Raspberry

Black raspberries turn from red to black when fully ripe

Common Name: Raspberry, Black raspberry (photo above. Note that black raspberries are initially red), Blackcap, Thimbleberry, Framboisier noir (Quebec) – The etymology of raspberry is uncertain. One hypothesis is that it is simply a combination of rasp in the sense of being rough or harsh from French rasper, to scrape together. An alternative origin is from raspis, a sweet red wine popular in Europe in the Middle Ages. Berry is from beri, a Germanic word for grape. The red raspberry is also known as European red raspberry.

Scientific Name: Rubus occidentalis (black raspberry) and Rubus idaeus (red raspberry) – Rubus is Latin for bramble-bush and, by extension, blackberry. The species occidentalis is from the Latin occidens meaning to go down or set, generally used to refer to the western hemisphere. The Black raspberry is indigenous to eastern North America where it was first classified. The species idaeus refers to Mount Ida in Asia Minor, where red raspberries originated.

Potpourri: The ubiquitous raspberry was indisputably one of the first plants to be recognized as a source of food for many animals, especially the naked apes that eventually evolved to Homo sapiens about 60,000 years ago. The prominently colorful berries, raspberry red in Eurasia where they originated, stood out from the verdant foliage, a distinction unseen by other mammals lacking the red vision of primates. Raspberries were almost certainly spread globally by migrating birds where new species arose as a result of evolutionary diverse habitats. In its current bramble form, raspberries resist consumption of its growing plant parts with conspicuous thorny outgrowths characteristic of its Rose Family taxonomy. Growing in dense thickets from root extensions called rhizomes, brambles like raspberry produce copious quantities of enticing berries to perpetuate its dominance in open, sunny areas. Black raspberries form impenetrable hedges along many trails, offering a succulent snack and an occasional prick to passing hikers.

Raspberries are aggregate fruits with prickles

Raspberries are not berries and they do not have thorns. The fruit is an aggregate, and the sharp-pointed protuberance is a prickle. The use of berry for any small, roundish fruit is as fraught in common parlance as the distinction between fruits and vegetables. A fruit is “a ripened ovary and its contents together with any adjacent parts that may be fused to it.” Fruits are the seed carriers of propagation. Grains like barley, vegetables like peas, and nuts like acorns are fruits. A fruit “in which the entire ovary ripens into a fleshy, often juicy and edible” is the botanist’s berry, inclusive of tomatoes, eggplant, red peppers, and watermelons. A drupe is different, having a layered ovary that gives rise to a central stone or pit that encloses the seed, like plums and peaches. Raspberries arise from flowers with multiple pistils (central organ of a flower), each producing a small drupe, sometimes called a drupelet. The multiple small fruits cling together, separating as a single unit that is called an aggregate. Rasp-aggregate would be a more correct name, but hardly useful. Spines, thorns, and prickles are all sharp-pointed outgrowths from a plant surface that evolved to repel herbivores. Spines like those on barberries originated from leaves. Thorns like those on Osage orange arose from branches. Prickles like those on raspberries are the real stickers, emerging directly from stem tissues. [1]

Raspberries are classified as members of Rosaceae, the family of roses in the genus Rubus, known colloquially as brambles. With about 3,000 species, the rose family is not that large compared to the 20,000 species of the orchid family and 19,000 species of the composite family, inclusive of asters, daisies, and sunflowers. [2] However, the rose family is arguably the most renowned of all plant families from the human perspective. Its prominent floral and fruit products that proliferate the temperate zones of primary habitation are without equal in the kingdom Plantae. In addition to the many cultivars of roses that dominate the floral trade, they are the sine qua non for spectacles like the annual Pasadena parade and namesake bowl game and Kentucky’s running of the roses in the first of the three horseracing crowns. English wars have been named for them. The red rose Lancasters and white rose Yorks have nothing to do with the Lannisters and Starks even though they were both involved in throne games of a sort. However, the fruits of the rose family that dominate at the supermarket are its most enduring legacy. Life would be lessened absent apples, pears, cherries, plums, and the various bramble berries. The success of the rose family is a result of the evolution of a number of traits that promote reproduction and dispersion. Having a diversity of fruits with the color, shape, and taste that appeal to birds and mammals results in spreading seeds far and wide in a dollop of fertilizer. More important, however, is asexual reproduction called apomixis by which rose plants can spread without pollinators. This is especially true of the brambles like raspberry that extend by horizonal, leafless stem structures called rhizomes. [3]

