Development of biological control of Tetranychus urticae (Acari: Tetranychidae) and Phorodon humuli (Hemiptera: Aphididae) in Oregon hop yards

The temporal development of biological control of arthropod pests in perennial cropping systems is largely unreported. In this study, the development of biological control of twospotted spider mite, Tetranychus urticae Koch, and hop aphid, Phorodon humuli (Schrank), in a new planting of hop in Oregon is described over a period of 9 yr (2005-2013). Both the abundance and diversity of natural enemies increased over time. Known predators of hop aphid (Coccinellidae and Anthocoridae) were present in all years; however, stable biological control of hop aphid was not achieved in most years and aphicides were required to suppress populations at commercially acceptable levels in 5 of 9 yr. Populations of aphidophagous coccinellids developed synchronously with hop aphid populations, and temporal correlations indicated these are the primary predatory insect associated with hop aphid regulation. However, sampling methods did not assess levels of aphid parasitoids and hyperparasitoids and their contribution to biological control was unquantified. Spider mite biological control was associated primarily with predatory mites (Phytoseiidae) and Stethorus spp. (Coccinellidae). The magnitude of temporal correlations of abundance of these predators with spider mites was found to be greatest on the same sampling dates and at lags of 7-14 d. Stable biological control of spider mites occurred after four field seasons, suppressing spider mites to levels similar to those commonly achieved with chemical control. A survey of 11 commercial hop yards in Oregon documented pest and natural enemy densities under commercial management practices over a period of 4 yr (2008-2011). Natural enemy abundance in commercial hop yards was similar to that of a 2- to 3-yr-old hop yard with limited disturbance. Whereas total reliance on biological control for hop aphid is unlikely to be successful, there appears to be unrealized potential for biological control of spider mites in commercial production. Dynamic action thresholds that consider the value of natural enemies are needed for both pests.

Identification, synthesis, and bioactivity of a male-produced aggregation pheromone in assassin bug,Pristhesancus Plagipennis (Hemiptera: Reduviidae)

Pristhesancus plagipennis, a large Australian assassin bug, possesses three pairs of dorsal abdominal glands (DAGs). In the male, the anterior and posterior glands are hypertrophied and secrete an attractant pheromone. Gas chromatography-mass spectrometry (GC-MS) analyses of male DAG extracts and airborne volatiles emitted from calling males showed the pheromone signature to be dominated by a novel component. Subsequent chemical manipulations, GC-MS, and chiral-column analyses established its identity as (Z)-3-hexenyl (R)-2-hydroxy-3-methylbutyrate. Minor components included 3-methylbutanol, 2-phenylethanol, (Z)-3-hexenol, decanal, (E)-2-hexenoic acid, and three minor hexenyl esters. Bioactivity studies using laboratory olfactometers and outdoor flight cages demonstrated attraction by femaleP. plagipennis to calling males, heptane extracts of male posterior DAGs and a synthetic formulation of the (Z)R enantiomer of the major ester, alone or in combination with other components of male anterior and posterior DAGs. Males were also attracted to the major ester. The racemate andS enantiomer of the ester were not attractive. Contamination of the (Z)R enantiomer with 30-60% of theE isomer also made the compound nonattractive. This is the first report of an aggregation pheromone in the Reduviidae. The prospects for pheromonal manipulation ofP. plagipennis populations to enhance the value of this predator in horticultural ecosystems, are discussed.

Field attraction ofBiprorulus bibax Breddin (Hemiptera: Pentatomidae) to synthetic aggregation pheromone and (E)-2-hexenal, a pentatomid defense chemical

A synthetic blend of the aggregation pheromone [(3R,4S,1'E)-3,4-bis(1'-butenyl)tetrahydro-2-furanol, linalool, farnesol, and nerolidol] of the spined citrus bug,Biprorulus bibax, and the pentatomid defense chemical, (E)-2-hexenal, both attracted adultB. bibax to individual trees in citrus orchards. Lemon trees containing single glass vials with aggregation pheromone or (E)-2-hexenal were colonized by significantly greater numbers of reproductiveB. bibax than unbaited trees. There was no significant difference between the treatments and bug recruitment was not improved by using both treatments.B. bibax did not enter cylinder/funnel traps baited with aggregation pheromone but colonized trees containing the traps. Orange or lemon trees containing aggregation pheromone on orchard perimeters recruited significantly larger populations of emigrating, nonreproductiveB. bibax during fall than untreated trees. Nonreproductive bugs were not attracted to trees containing (E)-2-hexenal. The potential for using these semiochemicals as management tools forB. bibax is discussed.

