h of ingestion treatment on neonate larvae, based on the overlap of 95% CL. Similarly, on fourth instars, no significant differences were observed between LC₅₀ (2.98 and 5.17 mg [AI];/kg diet for spinosad and methoxyfenozide, respectively, at 96 h after ingestion of artificial diet) and LD₅₀ (4.74 and 2.68 μg [AI];/g larva for spinosad and methoxyfenozide, respectively, at 144 h after topical application). In addition, spinosad and methoxyfenozide significantly suppressed weight gain of neonates and fourth instars continuously fed with artificial diet containing the insecticides. The second part of this project was focused on the effects of methoxyfenozide on the reproduction of S. littoralis by determining the effect on oviposition in three different crosses and the pharmacokinetics pattern of (¹⁴C)-methoxyfenozide in the body tissues of female and male adults after topical application in their excrement and in the deposited eggs to test transport through the female and the male adult. Methoxyfenozide negatively affected the reproduction of adults regardless the treated sex, presumably because of its presence in the adult body, accumulation in the laid eggs, and slow excretion of the product. We conclude that spinosad and methoxyfenozide represent an important choice to be used in integrated pest management where S. littoralis is a major pest.

Anoplophora glabripennis (Motschulsky) (Coleoptera: Cerambycidae) is a recently introduced non-native invasive species in North America that has the potential to destroy several tree species in urban and forest habitats. Adult survival, reproduction, and egg hatch of A. glabripennis from two populations (Ravenswood, Chicago, IL, and Bayside, Queens, NY) were evaluated at seven constant temperatures (5, 10, 15, 20, 25, 30, and 35°C), and adult survival was evaluated at −1°C. Nonlinear regressions were used to estimate the temperature optimum and thresholds for each life history parameter. The estimated optimum temperature for median longevity was 18°C, and upper and lower thresholds were 39 and −3°C for females and 38 and −2°C for males. The estimated upper and lower thresholds for fecundity were 35 and 11°C for the New York population and 34 and 14°C for the Illinois population. The estimated optimum temperature for maximum fecundity was 23 and 24°C for the New York and Illinois populations, respectively. Both longevity and fecundity declined as temperature increased or decreased from the optimum. Oviposition was arrested at temperatures ≤10 and ≥35°C, and either eggs did not mature or were reabsorbed by females that did not oviposit at the higher temperatures. Days to first oviposition approached infinity near 10°C and declined exponentially to a minimum of 16 d at 30°C. The lower threshold for egg hatch was estimated as 10°C and the upper threshold at 32°C, and eggs would be predicted to hatch the fastest at 29°C. Maximum percentage hatch was estimated to occur at 23°C, and the estimated upper and lower thresholds were 34 and 12°C, respectively. These results indicate that summer temperatures throughout most of the lower 48 United States should support beetle survival and reproduction, although oviposition may be suspended and adult survivorship would decline when summer temperatures are sustained for full a day or more at or above 30°C, and there are no cooler locations where the beetles can retreat. In addition, although beetles may survive into the fall, they may lay fewer eggs at lower temperatures, and those eggs may not hatch until spring. These responses of A. glabripennis to temperature can be used for predicting the potential geographical range of this species and in developing phenological models to predict the timing of egg hatch and adult mortality, which are important for management programs.

A new species of wasp, Stethynium sp. (Hymenoptera: Mymaridae), was found parasitizing eggs of an introduced weed biological control agent, Zygina sp. (Hemiptera: Cicadellidae), a leafhopper released against bridal creeper (Asparagus asparagoides L. Druce). A series of laboratory experiments was conducted to determine the development time and longevity of the wasp under different temperatures and the oviposition preference of the wasp for leafhopper eggs of different ages. Parasitized leafhopper eggs were placed in controlled temperature rooms set at either 15, 20, or 25°C and monitored for adult emergence. It was determined that development time of Stethynium sp. from egg to adult eclosion decreased as temperature increased and female wasps took longer to develop than males. Adult male and female wasps were placed in controlled temperature rooms set at these same temperatures and provided either water, a 10% sugar solution, or no food at all. Female wasps lived longer than males and sugar solution increased longevity significantly over no food or water alone, but this effect decreased with increasing temperature. Adult female wasps, given a choice between 1-, 2-, 3-, 5-, and 7-d-old eggs, showed no preference, and all progeny were able to develop and emerge at the same rate from any aged egg. Adult females also laid eggs in 8- and 9-d-old host eggs. There was a slight decrease in emergence rate from 9-d-old host eggs compared with 8-d-old eggs.

