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The bagworm family (Lepidoptera: Psychidae) includes approximately 1000 species, all of which complete larval development within a self-enclosing bag. The family is remarkable in that female aptery occurs in over half of the known species and within 9 of the 10 currently recognized subfamilies. In the more derived subfamilies, several life-history traits are associated with eruptive population dynamics, e.g., neoteny of females, high fecundity, dispersal on silken threads, and high level of polyphagy. Other salient features shared by many species include a short embryonic period, developmental synchrony, sexual segregation of pupation sites, short longevity of adults, male-biased sex ratio, sexual dimorphism, protogyny, parthenogenesis, and oviposition in the pupal case. The unusual mating behavior of bagworms, characterized by an earlier emergence of females than males and a high proportion of females that do not mate as adults, challenges conventional wisdom regarding the evolution of mating systems.

Modeling the effect of temperature on the sustainability of insect-plant interactions requires assessment of both insect and plant performance. We examined the effect of temperature on western flower thrips, Frankliniella occidentalis (Pergande), a generalist herbivore with a high reproductive rate, and chrysanthemum inflorescences, a high quality but relatively fixed, ephemeral resource for thrips population growth. We hypothesized that different thrips versus plant responses to temperature result in significant statistical interaction of temperature with thrips abundance and flower damage attributes over time. Experiments were conducted at five temperatures between 20.7 and 35.3 degrees C, with thrips infestation and time after infestation as main effects. Only minor, uncontrolled variations in relative humidity and light intensity may otherwise have influenced the results. High temperatures lead to an initially rapid increase in density of thrips followed by abrupt declines in abundance. The rate of floral senescence increased with temperature and thrips infestation, as indicated by a reduced fresh biomass and greater leaching of yellow pigments. Multiple regression indicated that indices of plant damage responded more directly to thrips density at low than high temperature, supporting the conclusion that temperature affected the outcome beyond what was predictable simply from differential plant and insect optima. The relative intensity of damage caused by individual thrips decreased with increasing temperature, likely caused by thrips competition and reduced survival, growth, and fecundity on depleted inflorescences. Reduced per capita damage at high temperature may be common in insects exploiting fixed plant resources that exhibit an accelerated rate of deterioration at high temperatures.

The Paulownia bagworm, Clania variegata Snell. (Lepidoptera: Psychidae), is one of the most significant forest defoliators in China. In gas chromatographic (GC)-electroantennographic detection analyses of pheromone gland extracts of female C. variegata on three GC columns (DB-5, DB-23, DB-210), two compounds (A and B) elicited strong responses from male antennae. The more abundant component B was isolated by high-performance liquid chromatography and identified as 1-ethyl-2-methylpropyl 3,13-dimethylpentadecanoate by transesterification, GC-mass spectrometry (MS), and comparison of its spectral and GC retention characteristics with those of synthetic compounds. In field trapping experiments in China, racemic and (1S)-1-ethyl-2-methylpropyl 3,13-dimethylpentadecanoate [but not the (1R)-stereoisomer] attracted male C. variegata. The absolute configuration of B (a molecule with three chiral centers) and the structure of component A remain to be determined.

Background: Respiratory disease is a major cause of morbidity in young people. It is now recognized that atopy plays an important role in the development of chronic respiratory symptoms in children., Objective: To examine the determinants and consequences of serum total and specific immunoglobulin E (IgE) in a general population sample of Québec children and adolescents., Methods: In 1999, 2349 children and adolescents (nine, 13 or 16 years of age) who had participated in a respiratory symptom and disease questionnaire had their total IgE measured. Of these participants, a subsample of 451 children and adolescents was analyzed to detect antibodies to eight specific allergens (ie, allergens of dust mites [Dermatophagoides farinae and Dermatophagoides pteronyssinus], cat, dog, ragweed, Timothy grass, mould [alternaria] and cockroach)., Results: The geometric mean of the total IgE was 44.4 U/mL among all participants. Concentrations were higher in boys and increased with age. More than 41% of the participants were sensitized to at least one specific allergen. Such sensitization was strongly associated with the occurrence of respiratory conditions and symptoms, namely asthma, wheezing and rhinitis. Family history, school location and ethnic origin had an impact on the prevalence of atopy and total IgE levels., Conclusions: Allergic sensitization is a major determinant in the development of asthma, wheezing and rhinitis in children and adolescents in the province of Québec.

