We describe 10 patients with severe coronavirus disease 2019 (COVID-19) who received tocilizumab and dexamethasone. We correlated isolation duration with cycle thresholds (Ct) values of nucleic acid amplification tests, clinical state and viral cultures. Isolation duration exceeded 21 days for 7 patients due to positive viral cultures or Ct values <30.

We performed viral culture of respiratory specimens in 118 severe acute respiratory coronavirus virus 2 (SARS-CoV-2)–infected healthcare workers (HCWs), ∼2 weeks after symptom onset. Only 1 HCW (0.8%) had a positive culture. No factors for prolonged viral shedding were identified. Infectivity is resolved in nearly all HCWs ∼2 weeks after symptom onset.

Bradynema listronoti is a parasitic nematode described from infected specimens of the carrot weevil Listronotus oregonensis. Prevalence of infection by B. listronoti under field conditions was followed over a period of 16 years in an untreated carrot field. Susceptibility of different carrot weevil life stages was evaluated as well as the impact of infection on fecundity and mortality. Gene expression in infected and uninfected carrot weevils was also compared to evaluate the impact of the parasite on the host transcriptome. Prevalence of B. listronoti in carrot weevil populations was sustained over the years ranging from 20 to 63%. All the weevil stages exposed to B. listronoti inoculum were susceptible to infection, larvae being more vulnerable (59 ± 8% infected) compared with pupae (4 ± 3% infected) and adults (7 ± 3% infected). The fecundity of infected female weevils was greatly reduced (60-fold) due to an inhibition of the maturation of the reproductive system. Transcriptomic analyses revealed that this parasitic castration may have been triggered by the inhibition of reproductive hormone production. The B. listronoti–L. oregonensis interaction represents a case of parasitic castration with a unique potential for biological control of an important pest of carrots.

We performed a molecular and epidemiologic study of a healthcare-associated rhinovirus outbreak to better understand transmission in neonatal intensive care settings. Sequencing of the 7 outbreak strains revealed 4 distinct clades, indicating multiple sources. A single clade infected 3 patients in adjacent rooms, suggesting horizontal transmission. We observed 1 rhinovirus-associated death.

Long-term trap catches of seedcorn maggot, Delia platura (Meigen), onion maggot, Delia antiqua (Meigen), and cabbage maggot, Delia radicum (Linnaeus) (Diptera: Anthomyiidae), were used to test the hypothesis that related species have more similar population variability than unrelated ones. Annual abundance was estimated from trap catches for 32 years (two species) or 17 years (one species). Population variability was quantified as PV, a proportion between 0 and 1. The three Delia Robineau-Desvoidy species had PV values of 0.51–0.55 that did not differ significantly. These PV values were found to differ significantly from two unrelated species studied over the same time period in the same habitat, which had PV values of 0.39 and 0.67. The hypothesis that related species have more similar population variabilities than unrelated species in the same habitat was supported. These data strengthen the view that PV is a species-specific trait reflecting the adaptation of life histories to their habitat, with related species showing more similar adaptations than unrelated species. The polyphagous and saprophagous seedcorn maggot had PV similar to the two oligophagous herbivores, casting doubt on the hypothesis that more generalist feeders have less variable populations than more specialised feeders.

Long-term, twice weekly, trap catches of the native carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), and the introduced carrot rust fly, Psila rosae (Fabricius) (Diptera: Psilidae), were used to test the hypothesis that native populations fluctuate less from year-to-year than those of introduced species, because the native species has had more time to adapt to temporal variability in its habitat than an introduced species. Variability in annual abundance was estimated for 33 years, and for 11-year or 16–17-year subsets of the 33-year time series. Temporal population variability was quantified as PV, a proportion between 0 and 1. The native carrot weevil had a PV of 0.39, less than that of the introduced carrot rust fly with a PV of 0.67, supporting the hypothesis. Generation 1 for both species showed a decline in PV over three decades consistent with the hypothesis that adaptation to variability in the habitat leads to lower PV. Over 33 years, the carrot weevil developed a second generation with a PV of 0.70, higher than that of the first generation, which is consistent with the hypothesis that adaptation is required to stabilise population dynamics in a new habitat, in this case a new temporally defined habitat.