The effect of host diet on the immature developmental time, fecundity, sex ratio, adult longevity, and size of Apanteles galleriae Wilkinson, a koinobiont, solitary, and early instar larval endoparasitoid of the lesser wax moth, Achroia grisella (F.), was investigated. All experiments related to the effect of diet were conducted at 25 ± 1°C, 60 ± 5% RH, and a photoperiod of 12:12 (L:D) h. The experiments were conducted by supplying hosts with three types of natural food (blackened, dark yellowish, and pure comb). The change in the type of host diet from blackened, to yellowish, and to pure comb prolonged immature developmental time, shortened the life span, increased sex ratio in favor of males, and reduced fertility and adult size of parasitoid species. The first adult eclosion occurred at 25, 30, and 52 d for males and 27, 33, and 54 d for females, with blackened, dark yellowish, and pure comb, respectively. The mean production of progeny per female parasitoid for each diet was 105.09, 45.49, and 0.46 (n = 30). Males lived an average of 43.46, 14.52, and 5.75 d and females lived an average of 40.86, 16.8, and 10 d in relation to host diet changes. Parasitoid length varied considerably with 2.84, 2.5, 2.2 mm, and 2.51, 2.27, 1.94 mm for females and males, respectively. Of the three kinds of natural food, the first was determined to be the most optimal diet for the parasitoid species.

We determined the effect of enhanced dietary nitrogen on the ovarian maturation of female primary and neotenic reproductives of the termite Zootermopsis angusticollis Hagen. Supplementing the wood diet of newly paired reproductives with a 0.05% uric acid solution resulted in both primaries and neotenics gaining less body mass. This may have occurred because the increased nitrogen content of their food allowed reproductives to consume less wood to meet their dietary needs, thereby reducing the mass of their gut contents. An abundance of exogenous nitrogen may have also stimulated females to excrete excess uric acid rather than store it, further reducing mass gain. Nitrogen supplementation resulted in significant increases in ovariole number and fecundity for neotenic females but not primary females. These results suggest that although enhancing dietary nitrogen may release newly molted neotenics from nutritional limitations on their fecundity, dietary enhancement with 0.05% uric acid does not significantly effect the reproductive development of recently dealated primaries. Possible reasons for each reproductive form’s response to enhanced dietary nitrogen are discussed.

In laboratory experiments, western cherry fruit flies, Rhagoletis indifferens Curran, were exposed to sweet cherries, aphid honeydew, and bird feces to determine fly longevity and fecundity. Longevity was not sustained in females and males exposed to intact unripe cherries or no food, whereas it was in females exposed to intact, fully-ripe cherries, and in females and males exposed to opened unripe or ripe cherries. Females exposed to intact fully-ripe cherries alone usually survived as long as females exposed to sucrose-yeast diets, but fecundity of flies exposed to cherries (79.5–110.8 eggs/female) was lower than that of flies exposed continuously to sucrose-yeast diets (277.5–326.2 eggs/female). Longevity of flies exposed to aphid honeydew was sustained and was similar to that of flies exposed to intact ripe cherries, sucrose-yeast, and sucrose diets. However, exposure to aphid honeydew or bird feces in the absence of ripe cherries did not result in high fecundity (4.6–32.2 eggs/female). Despite the inability of flies to extract nutrients from unripe cherries and the moderate fecundity of flies that were exposed to intact ripe cherries alone, R. indifferens was clearly capable of using its principal host fruit for both sustained longevity and egg production. Results suggest cherries damaged by birds throughout the season and intact fully-ripe cherries later in the season can contribute about the same nutrition as honeydew to female longevity, but that cherries contribute significantly more than either honeydew or bird feces to fecundity in nature.