Population density and phenology of Tetranychus urticae (Acari: Tetranychidae) in hop is linked to the timing of sulfur applications

The twospotted spider mite, Tetranychus urticae Koch, is a worldwide pest of numerous agronomic and horticultural plants. Sulfur fungicides are known to induce outbreaks of this pest on several crops, although mechanisms associated with sulfur-induced mite outbreaks are largely unknown. Studies were conducted during 2007-2009 in Oregon and Washington hop yards to evaluate the effect of timing of sulfur applications on T. urticae and key predators. In both regions, applications of sulfur made relatively late in the growing season (mid-June to mid-July) were associated with the greatest exacerbation of spider mite outbreaks, particularly in the upper canopy of the crop. The severity of mite outbreaks was closely associated with sulfur applications made during a relatively narrow time period coincident with the early exponential phase of spider mite increase and rapid host growth. A nonlinear model relating mean cumulative mite days during the time of sulfur sprays to the percent increase in total cumulative mite days (standardized to a nontreated plot) explained 58% of the variability observed in increased spider mite severity related to sulfur spray timing. Spatial patterns of spider mites in the Oregon plots indicated similar dispersal of motile stages of spider mites among leaves treated with sulfur versus nontreated leaves; however, in two of three years, eggs were less aggregated on leaves of sulfur-treated plants, pointing to enhanced dispersal. Apart from one experiment in Washington, relatively few predatory mites were observed during the course of these studies, and sulfur-induced mite outbreaks generally occurred irrespective of predatory mite abundance. Collectively, these studies indicate sulfur induces mite outbreaks through direct or indirect effects on T. urticae, mostly independent of predatory mite abundance or toxicity to these predators. Avoidance of exacerbation of spider mite outbreaks by sulfur sprays was achieved by carefully timing applications to periods of low spider mite abundance and slower host development, which is generally early to mid-spring for hop.

Evaluation of airborne methyl salicylate for improved conservation biological control of two-spotted spider mite and hop aphid in Oregon hop yards

The use of synthetic herbivore-induced plant volatiles (HIPV) to attract natural enemies has received interest as a tool to enhance conservation biological control (CBC). Methyl salicylate (MeSA) is a HIPV that is attractive to several key predators of two-spotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and hop aphid, Phorodon humuli (Schrank) (Homoptera: Aphididae). A 2-year study was conducted to evaluate the recommended commercial use of MeSA in hop yards in Oregon. Slow-release MeSA dispensers were stapled to supporting poles in 0.5 ha plots and these plots were compared to a paired non-treated plot on each of three farms in 2008 and 2009. Across both years, there was a trend for reduced (range 40-91%) mean seasonal numbers of T. urticae in five of the six MeSA-baited plots. Stethorus spp., key spider mite predators, tended to be more numerous in MeSA-baited plots compared to control plots on a given farm. Mean seasonal densities of hop aphid and other natural enemies (e.g., Orius spp. and Anystis spp.) were similar between MeSA-treated and control plots. Variability among farms in suppression of two-spotted spider mites and attraction of Stethorus spp. suggests that the use of MeSA to enhance CBC of spider mites in commercial hop yards may be influenced by site-specific factors related to the agroecology of individual farms or seasonal effects that require further investigation. The current study also suggests that CBC of hop aphid with MeSA in this environment may be unsatisfactory.