Adult parasitoid females can obtain proteins and lipid by consuming the haemolymph of their host. In Trichogramma Westwood (Hymenoptera: Trichogrammatidae) species, host feeding on the host egg occurs after oviposition and leads to smaller offspring. We tested the effect of age and hunger on host-feeding behaviour of female Trichogramma euproctidis Girault. Young and old females, either starved, water fed, or honey fed, were observed and the host-feeding frequency, duration, distribution, and number of hosts used for nutrition were measured. The sex ratio (proportion of males) allocated to parasitised hosts where host feeding occurred and time taken to parasitise 10 hosts (indicator of female mobility) were also noted. The majority of females host fed on the first host encountered. Age had no impact on frequency, duration, number of hosts used, and mobility of T. euproctidis. Starved females host fed longer and were less mobile. The sex ratio of the progeny emerging from the first host parasitised was more male biased when host feeding occurred. Host feeding had no effect on the sex ratio deposited elsewhere in the sequence of hosts encountered. Age of female had no effect on host feeding, possibly because host feeding incurs little cost for this species. To host feed on the first host parasitised, in which a male is allocated, is less costly in terms of fitness and represents a strategic choice for the female.

Eggs, larvae, and adults of diamondback moth, Plutella xylostella (L.), and imported cabbageworm, Artogeia rapae (L.), were monitored on cabbage, broccoli, and brussels sprouts [Brassica oleracea (L.) var. capitata, italica, and gemmifera] for 2 years in southwestern Quebec. The first eggs and adults of P. xylostella were observed during the first week of June, and the use of pheromone traps combined with plant sampling permitted detection of three to four generations on each cultivar type. However, adult counts in pheromone traps were not correlated with the number of eggs and larvae on plants. The date at which each generation appeared and their duration varied little between the three Brassica cultivars. An average of 352.7 degree-days (DD) above 7.3 °C were required to complete one generation, but the considerable overlap between generations reduced the usefulness of DD accumulations to predict P. xylostella occurrence. Visual counts of adult A. rapae and plant sampling of eggs and larvae permitted detection of three generations of this species on each cultivar type. The first A. rapae eggs were found during the last week of May, at least 2 weeks before adults were observed. However, butterfly counts were generally correlated with the number of larvae on plants. The dates at which each generation of A. rapae started were similar between cultivar types, and an average of 319.7 DD above 10.0 °C was required to complete one generation.

Five trap designs were evaluated for their efficiency in capturing overwintering adults of the carrot weevil, Listronotus oregonensis (Le Conte). Trap catches were compared with counts of oviposition and nutrition cavities found in carrots placed on the ground. A trap consisting of 22 wooden plates, separated by metal washers and placed over a carrot which was used as bait, proved to be the most efficient. The weevils crawl between the plates, feed on the carrot, and are collected by dismantling the trap over a pan. This technique provided a seasonal record of carrot-weevil activity comparable to that obtained with carrot sections and can be used to issue insecticide-treatment recommendations prior to the beginning of the carrot-weevil oviposition period.

The carrot weevil, Listronotus oregonensis (Le Conte), is an important pest of carrot and celery in eastern Canada (Stevenson 1985). In Quebec, it is univoltine and overwinters as adults (Boivin 1985). At present, the only way to control this pest is with chemical insecticides applied either as granules at seeding time to control the larvae or as foliar sprays to control the adults before they start to oviposit. If integrated pest management (IPM) programs are to be applied to crops attacked by the carrot weevil, additional control methods are needed.