Little information regarding the biology and ecology of dermapteran predators has been reported. For possible use of Euborellia annulipes (Lucas) (Anisolabididae) in biological control programs against the cotton boll weevil Anthonomus grandis grandis Boheman (Curculionidae), it is important to know the effect of temperature on reproduction in this predator. Our objective was to evaluate the reproductive potential and the longevity of females of E. annulipes under laboratory conditions using an artificial diet, at 25 and 30°C, and to estimate life-fertility tables and growth rates. Fecundity began to decline on day 84 at 25°C and on day 74 at 30°C of adult age and ended with the death of the females at both temperatures. Females of E. annulipes oviposited an average of 206 and 306 eggs, and had a mean longevity of 198 and 149 d at 25 and 30°C, respectively. The gross reproductive rates were 89.2 at 25°C and 91.4 at 30°C; the net reproductive rates were 65.3 at 25°C and 40.3 at 30°C; the generation times were 195.2 d at 25°C and 142.9 d at 30°C; the doubling time was 33.0 d at 25°C and 26.7 d at 30°C; the intrinsic rates of increase were 0.02 at 25°C and 0.03 at 30°C, and the finite rates of increase were 1.02 at 25°C and 1.03 at 30°C. The predator population increased by 52 at 25°C and 20 at 30°C adult progeny per female per generation in the laboratory. The best age for inoculative releases of E. annulipes against cotton boll weevil populations is the age with the highest age-specific reproductive values, that is, newly emerged females at 25 or 30°C.

The cerambycid beetles Phoracantha recurva Newman and Phoracantha semipunctata F. were accidentally introduced into southern California where they have caused significant mortality to eucalyptus trees. In recent years, P. recurva populations have increased rapidly with a concomitant decrease in P. semipunctata numbers in their shared habitat in southern California. P. recurva has been collected in field surveys earlier in the season, suggesting that this species may be active over a broader range of temperatures and consequently have a longer seasonal activity period. We conducted lifetime fecundity studies to examine egg production, egg hatch, and adult longevity of beetles of both species subjected to temperatures typical of late fall and late winter/early spring in southern California. Overall, there were no differences in lifetime fecundity between P. recurva and P. semipunctata. P. recurva did not seem to reproduce over a larger range of temperatures than P. semipunctata, and there did not seem to be any substantial differences in their reproductive biologies. P. recurva eclosed slightly faster and lived slightly longer at reproductive temperatures than P. semipunctata, suggesting that P. recurva may have a slight reproductive advantage over P. semipunctata. However, it seems unlikely that such an advantage can account for the rapid increase in P. recurva populations and the simultaneous decrease in P. semipunctata populations in southern California.

The elm spanworm, Ennomos subsignarius Hübner (Lepidoptera: Geometridae), is an eruptive herbivore that feeds on numerous tree species in forests throughout its range. An unprecedented outbreak in an urban environment in St. John's, Newfoundland, Canada, caused severe levels of defoliation to a number of native and exotic hardwood tree species, some of which represent novel hosts for this insect. Increased insect performance on these novels hosts was hypothesized as having contributed to the outbreak. To assess this, percentage larval survival and pupal weight were measured for larvae reared on foliage from six different tree species in a no-choice laboratory bioassay. Adult longevity and fecundity (no. eggs laid per female) were assessed for laboratory-reared individuals, as well as for pupae collected from eight different host tree species from the field. A survey to assess feeding occurrence measured defoliation on eight tree species. During this urban outbreak, sycamore maple, Acer pseudoplatanus, a tree species not native to North America, experienced the highest levels of defoliation. Performance of E. subsignarius (pupal weight, female longevity, and fecundity) on this host was comparable with the known host of elm (Ulmus spp.). Despite the fact that E. subsignaria performed well on several introduced hosts, fecundity levels were much lower than previously published reports, suggesting that the current outbreak is not caused by increased fecundity on these novel hosts in contrast to the hypothesis.

