Taxonomy, principles and procedures

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Dr. T. KRISHNA CHAITANYA
Assistant Professor (Agricultural Entomology)
School of Agricultural Science & Technology, NMIMS, Shirpur
ENTO 131 - Fundamentals of Entomology (3+1)

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Taxonomy, principles, procedures,
Nomenclature, Identification and
Classification of insects

3. • Aristotle is considered as the “Father of Biological Classification”
• Most widely accepted classification “Omniseptive classification”
given by Black welder
• Broad classification of Animal Kingdom (Phylogenetic tree) is given
by Hymen.
• The Term taxonomy was first proposed by the scientist deCandolle
• Carl Linnaeus is considered as the “Father of Taxonomy”
• Tenth edition of “Systema Nature” (1758) contains Binomial
Nomenclature.
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TAXONOMY, PRINCIPLES AND PROCEDURES

4. • Classification: is the ordering of animals into groups on the basis of
their relationship.
• Taxonomy: is the theoretical study of classification, including its
bases, principles, procedures and rules.
• Systematics: is the scientific study of kind and diversity of organisms
and of any and all relationships among them. It is study of phylogeny
and taxonomy.
Stages of taxonomy:
(i) Alpha taxonomy (α): It is concerned with naming and characterization
of species.
(ii) Beta taxonomy (β): Concerned with classification
(iii) Gama taxonomy (γ): Concerned with evolutionary relations and
phylogeny.
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5. Points considered while classifying are
(i) external structure,
(ii) internal characters,
(iii) developmental history,
(iv) physiological data and
(v) cytogenetic data.
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Oogenesis
(occurs inside egg tube)
Oogonia
Mitosis
Primary oocytes (2n)
Meiosis
Secondary oocytes (n)
Mitosis
Oocytes (n)
Vitellogenesis
Ovum (n)

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33 categories in Hierarchic Classification
Kingdom – Subkingdom – Infrakingdom – Superphylum
– Phylum – Subphylum – Infraphylum – Superclass –
Class – Subclass – Infraclass – Supercohort – Cohort –
Subcohort – Infracohort – Superorder – Order – Suborder
– Infraorder – Superfamily – Family – Subfamily –
Infrafamily – Supertribe – Tribe – Subtribe – Infratribe –
Supergenus – Genus – Subgenus – Superspecies – Species
– Subspecies.

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The standardized endings are
Superfamily - oidea (Ichneumonoidea)
Family - idae (Ichneumonidae)
Subfamily - inae (Pimplinae)
Tribe - ini (Poemeniini)
Subtribe - ina (Poemeniina)