As a number of seasonal factors affect cutaneous synthesis of vitamin D, especially in young children, our objective was to verify if winter and summer vitamin D intakes in Quebec preschoolers reach the adequate intake of 5 microg/day. A three-month retrospective food frequency questionnaire and a 24-hour food recall were used with parents of 98 children (mean age 56 months) in summer and of 72 of these children (mean age 65 months) in winter. To ensure completeness of data, vitamin D content of foods not covered in the Canadian Nutrient File was taken from other sources. According to the food frequency questionnaire, total vitamin D intakes were 9.7 +/- 4.3 microg/day in summer and 11.6 +/- 4.8 microg/day in winter. Only 10% of children in summer and 7% in winter had an intake below 5 microg/day. The 24-hour food recall vitamin D intake estimate was lower (summer 7.0 +/- 3.8 microg/day, winter 7.2 +/- 4.2 microg/day). This difference could be partly due to a discrepancy in the estimation of multivitamin supplement intake. However, according to both estimates, vitamin D intakes appeared generally adequate in this sample of Quebec preschoolers.

Background: The Health and Social Survey of Quebec Children and Youth, conducted on representative samples of children nine, 13 and 16 years of age, provided data on the prevalence and determinants of asthma and allergic rhinitis in Quebec., Objectives: To determine the prevalence of asthma and allergic rhinitis among children in the province of Quebec and to identify the determinants of these pathologies., Methods: Three groups of more than 1100 children aged nine, 13 and 16 years were recruited. Respiratory symptoms were documented using the International Study of Asthma and Allergies in Childhood questionnaire. Questions enquiring about family income, smoking, degree of urbanization of the child's school's location and various variables related to indoor air were also included. The comparisons of proportions were done using the chi2 test., Results: The prevalence rates for reported history of asthma varied from 14% to 15% depending on the age group. The prevalence of wheezing in the past year was 7% to 8%. Asthma was the primary cause of the limitation of activities due to a health problem in nine- and 13-year-old Quebecers, and the second most common cause in 16-year-old Quebecers. The prevalence of rhinitis, rhinoconjunctivitis and reported history of hay fever increased with age, reaching 28.0%, 15.9% and 21.1%, respectively, in the 16-year-old group. The prevalence of asthma and wheezing was associated with family history and allergies, and inversely related to family income., Conclusions: The prevalence of childhood asthma is high in the province of Quebec. It is a major cause of the limitation of activities due to a health problem for young Quebecers. A family history of asthma and an atopic predisposition are important determinants in the development of asthma in Quebec.

Seafood consumption during pregnancy carries both benefits (high n-3 FA intake) and risks (exposure to environmental contaminants) for the developing fetus. We determined the impacts of marine n-3 FA and environmental contaminants on gestational age (GA) of Nunavik women and the anthropometric characteristics of their newborns. FA and contaminant (polychlorinated biphenyls and mercury) concentrations were measured in cord plasma of Nunavik newborns (n = 454) and compared with those of a group of newborns (n = 29) from southern Québec. Data were collected from hospital records and birth certificates. In Nunavik newborns, arachidonic acid (AA) was two times lower (P < 0.0001), whereas DHA concentration, the sigman-3 / sigman-6 ratio, and the percentage of n-3 highly unsaturated FA (HUFA) (of the total HUFA) were three times higher (P < 0.0001) compared with southern Québec newborns. After controlling for confounders, GA and birth weight were higher by 5.4 d [95% confidence interval (CI): 0.7-10.1] and 77 g (95% CI: -64 to 217) in the third tertile of percentage of n-3 HUFA (of the total HUFA) as compared with the first tertile. There was no evidence that contaminants had negative effects on GA or birth weight. In this seafood-eating population, an increase in the proportion of n-3 HUFA (of the total HUFA), measured in umbilical cord plasma phospholipids, was associated with a significantly longer GA.