Ophraella communa (Coleoptera: Chrysomelidae) is a leaf beetle that is unintentionally introduced in China. It is a potential biological control agent against common ragweed, Ambrosia artemisiifolia (Asterales: Asteraceae). The effects of temperature on the development and fecundity of O. communa were studied at eight constant temperature regimens (15, 20, 22, 25, 28, 30, 32, 36°C) in the laboratory. The results showed that the developmental periods for egg, larva, pupa, and entire immature stages decreased in response to the increasing temperature, with the exception of 30°C. The survival rates at different developmental stages were higher at 25 and 28°C than at other temperatures. Ovipositional period and longevity of female shortened with the increasing temperature. The highest fecundity of female was observed to be 2,712.3 eggs/female at 28°C. Life table of O. communa was constructed based on the data at 20–32°C. The innate capacity for increase (r _m), the net reproductive rate (R ₀), and the finite rate of increase (λ) reached the maximum at 28°C, with values of 0.247, 1,773.0, and 1.280, respectively. The shortest period of a generation (T) was 24.6 d at 32°C, whereas the longest T value was recorded as 79.3 d at 20°C. These results offer valuable insight on the establishment potential of O. communa in new environments with diverse temperature regimens and on its massrearing techniques in laboratory.

The effect of temperature on the development, survivorship, fecundity, and life table parameters of Octodonta nipae (Maulik) (Coleoptera: Chrysomelidae), was studied at seven constant temperatures of 17.5, 20, 22.5, 25, 27.5, 30, and 32.5°C. Preliminary experiments showed that no development was observed at 15 and 35°C. All individuals completed development and females laid eggs from 20 to 30°C. There was a significant decrease in male and female longevity with increasing temperatures from 20 to 30°C. The longest and shortest longevity were 203.5 and 73.7 d for males, and 178.7 and 57.6 d for females, respectively. Females produced on average 62.7, 88.9, 116.8, 70.0, and 47.3 eggs and the life expectancy for a newborn egg was 171.6, 148.7, 114.9, 89.2, and 94.8 d at 20, 22.5, 25, 27.5 and 30°C, respectively. Life history data were analyzed by using an age-stage, two-sex life table. The intrinsic rate of increase (r) and the finite rate of increase (λ) of O. nipae increased with increasing temperatures from 20 to 30°C, while the mean generation time (T) decreased within this temperature range. The r was 0.0155, 0.0249, 0.0339, 0.0361, and 0.0383 d^-1 at 20, 22.5, 25, 27.5, and 30°C, respectively. The net reproductive rate (R₀) was highest at 25°C (35.0 offspring), and lowest at 20°C (17.0 offspring). T was shortest at 30°C (76.4 d). The results showed that temperature greatly affected the fecundity and life table parameters of O. nipae, and a suitable temperature for population development and fecundity was at 25°C. The life table data can be used for the projection of population growth and evaluation of control programs.

The lesser cornstalk borer, Elasmopalpus lignosellus (Zeller) (Lepidoptera: Pyralidae) is an important pest of sugarcane (a complex hybrid of Saccharum spp.) in southern Florida. Reproductive and life table parameters for E. lignosellus were examined at nine constant temperatures from 13 to 36°°C with sugarcane as the larval food source. The pre- and postoviposition periods decreased with increasing temperatures and reached their minimums at 33 and 36°°C, respectively. The oviposition period was longest at 27°°C. The mean fecundity, stage-specific survival, stage-specific fecundity, intrinsic rate of increase, and finite rate of increase were greatest at 30°°C and decreased with increasing or decreasing temperature. The net reproductive rate was greatest at 27°°C. The Logan-6 model best described the relationship between temperature and intrinsic rate of increase. The generation and population doubling times were longest at 13 and shortest at 33 and 30°°C, respectively. The most favorable temperatures for E. lignosellus population growth were between 27 and 33°°C. Life table parameters for E. lignosellus reared on sugarcane were greater than for the Mexican rice borer [Eoreuma loftini (Dyar) (Lepidoptera: Crambidae)] reared on an artificial diet at 30°°C. The intrinsic rates of increase for the sugarcane borer [Diatraea saccharalis (F.) (Lepidoptera: Crambidae)] reared on sugarcane or corn were the same as for E. lignosellus reared on sugarcane at 27°°C, but the net reproductive rate was four times higher for the former than the latter borer species.