Rose family fruits in general and raspberries in particular have spread far and wide, part of Darwin’s “endless forms most beautiful and most wonderful” due to hybridization that results from a combination of seed dispersion and asexual apomixis. Apples abound in variety and raspberries are not far behind. There were already 41 varieties of raspberry in the United States in 1866. [4] Both apples and raspberries tend toward polyploidy, having multiples of the basic number of chromosomes, which can result in the reestablishment of sexuality to create new hybrids. This is further complicated with raspberries, that can have one of three different basic chromosome numbers (7, 8, or 9) to start with. This means that from their inception in Asia Minor, raspberries have spread across the globe in many hybrid forms, drawing the attention of the hominids doing the same thing. That they were well known by the time of the Roman Empire is well established. Pliny the Elder (aka Gaius Plinius Secundus), the noted Roman military leader and naturalist author, wrote in his magnum opus Naturalis Historia that the raspberry was “known to the Greeks as the Idæan bramble, from the place where it grows.” Mount Ida is in Northwestern Turkey near the site of Troy, providing the species name idaeus of red raspberry. It was even then regarded as a medicinal plant, for Pliny notes that: “Its flower, mixed with honey, is employed as an ointment for sore eyes and erysipelas, and an infusion of it in water is used for diseases of the stomach.” [5] As raspberry seeds have been found at Roman forts on the British Isles, it is considered likely that the Romans spread the raspberry from its Asian origins throughout their vast empire into Europe and Africa. [6]

Raspberries have served as a wellspring for both nutritious food and medicinal remedy for the millennial span of western civilization. They found their way into the various herbal collections that appeared in Europe in the late 16^th century. John Gerard, calling it the Raspis, Hinde-berry, or Framboise (French), notes that “the floures (sic), the leaves, and the unripe fruit, being chewed, stay all manner of bleedings. They heal the eies (sic) that hang out.” The ripe fruit is described as sweet, and “not unpleasant to be eaten,” [7] As the modern era erupted from the rediscovery of Greco-Roman writings in the Renaissance, the expansion of raspberries as one of the first fruits followed. By the 17^th century, white and red cultivar raspberries were recognized in Great Britain that differed only in the color and taste of the fruit, the “white raspis a little more pleasant than the red.” Red wines were available at the “vintners made from the berries of Raspis that grow in colder countries.” The medicinal uses had also expanded, extending to the use of leaves “in gargles and other decoctions that are cooling and drying, but not fully to that effect” whatever that means. A syrup made from the berries “is effectual to cool a hot stomach, helping to refresh and quicken up those that are overcome with faintness.” And of course the berries were eaten “to please the taste of the sick as well as the sound.” [8] As the consumer era took off in the middle of the last century, the raspberry became a mass market food and one of the myriad herbal remedies to assuage modern melancholia.

Raspberries are nutritious, contributing to a healthy diet. They are one of the highest sources of dietary fiber (6.5 grams fiber per 100 grams wright) relative to the energy provided (100 kilocalories per 12.5 grams). In addition, they are high in vitamins C and K and in the minerals calcium, magnesium, potassium, and iron. Raspberries also contain a unique set of phytochemicals, secondary substances not involved in plant metabolism, that are likely the basis for the many historic folk medicinal uses. Anthocyanins, which are what make berries (and fall leaves) red, are noted for their antioxidant and anti-inflammatory activity, deactivating the free radicals (ionic forms) that tend to disrupt cellular activity. In vivo animal studies have found that consuming raspberries resulted in “reduced blood pressure, improved lipid profiles, decreased atherosclerotic development, improved vascular function, stabilization of uncontrolled diabetic symptoms (e.g., glycemia), and improved functional recovery in brain injury models”. [9] It may be concluded that the use of raspberries in the treatment of a variety of ailments has at least some rational basis due to actual chemical interactions operating above and beyond the placebo effect.

