The Pennsylvania Vector Control Association the Pennsylvania Vector Spreading News to the Vector Control Community
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The Pennsylvania Vector Control Association The Pennsylvania Vector Spreading News to the Vector Control Community Volume 11, Issue 3 November 1, 2013 Inside this issue: Sylvatic Plague Immunization Moose Die-off Alarms 2 in Black-footed Ferrets and Prairie Dogs Scientists Submitted by Tom Smith What’s Up: Region 1 4 What’s Up: Region 2 4 Sylvatic plague is a bacterial disease cines are not practical for field use in free- of wild rodents that is transmitted by ranging animals, such as prairie dogs. Ulti- What’s Up: Region 3 6 fleas. It can afflict numerous species mately, management of the disease in fer- What’s Up: Region 4 6 of mammals, including humans. Prai- rets will depend on managing the disease in What’s Up: Region 5 7 rie dogs are highly susceptible to prairie dogs. plague and are the primary food Currently, efforts to halt the spread of What’s Up: Region 6 7 source of the highly endangered plague rely on dusting individual prairie dog Biotech Weapons 8 black-footed ferret, which is also sus- burrows with pesticides that kill plague- Against Dengue Fever Mosquitoes Proves ceptible to the disease. Sylvatic infected fleas, but pesticide application is Controversial plague can decimate prairie dog colo- labor intensive, costly and difficult to sus- nies, with mortality rates of 90 per- tain over time. Why Do Mosquitoes 11 Bite Some People More cent or more, resulting in local extinc- Than Others? tions and population reductions. Be- Sylvatic Plague Vaccine (SPV) cause of the susceptibility of prairie Immunizing entire populations of free- Pest Control Firms 12 Turn to the Dogs to dogs to sylvatic plague, coupled with ranging prairie dogs and other rodents is Fight Bed Bugs the potentially devastating effect the highly challenging, but preliminary NWHC disease can have on black-footed fer- studies indicate prairie dogs can be success- Northeast IPM Partner- 13 ship Grants rets, plague control is a vital concern fully immunized by voluntarily eating vac- for ferret recovery programs and con- cine-laden baits. These studies suggest that Growing Numbers of 14 Bed Bugs, Mosquitoes servation efforts. plague in prairie dogs could be managed and Tick are Spreading Scientists at the USGS National Wild- through oral immunization, which would be Misery and Frustrating life Health Center (NWHC), in collabo- especially useful in areas where black- ration with colleagues at the Universi- footed ferrets reside and in populations of Sustaining Members 16- ty of Wisconsin, state agencies, and prairie dogs of conservation concern. Advertising 21 other Federal agencies, have tested (Continued on page 3) Presidents Corner 22 the feasibility of vaccinating black- Editor’s Corner 22 footed ferrets and prairie dogs against sylvatic plague infections. The Special points of interest: plague vaccine was developed for humans by the U.S. Army Medical 2013 Pennsylvania State Report on page 10 Research Institute for Infectious Dis- ease and is being tested for use on Mini-Monster iPad App animals at the USGS National Wildlife on page 13 Health Center. Vaccination of ferrets Calendar of upcoming by injection was shown to be highly events on page 17 successful both in the laboratory and in the field. However, injectable vac- VOLUME 11, ISSUE 3 THE PENNSYLVANIA VECTOR PAGE 2 Moose Die-Off Alarms Scientists Submitted by Louise Bugbee CHOTEAU, Mont. — Across North “Something’s changed,” said Nicholas spend part of their life cycles in America — in places as far-flung as DeCesare, a biologist with the Mon- snails, which thrive in moist environ- Montana and British Columbia, New tana Department of Fish, Wildlife and ments. Hampshire and Minnesota — moose Parks who is counting moose in this Another theory is heat stress. Moose populations are in steep decline. part of the state — one of numerous are made for cold weather, and And no one is sure why. efforts across the continent to meas- when the temperature rises above Twenty years ago, Minnesota had ure and explain the decline. “There’s 23 degrees Fahrenheit in winter, as two geographically separate moose fewer moose out there, and hunters has happened more often in recent populations. One of them has virtu- are working harder to find them.” years, they expend extra energy to ally disappeared since the 1990s, What exactly has changed remains a stay cool. That can lead to exhaus- declining to fewer than 100 from mystery. Several factors are clearly at tion and death. 