Biology of the leech Actinobdella inequiannulata Moore, 1901 (Annelida: Hirudinea: Rhynchobdellida: Glossiphoniidae), parasitic on the white sucker, Catostomus commersoni Lacepede, 1803, and the longnose sucker, Catostomus catostomus Forster, 1773, in Algonquin Provincial Park, Ontario, Canada

Actinobdella inequiannulata was found on the white sucker. Catostomus commersoni, and less frequently on the longnose sucker, Catostomus catostomus, in Algonquin Provincial Park, Ontario, Canada. Catostomus commersoni parasitized with Act. inequiannulata was collected from July to October 1973 and May to October 1974. In May and October, less than 3% of the fish carried leeches. In July, 80% of the fish were parasitized with an average of 1.5 leeches/fish. Observations on leech weight suggest that young leeches attach to fish from May to September, some mature in July, and a second generation of leeches reparasitize the fish in August and September. The mean size of leeches on suckers increased from May until July, after which the size remained relatively constant. Leeches produced characteristic lesions on the opercula of suckers. Fully developed lesions on fish opercula produced by aggregated leeches had varying amounts of central erosion, extravasation, dermal and epidermal hyperplasia, and necrosis.

Discrimination among host plants (Leucaena species and accessions) by the psyllid pest Heteropsylla cubana and implications for understanding resistance

1 The herbivorous bug Heteropsylla cubana Crawford (Homoptera: Psyllidae) is a pest of the cattle fodder crop Leucaena (Leguminosae: Mimosoideae). The interaction between the psyllid and three varieties of its Leucaena host plant was investigated in relation to the apparent resistance of some Leucaena varieties (Leucaena leucocephala, Leucaena pallida and their hybrids) to attack. 2 Field trials demonstrated that adult psyllids distinguished among the different varieties of Leucaena over a distance, and were attracted to L. leucocephala in significantly higher numbers than to L. pallida or to the hybrid. Pesticide treatment increased the attractiveness of Leucaena plants, even of those deemed to be psyllid resistant. Numbers of psyllid eggs and nymphs, sampled in the field, reflect the arrival rates of adults at the three plant varieties. 3 Wavelength reflectance data of the three Leucaena varieties were not significantly different from one another, suggesting that psyllids cannot discriminate among the three plants using brightness or wavelength cues. There was a differential release of caryophyllene among the three varieties. Release of caryophyllene in L. leucocephala and the hybrid appeared to be influenced by environmental conditions. 4 Experiments demonstrated that caryophyllene (at least on its own) did not influence the behaviour of leucaena psyllids in relation to leucaena plants. 5 The results suggest that host plant volatiles cannot be dismissed as significant in the interaction between the leucaena psyllid and its Leucaena host plants. Further avenues for investigation are recommended and these are related to novel ways of understanding resistance in insect plant inter-relationships.

Isolation and characterization of microsatellite loci from mother-of-millions, Bryophyllum delagoense (Crassulaceae), and its hybrid with Bryophyllum daigremontianum, 'Houghton's hybrid'

Nine microsatellite loci were developed, and are transferable, across the Madagascan succulents Bryophyllum daigremontianum, Bryophyllum delagoense (mother-of-millions) and their horticultural hybrid (Houghton's), from enriched libraries of the later two species. For B. delagoense, a tetraploid, three to 13 alleles per locus were found for native Madagascan (H-O = 0.4-1.0), and one to nine in invasive Australian (H-O = 0.0-1.0) samples. In addition for 91 Australian samples, only five multilocus genotypes were found (95% of individuals were of two genotypes), suggesting extensive clonality in its introduced range. These loci will be used to examine genetic diversity, hybrid origin and mating system in natural and introduced populations.

Increasing the efficacy of Judas goats by sterilisation and pregnancy termination

The use of Judas goats to locate remnant animals is a potentially powerful tool for enhancing goat-eradication efforts, which are especially important to island conservation. However, current Judas goat methodology falls short of its potential efficacy. Female Judas goats are often pregnant at the time of deployment or become impregnated in the field; pregnant females leave associated goats to give birth, causing downtime of Judas goat operations. Further, male Judas goats may inseminate remnant females. Sterilising Judas goats prior to deployment removes these inefficiencies. Here, we describe two methods (epididymectomy for males and tubal occlusion for females) that sterilise Judas goats while still maintaining sexual motivation and other behaviours associated with intact animals. These surgeries are straightforward, time efficient, and may be conducted in the field by staff with minimal training. Given the widespread and deleterious impacts of non-native herbivores to ecosystems and the importance of Judas operations in detecting animals at low densities, sterilisation and termination of pregnancy should be applied routinely in Judas goat (and possibly other species) programs to increase the efficacy of low-density control operations and eradication campaigns.