Native American herbal remedies provide one of the best examples of genuine folk medicine unadulterated by marketing hucksterism. The Iroquois Confederacy of the northeast had many uses for raspberry leaves and roots, including treating bloody diarrhea, as an emetic, to remove bile, to treat children with whooping cough, and, perhaps with some hyperbole, as a “decoction taken by a hunter and his wife to prevent her from fooling around.” Raspberries were also important as food, especially in winter when dried fruits were combined with hominy. Further south, Cherokee also used raspberry plants for digestive problems and as food but in the form of pies and jellies suitable for the milder climate. On the more practical side, the prickly stems were used for scratching itchy hard to reach places. In addition, it was used for coughs, boils, and, most significantly to current usage, to treat postpartum pain. [10] Current usage as an herbal remedy follows those of Native American usage, with an emphasis on pregnancy issues.

The most prevalent use of raspberry over the last century has been during the last trimester of pregnancy to “relax the uterine muscles and facilitate birth.” [11] However, in Germany this is proscribed “because of lack of scientific support of claimed activities as a uterine tonic.” [12] The widespread use of raspberry leaves in herbal preparations for pregnancies has resulted in some serious scientific assessment. Approximately 50 percent of all pregnant women use some form of herbal treatments during pregnancy and the use of raspberry extracts as tea, tablets, or tincture ranges from 7 to 56 percent depending on the country. The claim made by the herbal industry is a “positive effect on childbirth through the induction of uterine contractions, acceleration of the cervical ripening, and shortening of childbirth.” No studies clearly demonstrate that products derived from raspberries have a clear effect on the biochemical pathways of pregnancy. A recent review concludes that “the consumption of raspberry extracts could translate into decreased dynamics, or even the inhibition of the cervical ripening process, which could undoubtedly translate into a more tumultuous and traumatic childbirth course.” It is increasingly clear in the medical community that the best way to stay healthy is to eat a balanced diet, exercise regularly, and avoid stress. Hiking along trails in the quiet of the forest and eating raspberries is a good place to start.

References:

1. Wilson, C. and Looms, W. Botany, 4^th Edition, Holt, Rinehart and Winston, New York, 1967, pp 30-31, 285-304.

2. Niering, W. and Olmstead, N. National Audubon Society Field Guide to North American Wildflowers. Alfred A. Knopf, New York, 1998, p.354, 646, 746.

3. Cowan, R. “Rosales” Encyclopedia Britannica Macropedia, William and Helen Benton, Publishers, Chicago, 1972 Volume 15, pp 1150-1154.

4. Stuart, M. ed The Encyclopedia of Herbs and Herbalism, MacDonald and Company Publishers, London, 1987, p 255.

5. Pliny the Elder, The Natural History – John Bostock, M.D., F.R.S. H.T. Riley, Esq., B.A. London. Taylor and Francis, Red Lion Court, Fleet Street. 1855. Book 16 Chapter 71 – https://www.perseus.tufts.edu/hopper/text?doc=Perseus:text:1999.02.0137:book=16:chapter=71&highlight=raspberry

6. Burton-Freeman, B. et al “Red Raspberries and Their Bioactive Polyphenols: Cardiometabolic and Neuronal Health Links” Advanced Nutrition, Volume 7, Number 1 January 2016 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4717884/

7. Gerard, J. Herball – Or, Generall Historie of Plantes, John Norton, London, 1597. Pp 260-261

8. Parkinson, J. Paradisi in Sole, Paradisus Terrestris 1629. Reprinted by Methuen &Company, London, 1904, p 557 -558 https://www.gutenberg.org/files/69425/69425-h/69425-h.htm#Page_557

9. Burton-Freeman et al, op. cit.

10. Native American Ethnobotany Data Base. http://naeb.brit.org/

11, Polunin, M. and Robbins, C. The Natural Pharmacy, Collier Books, New York, 1992, p 122.

12. Foster, S. and Duke, J. Medicinal Plants and Herbs, Petterson Field Guide Series, Houghton Mifflin Company, New York, 2000, pp 264-265

13. Socha, M. et al “Raspberry Leaves and Extracts-Molecular Mechanism of Action and Its Effectiveness on Human Cervical Ripening and the Induction of Labor” Nutrients, Volume 15 Number 14, 19 July 2023. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10383074/

Lone Star Tick

Common Name: Lone Star tick, Turkey tick– The prominent single white spot that marks the center of the carapace of females gave rise to the “lone star” metaphor. Although the tick is found in Texas, there is no evidence that it got its name from the state.