8. Systematic position of Indian honey-bee
• Kingdom: Animalia
• Phylum: Arthropoda
• Class: Insecta
• Sub class: Pterygota
• Order: Hymenoptera
• Suborder: Apocrita
• Super family: Apioidea
• Family: Apidae
• Subfamily: Apinae
• Genus: Apis
• Species: indica
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9. Species is a natural, interbreeding population which is reproductively
isolated from the individuals of other species
Functions of species
i. Reproductive community: The individuals of the species are able to
recognize each other as potential mate and seek each other for the
purpose of reproduction.
ii. An ecological unit: Irrespective of the number of individuals they act
as a unit and interact with the individuals of other species with which
they share the habitat.
iii. A genetic unit: it consists of a large number of inter-communicating
gene pool in which the individual is a temporary reservoir holding a
portion of genes for a short period.
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10. Nomenclature and Identification
A name is required for identification of any organism. Generally, two
types of names are used (i) common name (ii) scientific name.
I. Common name
(i) They are inaccurate because it varies from region to region and
country to country and there is no uniformity followed in naming the
organisms.
e.g. Locust is a bug referring cicada in European countries and normally
locusts also refer to short horned grasshoppers living in groups.
(ii) Common name is not available for all organisms
e.g. Squash bugs present in cucurbitaceous plants are represented by
many species, but no common name is available for each species. It is
available only for a large group like order and family.
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11. (iii) Same common name is used for insects of different orders.
e.g. Flies. A true fly has only 2 wings, whereas other insects like mayfly,
dragonfly, etc., are also mentioned as flies.
(iv) Homonym - Same name is used for describing two different type of
insects.
e.g. Boll worm is a common term used for more than five species of boll
feeding insects.
(v) Synonym - More than one name denoting a single insect.
e.g. Gram pod borer, American bollworm denotes Helicoverpa armigera
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12. II. Scientific name: The system of naming organisms using two words is
called Binomial nomenclature (Trinomial nomenclature if three words
are used).
• The rule regarding the naming of organisms is contained in
International code for zoological nomenclature.
• Normally there are two names, the first name is the generic name and
the second name is the species name. The names that follow the
generic name are called Trivial names. The trivial names may be
either species or a subspecies name.
e.g. Head louse: Pediculus humanus captis
Body louse: Pediculus humanus corporis
Parasitoid: Pentelicus punctatus (Krishna Chaitanya)
Fruit fly: Gitona distigma (Meigon)
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13. • IDENTIFICATION
• Most of the keys are dichotomous i.e., always dividing into two or
they are always in the form of couplets and give a clear cut
alternative.
• Keys can be constructed based on single character (monothetic key)
or many characters (polythetic key). Polythetic key is more
advantageous.
• Monothetic key has three disadvantages (i) the organism may be an
exception for a particular character (ii) chances of erring is more (iii)
if the particular body part is broken on which the key is made, then the
key cannot be used.
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The first step in the key could be organized the following way:
1.wings covered by an exoskeleton. . . . . . . . . . . . . . go to step 2
2.wings not covered by an exoskeleton . . . . . . . . . . go to step 3
Step 2 consists of a pair of statements that distinguishes between the ladybug
and the grasshopper.
1.body has a round shape . . . . . . . . . . . . . . . . . . . . . ladybug
2.body has an elongated shape. . . . . . . . . . . . . . . . . Grasshopper
Step 3 consists of a pair of statements that distinguishes between the dragonfly
and the housefly.
1.wings point out from the side of the body . . . . . . dragonfly
2.wings point to the posterior of the body. . . . . . . . housefly

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STEP FROM CHARACTERS ORDER / CLASS
1a One pair of wings. . . . . . . . . . go to 2
1b Two pairs of wings. . . . . . . . . . go to 3
2a 1a
Hind wings reduced to tiny knobs (halteres), tip of
abdomen without 2-3 thread-like tails
DIPTERA
(Flies)
2b 1a
Hind wings not reduced to tiny knobs, tip of abdomen
with 2-3 thread-like tails (caudal filaments)
EPHEMEROPTERA
(Mayflies)
3a 1b
Front and hind wings have similar texture. . . . . . . . . .
go to 4
3b 1b
Front wings a rigid or leathery covering for clear hind
wings. . . . . . . . . . go to 14
4a 3a
Wings covered with powdery scales, mouthparts
usually a coiled tube (proboscis) for sucking
LEPIDOPTERA
(Moths / Butterflies)
4b 3a
Wings not covered with powdery scales, mouthparts
not a coiled tube. . . . . . . . . . go to 5
5a 4b
Wings slope downwards (rooflike) from the center at
rest. . . . . . . . . go to 6
5b 4b Wings not held rooflike at rest. . . . . . . . . . go to 9

