Diurnal and nocturnal herbivore induction on maize elicit different innate response of the fall armyworm parasitoid, <Emphasis Type="Italic">Campoletis flavicincta</Emphasis>

Herbivore-attacked plants produce specific volatile substances that represent important cues for host finding by natural enemies. The fall armyworm Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) is a voracious herbivore and usually feed on maize in all periods of the day. Given that plant needs light to synthesize de novo herbivore-induced volatiles, volatile blend may be changed depending on time of the day the plant is induced, what could interfere in natural enemy foraging. In this sense, the current study aimed to investigate differential attractiveness of maize elicited by fall armyworm regurgitant under light and dark conditions to its specialist larval parasitoid Campoletis flavicincta (Ashmead) (Hymenoptera: Ichneumonidae). All bioassays were conducted in Y-tube olfactometer to assess parasitoid response to odors from undamaged maize, mechanical damage, and regurgitant-treated plants at 0–1, 5–6, and 24–25 h after induction. The results showed that naïve wasps were attracted to volatiles emitted by nocturnal regurgitant-treated maize at 5–6 h, but not to odors from diurnal regurgitant-treated plants. The differential attractiveness is likely due to blend composition as nocturnal regurgitant-treated plants emit aromatic compounds and the homoterpene (3E)-4,8-dimethyl-1,3,7-nonatriene in larger amounts than diurnal-treated plants.     

Venturia inaequalis resistance in local Spanish cider apple germplasm under controlled and field conditions

Host resistance is a key method for the integrated management of apple scab caused by Venturia inaequalis, which is one of the most important diseases of apple. Artificial inoculation of 92 cider apple cultivars with a mixed inoculum of V. inaequalis identified 19 weakly resistant and 19 resistant cultivars. Twelve of these resistant cultivars were previously classified as having low susceptibility to fire blight, and four of them showed complete or weak resistance to races (1), (1, 6) and (6, 7, 13) of V. inaequalis. The analysis of a selection of 72 cultivars for 6 years under field conditions identified 14 cultivars that were classified as resistant to apple scab under high disease pressure involving one to six Mills periods of severe risk of infection each year. Eight out of these 14 cultivars previously showed high levels of resistance to fire blight, which would allow the incorporation of genetic resistance in the integrated production of cider apples in Spain through their use in breeding programs.     

Ocular consequences of blunt trauma in two species of nocturnal raptors (Athene noctua and Otus scops)

Objective To determine the type, prevalence, and prognosis of ocular and periocular lesions in free‐living little owls (LO) and scops owls (SO), injured by blunt trauma. Procedures Medical records from LO and SO with ocular or periocular lesions secondary to blunt trauma were reviewed. A complete ophthalmic examination was performed in all birds. Short protocol electroretinography (ERG) and ocular ultrasound were performed as dictated by the case. Results During the study period, a total of 158 LO and 99 SO with blunt trauma were admitted. Among these, 43 LO (27.8%) and 27 SO (27.3%) had ocular or periocular lesions. Bilateral injuries (72.1% LO and 81.5% SO) were more common than unilateral. Common findings in both species were: corneal erosions/superficial ulcers, anterior and posterior uveitis, cataracts, hyphema, posterior synechia, vitreal hemorrhage, and retinal detachment. Electroretinography was performed in 32 LO and eight SO, which had posterior segment lesions or opacity of the transparent media. Normal to nonrecordable b‐wave amplitudes were observed. Follow‐up was available in 13 LO and 11 SO. Among these, nine LO (14 eyes) and 10 SO (17 eyes) had resolution of the clinical signs following medical treatment. Conclusions Ocular lesions are common in LO and SO injured by blunt trauma. Electroretinography is a valuable diagnostic tool to assess the severity of retinal dysfunction secondary to blunt trauma and to determine the response to medical treatment. A complete ophthalmic examination is a determining factor in the early management of trauma in these species.     