Damage to apple (cv. McIntosh) by five species of phytophagous mind bugs was characterized by confining numbers of them in sleeve-cages placed on apple-bearing branches. Overwintering adults of Lygus lineolaris (P. de B.) pierced apple buds and flowers early in the spring but did little damage after fruit-set. The damage caused to apples by young nymphs of Lygocoris communis (Knight) and Lygidea mendax Reuter was mostly either deep circular depressions or long sinuous scars. Campylomma verbasci (Meyer) and Heterocordylus malinus Reuter were of little importance in the orchard studied. All species did cause circular depressions (“pits”) in fruit and some damage to leaves.

Economic injury levels and economic thresholds for nymphs of Lygocoris communis (Knight) were defined in apple orchards, using the beating technique. These were determined with 1987 apple market value and chemical control costs. Economic thresholds were established, assuming a 24-h period required for control implementation. Highly significant relationships were found between the damage at harvest and the captures of young nymphs of L. communis. The economic injury levels ranged from 0.4 to 5.8 young nymphs per sample unit depending on the sample unit and insecticide used.

Three new mymarid egg parasitoids of the carrot weevil, Listronotus oregonensis (LeConte) (Coleoptera: Curculionidae), are described: Anaphes cotei Huber from Nova Scotia; Anaphes listronoti Huber from Quebec; and Anaphes victus Huber from Quebec, Michigan, and Texas. A key to the species is given. Anaphes sorditatus (Girault), with which at least one of the new species was previously confused, is redescribed. Although listronoti and sorditatus cannot presently be distinguished morphologically, they are biologically distinct and have different hosts. Crosses between male sordidatus and female victus yielded female offspring in 27% of the tests but none in the reciprocal crosses. The corresponding control crosses resulted in 90 and 30% female offspring. Mating did not occur in attempts to cross sordidatus with listronoti. On three occasions an unidentified species of Anagrus was reared from field-collected carrot weevil eggs. This represents the first report of an Anagrus species from Curculionidae.

The seasonal occurrence of four species of egg parasitoids of the tarnished plant bug (Lygus lineolaris) was determined in three different habitais: fields of mixed weeds. alfalfa (Medicago sativa L.). and crown vetch (Coronilla varia L.) in southwestern Quebec in 1991 and 1992. Parasitoids studied were the mymarids Anaphes iole Girault, Polynema pratensiphagum (Walley), and Erythmelus miridiphagus Dozier and a scelionid, Telenomus sp. Adult populations of these parasitoids showed three or four population peaks in all habitats throughout the season. Adult parasitoid activity started during the first egg-laying period of L. lineolaris at a temperature accumulation of 73 degree-days (DD). The overwintering period began in mid-October at 1277 and 1058 DD for 1991 and 1992, respectively. All the parasitoids had a strong synchrony with L. lineolaris populations; specifically, marked peaks in the adult population of all species were in synchrony with the egg-laying periods of L. lineolaris.

During a study on the parasitoids of the imported cabbageworm, Artogeia rapae (L.) (Lepidoptera: Pieridae), undertaken in 1993 and 1994, we recovered Cotesia rubecula (Marshall) (Hymenoptera: Braconidae) for the first time in Quebec, Canada. Samples were taken from pesticide-free plots of cabbage, broccoli, and Brussels sprouts located at Ste-Clotilde (45°09′N, 73°41′W) and L'Acadie, Quebec (45°18′N, 73°21′W), as described by Godin and Boivin (1998). In addition, survival of diapausing C. rubecula was evaluated after a 5-month incubation at 4°C (Godin 1997). Both A. rapae and C. rubecula are introduced species and originate most likely from Europe (Richards 1940). Artogeia rapae was discovered in 1860 in Quebec (Harcourt 1963), and C. rubecula was first reported in 1963 in British Columbia (Wilkinson 1966).