Scientific Name: Amblyomma americanum – Ambly is a combining form directly from Greek that means blunt or obtuse. Omma is similarly derived meaning eye. The genus was originally named by Carolinus Linnaeas in 1758 with the lone star tick as its type species. It is probable that “blunt eye” was due to the presence of the white dot. The species name is from its origination in the North America.

Potpourri: Up until about ten years ago, the lone star tick was dismissed as an interesting but esoteric member of Ixodidae, the tick family. It is not even included in popular field guides. [1] It was overshadowed by the black-legged tick, a cynosure due to the prevalence of Lyme Disease as a human pathogen. The wood tick, almost identical to the lone star tick lacking only the white dot, is much more common in the mid-Atlantic region. That all changed when people reported having a severe allergic reaction after eating red meat. This inexplicable and widespread medical issue that often led to hospital emergency rooms drove a quest for causation. Epidemiological research that spanned a decade eventually correlated times and locations of the severe and tellingly delayed anaphylactic shock of the red meat allergy to having been bitten by the lone star tick. Its spread eastward and northward over time has led to continued study and research as a public health issue.

The lone star story (not the one about the Alamo) started as an attempt to find the root cause of a disturbing sequence of unusual and serious medical anomalies. This is not unlike most complex interactions between human health and nature exemplified by the English physician John Snow, who traced the cause of cholera to the contaminated Broad Street water pump in London in 1854 and true also for Lyme Disease. The first recorded correlation between lone star ticks and allergic reactions due to the consumption of mammalian meat occurred in Athens, Georgia in 1989. Dr. Antony Deutsch and Mrs. Sandra Latimer noted that there had been ten cases in which delayed anaphylaxis and/or hives occurred in patients who consumed red meat and who also been bitten by ticks some months before. Blood tests revealed that all of those affected had elevated blood levels of Immunoglobin E (IgE), a naturally occurring antibody that is an integral part of the immune system of all mammals that had supposedly been stimulated by something contained in red meat. Although reported to the Centers for Disease Control (CDC) in 1991, there was no follow-up. [2]

Fifteen years later, a University of Virginia allergy researcher named Thomas Platts-Mills was trying to understand why some cancer patients had experienced severe allergic reactions when given the drug cetuximab. The key to the puzzle was a chemical named with the tongue twisting lexicon of organic chemistry galactose-alpha-1,3-galactose. This is a type of sugar in red meat (including pork, “the other white meat”) which was also one of the ingredients found in the cancer drug cetuximab. While the nickname alpha-gal seems to have been an innocuous shorthand version of the longer name, it does offer some speculation about its origination. The similarity to the sexist archetype alpha-male of boardroom and bedroom notoriety can hardly be ignored. That it is a component of red meat, the consummate breakfast of champions borders on sardonic, alpha-gal for alpha-male. The final piece of the puzzle was geographic. Those cancer patients who experienced anaphylaxis when given cetuximab were from the so-called tick belt of the southeastern states, some with “massive tick bites on their ankles.” Dr. Platts-Mills confirmed his hypothesis a year later when he went on a hiking trip in the Appalachian Mountains near UVA in 2007. He returned to discover his ankles covered with lone star larva and a self-administered blood test confirmed high IgE levels. After a lamb dinner several months later, he awoke in the middle of the night covered with hives. [3]

In the succeeding fifteen years that brings us to the present, the correlation between lone star tick bites and red meat allergy has been accepted beyond correlation to causation. A report issued by the Centers for Disease Control in 2023 found that there were 110,000 confirmed cases of what has come to be known as the alpha-gal syndrome (Electra complex was ruled out) in the United States between 2010 and 2022. The number was based on data from laboratory testing incident to patients seeking medical care for life-threatening respiratory distress. The CDC concluded that underreporting of the condition was likely and that there were approximately four cases for every one reported and analyzed. With an estimated 450,000 cases during the twelve-year period of evaluation, tick-red meat allergy is in the top ten of food allergies in the United States. The reasons for the dearth of reported cases are uncertainty of symptoms and lack of awareness. The anaphylactic reaction usually occurs two to six hours after a meaty meal and months after a tick bite and can vary in severity across populations. A survey of 1500 clinicians revealed that almost half had never heard of the condition, precluding a diagnosis altogether. That lone star ticks are spreading north, and east is reflected in the data. The two states with the highest reported red meat allergy cases were Virginia and New York, where Suffolk County, the eastern two thirds of Long Island, accounted for four percent of all cases nationwide. [4]