The current study evaluated whether flowering phenology and yield attributes of different strawberry cultivars affect the abundance and feeding impact of tarnished plant bug, Lygus lineolaris (Palisot de Beauvois), as well as behavioral decisions made by feeding nymphs and ovipositing adults. The distribution of emerged nymphs in cage experiments involving nine different cultivars of June-bearing strawberry cultivars suggests that females lay more eggs on plants with numerous flower receptacles, while cultivar per se did not influence their oviposition behavior. A large number of nymphs emerged from receptacles of strawberry plants, while the distribution of emerged nymphs among receptacles, petioles, leaves, and stems varied for different cultivars. These results suggest that the relative intensity of damage caused by ovipositing females may vary for different cultivars. Foraging nymphs did not exhibit a preference for any strawberry cultivar per se, although the abundance of nymphs increased with the weight of receptacles, especially for late instars. Evaluating the density and feeding impact of L. lineolaris for different cultivars under field conditions revealed that some host plant attributes affect the abundance of plant bugs, such as early flowering season and high productivity. Decreasing number of emerged nymphs per flower per plant with increasing density of receptacles per plant suggests that females lay relatively more eggs per receptacle on plants with few receptacles; this pattern of oviposition may explain, in part, why patches with low density of plants typically have high incidence of damage. Planting a high yielding early season cultivar such as 'Cavendish' may contribute to reduce the incidence of damage by L. lineolaris.

Sunscreens are known to-protect against sunlight-induced erythema and sunburn, but their efficiency at protecting against skin cancer is still a matter of debate. Specifically, the capacity of physical sunscreens to prevent or reduce tissue and DNA damage has not been thoroughly investigated. Our objective was to assess the ability of a broad-spectrum sunscreen containing TiO2 to protect human skin against tissue and DNA damage following ultraviolet radiation. For this purpose, engineered human skin (EHS) was generated and either treated or not treated with an SPF 28 physical sunscreen and exposed to increasing doses of simulated sunlight (SSL). Immediately after irradiation, histological, immunohistochemical and molecular analyses were performed. Cyclobutane pyrimidine dimers and pyrimidine (6-4) pyrimidone photoproducts were measured by radioimmunoassay, photooxidative lesions were measured by neutral glyoxal gel electrophoresis. The unprotected irradiated EHS showed significant epidermal disorganization accompanied by a complete absence of laminin deposition. The physical sunscreen prevented SSL-induced epidermal damage at low doses and allowed laminin deposition at almost all SSL doses tested. The frequencies of all 3 types of molecular photodamage were significantly reduced in the sunscreen-protected tissues. In conclusion, although, the level of protection against erythema offered by this sunscreen does not correlate with the level of protection against DNA damage, these results strongly suggest that an SPF 28 physical sunscreen significantly protected human skin against solar UV radiation. Thus, tissue and DNA damage may provide excellent quantitative endpoints for assessing the photoprotective efficiency of sunscreens.

The current study investigated the seasonal phenology, spatial distribution, feeding damage and economic impact of two plant bugs, Lygocoris inconspicuous Knight and Taedia scrupeus Say, in commercial vineyards. For both plant bugs, densities of nymphs were higher on vines located near the edge of woodlots rather than in the interior of vineyards, which may be attributed to the presence of wild vines and other alternate host-plants in wooded areas. Nymphs of both species fed on apical leaves and developing fruit clusters of vine shoots, initiating development after swelling of buds in the spring and reaching the adult stage when vines were in bloom. Confining high densities of L. inconspicuous (10 nymphs) on individual shoots early in the season resulted in significant reduction of the number of fruit clusters per shoot, even when feeding was restricted to short (7 d) duration; the average weight of fruit clusters, in contrast, was not affected to a large extent by feeding activity of nymphs. An experiment evaluating the impact of low density of L. inconspicuous (0-0.3 nymphs per shoot) indicated a marginally significant negative relationship between density of nymphs and average weight of fruit clusters. Control measures may be economically justified when population density exceeds a combined threshold of one nymph of either L. inconspicuous or T. scrupeus per 10 shoots of vines.