Because the detectability of host eggs is low, egg parasitoids rely on infochemicals other than those from the host egg itself, such as host plant synomones (Nordlund 1994; Meiners et al. 2000) and adult host kairomones (Nordlund et al. 1983; Nordlund 1994; Colazza et al. 1999; Meiners et al. 2000). Egg kairomones are used only in the final stages of host selection (Kainoh et al. 1982; Strand and Vinson 1982, 1983; Nordlund et al. 1987; Meiners et al. 2000; Takasu and Nordlund 2001).

The tubercles present on the egg chorion of the carrot weevil, Listronotus oregonensis (LeConte), are described and their variability in density quantified between females. Tubercle density varied by a factor of six between females, from 19 000 to 115 000 tubercles per mm2. The average density of tubercles for a given female remained constant throughout its oviposition period. When isofemale lines were created, the average tubercle density remained constant from generation to generation, and crossing experiment suggested that tubercle density was transmitted by the female. Using isofemale lines with low and high densities of tubercles, no effect on egg survival in water or susceptibility to egg parasitism was found. Tubercle density and the heritability of this character suggest a probable reproductive advantage for females that produce eggs with this chorionic pattern even though the precise role of these traits remains to be determined.

We compared the results of different methods for diagnosing zygosity in a sample of 237 same-sex pairs of twins assessed at 5 and 18 months of age. Despite the twins' very young age and early stage of development, physical similarity was concordant with genotyping in 91.9% of cases at 5 months and 93.8% of cases at 18 months, for a subsample of 123 and 113 pairs, respectively. This concordance rate was obtained following a case-by-case assessment of each pair's physical similarity using a shortened version of the Zygosity Questionnaire for Young Twins (Goldsmith, 1991). Taking into account the chorionicity data available from the twins' medical files, we were able to classify correctly 96% of the pairs, an accuracy rate comparable to previously reported rates obtained with older twins. Chorionicity data is especially useful since we found that monochorionic MZ twins are more difficult than dichorionic MZ twins to diagnose by physical similarity at these young ages. The relative cost-benefit of methods based on reported physical similarity and DNA analysis is discussed in light of these results.

Microarrays have become one of the most convenient tools for high throughput screening and have catalyzed major advances in genomics and proteomics. Other important applications can be found in medical diagnostics, detection of biothreats, drug discovery, etc. Integration of microarrays with microfluidic devices can be highly advantageous in terms of portability, shorter analysis time and lower consumption of expensive biological analytes. Since fabrication of microfluidic devices using traditional materials such as glass is rather expensive, there is a high interest in employing polymeric materials as a low cost alternative suitable for mass production. We present proof-of-concept DNA arrays on a plastic platform for the detection of four important respiratory pathogens: Influenza A virus, respiratory syncytial virus, human enterovirus, and human metapneumovirus.

This was accomplished by amplifying the genetic material from the viruses and simultaneously labeling the amplicons with a fluorescent dye (Cy3) via a highly sensitive multiplex Reverse Transcription Polymerase Chain Reaction (RT-PCR). The resultant RT-PCR product was hybridized, without further purification, with an array of specific oligonucleotide probes (20 mers) that had been covalently bound to a plastic substrate. Results indicate a high signal to background ratio that is comparable to commercially available microarray glass slides. In addition, 5 minute hybridization on this plastic substrate has been demonstrated using a centrifugal microfluidic platform, paving the way to a rapid medical diagnostic device for point-of-care use that is based on a low-cost portable Micro-Total-Analysis-System (μ-TAS).

Cutting millet stem at harvest until the end of November reduced by 76 to 92.5% the number of third generation larvae of Coniesta ignefusalis entering diapause. When harvest was done after the beginning of December, reduction of diapausing larvae in millet stems did not exceed 50%. Weekly harvests from beginning of November to the end of January 1988–1989 and 1989–1990 showed an increased percentage of larvae in diapause. The percentages of larvae in diapause reached 100% at the end of January in 1988–1989 and between the end of December and beginning of January in 1989–1990. The distribution of diapausing larvae in the stems was not regular with 60% of the larvae located between 40 and 80% of the total stem height.