Mecoptera - Scorpion files

This presentation tells about the insect order 'Mecoptera", their characteristic features, life cycle and families included under the order, and also about typical mating or copulation mechanism in them

1. MECOPTERA (Scorpion flies,Hangingflies)
Systematic position :
Kingdom : Animalia
Phylum : Arthropoda
Class : Insecta
Order : Mecoptera

2. •The term ‘Mecoptera’, is derived from Greek
words “meco” meaning long and the “ptera”
meaning wings , refers to the shape of the
both front and the hind wings.

3. Mecoptera
➢Mecopterais a small holometabolousinsect order
with approximately 600 extant described species
placed in 9 families and 32 genera.(Penny & Byers
1979;Penny 1997).
➢Two families –Panorpidaeand Bittacidaecontain
90% of mecopteranspecies.
➢The majority of the members of this group are
easily recognisedby beak-like prolongation of the
front of the head, and their often maculated wings.

4. •Insects of this group are commonly called as
scorpion flies because the 9
th
abdominal
segment in the males of family Panorpidaeis
enlarged,bulbousand curves ante-
dorsally,resembligthe stinger of a scorpion.

5. •Bittacidaesometimes commonly known as
hanging flies because species hang from the
plants by the fore or middle legs.

6. EXTERNAL CHARACTERS
•HEAD:
•The anterior region of the head is usually
prolonged into a rostrum which is formed by the
elongation of the head capsule together with
clupeus,labrum and maxillae.
LABRUM
FRONTAL VIEW OF HEAD

7. •The compound eyes are well developed and there are
usually three ocelli.
•The antennae are more or less filiformand many jointed,
there being about 40-50 joints in Panorpaand 16-20 in
Bittacus.
•The mandibles are slender and elongate ;they are only
dentate at their apices,eachbearing 1-3 sharp teeth.
•The maxillae are complete,theirpalpiare five jointed,and
galeaeand laciniaeare hairy lobes of somewhat complex
structure.
•The labium consists of an elongated submentum,not
always differentiated from the short mentum,the
prementumexhibits a traces of bilobedstructure,ligulais
disappeared.Labialpalpiare 1-3 segmented.

8. HEAD (FRONTAL VIEW)
GALEA
LACINIA

9. THORAX
•The thorax is elongate in some groups(i.e.
Panorpidae,Bittacidae,Choristidae) with pronotum
generally saddle like ,wider than long and often with
transverse ridges.Bothmesoand metathoraxare well
developed.
•The legs are generally adapted for walking ,the claws
are usually paired, and in Panorpathey are strongly
pectinated.
•In Bittacus,the claws are single ,and the 4
th
and 5
th
tarsal joints are provided with fine teeth along their
inner margins,the5
th
joint is capable of closing on to
the 4
th
in the manner of the blade of a pocket knife.

10. •Mecopterahave four membranous wings with
several cross veins , many species bear spots, or
transverse colored bands.
•Hind wings are slightly shorter than fore wings
and usually have similar markings.
•The venation is extremely archaic,theprincipal
veins and their branches(expecting those of Cu1)
frequently being present.
•In the venationalfeatures also,twopairs of
wings are alike ,the principal difference being
the basal fusion of Cu2 and 1A in the hind wing.

12. ABDOMEN
•The abdomen is 11-segmented ndis often slightly
constricted at the attachment of thorax.
•A genital bulb,resemblingbthatof a scorpion ‘stinger’ is
located on 9
th
abdominal segment of male panorpoids,
giving vernacular name scorpion flies Similar but less
pronounced male genital morphology can be found in
apteropanorpids,panorpodids.
•The 10
th
segment is very inconspicuous and bears a pair
of short 1 jointed cerci.
•In females,7
th
-10
th
segments are cylindrical and each is
telescoped into preceding segment,atthe apex of
abdomen is a pair of 2-jointed cerci.

13. Abdomen of Panorpabashanicola
male
female
Yuan Huaet al.(2018)

14. •Most mecopteransinhabit moist environment,
although a few species inhabit semi desert
environments.
•Adults are requentlyassociated with broad
leaved plants and can be occassionallyobserved
in open sunny areas.
•Scorpion flies (Panorpidae) are likely to be
encounter in wooden habitats where deciduous
trees growing in rich shaded soils.
•Boreidadults (Boreidae:snowscorpion flies)
occur occurin winter months , and in mountain
habitats.
•Bittacidsare known to inhabit grasslands,forests
and caves where high moisture occurs.
HABITAT

15. •The larval stage is difficult to locate and
unknown in some families,butthey tpically
occur in mosses,deadleaves and in soil cover in
wooded areas.
•Nannochoristaphilopotti,hasaquatic larvae.
•Many mecopteranspecies feed on decaying
vegetation or dead or dying soft bodied
arthropods as larvae and or adults.
•Some groups are reported to feed on nectar
,pollen, mosses and larval midges.