Clinical effects of stings by sponges of the genus Tedania and a review of sponge stings worldwide

Contact with sponges (Phylum Porifera) usually results in minimal effects or abrasions, except for species that produce crinitoxins and can cause irritation and dermatitis. There are few reports of sponge stings, mainly in divers or collectors. We report a group of sponge stings from handling flame red/orange sponges on the beach, confirmed to be Tedania anhelans in five cases. All seven patients suffered immediate effects ranging from mild to severe pain, and local inflammation. A 38-year-old female and three children had delayed skin involvement including itchiness, pain, swelling and redness. Blistering and desquamation occurred in the female adult and limited desquamation in one child. Similar delayed effects have been reported in Tedania spp. stings previously. (c) 2005 Elsevier Ltd. All rights reserved.

Clinical signs and duration of cyanide toxicosis delivered by the M-44 ejector in wild dogs

Sodium cyanide poison is potentially a more humane method to control wild dogs than sodium fluoroacetate (1080) poison. This study quantified the clinical signs and duration of cyanide toxicosis delivered by the M-44 ejector. The device delivered a nominal 0.88 g of sodium cyanide, which caused the animal to loose the menace reflex in a mean of 43 s, and the animal was assumed to have undergone cerebral hypoxia after the last visible breath. The mean time to cerebral hypoxia was 156 s for a vertical pull and 434 s for a side pull. The difference was possibly because some cyanide may be lost in a side Pull. There were three distinct phases of cyanide toxicosis: the initial phase was characterised by head shaking, panting and salivation; the immobilisation phase by incontinence, ataxia and loss of the righting reflex; and the cerebral hypoxia phase by a tetanic seizure. Clinical signs that were exhibited in more than one phase of cyanide toxicosis included retching, agonal breathing, vocalisation, vomiting, altered levels of ocular reflex, leg paddling, tonic muscular spasms, respiratory distress and muscle fasciculations of the muzzle.

Development of an animal repellent - selection, efficacy and presentation

Under some circumstances it may be desirable to repel herbivorous pests (e. g. goats and wallabies) from plants (e. g. horticultural or forestry seedlings) rather than to kill them. These circumstances may include using these animals as a resource at a later time, and there may also be welfare, public perception or legislative issues where repelling animals from particular plants or area is preferable to killing them. The first experiment tested the efficacy of 5 different materials (tiger fecal extract, maggot brew-the liquid exudate from a flyblown goat, capsaicin, dog urine, and burnt goat hair, skin and carcass+fat) to repel groups of goats in a feedlot pen from 1 trough of feed when another trough of feed was available to them to eat. Each repellent was tested on 5 groups of mixed age female goats for periods of 3 days. All 5 groups were exposed to the 5 repellents. Both tiger fecal extract and maggot brew reduced intake of feed from the 'protected' feed trough and significantly (P < 0.05) delayed 'normal' feeding behaviour by more than 5 h from that trough. The repellents became less effective with repeated use even with different groups of goats. The reduction in effectiveness was indicated by higher intakes of feed and earlier feeding from the protected trough. This habituation to the repellents, where the effectiveness is reduced with repeated exposure, is of concern. In the second experiment, we selected the most effective repellent (tiger fecal extract) and tested its efficacy under similar conditions, after the repellent had been mixed with a carrier (bentonite) in an endeavour to increase the duration of its effectiveness. This repellent was significantly more effective in repelling groups of 3 goats in a feedlot pen from 1 trough of feed for 3 days, when another trough of feed was available to them to eat.

Predicting population dynamics of weed biological control agents: science or gazing into crystal balls?

Various factors can influence the population dynamics of phytophages post introduction, of which climate is fundamental. Here we present an approach, using a mechanistic modelling package (CLIMEX), that at least enables one to make predictions of likely dynamics based on climate alone. As biological control programs will have minimal funding for basic work (particularly on population dynamics), we show how predictions can be made using a species geographical distribution, relative abundance across its range, seasonal phenology and laboratory rearing data. Many of these data sets are more likely to be available than long-term population data, and some can be incorporated into the exploratory phase of a biocontrol program. Although models are likely to be more robust the more information is available, useful models can be developed using information on species distribution alone. The fitted model estimates a species average response to climate, and can be used to predict likely geographical distribution if introduced, where the agent is likely to be more abundant (i.e. good locations) and more importantly for interpretation of release success, the likely variation in abundance over time due to intra- and inter-year climate variability. The latter will be useful in predicting both the seasonal and long-term impacts of the potential biocontrol agent on the target weed. We believe this tool may not only aid in the agent selection process, but also in the design of release strategies, and for interpretation of post-introduction dynamics and impacts. More importantly we are making testable predictions. If biological control is to become more of a science making and testing such hypothesis will be a key component.

Use of CLIMEX modelling to identify prospective areas for exploration to find new biological control agents for prickly acacia

Selection of biocontrol agents that are adapted to the climates in areas of intended release demands a thorough analysis of the climates of the source and release sites. We present a case study that demonstrates how use of the CLIMEX software can improve decision making in relation to the identification of prospective areas for exploration for agents to control the woody weed, prickly acacia Acacia nilotica ssp. indica in the arid areas of north Queensland.