While much has been learned about the lone star tick to date, research continues. The first order of business is to determine the ultimate source of the chemical that induces the IgE autoimmune spike. There are three hypotheses. The first is that the IgE stimulant is contained in the lone-star tick’s saliva, which, like all ticks, is a complex chemical mix that contains anticoagulants to ensure blood flow from the host, anesthetics to dull the host’s senses so as to avoid detection, and immunosuppressive agents to blunt host rejection. The second is that mammal blood from a previous meal contained the IgE antigens, a not unreasonable hypothesis given its provenance. The third is that the lone star tick is a vector to transfer the inflicting agent from one host to another, similar to the transmission of Borrelia burgdorferi that causes Lyme Disease from the white footed mouse to humans by the black-legged tick. Based on the results of the investigations, some form of antidote could presumably be devised. At present there is no cure beyond avoiding future tick bites and hoping that the autoimmune response will abate over time. [5] However, the anxiety for a potential midnight ambulance ride to the emergency room after having hamburger helper for dinner causes most victims to avoid meat altogether, which is not necessarily a bad thing when health and the environment are taken into account. But for those who cannot imagine a life without pork chops and bacon, a company in Blacksburg, Virginia has developed an FDA approved genetically engineered pig that lacks the alpha-gal gene, called (what else?) Galsafe. While ostensibly to produce organs for use in humans that might otherwise be rejected, the company offers Galsafe meat to alpha-gal patients. [6]

A second line of research seeks to understand the cause or causes of the tick diaspora over the last several decades The spread of the lone-star tick outside its historical range is not unique, but a pattern now typical for most if not all ticks. One possibility would be the movement of the winter freeze line northward due to the now perceptible higher temperatures which opens new habitats for invertebrates like insects and ticks, the bark beetle’s devastation of western pine forests a case in point. However, ticks don’t fly, have miniscule legs, and can only crawl a short distance during their brief lives. The commonly accepted reason for the spread of ticks is the burgeoning numbers of white-tailed deer across the eastern half of North America, long a matter of public concern due to environmental damage and deadly vehicular collisions―and now lone star tick vectors to boot. Deer feeding habits take them through ideal tick habitats where they stand and graze placidly while the ticks gleefully jump on board for a meal. Deer provide ticks geographic mobility. The lone star tick is also commonly found on wild turkeys. So much so that in the Midwestern states, they are called turkey ticks (just as the black-legged tick is called bear tick in northern states). [7] The upshot of more ticks is more tick-borne diseases, now more common and with more variety. Two additional diseases associated with the lone-star tick have become a matter of public health concern (over and above red meat allergy) over the last ten years.

Southern tick-associated rash illness (STARI) emerged from the fog of tick-borne disease data only gradually. Metabolic measurements of the blood from individuals with both Lyme Disease and with STARI revealed different biosignatures, confirming an alternative etiology. [8] The CDC recognizes STARI as a new disease but considers it to be of unknown origin, noting only that it is correlated with individuals bitten by lone-star ticks. The symptoms are the red circular rash, generally described as “bull’s eye” identical in appearance to that of the black-legged tick when Lyme Disease is contracted. [9] To complicate matters, a spirochete similar to that causing Lyme Disease, tentatively named Borrelia lonestari, has been found in at least one patient but does not seem to be routinely present in other victims; the search continues.

A second emerging disease attributed to lone star tick bites is Heartland virus, named for the Heartland Regional Medical Center in St. Joseph, Missouri, where the first two patients were treated in 2009. When seven additional cases including two fatalities occurred several years later, the quest for the source of the virus began in earnest. In 2013, 50,000 ticks were collected in Missouri and surrounding states and tested for Heartland virus. Only the lone-star ticks were found to have the virus. In parallel, between 2009 and 2014, blood samples from 1428 animals including white-tailed deer, raccoons, moose, and coyotes were analyzed to reveal that 103 tested positive. The tentative theory is that the lone star tick nymph has a blood meal on an infected animal, most likely deer, and then transmits it to a human as an adult. [10] And that is not all, the lone star tick has also been identified in the transmission of many of the known tick-borne diseases including ehrlichiosis, rickettsiosis, tularemia and protozoan infections. The spread of tick-borne diseases is a concern for anyone who spends time outdoors in grassy areas―like hikers.

