This document discusses the order Blattodea, commonly known as cockroaches. It provides details on two common species: the oriental cockroach (Blatta orientalis) and the American cockroach (Periplaneta americana). It describes their physical characteristics, life cycles, habitats, and economic significance. Key points include that oriental cockroaches are smaller than Americans, prefer damp areas, and females lay egg cases containing 16 eggs. American cockroaches can grow over 4 cm long, undergo 6-14 molts as nymphs, and males are able to fly. Both species can harbor human pathogens and contaminate areas with waste.

1. BLATTIDAE
by,
Bharath Kumar Ayyapan Krishnasamy,

2. ORDER : DICTYOPTERA
(Dictyon=network,ptera=wings)
• Sub order: Blattodea(Cockroach) ,Mantodea(Preying Mantis)
• Subclass : Pterygota
• Division : Exopterygota
• Sub Group : Neopteran orders
• Group : Orthopteroid orders
• Sub order: Blattodea(Cockroach)
Families : Blattidae (Oriental Cockroach & American
Cockroach)
Blatellidae (German Cockroach)

3. ORDER CHARACTERS
• BODY : Medium to large sized nocturnal insect.Body is dorsoventrally flattened.
• Head : Hypognathous .Compound eyes large amd widely separated.
Two ocelli present.Antenna is Filliform.Mouthparts biting and chewing type.
• Thorax :
• Tarsus is five segmented.
• Forewings are more or less thickened,leathery with marginal costal vein.
• They are tegmina.
• Hindwings are large ,membranous and folded like a fan and kept beneath the forewings.
• Abdomen : cerci are short and many segmented.
• Development: Eggs are contained in an ootheca or egg case.metamorphosis is gradual .Parental
care is present.

4. SUBORDER : BLATTODEA
• EGG :
• Laid inside a chitinous ootheca.
• Hard ,regular shape ,16 eggs in two parallel rows
• Dropped on ground,glued to substrate retained within female’s body.
• NYMPH:
• Structurally similar to adults
• Not cannibalistic.
• Developing wingpads often visible on thorax.

5. ADULTS
• BODY: Oval , somewhat flattened
• Head:
• It is not mobile in all directions.
• Two fenestrae (Degnerated ocelli ,sensitive to light ) occur in the place of dorsal ocelli.
• Antenna slender and filiform
• Thorax:
• Pronotum is oval,shield like,covering much of thorax and head)
• Meso and metathoracic segments are rectangular.
• Legs are cursorial,long and spiny, adapted for running.
• Autoamputation is absent.
• Tarsi 5 segmented
• Wings found in both sexes
• Forewings are thickened and hindwings are membramous,peated.

6. • ABDOMEN:
• Cerci are short and multi_segmented.
• Anal styli are present only in males,which is used to hold females.(sexual dimorphic
character).
• ANATOMY
• Gizzard is powerfully armed with chitinous teeth to grind food.
• Scent glands present in abdomen impart foul smell.
• BEHAVIOUR AND ADAPTATIONS
• Female does not devour the male during mating
• Body is well-adapted for running and squeezing into narrow openings
• They are positively thigmotrophic and weak fliers
• Rather than flying to escape danger ,cockroaches usually rush into cracks and crevices.
• No mimicry is found
• They are gregarious , nocturnal and omnivores.

7. Blatta orientalis(oriental cockroach)
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Blattodea
Family: Blattidae
Genus: Blatta
Species: B. orientalis

8. • It is dark brown or black in color and has a glossy body.
• Cockroaches are mainly nocturnal.
• Oriental cockroaches can be elusive in that a casual inspection of an
infested dwelling during the day may show no signs of roach activity.
• Oriental cockroaches can be found in usually damp places such as
sewer pipes, sink drains, and any other form of damp areas in
households.

9. EGG
• Oothecae are formed a day after mating, and typically deposited a day or two after formation,
though can be deposited up to 7 days later, typically in a sheltered area or attached to a substrate
by oral secretion.
• They are initially a yellow white, turning reddish- then blackish-brown.
• Parthenogenesis occurs and resulting ones are female
• A female oriental cockroach produces an average of eight egg capsules per lifetime.
• Each egg capsule or ootheca contains about 16 eggs that are lined up vertically, two by two in the
egg case.
• The incubation period for the oriental cockroach is about 42 to 81 days.

10. NYMPH
• The female gives no assistance to the young.
• Nymphs go through seven molts before becoming adults, which takes
approximately one year.
• An adult Blatta orientalis can live from 34 to 180 days.

11. ADULT
• The male has long wings, which cover two-thirds of the abdomen and
are brown in color, and has a narrower body.
• Female oriental cockroaches have vestigial tegmina (reduced fore
wings) and males have longer tegmina.

12. • The female has a somewhat different appearance from the male,
appearing to be wingless at casual glance, but is brachypterous,
having non-functional wings just below her head.
• She has a wider body than the male.

13. Periplanta americana(American cockroach)
Kingdom: Animalia
Phylum: Arthropoda
Class: Insecta
Order: Blattodea
Family: Blattidae
Genus: Periplaneta
Species: P. americana
Binomial name
Periplaneta americana
(Linnaeus, 1758)

14. NYMPH
• The number of times an American cockroach molts varies from six to 14
• The first instar American cockroach is white immediately after hatching then
becomes a grayish brown.

15. • molting, subsequent instars of the cockroach nymphs are white and
then turn reddish-brown, with the posterior margins of the thoracic and
abdominal segments being a darker color.
• Wings are not present in the nymphal stages and wing pads become
noticeable in the third or fourth instar.
• Complete development from egg to adult is about 600 days.
• The nymphs as well as the adults actively forage for food and water.

16. ADULT
• The adult American cockroach is reddish brown with a pale brown or yellow band around the
edge of the pronotum.
• The males are longer than the females because their wings extend 4 to 8 mm beyond the tip of
the abdomen.

17. • Males and females have a pair of slender, jointed cerci at the tip of
the abdomen.
• The male cockroaches have cerci with 18 to 19 segments while the
females’ cerci have 13 to 14 segments.
• The male American cockroaches have a pair of styli between the cerci
while the females do not.

18. ECONOMIC SIGNIFICANCE
• At least 22 species of pathogenic human bacteria, viruses, fungi, and protozoans, as well as five
species of helminthic worms, have been isolated from field collected American cockroaches.
• Cockroaches are also aesthetically displeasing because they can soil items with their excrement
and regurgitation.

19. COMPARISION OF ORIENTAL AND AMERICAN
COCKROACH
Roach Oriental cockroach American cockroach
Size
25 mm (2.5 cm) to 30 mm
(3.0 cm)
28 mm (2.8 cm) to 43 mm (4.3 cm)
Habitat
20 °C (68 °F) to 29 °C
(84 °F)
Same as German
Nymphal development
time
6 to 12 months 4 to 15 months
Lifespan 1 to 1.5 years 1 to 1.5 years
Able to fly No[4] Ye