Effects of powdery mildew fungicide programs on twospotted spider mite (Acari: Tetranychidae), hop aphid (Hemiptera: Aphididae), and their natural enemies in hop yards

Twospotted spider mite, Tetranychus urticae Koch (Acari: Tetranychidae), and hop aphid, Phorodon humuli (Schrank) (Hemiptera: Aphididae), are the most important arthropod pests of hop (Humulus lupulus L.) in the Northern Hemisphere. A potential barrier for greater adoption of conservation biological control strategies for spider mites and hop aphid is the extensive use of fungicides for management of hop powdery mildew, Podosphaera macularis (Wallr.:Fr.) U. Braun & S. Takamatsu. Field studies conducted in experimental plots in Oregon and Washington in 2005 and 2006 quantified the effects of powdery mildew fungicide programs (i.e., sulfur, paraffinic oil, and synthetic fungicides) on arthropod pests and natural enemies on hop. Fungicide treatment significantly affected spider mite populations in all four studies. Multiple applications of sulfur fungicides applied before burr development resulted in 1.4-3.3-fold greater spider mite populations during summer. Near the cessation of the sulfur applications, or after a lag of 20-30 d, spider mite populations increased significantly faster on sulfur treated plants compared with water-treated plants in three of four experiments. The effect of paraffinic oil on spider mites was varied, leading to exacerbation of spider mites in Oregon and Washington in 2005, suppression of mites in Oregon in 2006, and no significant effect compared with water in Washington in 2006. Significant relative treatment effects for cone damage due to spider mite feeding were detected in Oregon in 2005 in plots treated with sulfur and paraffinic oil compared with water and synthetic fungicides. Mean populations of hop aphids were similar among treatments in Oregon, although sulfur treatment suppressed hop aphid populations in Washington in 2005 and 2006. Populations of individual predacious insect species and cumulative abundance of macropredators were not consistently suppressed or stimulated by treatments in all trials. However, predatory mite abundance in Washington was affected by fungicide treatments, with plots treated with sulfur consistently having 10-fold fewer phytoseiids per leaf compared with the other treatments. Based on the results of these studies, powdery mildew fungicide programs that minimize or eliminate applications of sulfur and paraffinic oil would tend to conserve predatory mites and minimize the severity of spider mite outbreaks. However, mechanisms other than direct or indirect toxicity to phytoseiid mites likely are associated with exacerbation of spider mite outbreaks on hop.

Whipple's disease: a granulomatous masquerader

Whipple's disease is a multisystemic infection that affects middle-aged white men. It typically presents with fever, polyarthritis, diarrhea, steatorrhea, and weight loss. Many other systems can be involved, however, including the central nervous system, heart, lymphatics, lungs, bone marrow, and skin. Recent work has demonstrated the causative organism to be a complex bacteria, Tropheryma whipplei. The diagnosis is established most securely by periodic acid-Schiff staining of foamy monocyte-macrophages in biopsy tissue and body fluids, by electron microscopy, which reveals bacilli within membrane-bound vesicles, and by molecular amplification techniques using polymerase chain reaction of tissues and body fluids. The differential diagnosis includes chronic multisystemic infections and granulomatous disorders, because Whipple's disease is a fascinating blend of both. The condition can resemble sarcoidosis and mycobacterial disease and fungal, protozoal, and bacillary infections. Earlier diagnosis leads to earlier treatment and hopefully the prevention of chronic disabling complications and needless mortality from this once uniformly fatal condition.

Identification of a female-specific, antennally active volatile compound of the currant stem girdler

We identified (Z)-9-octadecen-4-olide as a female-specific, antennally active compound from the currant stem girdler Janus integer Norton. Female specificity was demonstrated by gas chromatographic comparison of liquid chromatography fractions of male and female volatile emissions and whole body extracts. The gamma-lactone was identified by coupled gas chromatographic-electroantennographic detection (GC-EAD), coupled gas chromatographic-mass spectrometric (GC-MS) analysis, microchemical reactions, and GC and MS comparison with authentic standards. GC-EAD analysis of female volatile emissions and cuticular extracts showed a single peak of activity on male antennae, which was not present in male-derived materials. Female antennae did not respond to any of the tested materials. The hydrogenation product of the natural EAD-active material was a known saturated gamma-lactone. The mass spectrum of the dimethyl disulfide derivative of the natural y -lactone was consistent with a double bond present in the 9 position. Comparison of the natural gamma-lactone and a synthesized racemic mixture of (Z)-9-octadecen-4-olide on a chiral GC column showed the presence of a single enantiomer in the natural material.