4,000. work. But a common thread in most In the Cariboo Mountains of British The other population, in northeast- hypotheses is climate change. Columbia, a recent study pinned the ern Minnesota, is dropping 25 per- Winters have grown substantially decline of moose on the widespread cent a year and is now fewer than shorter across much of the moose’s killing of forest by an epidemic of 3,000, down from 8,000. (The range. In New Hampshire, a longer fall pine bark beetles, which seem to moose mortality rate used to be 8 with less snow has greatly increased thrive in warmer weather. The loss percent to 12 percent a year.) As a the number of winter ticks, a devas- of trees left the moose exposed to result, wildlife officials have sus- tating parasite. “You can get 100,000 human and animal predators. pended all moose hunting. ticks on a moose,” said Kristine Rines, In Smithers, British Columbia, in Here in Montana, moose hunting a biologist with the state’s Fish and April, a moose — starving and se- permits fell to 362 last year, from Game Department. verely infested with ticks— wan- 769 in 1995. In Minnesota, the leading culprits are dered into the flower section of a brain worms and liver flukes. Both Safeway market. It was euthanized. Moose dies after B.C. Safeway stroll. Unregulated hunting may also play a role in moose mortality. So may wolves in Minnesota and the West. Scientists and officials say other fac- tors could still emerge. Because most moose die in the fall, the next few months may provide insight. “It’s complicated because there’s so many pieces of this puzzle that could be impacted by climate change,” said Erika Butler, until recently the wildlife veterinarian at the Minneso- ta Department of Natural Resources. (Continued on page 3) VOLUME 11, ISSUE 3 THE PENNSYLVANIA VECTOR PAGE 3 The stakes go beyond the moose “If the heart stops beating, it sends a But then, so are moose. The animals themselves. The animals are ecosys- text message to our phone that says, were hunted out of existence during tem engineers; when they browse ‘I’m dead at x and y coordinates,’ ” Colonial times; they returned to the shrubs, for example, they create said Dr. Butler, who leads the study. state only in the 1970s. habitat for some nesting birds. The messages are monitored around While deer have evolved to an eco- And moose contribute to the econo- the clock; when a moose dies, a team logical balance with ticks, moose my. In New Hampshire, for instance, on call rushes to the scene by car or have not. moose-watching tourism is a $115- helicopter. Deer are grooming animals, so they million-a-year business, according to The winter tick problem in New are able to keep tick numbers fairly Ms. Rines. Hunting permits also gen- Hampshire is particularly vexing. The low. By contrast, said Ms. Rines, the erate revenue. animals lose so much blood they can biologist, “moose didn’t evolve with Moose deaths are hard to study, become anemic. Worse, the ticks ticks, and they don’t groom them scientists say. The moose is a mem- drive the moose crazy; they constant- off.” That has led to swarms of ticks. ber of the deer family, but unlike ly scratch, tearing off large patches of The solution to the tick problem deer it is a solitary animal that does hair. might be, paradoxically, more moose not run in herds, so it can be hard to Some moose lose so much hair they hunting. “It’s up to the public,” she track. Moreover, moose have such look pale, even spectral; some people said. “We could kill more if we want high levels of body fat that they de- call them “ghost moose.” When it healthy moose.” compose rapidly; after 24 hours, a rains in the spring, the moose, de- necropsy has little value. prived of their warm coats, then be- Article by: Mark Keech, right, a In January, Minnesota started an come hypothermic. research biologist, and Tiffany unusual $1.2 million study using ad- Winter ticks hatch in the fall and Wolf, a veterinarian, fitted a vanced monitoring technology to begin to climb aboard their host. moose with a radio collar and took find moose as soon as they die. Live They are dormant until January or samples as part of a Minnesota animals are captured and fitted with February, when they start to feed, study of why the animals die. collars that give their location every molt into adults and then drop off. By JIM ROBBINS 15 minutes, and they are given feed Moose spend a lot of time feeding in Published: October 14, 2013 containing a tiny transmitter that lakes, but wading in water doesn’t Photo Credit: Brian Peterson/ remains in the body and monitors drown the ticks, which form an air Minneapolis Star Tribune heart rate and temperature. Then bubble that allows them to survive the moose are released back into immersion in water. the wild. New Hampshire’s winter tick problem is a relatively recent phenomenon. (Continued from page 1) ing with USDA’s Center for Veterinary the occurrence of plague outbreaks The Sylvatic Plague Vaccine Subcom- Biologics to register SPV for use in the and thus to enhance ferret recovery mittee of theBlack -footed Ferret field.