Little is known about the potential cumulative long-term effects of transgenic crops on nontarget organisms. In the present laboratory study, the potential cumulative effects of transgenic Bacillus thuringiensis (Bt) rice on parasitoids in successive generations were observed for an egg parasitoid, Anagrus nilaparvatae parasitizing eggs of Nilaparvata lugens (Ståål) (Hemiptera: Delphacidae) feeding on Bt rice. Enzyme-linked immunosorbent assay test confirmed that Cry1Ab insecticidal protein could be detected in newly eclosed parasitoid adults. However, no significant effect on the fecundity of Anagrus nilaparvatae Pang et Wang (Hymenoptera: Mymaridae) was observed between Bt and non-Bt rice. Developmental times of both genders of A. nilaparvatae parasitizing host eggs laid in Bt (KMD1 and KMD2) rice lines were significantly prolonged from first generation to second generation, but not always prolonged from third generation to 11th generation as compared with the control rice line. Furthermore, the sex ratio of A. nilaparvatae progeny from the first generation to 11th generation in three rice lines was not significantly different. In general, our results suggested that the effect of Bt rice on this parasitoid could be negligible.

The effects of pollen of regular cotton and transgenic Bt+CpTI cotton expressing the Cry1Ac protein of Bacillus thuringiensis and cowpea trypsin inhibitor (CpTI) as a food source for Trichogramma chilonis (Hymenoptera: Trichogrammatidae) were assessed in the laboratory by studying longevity, parasitization rate, progeny survival, and sex ratio. Females fed on suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in water lived as long as those fed on water alone or those that were unfed. However, the females’ longevity was significantly reduced compared with that of females fed on 10% honey alone or suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in 10% honey, either with or without eggs of rice moth (Corcyra cephalonica). T. chilonis females fed on suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in 10% honey parasitized more eggs and produced significantly more offspring than those fed on 10% honey or water alone, suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in water, or nothing. T. chilonis females fed on 10% honey parasitized more eggs and produced significantly more offspring than those fed on suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in water, water alone, or nothing. No significant differences were found among those feeding on suspension of pollen of regular cotton or transgenic Bt+CpTI cotton in water, water alone, or nothing. The longevity, numbers of parasitized eggs, numbers of progeny emerged, and sex ratio of T. chilonis fed on suspension of pollen of transgenic Bt+CpTI cotton in water or 10% honey did not differ significantly from those fed on suspension of pollen of regular cotton in water or 10% honey. Pollen and honey supplied a complete diet for reproduction and survival of T. chilonis, and transgenic Bt+CpTI cotton pollen did not adversely affect T. chilonis.

