Comparison of two methods of monitoring thrips populations in a greenhouse rose crop

The thrips, Frankliniella occidentalis (Pergande) (Thysanoptera: Thripidae) is among the most important pests of greenhouse crops in Europe and causes considerable damage to commercial rose crops. The usage of pesticides is associated with major problems, and thus the interest of implementing integrated pest management (IPM) for rose crops is increasing. One essential component of IPM is field monitoring/scouting. Growers use information gathered from scouting to select and schedule appropriate control tactics. Thrips populations were surveyed in 2005 and 2006 in a greenhouse planted with roses, Rosa x Hybrida in Southern of France. From April to August, thrips were counted using yellow sticky traps (YST), knock-down techniques [i.e., tapping flower heads (FT)] and actual counts of entire plants. Thrips abundance recorded using YST correlated well with abundance levels determined through FT or actual counts (whole plant). Our results demonstrate that it is accurate to estimate thrips populations using YST in rose crops in greenhouse. Because YST takes at least twice less time than other monitoring methods, it could be used as a valid and easy monitoring technique in further development of IPM programs on roses. The possibility of setting a damage threshold using the data from the YST in the greenhouse is discussed.     

Parasitoid and host egg ages have independent impact on various biological traits in a Trichogramma species

Trichogramma (Hymenoptera: Trichogrammatidae) are species used worldwide for the biological control of Lepidopteran pests, notably through inundative releases on millions of hectares. The optimal use of Trichogramma parasitoids in crop protection requires an accurate knowledge of their biology. More specifically, the importance of age factor in parasitoids during the time they forage in crops for host eggs (after initial release) and how the aging of host eggs could impact parasitoid biological traits may be important for overall efficiency in terms of crop protection. In this context, the importance of parasitoid female and host egg ages on parasitism rate and the development of offspring was studied in laboratory conditions on Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae) and the eggs of the pest Lobesia botrana Denis and Schiffermüller (Lepidoptera: Tortricidae). Host eggs tested were 1–2- and 3–4-day-old, while the ages of T. cacoeciae adult females varied from 1-day-old to 4-day-old post-emergence. When L.?botrana eggs were 3–4-day-old, they were less parasitized by T. cacoeciae than 1–2-day-old eggs, and this was not linked to the age of T. cacoeciae females. The age of parasitoid females has an effect on parasitism, as 1-day-old females produced fewer parasitized eggs than 2, 3, and 4-day-old females. For the total number of L. botrana eggs killed by T. cacoeciae, the two factors did not show significant effects. When L. botrana eggs were 1–2-day-old, parasitoid emergence increased according to the age of parasitoid females with the highest success observed for 3-day-old females. The lowest emergence rates were obtained with T. cacoeciae females 1-day-old. The development time was also longer with the young 1-day-old parasitoid females. This study demonstrated that both the aging of parasitoids and host eggs play a role in the subsequent development of parasitoid offspring. The importance of these results in the context of biological control programs involving Trichogramma parasitoids is discussed.     

Imaging diagnosis--lack of contrast enhancement in metastatic cerebral adenocarcinoma

A 7-year-old female spayed Scottish Terrier was presented with central nervous system symptoms suggestive of a lesion in the forebrain. Magnetic resonance (MR) imaging revealed multifocal disease in the forebrain. Because of complete lack of contrast enhancement, the changes were attributed to lesions of inflammatory origin. Histopathology of the brain revealed multiple metastatic lesions of an adenocarcinoma. Brain metastases in general show contrast enhancement. The reason for a complete absence of contrast enhancement is unknown. Previous administration of corticosteroids, increased diffusion time of contrast medium, increased intracranial pressure in combination with an intact blood-tumor barrier is discussed as possible reasons.     

Drivers of plant species richness and phylogenetic composition in urban yards at the continental scale

Landscape Ecology - As urban areas increase in extent globally, domestic yards play an increasingly important role as potential contributors to ecosystem services and well-being. These benefits...     

