Effect of native natural enemies and augmentative releases of Chrysoperla rufilabris Burmeister and Aphidoletes aphidimyza (Rondani) on the population dynamics of the green apple aphid,Aphis poMi De Geer

Abstract

The impact of native natural enemies, supplemented by augmentative releases of the green lacewing, Chrysoperia rufilabris Burmeister (Neuroptera: Chrysopidae), and/or the cecidomyiid, Aphidoletes aphidimyza (Rondani) (Diptera: Cecidomyiidae), on the population dynamics of the green apple aphid, Aphis pomi De Geer (Homoptera: Aphididae), was assessed in a series of experiments conducted in north central Washington State, USA. In one trial, C. rufiabris alone was released at a rate of 200 eggs or first instar larvae per tree per week for 6 weeks; in a second experiment, it was released in combination with A. aphidimyza at rates of 400 eggs and 250 pupae respectively per tree per week. In a final trial, A. aphidimyza alone was released at a rate of 200 pupae per tree per week for the duration of the growing season. The dominant native natural enemies in the study area were Chrysopa nigricornis Burmeister, A. aphidimyza. Onus sp. (Hemiptera: Anthocoridae), and various species of Syrphidae, Chamaemyiidae, and Coccinellidae (principally Coccinelle transversoguttata Faldermann and Hippodamia convergens Guerin). Exclusion cage techniques indicated that this native natural enemy complex caused significant mortality of A. pomi. However, no effect of the augmentative release treatments could be demonstrated, and where plant growth was vigorous and aphid populations high, the numerical response of indigenous generalist predators was insufficient to keep A. pomi densities below damaging levels.     

Histopathology of Infection and Colonization of Susceptible and Resistant Port-Orford-Cedar by Phytophthora lateralis

ABSTRACT Port-Orford-cedar (POC) root disease, caused by Phytophthora lateralis, continues to kill POC in landscape plantings and natural forests in western North America. POC trees resistant to P. lateralis have been identified and propagated. Cytological observations of P. lateralis in susceptible and resistant roots and stems were made with light and transmission electron microscopy to identify resistance mechanisms. No differences in infection pathway and initial colonization were observed between susceptible and resistant roots, although there were differences in the rate and extent of development. Germ tubes formed appressoria, and penetration hyphae grew either between or directly through epidermal cell walls; inter- and intracellular hyphae colonized the root cortex. In susceptible roots, hyphae penetrated into the vascular system within 48 h of inoculation. In contrast, hyphae in roots of resistant seedlings grew more slowly in cortical cells and were not observed to penetrate to the vascular tissues. In resistant roots, infection was marked by general thickening of cortical cell walls, wall appositions around penetrating hyphae, collapse of cortical cells, and accumulation of osmophillic granules around hyphae. In susceptible stems, hyphae grew inter- and intracellularly in all cells of the secondary phloem except fiber cells, but were concentrated in sieve and parenchyma cells in the functional phloem. The pattern of penetration and colonization of hyphae was similar in the resistant stems, except that hyphae were found in the fiber cells of the xylem. In resistant stems, there were fewer hyphae in the functional phloem, and cytological changes such as damaged nuclei and disintegrated cytoplasm were evident. Structural changes in resistant stems included collapsed cells, wall thickening, secretory bodies, apposition of electron dense materials, and crystals in cell walls.     

Liquid chromatographic determination of methocarbamol in injection and tablet dosage forms: collaborative study

A reverse phase liquid chromatographic method was developed for determining methocarbamol in injection and tablet dosage forms. The injections require dilution only; the tablets require a filtration step before introduction into the chromatograph. Response for methocarbamol was linear over the range 0-18 micrograms, using an ultraviolet detector at 274 nm. Recoveries by the author ranged from 96.1 to 101.9% for authentic injection formulations and 98.0 to 101.0% for authentic tablet formulations. A collaborative study of the method by 6 laboratories resulted in standard deviations of 1.70 and 2.22 for injection and tablet dosage forms, respectively. The method has been adopted official first action.     

Efficacy of a novel topical combination of fipronil, amitraz and (S)-methoprene for treatment and control of induced infestations of brown dog ticks (Rhipicephalus sanguineus) on dogs

Four laboratory studies were conducted to demonstrate that a single topical dose of a novel spot-on combination containing fipronil, amitraz and (S)-methoprene (CERTIFECT?, Merial Limited, GA, USA) is efficacious against the brown dog tick, Rhipicephalus sanguineus. In each study, 6-8 male and 6-8 female purpose-bred, laboratory mongrels, terrier cross or Beagles were randomly assigned to one of two study groups (treated and untreated), based on pre-treatment parasite counts. Starting on the day before treatment, each dog was infested weekly with 50 ticks. Ticks were thumb counted at various time points after treatment and weekly infestations starting as early as 6h and continued at 12, 18 and 24h depending on the study. Ticks were removed and counted at 48 h after treatment and weekly infestations. CERTIFECT provided rapid and excellent control of pre-existing and newly acquired infestations of R. sanguineus with efficacy as high as 93% within the first 12h after a single topical treatment. Excellent control (>96%) of R. sanguineus as early as 18 h, following post treatment infestations was maintained for at least 35 days.     