A resurgence of the wheat stem sawfly, historically the most important pest of wheat in the northern Great Plains, has been observed in western Canada over the past decade. Host plant resistance in the form of solid-stemmed cultivars remains the primary management strategy for this pest. The objectives of this study were to determine the effects of wheat cultivar on wheat stem sawfly fitness and sex ratio. The cultivars studied varied with respect to stem diameter and pith expression and included representatives of the red seed, solid-stemmed spring and red seed, hollow-stemmed common and durum wheat classes. We present results from a primary study conducted in southern Alberta from 2001 to 2003 and a similar smaller study conducted in 1987 and 1991. All of the solid-stemmed cultivars (AC Eatonia, AC Abbey, Lancer, Leader) reduced female weights, size, fecundity, and in some cases, larval survivorship in the cut stubs and delayed date of adult emergence in the laboratory. Males were less responsive to this aspect of host quality. The hollow-stemmed durum cultivar AC Navigator had similar negative effects and deserves further study. A number of other hollow-stemmed wheats (McKenzie, AC Intrepid, Katepwa, and the durum AC Avonlea) had intermediate but inconsistent negative effects on sawfly fitness. The varieties that maximized sawfly fitness were AC Cadillac, CDC Teal, and Kyle (durum). Sawfly sex ratios were affected by stub diameter in our current and historical cultivar studies. Larger diameter stubs produced significantly more females and smaller diameter stubs produced more males. Furthermore, stubs that failed to produce adults had significantly smaller diameters than those that produced females but similar to those that produced males. The effect of the solid stem trait on sex ratio was inconsistent. Only Lancer had a male-biased sex ratio, whereas the other varieties had no consistent pattern. These results, however, are similar to other published reports that have noted inconsistent effects of the solid trait on sex ratio. Planting a solid-stemmed cultivar in a rotation that includes broad-leaved crops is recommended to reduce sawfly damage and future populations.

We studied the intergenerational effects of nitrogen (N) fertilizer applications to rice plants on the size, fecundity, and intrinsic rate of increase (r_m) of Hysteroneura setariae (Thomas). Treatments consisted of rearing aphids on rice plants receiving 0, 50, 100, and 150% of the standard N fertilizer rates. Adult females produced on the 0 and 150% treatments were transferred to new plants at 0 or 150% N levels to create a matrix of four treatments: 0–0, 0–150, 150–0, and 150–150%. Second-generation aphids produced on 150% N plants had significantly higher survivorship, fecundity, and r_m regardless of the N treatment of plants that parents fed on. N levels had no observed effect on head width. Aphids reared on 0% N plants whose parents were also reared on 0% N plants had significantly shorter body lengths than aphids on all other treatments, including the 150–0% treatment, indicating that the effect of a high N diet was expressed in a second generation of aphids. Results are discussed in the context of aphid population outbreaks in rice fields and in greenhouses.

Age-specific life tables of the lettuce aphid, Nasonovia ribisnigri (Mosley), feeding on lettuce were determined at different constant temperatures under controlled conditions. Our results showed that the proportion of alates increased with increasing temperatures, remaining below 7% at 16°C and increasing to 40–57% at a temperature above 20°C. The longest developmental time of apterous aphids was obtained at 8°C (31.5 d), and the shortest was at 26°C (6.2 d), whereas the developmental time of alates was always 0.7–1.1 d longer than for apterous. Most aphids needed four instars to reach adult stage, but at 8, 26, and 28°C, many individuals passed through five or six molts. Age-specific survivorship (lx) was always above 90% at the temperature range of 16–24°C. Mortality rate (qx) was rather low but constant at 8°C. However, mortality was high at 28°C and occurred mainly in the last nymphal instars and adult stage. Unexpectedly, no nymphs were produced by the adult morphs at 28°C, but effective fecundity was high at 8°C. Fecundity for alates was always lower than for the apterous aphids at the same temperature. The largest intrinsic rate of natural increase (r_m), and the mean relative growth rate (RGR) occurred at 24°C, for both apterous and alate morphs, and the lowest at 8°C. Our results show that lettuce aphid is better adapted to survive and reproduce at low (8°C) than at high (28°C) temperatures, and its best performance occurred at 20–24°C.