Sampling studies were conducted in coffee plantations in South Yunan to assess the incidence, symptoms, and intensity of damage by three stem borers: Xylotrechus quadripes (Chevrolat), Acalolepta cervina (Hope), and Bacchisa sp. near pallidiventris (Thomson). Of 5,690 plants sampled in eight plantations, 440 were infested with A. cervina, 63 with X. quadripes, and three with B. pallidiventris. Plants 5-7 yr old were 10 times more heavily infested with X. quadripes than 3- to 4-yr-old plants, whereas both age groups of plants had similar levels of infestation with A. cervina. Larval galleries of the three borer species markedly differ: A. cervina and B. pallidiventris larvae develop in subcortical galleries in the main stem (A. cervina) and lateral branches (B. pallidiventris), whereas larval galleries of X. quadripes intermittently punctuate and transverse the xylem of main stems or lateral branches. Significantly more plant tissue was damaged in stems infested with X. quadripes than in those infested with A. cervina or B. pallidiventris. Stems infested with A. cervina or B. pallidiventris generally had only one or a few pupation chambers, whereas stems infested with X. quadripes contained numerous chambers. Quantitative and qualitative data collected through this study provide farmers with diagnostic tools to determine which borer species infested coffee plants. Comparison of life history traits and intensity of damage for the three borer species indicates that X. quadripes is the most severe pest of coffee in Yunan, and suggests that populations of X. quadripes have the greatest potential to steadily increase with time.

Wood heating represents an interesting economic alternative to electrical or heating oil and gas systems. However, many people are concerned about poor indoor air quality in homes equipped with wood-burning appliances. We conducted a study in the Quebec City region (Canada) to verify the extent of indoor air contamination, and to examine the frequency of respiratory symptoms and illnesses among occupants of wood-heated homes. One child attending primary school (median = 8 years old; range = 5-14 years old) and an adult (median = 37 years old; range = 23-52 years old) were recruited in each eligible house. Eligible houses were without known sources of combustion products (smokers, attached garage, oil or gas furnace, gas stove, etc.) except for wood-burning appliance. Out of the 89 houses included in the study, 59 had wood-burning appliances. Formaldehyde, nitrogen dioxide, respirable particles (PM10) and carbon monoxide were measured in a sub-set of 49 houses (41 with a wood-burning appliance and 8 without). The frequency of respiratory symptoms and diseases among participants were documented using a daily symptom diary. Concentrations of contaminants were low in most houses, both with or without a wood-burning appliance. Globally, there was no consistent relationship between the presence of a wood-burning appliance and respiratory morbidity in residents. Nevertheless, residents who mentioned being exposed to fumes emitted by such an appliance reported more respiratory illnesses and symptoms. The presence of animals or molds, and keeping windows closed most of the time in winter were other factors associated with respiratory problems. We conclude that wood burning appears to be a respiratory health risk for occupants if the appliance is not maintained and used properly.

In the course of the "1998 Health and Social Survey", questions were included to verify the prevalence of chronic respiratory diseases and also of wheezing. The objectives of this study were 1) to verify the prevalence of wheezing and its validity as an indicator of chronic respiratory diseases in Québec; and 2) to examine the relationship between chronic respiratory diseases and some of their potential determinants. A total of 30,386 individuals participated in the study. For all ages, the prevalence of wheezing was 5.4%. It was associated with asthma, allergies, chronic bronchitis and emphysema. A low familial income and tobacco smoking were associated with wheezing, asthma, chronic bronchitis and emphysema. Passive smoking was associated with wheezing whereas the presence of carpets was associated with wheezing and asthma. Between 32 and 48% of families with an asthmatic or an allergic member modified their dwelling to alleviate respiratory problems. The prevalence of wheezing documented here was lower than in anglosaxon countries. This result could be explained by a cultural factor (the French translation or the perception of wheezing). This study emphasizes the role of reducing tobacco smoking in the prevention of chronic respiratory diseases.

