3
CHAPTER
1
General
Introduction
to
Acarology
Acarology
.is.the.study.of.mites,.or.Acari.or.Acarina
.
.It.is.a.specialized.field.of.study.in.the.
larger.topics.of.invertebrate.zoology.and.entomology
.
.Because.some.mites.are.economically.impor-
tant. pests. of. agriculture. (crops,. honey. bees,. stored. food. products,. and. livestock),. are. household.
pests,.or.are.vectors.of.diseases.of.humans.and.livestock,.acarology.is.often.studied.in.entomology.
departments.
Mites.have.been.studied.for.centuries
.
.A.tick-transmitted.fever.was.mentioned.in.an.ancient.
Egyptian.papyrus.in.1550.BC
.
.Homer.mentioned.ticks.in.850.BC,.and.Aristotle.described.mites.
parasitic.
on.
locusts
.
.
Hippocrates,.
Plutarch,.
Aristophanes,.
and.
Pliny.
all.
mentioned.
mites
.
.
Until.
about. 1660,. mites. were. referred. to. as. ‘lice,’. ‘beesties,’. or. ‘little. insects
.’
.The.terms.‘Akari’.and.
‘mite’.began.to.be.used.about.1650
.
.Linnaeus.used.the.generic.name.
Acarus
.in.the.first.edition.of.
the.
Systema
Naturae
.and.named.the.type.of.the.genus.
Acarus
siro
.(a.grain.mite).in.1758
.
Acarology.was.an.active.field.in.Europe.in.the.late.19th.and.early.20th.centuries
.
.Beginning.
with.World.War.II,.an.increased.awareness.of.the.economic.importance.of.mites.and.ticks.arose.in.
the.United.States.and.elsewhere.due.to.a.concern.about.diseases.transmitted.by.ticks.and.chiggers.
(which.transmit.scrub.typhus)
.
.After.the.war,.with.the.increased.use.of.synthetic.organic.pesticides.
such.as.DDT.to.control.a.wide.array.of.insect.and.mite.pests,.spider.mites.became.much.more.seri-
ous.agricultural.pests.around.the.world,.and.applied.agricultural.acarology.developed.(Baker.and.
Wharton.1952,.Jeppson.et.al
.
.1975)
.
Mites.are.not.just.agricultural.pests,.however
.
.They.are.of.intrinsic.interest.to.zoologists.and.
ecologists.because.they.rival.the.insects.in.their.numbers.and.diversity
.
.Admittedly,.mites.usually.
are.less.obvious.due.to.their.small.size
.
.Most.mites.are.0
.08
.to.1
.0
.millimeters.(mm).in.length;.how-
ever,.some.ticks.and.red.velvet.mites.may.reach.lengths.of.10.to.20 mm
.
.We.do.not.know.just.how.
diverse.or.abundant.mites.are.due.to.the.fact.that.the.taxonomy.of.mites.is.50.to.100.years.behind.
that.of.the.insects
.
.This.is.because.mites.are.so.small.that.they.require.rather.specialized.methods.
and.equipment.to.study.them,.and.if.they.are.not.of.economic.importance.they.often.are.overlooked
.
.
It.is.not.unusual.for.new.species,.genera,.and.even.families.of.mites.to.be.discovered,.and.collecting.
in.distant.or.exotic.regions.is.not.required.to.discover.new.mite.taxa
.
.By.1950,.about.30,000.species.
of.mites.in.1700.genera.had.been.described
.
.As.of.1999,.approximately.40,000.species.of.mites.had.
been.described,.and.estimates.of.unnamed.species.range.from.0
.5
.to.1.million.species.(Walter.and.
Proctor.1999)
.
Some.taxonomists.have.suggested.there.may.be.more.mite.species.than.insect.species.because.
mites.are.smaller.and.able.to.occupy.smaller.niches.than.insects
.
.Certainly,.they.outdo.the.insects.
in.the.diversity.of.habitats.they.lay.claim.to.because.of.their.small.size
.
.Mites.have.colonized.all.of.
the.habitats.that.insects.have.colonized;.some.are.terrestrial.and.some.aquatic.in.freshwater,.and.
some.are.even.found.in.the.oceans.(Evans.1992,.Houck.1994,.Proctor.2006,.Krantz.and.Walter.
2009).
.Mites.are.freeliving.or.are.parasitic.on.plants.and.on.vertebrate.and.invertebrate.animals;.for.