16. •Bittacidaebear modified legs for grasping and
holding prey such as Diptera,Hymenoptera
and Lepidoptera.
•KleptoparasiticPanorpascorpion flies are
known to feed on dead or dying insects
captured in spider webs.

17. MATING/COPULATION
•The males in many mecopterans(e.g
Panorpa,Bittacus) emit pheromones to attract
females, in some cases from several meters
distance.
•Mating behavior usually involves an offering of
food from the male ,and this is often a dead
insect or brown salivary secretion.
•The males of many boreidspecies bear slender
hook-like wings that are used to carry females on
their backs during mating.
•Male Panorpavibrate their wings rapidly , and
some species may stridulate as they approach
the female and seize them just before copulation
takes place

18. BITTACIDAE
BOREIDAE

19. LIFE CYCLE
•Eruciform(Panorpidae,
Bittacidae)
•Grub(Boreidae,Panorp
odidae)
•Exarate
pupa,capableof
abdominal
movement,with
decticousmandibles
•Loose cavities in
soil(Panorpasp)
•Dropped
randomly on to
the
ground(Bittacus
sp)
•Boreus(In mosses
•(winter-spring)
•Adult longevity depends
to a large extent on
reproductive biology.
•Males-risky acts-mating
•Eg;Meropeids(claspers)
•Panorpanuptialis
•One month…
Adult
2-3 months
in lab
conditions
EGGS(5-10
days)
Larva
Pupa(10-21
days)

20. ▪EGG: Eggs are either singly laid or in masses,theyare ovoidal
in Panorpasp & cuboidalin Bittacussp.
▪LARVA : It is eruciformbears a close resemblance to
caterpillar.
▪The head is rather large with prominent 4 jointed antennae
and it bears a group of about 20-28 simple eyes on either side
▪The mandibles are sharply toothed,themaxillae are divided
into lobes corresponding with galeaeand laciniae.The
maxillary palpiare 4 jointeand labium is small with labial
palpi3 jointed.
▪The thorax bears 3 pairs of legs,eachcomposed of 4 joints.The
abdomen is 10 segmented and the first eight somiteseacg
carry a pair of abdominal feet.
▪A median dorsal chitinisedshield is present on all the body
segments.Thefirst 9 abdominal shields each carry a pair of
annulated process,thelast two pairs being considerably
larger.

21. •The 10
th
segment bears a single median process of
similar character together with a curious retractile
lobed vesicle on its ventral side.
•9 pairs of spiracles are present (one on prothorax,8
on 1
st
eight abdominal segments)

22. Classification
S.NO FAMILY COMMON NAMES
1 Nannochoristidae
2 Bittacidae Hanging flies
3 Boreidae Snow scorpions
4 Meropeidae Earwig flies
5 Eomeropidae
6 Apteropanorpidae Winglessscorpion flies
7 Choristidae
8 Panorpodiadae Short faced scorpion flies
9 Panorpidae Scorpion flies

23. Classification.-The order has been recently
monographedby EsbenPetersen,whosefamily
divisions are as below :
Tarsi single clawed and modified for raptorial use-
BITTACIDAE
Wings vestigeal-BOREIDAE
Wings well developed-PANORPIDAE

24. •A sister group relation between Boreidaeand
Siphanopterais supported by morphological
evidence.
•The process of resilinsecretion in the flea(pleural
arch) and Boreus(wing base) is similar, and
different from that of the locust and dragonfly.
•The unusual proventricularspines in fleas and
boreidsare morphologically similar.
•Both groups have multiple sex chromosomes.
•Most convincing morphological evdencecomes
from recent research on ovarioles,which
demonstrates that boreidovariolesare
fundamentally different from those in other
mecoptera, but similar to those found in fleas.

25. •Mecopterapossess polytrohic-meroistic
ovarioles,whereas the ovariolesin Boreus
are devoid of nurse cells and therefore
panoistic.
•Molecular data also provides a compelling
argument for a sister group relationship
between Boreidaeand Siphanoptera.
Whiting, M. F. (2002). Mecopterais paraphyletic:
multiple genes and phylogeny of Mecopteraand
Siphonaptera. Zoologica scripta, 31(1), 93-104.
REFERENCE

26. Submitted to:
Dr.T.UmaMaheswari
Professor
Dept. of Entomology
Submitted by :
G.Satish
RAM/18-48

27. Thank you