Uveodermatologic lymphoma in two young related Portuguese water dogs

Purpose Canine lymphoma (CL) is one of the most common forms of spontaneous canine neoplasia. Improved understanding of the genetic and environmental factors associated with CL may provide benefits for the study of non‐Hodgkin’s and Hodgkin’s lymphoma in humans. Uveodermatologic lymphoma is reported in a single household of Portuguese water dog, and the etiology is discussed. Methods A 1‐year‐old female intact Portuguese water dog was referred to the Ophthalmology Service of the Veterinary Teaching Hospital of the Autonomous University of Barcelona because of acute blepharospasm of the right eye in association with a multinodular dermatosis. Physical and ophthalmological examination and a complete diagnostic work‐up, including skin and ocular histopathology and immunohistochemistry, were performed. Three months prior, in Galicia (Spain), 1200 km away from Barcelona, a male dog of the same litter showed very similar oculodermatological clinical signs and skin histopathology, and immunohistochemistry were obtained. Results The clinical diagnoses were anterior exudative uveitis, iridal masses, and secondary glaucoma. Histopathology and immunohistochemistry revealed a nonepitheliotropic lymphoma rich in B cell in dog 1 and rich in T cell in dog 2. Conclusion It is proposed that an underlying genetic predisposition could have played a role in the development of lymphoma in these two young related dogs.     

Analysis of Decadal Time Series in Wet N Concentrations at Five Rural Sites in NE Spain

Nitrogen emissions have grown in Spain during the last 15 years. As precipitation scavenges gases and aerosols from the atmosphere, an effect on rainwater concentrations can be expected. However, time-series studies on wet N concentrations in the Iberian Peninsula are very scarce. This paper aims to fill this gap by analysing weekly rainfall N concentrations at a set of rural sites in Catalonia (NE Spain) from 1995/1996 to 2007 and a forest site monitored from 1983 to 2007. The sites encompass a range of rural environments and climate conditions, from the inland pre-Pyrenees (Sort) to the Mediterranean coast (Begur) and from north (Sort and Begur) to central (Palautordera and La Castanya) and south Catalonia (La Senia). We found a 1-year cycle for concentrations of NH ₄ ⁺ and NO ₃ ^? whereby higher values were reached at the end of spring–early summer, except at the easternmost coastal site of Begur. Weekly NH ₄ ⁺ concentrations decreased with time at all sites (except at La Senia) whilst NO ₃ ^? concentrations increased at all sites during the same period. Rainfall SO ₄ ^2? concentrations decreased with time at all sites. The opposite trends in NO ₃ ^? and SO ₄ ^2? concentrations determined a shift in the relative acid contribution of those anions during the 12–13-year period. To interpret the increasing trend, mean annual NO ₃ ^? concentrations were regressed against NO₂ Spanish emissions and to some indicators of local anthropogenic activity. The increase at Sort and Palautordera showed good correlation with local anthropogenic indicators. Wet inorganic N deposition ranged between 4.2 and 6.7 kg ha^?1 year^?1. When including estimates of dry deposition, total annual deposition rose up to 10–20 kg ha^?1 year^?1, values that have been found to initiate adverse effects on Mediterranean-type forest ecosystems.     

Cover crops under different managements vs. frequent tillage in almond orchards in semiarid conditions: Effects on soil quality

Frequent tillage has been widely used in rainfed orchards in SE Spain in order to impede weed establishment and to increase water reposition in the soil profile. However, this practice may lead to soil degradation by decreasing structural stability, organic carbon content and microbial activity. This work examines the effect of different cover crop managements and frequent tillage on soil physical, chemical and biological properties in almond orchards in SE Spain. Two cover crops (oat – Avena sativa L. and oat-vetch – Vicia sativa L.) with two fertilization managements (mineral and organic) and three harvesting regimes (grazing in mid May, hay in early June, and grain-straw in mid July) were compared to a frequently tilled orchard system (three or four tillages per year). Most parameters were sensitive to soil management. Wet aggregate stability, total organic carbon, total nitrogen, carbon:nitrogen ratio, phosphatase, and β-glucosidase activities increased with cover crops, whereas the soil–water content declined, especially for the grain-straw treatment. The kind of fertilizer affected the available P content, which was higher for mineral fertilizer, and influenced the β-glucosidase activity, which augmented for the organic fertilizer. Livestock dejections depressed phosphatase activity, and increased WSC and available P.This study suggests that cover crops in semiarid environments improve soil quality compared to frequently tilled management, by increasing the organic matter content, improving the chemical and physical fertility of the soil, and enhancing the soil biological activity. Only higher water extraction by the plants could affect the orchard development and/or productivity; however, early cover crop removal would minimize possible yield losses.     

