The potential for monitoring and control of insect pests in Southern Hemisphere forestry plantations using semiochemicals

Context

Southern Hemisphere plantation forestry has grown substantially over the past few decades and will play an increasing role in fibre production and carbon sequestration in future. The sustainability of these plantations is, however, increasingly under pressure from introduced pests. This pressure requires an urgent and matching increase in the speed and efficiency at which tools are developed to monitor and control these pests.

Aim

To consider the potential role of semiochemicals to address the need for more efficient pest control in Southern Hemisphere plantations, particularly by drawing from research in other parts of the world.

Results

Semiochemical research in forestry has grown exponentially over the last 40?years but has been almost exclusively focussed on Northern Hemisphere forests. In these forests, semiochemicals have played an important role to enhance the efficiency of integrated pest management programmes. An analysis of semiochemical research from 1970 to 2010 showed a rapid increase over time. It also indicated that pheromones have been the most extensively studied type of semiochemical in forestry, contributing to 92% of the semiochemical literature over this period, compared with research on plant kairomones. This research has led to numerous applications in detection of new invasions, monitoring population levels and spread, in addition to controlling pests by mass trapping or disrupting of aggregation and mating signals.

Conclusion

The value of semiochemicals as an environmentally benign and efficient approach to managing forest plantation pests in the Southern Hemisphere seems obvious. There is, however, a lack of research capacity and focus to optimally capture this opportunity. Given the pressure from increasing numbers of pests and reduced opportunities to use pesticides, there is some urgency to develop semiochemical research capacity.     

Ecological role of the giant root‐rat (Tachyoryctes macrocephalus) in the Afroalpine ecosystem

Rodents with prevailing subterranean activity usually play an important role in the ecosystems of which they are a part due to the combined effect of herbivory and soil perturbation. This is the case for the giant root‐rat Tachyoryctes macrocephalus endemic to the Afroalpine ecosystem of the Bale Mountains, Ethiopia. We studied the impact of root‐rats on various ecosystem features within a 3.5‐ha study locality dominated by Alchemilla pasture, which represents an optimal habitat for this species, in 2 periods of a year. The root‐rats altered plant species composition, reducing the dominant forb, Alchemilla abyssinica, while enhancing Salvia merjame and a few other species, and reduced vegetation cover, but not the fresh plant biomass. Where burrows were abandoned by root‐rats, other rodents took them over and A. abyssinica increased again. Root‐rat burrowing created small‐scale heterogeneity in soil compactness due to the backfilling of some unused burrow segments. Less compacted soil tended to be rich in nutrients, including carbon, nitrogen and phosphorus, which likely affected the plant growth on sites where the vegetation has been reduced as a result of root‐rat foraging and burrowing.     

Safety and immunogenicity of ERA strain of rabies virus propagated in a BHK-21 cell line.

The ERA strain of rabies virus was propagated in a baby hamster kidney cell line (BHK-21/C13). The viral titer was 10(1.8) tissue culture infective doses (TCID) higher than that of commercial ERA vaccine. The ERA/BHK-21 vaccine in baits retained titers of 10(6.3) to 10(6.4), TCID when subjected to daily temperature fluctuations from 9 degrees C to 24 degrees C for 21 days. This titer, according to a dose response in laboratory foxes, was still capable of immunizing up to 100% of foxes consuming a bait. The ERA/BHK-21 vaccine, when presented in baits, produced antibodies in 80 to 100% of dogs consuming more than one bait. Duration of immunity in foxes, from feeding the ERA strain rabies virus in baits, as determined by resistance to challenge with virulent virus, was at least 48 months. The vaccine strain retained some pathogenicity for nontarget species. In tests carried out on foxes, raccoons, dogs, cats and cattle, the vaccine did not cause vaccine-induced rabies. One of 14 skunks which consumed four baits developed vaccine-induced rabies, but virus could not be isolated from the salivary glands of this animal. The vaccine, when presented in baits, caused vaccine-induced rabies in 37% of laboratory mice, 3.4% of Microtus and 2.6% of Peromyscus species. Rabies virus could not be isolated from the salivary glands of rodents with vaccine-induced rabies. It was concluded that ERA virus propagated in BHK-21/C13 cells and incorporated in an acceptable bait produced a high titer, stable, immunogenic and safe vaccine for foxes.     