Evaluation of biochemical profile of dairy cows with metabolic diseases in tropical conditions

The aims of this study were to characterize the biochemical profile, the reproductive performance and to identify potential predictive biomarkers of disease state of dairy cows with hyperketonemia, lipomobilization and hypocalcemia raised in tropical conditions in southeastern Brazil. Dairy cows (n = 50) were divided into a group of healthy cows (n = 14), cows with lipomobilization (n = 14), cows with hypocalcemia (n = 11), and a group of cows with hyperketonemia (n = 11). Evaluation of body condition score (BCS), body weight (BW) and blood samples was performed on 21, 14, 7, 4 and 2 days before calving, parturition, 1, 7, 14, 21, 30, 45 and 60 days post-partum and milk production was recorded on days 7, 14, 21, 30, 45 and 60 after parturition. Blood samples were assayed for aspartate aminotransferase (AST), gamma-glutammyltransferase (GGT), albumin, total protein, globulin, fibrinogen, total cholesterol, triglyceride, urea and creatinine concentrations. The biochemical profile, BCS, BW, milk production and reproductive performance differed (p < .05) among the groups. Our findings indicate changes in the biochemical profile of dairy cows with metabolic diseases and impaired production and fertility of dairy cows in this group. Variable importance in projection plots demonstrated that cholesterol, urea, total protein, albumin and fibrinogen in the serum were the strongest discriminators between cows with hypocalcemia and healthy cows; and AST, cholesterol, urea and triglycerides for cows with hyperketonemia and healthy cows; and cholesterol, urea, triglycerides, total protein and fibrinogen for lipomobilization and healthy cows, which might be useful as predictive biomarkers of the disease state.     

Alterations in biochemical profiles and reproduction performance in postpartum dairy cows with metritis

The aim of the present study was to evaluate the biochemical profile and reproductive performance in postpartum dairy cows with clinical metritis. The research was carried out using performed on 213 pluriparous lactating cows from two dairy herds in southeast Brazil. Dairy cows were assigned into a group of healthy cows (n = 147) and cows with metritis (n = 66). Blood samples to assess serum albumin, cholesterol, fibrinogen, calcium, gamma-glutammyltransferase (GGT), aspartate aminotransferase (AST) and β-hydroxybutyrate (BHBA) concentrations were performed on day 8 ± 2 postpartum. Metritic cows had lower (p < .05) serum albumin, cholesterol and calcium concentration, and higher (p < .05) GGT and AST activity, and BHBA and fibrinogen concentrations when compared to the healthy group. The calving-to-conception interval and services per pregnancy were higher in metritic cows (p < .01) than in healthy cows and the conception rate at first service was lower in metric group (p < .01). Variable importance in projection plots demonstrated that cholesterol was the main discriminator between metritic and healthy cows. Our results indicated alterations in the biochemical profile and impaired reproduction performance in metritic cows.     

Contrasting drought survival strategies of sympatric willows (genus: Salix): consequences for coexistence and habitat specialization

Many willow species (genus: Salix) co-occur within habitats (α-diversity) and across the landscape (β-diversity) throughout North America. This high diversity is challenging to explain because closely related species often share similar functional traits and thus experience heightened competition and shared pest and pathogen susceptibility. To investigate whether traits related to drought survival are important in maintaining diversity, we conducted an experimental dry-down on six willow species in a greenhouse. We compared species' growth rates, stem and leaf hydraulics, leaf function and dieback and examined potential associations between their drought responses and habitat affinities. Habitat affinities were characterized based on species occurrence in randomly established field plots in central Minnesota. Overall, species that occur in drier, more seasonally variable habitats tended to have higher water-use efficiency, and faster growth rates than species from wetter habitats. However, the greatest difference in drought survival strategies was found between two species with similar habitat affinities. We conclude that differences in willow species could be important in both driving habitat differentiation and permitting temporal differentiation in resource utilization within habitats. Therefore, species' water-use strategies could be important in maintaining both α- and β-diversity across the landscape.     

