To the Editor:
Ticks are a year-round problem but not everyone is aware of this. It is important to have as much knowledge as possible about this growing danger as they can carry a multitude of diseases with Lyme being just one. Ticks can be found in every part of Nova Scotia, some areas are higher risk than others. I have put this information out in the past about the life cycle of the black-legged tick but I feel it is always good to refresh people and start them thinking about it again.
The black-legged tick is a three-host parasite with a three- to four-year life cycle. Eggs that are laid in the first spring can hatch into six-legged larvae during the spring as well as other times of the year. Some larvae feed in the first year and some overwinter without feeding and feed the next year. They tend to stay close to the egg mass and attach to a small host such as a mouse or other small mammals.
Larvae can be active from June to September, with their peak activity in August. After feeding, they molt into the eight-legged nymph stage and remain inactive through the first winter, emerging during the second spring.
Nymphs become active and attach to medium-sized mammals from May on into September. The nymphs then drop off and molt to the adult. All these times are approximate as ticks are poor time keepers.
Adult ticks seek a third and final larger host such as deer, in late September and peak in October and April. The male tick will take a small blood meal whereas the female takes a larger blood meal to help ripen her eggs. The adult can be found from September to May depending on the weather.
Putting things in a simplified form the life cycle goes like this. Eggs hatch in spring, larvae active June to September, and molt to nymphs which are active May to September and then molt to adults which can be found from September to May. If no host is found the ticks wait until there is a host.
After mating, the female drops to the ground and lays about 3,000 eggs in the leaf litter at the end of the second summer to complete the multi-year cycle. If the adult tick is unsuccessful in mating, it will remain dormant in the leaf litter until temperatures begin to rise above 4 degrees Celsius to try again.
Feeding/attachment time for larvae and nymphs is about four to seven days and adults can feed for six to 10 days; black legged ticks are slow feeders. The idea that the tick must be attached for 24 to 48 hours has only been tested on animals; there is NO scientific proof to show this is so for humans. There is also contradictory evidence showing transmission in less than 24 hours when a tick is re-feeding after being groomed off or disliking its first host.
No tick bite is good! The host during any of the tick’s stages of development can be human; it is about being in the wrong place at the right time for the tick to climb on board.
These ticks from established areas can spread out at a rate of 35 to 55 kilometres per year with an average of 46 kilometres. An individual tick will only move a few meters on its own during its lifetime but with the assistance of birds, mice, deer and other mammals travel out in the environment.
It is important to be aware that these ticks are out there questing and waiting for their next blood meal. So don’t let it be you!
Education is key!