A study on the possible role of chymotrypsin in the aetiology of equine chronic obstructive pulmonary disease (COPD)

The chymotrypsin activity of seven batches of Micropolyspora faeni and of five batches of Aspergillus fumigatus culture extracts, prepared for inhalation challenge in horses, was assayed and was found to range between 0.29 and 1.45 units/mg protein and 0.02 and 0.20 units/mg protein respectively. Horses affected with chronic obstructive pulmonary disease (COPD) were challenged with two batches of each antigen which had different chymotrypsin activities and no significant correlations were found between the degree of response to challenge and the chymotrypsin activity of the antigens. Inhalation of two doses of nebulised, purified chymotrypsin over 4 days did not induce signs of respiratory disease in COPD-affected horses. However, repeated chymotrypsin inhalations after an interval of 3 weeks caused an exacerbation of signs of COPD in one horse. These studies suggest that, although repeated inhalation of purified chymotrypsin may induce respiratory hypersensitivity in horses, the chymotrypsin-like enzymes of M. faeni and A. fumigatus do not play a major role in the precipitation of clinical signs of equine COPD.     

Simple radiography as an aid to the diagnosis of heart disease in the dog

Abstract— —The intention of this paper is to show how simple, plain radiography of the thorax can be a useful aid to the diagnosis of heart disease in the dog. The only radiographic changes that will be discussed are those that can be demonstrated on lateral and dorso-ventral radiographs of the thorax which are easily obtainable by any veterinary surgeon with a reasonable X-ray machine. The use of intravascular and intracardiac contrast media and other of the more complex techniques which have been evolved to demonstrate cardiac structure and function in detail will not be discussed. Résumé— —Le but de ce compte-rendu est de démontrer que la simple radiographie du thorax peut être une aide utile à la diagnose de maladie de coeur chez le chien. Les seuls changements radio-graphiques qui seront discutés sont ceux qui peuvent être démontrés sur des radiographies latérales et dorso ventrales du thorax qui sont facilement obtenables par un chirurgien vétérinaire avec une machine moyenne de Rayons-X. L'emploi du moyenne de contraste intavasculaire et intracardiaque et d'autres techniques plus complexes qui sont issues pour démontrer la structure et la fonction cardiaque en détails ne sera pas discuté. Zusammenfassung— —Der Zweck dieser Abhandlung ist vorzuführen, wie einfache, unkomplizierte Röntgenphotographie des Brustkorbes einen nützlichen Beitrag zue Diagnose von Herzfehlern bei Hunden leisten kann. Es werden nur solche röntgenologischen Veränderungen besprochen, die auf seitlichen und dorsoventralen Röntgenbildern des Brustkorbes nachgewiesen werden können und deren Aufnahme ganz leicht von jedem tierärztlichen Chirurgen mit einem passablen Röntgen-apparat gemacht werden können. Die Verwendung von intravaskulären und intrakardiologischen Kontrastmitteln und anderen komplizierteren Methoden, die für eine ausführliche Demonstration der Herzstruktur und Funktion entwickelt wurden, wird nicht besprochen.     

Production and physical characteristics of composted poultry carcases

1. Experiments were designed to determine whether composting could be a safe and effective method for the disposal of poultry carcases in the UK climate. Laying hen carcases (125) were composted in a wooden compost bin over autumn and winter months, using the United States Department of Agriculture method. 2. The process took 8 weeks and effectively decomposed the carcases to leave only leg and breast bones. The compost was turned once, which ensured that all the material reached the high temperatures (60 degrees to 70 degrees C) required to control pathogens. Salmonella was fully heat-inactivated, indicating that many poultry-associated bacterial pathogens would also have been inactivated. 3. It is concluded that this method is suitable for use in the UK and provides a sanitised fertiliser supplement.