Stability of benzodiazepines in formaldehyde solutions

Benzodiazepine-type drugs are used in the treatment of a number of pathologic disorders, but they may be implicated in forensic toxicology cases because of their abuse potential. Occasionally, it becomes necessary to measure drug levels following exposure to formaldehyde (postembalming or after tissue storage) if drug involvement was not previously suspected. Virtually no information exists on the decomposition of benzodiazepines in the presence of formaldehyde (the active ingredient in many embalming fluids), yet formaldehyde is known to be highly reactive, particularly with nitrogen-containing compounds. In order to evaluate the effects of formaldehyde on benzodiazepines, 10 benzodiazepine drugs were exposed to various concentrations of formaldehyde and various pH conditions (to simulate potential postembalming conditions), and the decomposition of each drug was measured by high-performance liquid chromatography over a 30-day period. The decomposition rates of all but one of the benzodiazepines were accelerated (to differing degrees) by formaldehyde as compared to controls, and this decomposition was in several cases both pH and formaldehyde concentration dependent. Thus, forensic examiners must be particularly cautious when attempting to determine benzodiazepine concentrations postembalming because the compound may have reacted with formaldehyde to form other products not inherently obvious analytically. Determination of these reaction products will serve to provide alternate analytes, allowing for establishment of accurate conclusions during forensic analyses.

Sarcoidosis 2001

In every decade, sarcoidosis makes a chameleon-like change so its profile needs to be updated. It was first recognised as a dermatological curiosity which evolved into a multisystem disorder with bone cysts, uveitis, and intrathoracic involvement. New dimensions were uncovered by biochemistry and immunology, bringing it still nearer the elusive enigma, namely the cause of sarcoidosis. Aetiology includes an understanding of a genetic predisposition and environmental trigger factors. What was left undone in the 20th century will become evident in the 21st century with more sophisticated technology. Likewise, conventional treatments of the past will be superseded by cytokines and other magic bullets of the millennium.

A clinicopathological classification of granulomatous disorders

Granulomatous disorders comprise a large family sharing the histological denominator of granuloma formation. A granuloma is a focal compact collection of inflammatory cells, mononuclear cells predominating, usually as a result of the persistence of a non-degradable product and of active cell mediated hypersensitivity. There is a complex interplay between invading organism or prolonged antigenaemia, macrophage activity, a Th1 cell response, B cell overactivity and a vast array of biological mediators. Differential diagnosis and management demand a skilful interpretation of clinical findings and pathological evidence. They are classified into infections, vasculitis, immunological aberration, leucocyte oxidase deficiency, hypersensitivity, chemicals, and neoplasia.

Bovine versus rat adrenal chromaffin cells: big differences in BK potassium channel properties

Both bovine and rat adrenal chromaffin cells have served as pioneering model systems in cellular neurophysiology, including in the study of large conductance calcium- and voltage-dependent K(+) (BK) channels. We now report that while BK channels dominate the outward current profile of both species, specific gating properties vary widely across cell populations, and the distributions of these properties differ dramatically between species. Although BK channels were first described in bovine chromaffin cells, rapidly inactivating ones were discovered in rat chromaffin cells. We report that bovine cells can also exhibit inactivating BK channels with varying properties similar to those in rat cells. However, a much smaller proportion of bovine cells exhibit inactivating BK current, the proportion of the total current that inactivates is usually smaller, and the rate of inactivation is often much slower. Other gating features differ as well; the voltage dependence of channel activation is much more positive for bovine cells, and their rates of activation and deactivation are faster and slower, respectively. Modeling studies suggest that channel heterogeneity is consistent with varying tetrameric combinations of inactivation-competent versus -incompetent subunits. The results suggest that chromaffin BK channel functional nuances represent an important level for evolutionary tailoring of autonomic stress responses.

Parotid gland sarcoidosis

Parotid gland sarcoidosis occurs in 6% of patients with sarcoidosis. It was bilateral in 24 (73%), slightly commoner in women, and presented in the majority in the 20 to 40 year age group. There was widespread involvement of other systems, particularly intrathoracic, peripheral lymph-adenopathy, uveitis, lacrimal gland enlargement and skin disease. Patterns of involvement may be pathognomonic as in Heerfordt's syndrome. This account provides the differential diagnosis, imaging and biopsy techniques, and treatment.