Sunscreens are known to protect against sunlight-induced erythema and sunburn, but their efficiency at protecting against skin cancer is still a matter of debate. Specifically, the capacity of sunscreens to prevent or reduce tissue and DNA damage has not been thoroughly investigated. The present study was undertaken to assess the ability of a chemical broad-spectrum sunscreen to protect human skin against tissue and DNA damage after solar UV radiation. Engineered human skin was generated and either treated or not with a broad-spectrum SPF 30 sunscreen and exposed to increasing doses of simulated sunlight (SSL). Immediately after irradiation, histological, immunohistochemical, and molecular quantitative analyses were performed. The unprotected irradiated engineered human skin showed significant epidermal disorganization accompanied by a complete absence of laminin deposition. The sunscreen prevented SSL-induced epidermal damage at low doses and allowed laminin deposition at almost all SSL doses tested. The frequencies of cyclobutane pyrimidine dimers, pyrimidine (6-4) pyrimidone photoproducts, and photooxidative lesions measured by alkaline gel electrophoresis and radioimmunoassay were significantly reduced by the sunscreen. Thus, tissue and DNA damage may provide excellent quantitative end points for assessing the photoprotective efficacy of sunscreens.

We conducted this study to evaluate blood levels of lead, mercury, and organochlorine compounds in newborns in the Province of Quebec. During 1993 to 1995, we carried out a survey in 10 hospitals located in southern Quebec. During that time, umbilical cord blood samples were obtained from 1109 newborns, and we analyzed each for lead, mercury, 14 polychlorinated biphenyl congeners, and 11 chlorinated pesticides. We used the geometric mean and 95% confidence interval (CI) to describe the results. Mean concentrations of lead and mercury in cord blood were 0.076 micromol/l (95% CI = 0.074, 0.079) and 4.82 nmol/l (95% CI = 4.56, 5.08), respectively. The mean concentrations of total polychlorinated biphenyls (Aroclor 1260) and dichlorodiphenyl dichloroethylene were 0.514 microg/I (95% CI = .493, 0.536) and 0.412 microg/l (95% CI = 0.390, 0.435), respectively. We observed a statistically significant relationship between maternal age and cord blood concentrations of (a) lead, (b) mercury, (c) polychlorinated biphenyls, and (d) dichlorodiphenyl dichloroethylene. In addition, maternal smoking during pregnancy was associated with cord blood lead levels. The cord blood concentrations of lead, mercury, polychlorinated biphenyls, and dichlorodiphenyl dichloroethylene we measured in our study were the lowest levels recently reported in industrialized countries. The results of this study underline the role of public health authorities in the evaluation of biological levels of environmental contaminants among children for the assessment of risk of adverse health effects.