A working knowledge of cradle to grave tick behavior helps establish actions needed to minimize the chances of getting bitten and contracting a tick-borne disease. Each lone-star tick hatches as a six-legged larva, one of about 5.000 eggs laid by a gravid female in a location chosen for likely success (females have been tracked moving over half a meter to find a suitable, moist location). The first of three blood meals is necessary to proceed to the eight-legged nymph stage (ticks are arachnids akin to spiders). The second blood meal provides the energy and nutrients to molt to an adult. Both larval and nymph stage ticks can survive up to six months without eating. A last supper for both males to produce spermatophores and for females to produce eggs and pheromones to attract a mate completes the life cycle with oviposition. While larvae and nymphs parasitize birds and small mammals, adults literally quest for larger prey like deer and humans. [11] The evolution of ticks to survive on three mammal blood meals for the entirety of their short lives is one of the wonders of the natural world. Only three sensory capabilities exist to achieve this end. Photosensitivity draws the tick upward on a blade of grass until it is at or near the apex. Once in position, the tick extends its front legs to attach to a passing animal in a stance appropriately called questing. Ticks, the epitome of persistence, can remain ready at the quest for up to three years. A second sensitivity is butyric acid, an exudation of all mammals, necessary to consummate the quest on a suitable host. A third sensitivity is surface warmth, triggering proboscis insertion to initiate feeding. It doesn’t matter what is on the other side of the warm surface. A tick will suck from a balloon filled with warm water. [12]

So how can you protect yourself from tickborne disease? Three methods have been prescribed. The first line of defense is to use tick repellent like DEET. An acaracide (Acarina is the order for ticks and mites in the Class Arachnida) like permethrin that kills them is preferable. However, nothing is absolute, and ticks are insidious, penetrating the shield at an untreated spot inevitably missed during application. The second line of defense is habitat removal, getting rid of the grasses that promote knee high access for successful attachment. Mowing may work around a farm, but it cannot be practical in open woods with passing trails. While it is good practice to hike in the middle of a trail where grass is beaten flat, a trip to the bushes will at some point be required. The third method is host removal. There have been studies that focus on the number of deer necessary to reduce tick populations which conclude that it would only work with near annihilation, neither feasible nor desirable. The one guaranteed method of preventing tick borne diseases is vigilance. A complete whole-body inspection down to bare flesh must be conducted after every hike in potential tick habitats between March and November, active tick season, If a tick is found and removed within 24 hours, the chances of protracting a disease are negligible. This is because it takes that long for the tick to drill the hole to reach blood and then to inject the chemical saliva that keeps the well open and flowing. The injected saliva carries disease pathogens. There will still likely be a maddingly itchy red spot to deal with, but topical creams and patience will suffice in remediation. However, an ambulance ride after a steak dinner can be averted.

References:

1. Milne, L. and Milne, M. National Audubon Society Field Guide to North American Insects and Spiders, Alfred A. Knopf, New York, 1980, pp. 423-430

2. Steinke, J. et al. “The alpha gal story: Lessons learned from connecting the dots”. The Journal of Allergy and Clinical Immunology. March 2015. Volume 135 Number 3, pp 589–597.

3. Beck, M. “Ticks that spread Red-Meat Allergy” The Wall Street Journal, 11 June 2013

4. Sun, L. “Tick-linked meat allergy may not be so rare, researchers say,” Washington Post, 28 July 2023. (The meat need not be rare either)

5. Steinke, op .cit.

6. Lewis, T. “Red Meat Allergy Caused by Tick Bite Is Spreading—And Nearly Half of Doctors Don’t Know about It” Scientific American, 7 August 2023.

7. University of Florida Entomology and Nematology Department https://entnemdept.ufl.edu/creatures/urban/medical/lone_star_tick.htm

8. Molins, C. et al “Metabolic differentiation of early Lyme disease from southern tick–associated rash illness (STARI)” Science. 16 August 2017, Volume 9 Issue 403

9. https://www.cdc.gov/lyme/about/about-southern-tick-associated-rash-illness.html

10. Enserink, M.” The Heartland virus may occur across eastern U. S.” Science 18 September 2015

11. University of Florida, op cit.

12. Wilson, N. “Acarina” Encyclopedia Brittanica, Macropedia Volume 1 pp 19-23 and Volume 2 p 805, William and Helen Benton Publishers, University of Chicago, Chicago Illinois, 1972.