Life-threatening situations in sarcoidosis

Life-threatening situations in sarcoidosis are extremely rare. They may be due to failure of vital organs--lungs, heart, kidney, liver and brain--and usually due to irreversible fibrosis. Respiratory failure follows irreversible pulmonary fibrosis and the development of cor pulmonale. Cardiac sarcoidosis is more sinister for it may be silent, ill-recognised with sudden death or high morbidity. It needs sophisticated techniques to uncover this latent iceberg. Renal failure may be due to granulomatous interstitial nephritis and/or nephrocalcinosis. Hepatic failure is due to intrahepatic cholestasis, portal hypertension and bleeding oesophageal varices. Neurosarcoidosis carries a mortality of 10 per cent, over twice that of sarcoidosis overall. The treatment of each situation is discussed including organ transplantation.

Seasonal variations in foraging by ants (Hymenoptera : Formicidae) in two New South Wales citrus orchards

Summary. Pitfall traps were used to monitor the seasonal activity of ants in 2 citrus orchards in the Murrumbidgee Irrigation Area of south-western New South Wales for 22–24 months (November 1992–August/October 1994). Twenty-four species were recorded (22 species at Yanco and 18 species at Cudgel), with Iridomyrmex rufoniger group species being numerically dominant at both sites (63 and 59% of total captures at Yanco and Cudgel respectively). Meat ants, Iridomyrmex purpureus (F.Smith), were a significant (9%) component of trap captures at Yanco where regular soil cultivation was practised, but were less common (<1% of captures) at Cudgel. Sample species richness was generally greater at the Yanco site (mean 9.3 species per trapping interval compared with 6.6 at Cudgel). Total ant captures and sample species richness showed a positive correlation with mean daily temperatures over trapping intervals. Variations in seasonal activity were shown by the numerically dominant species, with 2 distinct patterns being evident. Whilst all taxa were less active during winter, some species [I. rufoniger group sp. 2, Pheidole sp., Rhytidoponera metallica (F.Smith)] continued to forage, albeit at reduced levels. Other species of Iridomyrmex including I. rufoniger group sp. 1 and I. purpureus ceased foraging almost entirely during June–September. Iridomyrmex species are known to interfere with the biological control of honeydew-producing insects in citrus orchards, and our results indicate that ant control programs in southern New South Wales should be initiated in late August–early September to achieve optimal results.

Descriptive definition and historic aspects of sarcoidosis

Sarcoidosis is set within the framework of a large family of granulomatous disorders, so it has many mimics. Granuloma formation is defined with its immunologic basis. The criteria of activity of sarcoidosis are included in the broadly based definition. Future knowledge will derive from basic immunology and molecular biology. Historic aspects are based on pioneers, who have died, and their seminal contributions. Evolution of knowledge derives from information gained at international conferences and from our biennial journal, "Sarcoidosis, Vasculitis and Diffuse Lung Diseases."

Differential diagnosis of facial nerve palsy

Facial nerve palsy is the most frequent neurological presentation of sarcoidosis. It occurs with equal frequency on the right or left side, and equally unilateral or bilateral. When bilateral facial palsy develops in a young adult, sarcoidosis is the most likely cause. In our series of 147 patients with ocular sarcoidosis, facial palsy occurred in 12 per cent and parotid gland enlargement in 10 per cent. Resolution of facial palsy is complete in 80 per cent of patients. It does not recur, unlike orofacial granulomatosis in which facial palsy tends to be recurrent. The differential diagnosis is large (Table I) and needs full investigation in order to provide a better understanding of the treatment and prognosis. A 7-point scheme of management is set out for the patient with idiopathic facial nerve palsy.

The narrative skills of primary school children with a unilateral hearing impairment

The discourse skills of four boys with a unilateral hearing impairment (UHI), aged 7·2-10·7 years, were appraised over a 2-year period by examining their oral narrative use. All subjects exhibited delayed narrative skills, including features typical of children with a language disorder. These findings of language difficulties within this population were at variance with previous findings showing that children with UHI do not experience language problems. The subjects' language skills were discussed in relation to their academic performance. The implications of the findings for the process of narrative assessment were also discussed.