16. Key to the world species of Copidosomyia (Females)
1. Distal third of mid femur white, gaster black with white band at base [Australia &
Queensland] ................................................................................. C. cinctiventris Girault
- Entire mid femur white, gaster fully black …………….……………....………… 2
2. Mid tibia completely dark brown; post marginal vein longer than stigmal vein [India]
......................................................................................................C. abdulkalami sp. nov.
- Apical one third of mid tibia yellowish white, remainder brownish black; post
marginal vein shorter than stigmal vein ……........................................................…. 3
3. Hind femur dark brown with basal white band; hind basitarsus brown rest of tarsus
yellowish white (Fig. 3A of Tachikawa 1979) ………........ C. bhimolpornae Tachikawa
- Hind femur fully brown; hind tarsus completely dark brown (scape 9× as long as
wide; pedicel less than 0.25× scape length) ……….……..... C. ambiguous (Subba Rao)
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17. 1. Body completely dark brown to nearly black and partly with metallic shine, occasionally
frontovertex and partly the scutellum testaceous yellow ………………………………………... 2
– Body not completely dark brown; most of head, largely the axillae and scutellum, and sides of
thorax yellow or yellow brown, occasionally with pale fuscous suffusions ................................ 10
2(1). Pedicel about 3.2× as long as wide and as long as F1 and F2 combined .. H. longipedicellus
– Pedicel at most 2.8× as long as wide and shorter than F1 and F2 combined .............................. 3
3(2). Ovipositor at most 0.6× as long as mid tibia . ....................................................................... 4
– Ovipositor at least as long as mid tibia ....................................................................................... 6
4(3). Hind tarsus dark brown; clava white (pedicel 2.26× as long as wide) …..… H. hemipterinus
– Hind tarsus white; clava basal third or so dark brown to infuscate brown and …....................... 5
5(4). Mid tibial spur not serrate; scape about 6.4× as long as wide ............................. H. flaminius
– Mid tibial spur serrate; scape about 8.8× as long as wide ……………….. H. biharensis sp. nov.
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18. • Key can be classified based on evolutionary principles also as
phylogenetic key and arbitrary key
(i) Phylogenetic key: The key is based on the evolutionary
relationship. The group appears only once in the phylogenetic key.
(ii) Arbitrary key: The taxa or group appears at several places in the
key. It has more advantages.
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• Phylogenetic trees represent hypotheses about the evolutionary
relationships among a group of organisms. A phylogenetic tree may
be built using morphological (body shape), biochemical, behavioral,
or molecular features of species or other groups.

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Species is a natural, interbreeding population which is reproductively
isolated from the individuals of other species
Speciation is the evolutionary process by which populations evolve to
become distinct species.

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38. Division Apterygota (=Ametabola)
1. Order Protura (Telson tails)
2. Order Diplura (Campodeids and Japygids)
3. Order Collembola (Spring tails and Snow fleas)
4. OrderThysanura (Silver fish)
Pterygota (=Metabola)
Division Exopterygota (=Hemimetabola)
Paleopteran orders
1. Order Ephemeroptera (May flies)
2. Order Odonata (Dragon flies and Damsel flies)
Neopteran Orders
Polyneopteran or Orthopteroid orders
3. Order Orthoptera (Grasshoppers, Locusts, Crickets, Mole crickets)
4. Order Dictyoptera (Cockroaches and Mantids)
5. Order Phasmida (Leaf insects and Stick insects)

39. 6. Order Plecoptera (Stone flies and Salmon flies)
7. Order Isoptera (Termites)
8. Order Grylloblattoidea (Grylloblatta) (Not found in India)
9. Order Embioptera (Web-spinner)
10. Order Dermaptera (Earwigs)
11. Order Zoraptera (Zoropterans) (Not found in India)
Paraneopteran or Hemipteroid orders
12. Order Psocoptera (Book lice and Bark lice)
13. Order Mallophaga (Bird lice)
14. Order Anopleura (=Siphunculata) (Sucking lice)
15. Order Thysanoptera (Thrips)
16. Order Hemiptera (Bugs, Hoppers, Cicadas, White flies, Scale
insects)

40. Division Endopterygota (=Holometabola)
Oligoneopteran or Panorpoid complex
1. Neuroptera- Antilions, aphidlion, owl flies, mantispid flies.
2. Mecoptera - Scorpionflies.
3. Lepidoptera - Butterflies and moths. 4
4. Trichoptera - Caddisfly.
5. Diptera - True fly. 3
6. Siphonaptera - Fleas.
7. Hymenoptera - Bees, wasps, ants. 2
8. Coleoptera - Beetles and weevils. 1
9. Strepsiptera - Stylopids.

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