Developmental times and survivorship of tarnished plant bug nymphs, Lygus lineolaris (Palisot de Beauvois), and longevity and reproduction of adult tarnished plant bug adults reared on green beans were studied at multiple constant temperatures. The developmental time for each life stage and the total time from egg to adult decreased with increasing temperature. Eggs required the longest time to develop followed by fifth instars and then first-instars. Total developmental time from egg to adult was shortest at 32°C, requiring 18.0 ± 0.3 d and 416.7 ± 31.3 DD above 7.9°C, the estimated minimum temperature for development from egg to adult. Sex did not affect total developmental times and did not affect median survival time. Adults lived significantly fewer days at high temperatures (30–32°C: 17–19 d) compared with temperatures below 30°C (range: 24.5–39.4 d) and the number of eggs laid per day increased from ≈≈4 at 18°C to a maximum of 9.5 eggs per day at 30°C Total egg production over the lifetime of female tarnished plant bugs increased with temperature reaching a maximum of 175 eggs on average at 27°C, total egg production declined at temperatures above 27°C (30°C: 110.8, 32°C: 77.3 eggs per female). The highest net reproductive rate 74.5 (R₀) was obtained from insects maintained at 27°C. The intrinsic rate of natural increase (r_m) increased linearly with temperature to a maximum value of 0.1852 at 30°C, and then decreased at 32°C Generation and doubling times of the population were shortest at 30°C, 21.0 and 3.7 d, respectively.

Developmental times and survivorship of tarnished plant bug nymphs, Lygus lineolaris (Palisot de Beauvois), and longevity and reproduction of adult tarnished plant bug adults reared on green beans were studied at multiple constant temperatures. The developmental time for each life stage and the total time from egg to adult decreased with increasing temperature. Eggs required the longest time to develop followed by fifth instars and then first-instars. Total developmental time from egg to adult was shortest at 32°C, requiring 18.0 ± 0.3 d and 416.7 ± 31.3 DD above 7.9°C, the estimated minimum temperature for development from egg to adult. Sex did not affect total developmental times and did not affect median survival time. Adults lived significantly fewer days at high temperatures (30–32°C: 17–19 d) compared with temperatures below 30°C (range: 24.5–39.4 d) and the number of eggs laid per day increased from ≈≈4 at 18°C to a maximum of 9.5 eggs per day at 30°C Total egg production over the lifetime of female tarnished plant bugs increased with temperature reaching a maximum of 175 eggs on average at 27°C, total egg production declined at temperatures above 27°C (30°C: 110.8, 32°C: 77.3 eggs per female). The highest net reproductive rate 74.5 (R₀) was obtained from insects maintained at 27°C. The intrinsic rate of natural increase (r_m) increased linearly with temperature to a maximum value of 0.1852 at 30°C, and then decreased at 32°C Generation and doubling times of the population were shortest at 30°C, 21.0 and 3.7 d, respectively.

We assessed the life history parameters and temperature requirement of a Korean population of the endoparasitoid Aphelinus asychis Walker (Hymenoptera: Aphelinidae), using Aphis gossypii Glover (Hemiptera: Aphididae) as a host. We first measured the time from egg to mummification (i.e., pupation) and mummification to adult emergence (i.e., pupal period) at 25°C. The pupal period was significantly longer than the egg to pupation period in both genders, unlike in other regional populations of the species. Females produced an average of 342.9 mummies, he highest reported fecundity among the various regional populations of this species. Age-specific realized fecundity peaked between the 4th and 7th day (23.3–24.8 mummies a day). The intrinsic rate of increase (r_m) was 0.255 offspring per female per day. The parasitoids were then reared at eight constant temperatures between 15 and 32.5°C. The developmental time from egg to adult emergence decreased from 27.8 to 9.8 d. The lower developmental thresholds (T₀), estimated by linear regression, for the egg to mummy, mummy to adult, and egg to adult stages were 6.7, 6.8 and 6.7, respectively. The thermal constants for each of the three periods were 115, 126, and 243 DD. We compared these parameters with published data of A. asychis from other regions reared on different hosts and representative species of aphid parasitoids in Aphidiinae (Braconidae) reared on hosts including A. gossypii. The T₀'s of A. asychis were higher than those of Aphidius colemani and Aphidius matricariae when using A. gossypii.