A new immunosuppressant: tacrolimus

Tacrolimus is the new name for the Japanese immunosuppressant drug FK506. It blocks interleukin 2 transcription thereby inhibiting the CD4 Th-1 lymphocyte response to foreign antigens. It also selectively inhibits cytokine secretion of IL3, IL4 and interferon-gamma. It is metabolised by the cytochrome P-450 enzyme system. The results of two trials indicate that it is similar to cyclosporin in efficacy and toxicity.

Granulomatous infections: etiology and classification

Granulomatous disorders are frequently due to a wide variety of infections. Over the past decade advances in molecular diagnostic techniques have allowed identification of organisms involved in granulomatous disorders that previously were of unknown etiology. On the basis of currently available information, granulomatous infections can now be classified in three categories. Group 1 infections are due to a well-recognized organism. Group 2 comprises infections due to organisms that have been recently identified in granulomas by molecular methods but are not readily isolated by conventional microbiological techniques. Group 3 consists of disorders for which the causal organisms have not yet been identified but are strongly suspected; further advances in diagnostic techniques will lead to reclassification of some of these disorders as group 2. This review describes the etiology, histopathologic features, and classification of granulomatous disorders, with an emphasis on those of groups 2 and 3.

The sarcoidosis movement and its personalities

Sarcoidosis has been recognized for 125 years, but in every generation it makes a chameleon-like change, so updating is needed every so often. In Jonathan Hutchinson's day it was a dermatological curiosity, which gradually evolved into a multisystem disorder associated with bone cysts, and, with the introduction of X-rays, respiratory abnormalities. During the 1960s, epidemiology showed that this disorder, involving all systems of the body, was widely disseminated throughout the world. Each fresh approach, by investigators in different disciplines, has provided a new dimension, particularly in biochemistry and immunology. Each advance in knowledge brings us nearer the enigma which continues to elude us, namely the aetiology of sarcoidosis (Tables 1 and 2). This paper draws attention to the pioneers and personalities of the movement, and records the succession of congresses which have helped to define it worldwide.

A comparison of sarcoidosis and Behçet's disease

There are several diseases which present with both ocular and thoracic disease (Table I). Behçet's disease (BD) may be confused with sarcoidosis because they are both multisystem inflammatory disorders presenting with uveitis, polyarthritis, meningitis, cardiovascular disease, erythema nodosum and other cutaneous lesions, and abnormal chest radiographs. The aetiology of both disorders continues to elude us. Hopefully, a careful study of the one may shed light and knowledge on the other.

A comparison of Blau's syndrome and sarcoidosis

Blau's syndrome is a familial multisystem granulomatous inflammation which may be confused with childhood sarcoidosis because it presents with iridocyclitis, posterior uveitis, granulomatous skin disease, arthritis and elevated serum angiotensin-converting enzyme. They are distinguished by the absence of pulmonary involvement and a negative Kveim-Siltzbach skin test.

Sarcoidosis of the liver

There are many causes of granulomas of the liver including infections, immunological aberrations, enzyme defects, drugs and other chemicals, and neoplasia (Table I). The commonest causes are tuberculosis, sarcoidosis, schistosomiasis and intrinsic liver disease. About 10 per cent of granulomas remain unidentified. In sarcoidosis, liver granulomas are usually inconspicuous and featureless. They are not associated with symptoms or abnormal physical signs. Sarcoidosis of the liver has three well-recognised clinical syndromes-chronic intrahepatic cholestasis, portal hypertension and the Budd-Chiari Syndrome.

Pulmonary Langerhans' cell granulomatosis (LCG)

Pulmonary Langerhans' granulomatosis (LCG) is characterised by infiltration of peripheral airways by dendritic cell precursors and Langerhans' cells (LC) together with eosinophils and mixed chronic inflammatory cells. Consequent airways destruction commonly leads to cystic changes and frequent pneumothorax. LC's are best identified by the electron microscope finding of Birbeck granules. Immunocytochemical markers are also of value. They are frequent in the early stages though absent in end stage disease. LCG is distinguished from sarcoidosis by the absence of epithelioid cell granulomas, association with heavy cigarette smoking in young males and frequency of pneumothorax. Both diseases show lymphocytosis in bronchoalveolar lavage but differ in that LCG shows a predominance of T-suppressor cells and sarcoidosis an excess of T-helper cells.