Now that people are spending more time outdoors, it is time to watch for ticks.
Ticks are eight-legged arthropods (not insects) that feed on the blood of warm-blooded mammals, birds, reptiles and amphibians. Fish and other aquatic organisms are the only creatures not targeted by ticks.
There are nearly 500 species of ticks found worldwide, but in Maryland there are four predominant species: deer, wood, brown dog and lone star ticks. Each species has a two-year life cycle. The tick begins as an egg, hatches into a larvae, grows into a nymph, then develops into an adult. A tick needs to feed on blood to continue its development from larvae to nymph to adult to egg laying; once the adult tick mates and lays its eggs, it usually dies.
Ticks that feed on a diseased animal can transmit that disease to another creature. Most of our native ticks prefer to hide along woods trails, roads and short grasslands where they will wait for an unsuspecting host to come along.
The wood tick is the largest of the four ticks. It typically overwinters as an adult, laying its eggs in early spring. The larvae and nymphs develop from March to about June and typically feed on small animals like mice and other rodents. The adults, more common from mid June to September, feed on larger animals such as dogs and humans. This tick can spread Rocky Mountain spotted fever and perhaps Lyme disease.
The brown dog tick normally feeds on dogs. It is well-adapted to living indoors and can become a problem in unclean dog kennels. Its life cycle is similar to the wood tick, but the larvae, nymphs and adults feed mostly on dogs.
The deer tick hatches in early spring. The larvae normally feed on small animals. The nymphs emerge in May and June and feed on deer and larger animals such as humans. The nymphs enter a resting state when it becomes warm, then emerge as adults when the weather becomes cooler around September. The adult can stay active from September until early spring, as long as the temperatures are favorable. The deer tick is the most common vector for Lyme disease.
The lone star tick has eggs that hatch in early summer. The small larvae and nymphs normally feed on smaller animals throughout the summer. The nymphs transform to adults over winter and the adult is most active from March to May. It is the adult lone star tick that normally feeds on larger animals. Lone star ticks can transmit a number of diseases, including Rocky Mountain spotted fever and Lyme disease.
Despite these divergent life cycles, it is safe to assume that once the snow is off the ground, there is a good chance that ticks will be around and you need to look out for them.
Have you noticed that stink bugs are leaving homes now? A very noticeable exodus is occurring because the adults are heading outdoors to mate and lay their eggs. Once this is done, they will die. The eggs will hatch and the young nymphs will go through a series of five molts until they develop as adults in late September or early October. Then, once it begins getting cold, they will drop in to visit our homes again.
Article by FCFCDB
Nature Notes for 6/19/2011