The effect of the door-to-door tickler chain on the catch-rate of plaice (Pleuronectes platessa L.) taken by an otter trawl

1974 ◽  
Vol 35 (2) ◽  
pp. 210-212 ◽  
Author(s):  
F. R. H. Jones ◽  
P. Scholes
Author(s):  
M. R. Clarke ◽  
P. L. Pascoe ◽  
L. Maddock

The effect of two 70 W underwater electric lamps on the catch rate of a commercial bottom otter trawl was determined by comparative trials both at night and in daylight. It was found that, although the overall numbers and weights of fish caught did not differ, most of the species which were caught in large enough numbers for a judgement to be made showed a reaction to light. Three species, Trachurus trachurus, Merlangius merlangus and Trisopterus minutus were attracted and four species, Eutriglagurnardus, Micromesistius poutassou, Merluccius merluccius and Limanda limanda were scared off by light.The possible use of lights to further the development of selective commercial bottom trawling by attracting or scaring particular species is discussed.


2019 ◽  
Vol 35 (3) ◽  
pp. 645-654 ◽  
Author(s):  
Marc Eskelund ◽  
Caroline Methling ◽  
Peter Vilhelm Skov ◽  
Niels Madsen

Insects ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 207 ◽  
Author(s):  
Rachael Horner ◽  
Georgia Paterson ◽  
James T.S. Walker ◽  
George L.W. Perry ◽  
Rodelyn Jaksons ◽  
...  

Codling moth, Cydia pomonella (Lepidoptera: Tortricidae), is a phytosanitary pest of New Zealand’s export apples. The sterile insect technique supplements other controls in an eradication attempt at an isolated group of orchards in Hawke’s Bay, New Zealand. There has been no attempt in New Zealand to characterize potential sources of uncontrolled peri-urban populations, which we predicted to be larger than in managed orchards. We installed 200 pheromone traps across Hastings city, which averaged 0.32 moths/trap/week. We also mapped host trees around the pilot eradication orchards and installed 28 traps in rural Ongaonga, which averaged 0.59 moths/trap/week. In Hastings, traps in host trees caught significantly more males than traps in non-host trees, and spatial interpolation showed evidence of spatial clustering. Traps in orchards operating the most stringent codling moth management averaged half the catch rate of Hastings peri-urban traps. Orchards with less rigorous moth control had a 5-fold higher trap catch rate. We conclude that peri-urban populations are significant and ubiquitous, and that special measures to reduce pest prevalence are needed to achieve area-wide suppression and reduce the risk of immigration into export orchards. Because the location of all host trees in Hastings is not known, it could be more cost-effectively assumed that hosts are ubiquitous across the city and the area treated accordingly.


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