Gas chromatographic-electroantennographic detection (GC-EAD) analyses of pheromone extract of female bagworms,Oiketicus kirbyi (Guilding), revealed five EAD-active compounds. Retention index calculations, GC-mass spectrometry in both full-scan and selected-ion monitoring modes and GC-EAD analyses of authentic standards identified the compounds as 1-methylbutyl octanoate (MBO), 1-methylbutyl nonanoate (MBN), 1-methylbutyl decanoate (MBD), 1-methylpentyl decanoate (MPD), and 1-methylbutyl dodecanoate (MBDD). Of these five chiral esters, MBD was most abundant in extracts and elicited the strongest antennal response. In field experiments in Costa Rica, (R)-MBD attractedO. kirbyi males, whereas (S)-MBD in combination with (R)-MBD inhibited response.R but notS enantiomers of MBO, MBN, and MBDD strongly synergized attraction to (R)-MBD. (S)-MBO and (S)-MBDD were inactive, whereas (S)-MBN was inhibitory. (R)-, (S)- and racemic MPD were inactive. Blends of (R)-MBD in ternary combination with either (R)-MBO and (R)-MBN or (R)-MBN and (R)-MBDD were as attractive as the five-ester blend. Five- and four-ester blends were equally attractive, suggesting redundancy of pheromone components for attraction of males. The multiple sex pheromone component blend of chiral esters inO. kirbyi may have evolved to maintain species-specific communication in bagworm communities of tropical Americas.

Neuropsychological effects occurring in young children exposed to low blood lead levels are now better known. This paper reviews the need to systematically screen for blood lead levels compatible with subclinical lead poisoning in young Canadian children. Using standard criteria for judging the appropriateness of this measure, the authors found no evidence to support such a practice in Canada. Case-finding is recommended in clinical settings for children with disorders suggestive of lead poisoning, increased lead absorption or exposure to a potential source of lead. A population survey is also recommended in the presence of a well-documented community environmental lead source. There is a need for common protocols across Canada for evaluating and treating children with blood lead levels compatible with subclinical poisoning. Areas of priority research are: the impact of persistent environmental sources of lead such as old paint and lead in water; defining criteria for selective screening; and methods of cost-effective environmental remediation.

Small trunk pieces of a freshly felled 10-year-old oil palm,Elaeis quineensis (Jacq.), were placed in a modified Nalgene desiccator, and volatiles captured for six days on Porapak Q. Gas chromatographic (GC) analysis of Porapak-Q-trapped volatiles with both flame ionization (FID) and electroantennographic detection (EAD) using male or femaleR. phoenicis antennae revealed several EAD-active compounds. They were identified as: ethyl acetate, ethyl propionate, isobutyl propionate, ethyl butyrate, and ethyl isobutyrate. In field experiments in the La Me Research Station, Côte d'Ivoire, ethyl propionate (50 mg/24 hr) but not all esters combined (50 mg/24 hr each) significantly increased capture ofR. phoenicis in pheromone-baited (3 mg/24 hr) traps. One kilogram of 1- to 3-day-old palm tissue was significantly more effective than ethyl propionate in enhancing pheromone attraction. Superior attraction of palm tissue may be attributed to additional as yet unknown semiochemicals. Alternatively, release rates and/or ratios of synthetic volatiles differed from those of palm tissue at peak attraction.

The purposes of this study were to determine the umbilical cord blood lead levels in a nonindustrialized city and the effect of place of residence on the blood lead levels of newborns. During spring 1990, we conducted a survey of umbilical cord blood lead levels from 823 live newborns in two hospitals from the Québec City area. The geometric mean of cord blood lead levels was 0.094 mumol/l (95% confidence interval [95% CI] = 0.088-0.099). Less than 1% (95% CI = 0.2-1.7) of the babies had cord blood lead levels at 0.48 mumol/l or greater. We estimate that each year in the Québec City area between 150 and 200 newborns are at risk for developing psychoneurological problems during their first years of life. Frequency distribution of cord blood lead level did not differ significantly among urban, suburban, and rural areas; however, a higher proportion of cord blood lead levels greater than 0.25 mumol/l was observed in the urban area (9.4%), compared with suburban (2.6%) and rural (3.1%) areas. The proximity of potential environmental lead sources (highway, industry, city center) located within 1/2 mile (.8 km) of the mother's residence was associated with a high cord blood lead level. Cord blood lead levels were also elevated for newborns whose mothers lived in newer (< or = 5 y) and older buildings (> or = 50 y). We concluded that the environmental characteristics of the mother's residence are a better indicator of environmental lead exposure than the place of residence.(ABSTRACT TRUNCATED AT 250 WORDS)