Data from the MV Tick Programs 2018 yard surveys clearly document the spread and increase in numbers of lone star tick nymphs and adults. In addition, I have been receiving a disturbing number of reports about people who have encountered lone star larvae, primarily from Chappaquiddick and up-Island.

Female lone star ticks can lay as many as 5,000 eggs. Unlike deer ticks, when the lone star larvae hatch they do not disperse but tend to stay in clusters on vegetation. When an unlucky person (or other animal) brushes against this cluster, hundreds of tiny ticks move onto the person. In my experience, the larval clusters seem to occur about shin height, so they tend to end up between the ankle and the knee. Although the larvae are tiny, they move very quickly and tend to bite as soon as they encounter bare skin.

If the unlucky person has not taken proper precautions they can end up with hundreds of tick bites in a matter of minutes. The silver lining is that since the larvae have not fed yet, most do not carry any illnesses that can be transferred to humans. However, recent research indicates that a small percentage of may carry disease organisms transferred directly from the mother to the larvae, so we need to monitor this situation closely.

The bad news is that the bites itch terribly for a long time, as much as six weeks in some reports. Because of the number of bites and the fierce itching, many people believe they have gotten into chiggers, however as far as I know there are no chiggers on the Vineyard.

We have not had enough experience with lone star larvae on the Vineyard to know precisely when they are active. But it is clear that they are present in August and September and possibly well into October. We are also still learning about their habitat, but I have encountered larvae in tall grass and brush and lone star ticks seem to be partial to cedars, pitch pines and possibly other conifers.

The best way to avoid lone star larval bites is to wear long pants, tucked into your socks, both treated with permethrin. You can buy clothing pretreated with permethrin or purchase the spray and do your own clothes.

I like the Insect Shield brand of clothing, which can be purchased online or at outdoor stores. The treated socks are available on-Island at Basics in Oak Bluffs and Brickman’s in Vineyard Haven. If it is still shorts season, the next best thing is to spray your legs, feet and footwear with a good repellent; traditionally products that contain 25 per cent deet have been considered the most effective. Recently several plant-based products have been developed that seem to offer promise, including BioUD, Nookatone and a combination of essential oils.

For more information about these plant-based repellents, see the Center for Disease Control website at cdc.gov/lyme/prev/natural-repellents.html. 

Richard Johnson is an Island biologist who leads the Martha's Vineyard tick-borne illness reduction program.