Potential for combined use of parasitoids and generalist predators for biological control of the key invasive tomato pest Tuta absoluta

The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has recently invaded Mediterranean countries and is a major pest in tomato crops. Trichogrammatid oophagous parasitoids have shown promising potential for controlling the pest before the yield decreases in the greenhouse. In protected tomato crops (greenhouse), mirid predators are commonly used for biological control of whiteflies and they also prey on T. absoluta. These predators do not attack Trichogramma adults but they may partially decrease the overall impact of parasitoids on T. absoluta if intraguild predation (IGP) occurs on parasitized eggs. Under laboratory conditions, we tested if the mirid predator Macrolophus pygmaeus shows preference between parasitized and unparasitized T. absoluta eggs. We also tested if the predator reduces the number of parasitized eggs on caged tomato plants (microcosms) and assessed the efficacy of natural enemies used alone or together in limiting T. absoluta populations. We found that IGP is inflicted on the parasitoid Trichogramma achaeae by M. pygmaeus and that the risk of IGP depends on the developmental stage of T. achaeae inside the egg because the larva is at risk mostly early in its development (when parasitized egg is still yellow). In addition, we observed that non-consumptive events, likely probing of the predator on parasitized eggs, may induce mortality in parasitoid offspring without actual feeding on parasitized eggs. However, both IGP and non-consumptive events decreased when the predator was not confined with parasitized eggs in small arenas. Despite negative effects of the predator to the parasitoid, results demonstrate that adding Trichogramma parasitoids may significantly increase the level of control of the pest over what could be attained when only the mirid predator M. pygmaeus is present on tomato. Implications of results are discussed regarding potential of these natural enemies for biological control of T. absoluta in greenhouse tomato crops.     

Two cases of Neorickettsia (Ehrlichia) risticii infection in horses from Nova Scotia

Two horses from Nova Scotia were diagnosed with Potomac horse fever (PHF). Polymerase chain reaction analysis was performed on formalin-fixed colon tissue or whole blood to show the presence of Neorickettsia risticii DNA, the causative agent of PHF. These are the first reported cases of PHF in the Maritime Provinces.     

Outcome of tactile conditioning of neonates, or "imprint training" on selected handling measures in foals

Behavioural reactions to selected handling procedures were compared between conditioned, or imprint-trained, and untrained foals raised on the same farm. Nineteen randomly chosen healthy foals were imprint trained at birth and 24 h later (Group A). Twenty-one similar foals that were not imprint-trained served as age-matched controls (Group B). Training began within 10 min of birth and consisted of touch desensitization by gentle rubbing. Each tactile stimulus was repeated 30-50 times over 45-60 min, until the foal no longer resisted the procedure and appeared relaxed. The procedure was then repeated at 24 h of age. At that time a physical examination and blood analysis were performed to assess the foals' health status. Group B animals were not handled except for a brief physical examination and blood analysis at 24 h of age. Thereafter all foals were kept on pastures with their dams with no further handling until they were three months of age. Any foals handled for other reasons before that time were excluded from the study. At three months, each of the 28 foals that completed the study experienced the following handling procedures: acceptance of restraint, haltering, complete physical examination, acceptance of a plastic rebreathing bag, touching the whole body, intramuscular vaccination in the neck, intranasal vaccination, and deworming with oral paste. Response to each procedure was scored (1=not resistant, 2=low resistance, 3=strong resistance, 4=not possible without major physical restraint). Conditioned foals (Group A) were significantly less resistant to touching the front and hind legs and picking up the hind feet (P < 0.05). The administration of vaccines and paste dewormer and the collection of blood were tolerated by the majority of the foals of both groups with no or low resistance. It appeared that neonatal imprint training resulted in a learned behaviour that resulted in decreased self-defence responses towards handling the limbs at three months of age.