Partially Molten Middle Crust Beneath Southern Tibet: Synthesis of Project INDEPTH Results

INDEPTH geophysical and geological observations imply that a partially molten midcrustal layer exists beneath southern Tibet. This partially molten layer has been produced by crustal thickening and behaves as a fluid on the time scale of Himalayan deformation. It is confined on the south by the structurally imbricated Indian crust underlying the Tethyan and High Himalaya and is underlain, apparently, by a stiff Indian mantle lid. The results suggest that during Neogene time the underthrusting Indian crust has acted as a plunger, displacing the molten middle crust to the north while at the same time contributing to this layer by melting and ductile flow. Viewed broadly, the Neogene evolution of the Himalaya is essentially a record of the southward extrusion of the partially molten middle crust underlying southern Tibet.     

Femoral diaphysis fractures in cattle: 26 cases (1994–2005)

Objective   This retrospective study was conducted to evaluate the outcome for cattle with diaphyseal fractures of the femur, but not including capital physeal injuries.
Methods   Sources of information were medical records of cattle having a definitive diagnosis of diaphyseal femoral fractures and telephone survey of owners.
Results   Medical records for 26 cattle with femoral fracture were found; of the 20 aged less than 2 months, 15 were treated surgically, 4 conservatively (stall rest) and 1 was euthanased without treatment. The surgical treatment varied according to the configuration of the fracture and the surgeon's experience. Surgery for mid-diaphyseal fractures had a significantly better surgical outcome then distal diaphyseal fractures (P < 0.05), as there were significantly fewer postoperative complications. Of the 15 calves treated surgically, 10 were discharged from hospital and 5 were retained in the herd without noticeable lameness. Of the 4 calves treated conservatively, 3 were alive at follow-up, but 2 were still lame. Of the 6 older cattle, 3 were euthanased without treatment and 3 were treated conservatively, 2 of which were alive at follow-up but 1 was still lame.
Conclusion   Conservative treatment of femur fracture in cattle is possible but associated with complications during the convalescence. Continued research is needed to optimise distal diaphyseal fracture stabilisation in young cattle.     

Alkaline phosphatase, leucine aminopeptidase, and alanine aminotransferase activities with obstructive and toxic hepatic disease in cats

The activities of serum alkaline phosphatase (serum ALP), leucine aminopeptidase (serum LAP), and alanine aminotransferase (serum ALT) were determined in 15 cats before and after treatment by 3 methods: common bile duct occlusion, left hepatic duct(s) occlusion, and carbon tetrachloride administration. Significant increases in serum ALP, LAP, and ALT activities occurred in all cats in the 3 groups. Sustained mean increases of ninefold in ALP and 13-fold in LAP occurred in the cats with common bile duct occlusion. Lesser mean increases of these enzymes (fourfold) occurred in the cats with partial biliary occlusion. Transient mean increases (100-fold) in ALT occurred in the carbon tetrachloride-treated cats. Urine ALP excretion was measured in 3 cats with common bile duct occlusion. There was no significant difference between rates of urine ALP excretion before and after common bile duct occlusion. Specific ALP activities of hepatic extracts from normal cats and biliary-obstructed cats were compared. Mean specific activity was onefold higher in liver from cats with common bile duct occlusion of 21 days' duration. The findings in the present studies were interpreted to indicate that serum ALP and LAP are useful to detect biliary occlusive disease in cats and, in conjunction with serum ALT, may be used to differentiate primary hepatodegenerative disease and biliary occlusive disease.     

Chlamydia and Chlamydiales: more than meets the eye

This review summarizes the dramatic changes that have occurred in the taxonomy of bacteria known as Chlamydia. Best known for the diseases they cause in humans, these intracellular bacteria also comprise many species that are responsible for a wide variety of clinically and economically important diseases in livestock and companion animals. The old taxonomy grouped most of these species into C. psittaci because systematic methods for routinely distinguishing them were not available. DNA-based testing methods are now available that distinguish different chlamydial families, genera, and species. This summary reviews these tests and a number of oligonucleotide primers that distinguish these groups using PCR and PCR-RFLP. DNA-based methods are also being used to discover new families of chlamydia-like bacteria, at least one of which is responsible for abortion in cattle (Waddlia chondrophila). This review summarizes the pathogenic roles of the Chlamydiaceae, new families, and individual species within the order Chlamydiales. These discoveries create opportunities for veterinarians to carry out epidemiological studies of chlamydiae that previously were not possible.