Nutritional reference values for Opuntia ficus‐indica determined by means of the boundary‐line approach

Optimum concentrations and/or sufficiency ranges of nutrients are useful for a correct diagnosis and improvement of nutrient status of cultivated plants. To develop boundary‐line approach (BLA) standards for Opuntia ficus‐indica L., a database of N, P, K, Ca, and Mg concentrations in 1‐year‐old cladodes and cladodes fresh‐matter yield was used. The BLA optimum concentrations (associated with estimated maximum yield) for O. ficus‐indica were: N = 13.1 g kg^–1, P = 3.2 g kg^–1, K = 44.4 g kg^–1, Ca = 38.1 g kg^–1, and Mg = 17.3 g kg^–1. The BLA sufficiency ranges at 95% yield were 8.4–20.3 g kg^–1 for N, 2.4–4.2 g kg^–1 for P, 38.2–50.8 g kg^–1 K, 31.8–45.2 g kg^–1 for Ca, and 14.3–20.9 g kg^–1 for Mg. The BLA standards are comparable to those obtained in a previous study using compositional‐nutrient‐diagnosis (CND) approach.     

Occurrence of Cucurbit Yellow Stunting Disorder Virus (CYSDV) and Beet Pseudo-yellows Virus in Cucurbit Crops in Spain and Transmission of CYSDV by Two Biotypes of Bemisia tabaci

The relative occurrence in Spain of two whitefly transmitted closteroviruses causing similar yellowing diseases in melon and cucumber greenhouse crops was studied. Based on a RT-PCR assay, a 1994–1997 survey of Spanish greenhouses showed that the recently described Bemisia tabaci-transmitted cucurbit yellow stunting disorder virus (CYSDV) has displaced the Trialeurodes vaporariorum-transmitted beet pseudo-yellows virus (BPYV), a virus that was present in the area since the late 1970s. The CYSDV transmission rates by each of the two biotypes of B. tabaci present in Spain were compared. The results showed that the ubiquitous B biotype and the resident Q biotype (found in Spain and Portugal) were able to transmit CYSDV with similar efficiency.     

Connectivity in Heterogeneous Landscapes: Analyzing the Effect of Topography

Animal response to landscape heterogeneity directs dispersal and affects connectivity between populations. Topographical heterogeneity is a major source of landscape heterogeneity, which is rarely studied in the contexts of movement, dispersal, or connectivity. The current study aims at characterizing and quantifying the impacts of topography on landscape connectivity. We focus on ‘hilltopping’ behavior in butterflies, a dispersal-like behavior where males and virgin females ascend to mountain summits and mate there. Our approach integrates three elements: an individual-based model for simulating animal movements across topographically heterogeneous landscapes; a formula for the accessibility of patches in homogenous landscapes; and a graphical analysis of the plots of the simulation-based vs. the formula-based accessibility values. We characterize the functional relationship between accessibility values and landscape structure (referred to as ‘accessibility patterns’) and analyze the influence of two factors: the intensity of the individuals’ response to topography, and the level of topographical noise. We show that, despite the diversity of topographical landscapes, animal response to topography results in the formation of two, quantifiable accessibility patterns. We term them ‘effectively homogeneous’ and ‘effectively channeled’. The latter, in which individuals move toward a single summit, prevails over a wide range of behavioral and spatial parameters. Therefore, ‘channeled’ accessibilities may occur in a variety of landscapes and contexts. Our work provides novel tools for understanding and predicting accessibility patterns in heterogeneous landscapes. These tools are essential for linking movement behavior, movement patterns and connectivity. We also present new insights into the practical value of ecologically scaled landscape indices.