Insects Flashcards
Where are the genetalia of an insect found
At the tip of the adbomen
Name four different defence mechanisms used by insects
Physical defence; Colouration (Aposematic/Flash/Cryptic); Mimicry; Chemical Defence
What does metamorphosis mean?
Change
What is the purpose of flash colouration?
Give the predator a fright as well as distract the predator with a different colour when fleeing before hiding from danger with their original colouring.
What is Sclerotin?
A tough and indigestible substance that strengthens the Chitin that makes up the exoskeleton of certain insect species. This is known as a Sclerotized exoskeleton e.g. Armoured Ground Cricket
What is Chitin?
Chitin is what the exoskeleton of an arthropod is made of.
What is the name given to a sexually mature insect?
An imago
Explain the mutualistic relationship between Termitidae and Termitomyces
Fungus-growing termite workers will chew up and eat dead and decaying plant material. Because they are unable to fully digest it they return to the nest and excrete it. The job of digesting these faeces is done by fungi. The resulting compost is then eaten by the colony. The fungi are given an ideal environment to grow within the termitaria
What is unique about the Order Diptera that flies belong to?
Their hind-wings are reduced to vestigial appendages known as “halteres” and are used for balance during flight
What is stridulation?
Rubbing of one part of the body against another producing a sound e.g grasshoppers
What is thanatosis?
This is the act of feigning death practised by animals
Name three insects that have aposematic colouring
CMR Beetle; Elegant Grasshopper; Monarch Butterflies
Are Antlions diurnal or nocturnal?
Nocturnal
What is Batesian Mimicry?
Batesian mimicry is a form of mimicry where a harmless species has evolved to imitate the warning signals of a harmful species directed at a predator of them both. It is named after the English naturalist Henry Walter Bates; after his work on butterflies in the rainforests of Brazil e.g. Female Diadem and African Monarch butterflies
What is the tallest termite mound recorded?
12.8m High
What are flying ants?
Vernacular term often given to reproductive termites (alates)
How does a fungus-growing termite colony start?
Winged alates > Colony foundation > First workers > First workers create fungal comb > growth Termitomyces fungus on the comb > Workers gut transfer (dead plant material + fungal spore) > other castes form eventually > Finally alate formation; they again fly from the colony to form a new colony.
What is an imago?
A sexually mature insect
What is the sine qua non of mimicry?
The mimic population must be significantly lower than the species that it is mimicking
What diseases are mosquitoes vectors of?
- Malaria
- Yellow Fever
- Elephantitis
- Encephalitis
What is interesting about the light produced by fireflies?
“Bio-luminescence” – most efficient form of light known to man (“cold light” - no energy lost in the form of heat; all “visible” light rays) ;Some female fireflies (often wingless) mimic the “codes” of other species to attract males; who they then eat.
Do both sexes of mosquitoes suck blood?
Since blood is a good source of proteins and amino acids; female mosquitoes drink blood to grow mosquito eggs. The male mosquitoes fulfill their nutritional needs by feeding on nectar; water; and plant sap; which females feed on as well.
What Order & Family do Antlions belong to?
Order Neuroptera - Family Myrmeleontidae
What caste is the most numerous within a termite colony?
There are more worker termites than any other caste within the colony
How does a termite queen communicate with her colony?
Pheremones are transferred to the workers she’s in contact with then they will continue to pass on the message throughout the colony through an exchange of saliva with other termites
How do insects breathe?
They have no lungs so cannot actively “breathe”. Air enters their body via tiny apertures; called spiracles; situated along the sides of the adbomen. Fine tubes; called trachae; carry air to all parts of the body.
What is a proboscis and what is it used for?
Butteflies; moths & mosquitoes suck up liquid food; such as nectar or blood; through their proboscis which is a modified mouthpart that acts as a slender drinking tube.
Why are termite mounds referred to as Nutrient Hotspots?
Due to the well aerated soils from the termitaria as well as the high soil fertility created by the fungus growing within the fungus gardens leads to a perfect environment for plants to grow.
How long do termite queens live for?
A queen termite has a long lifespan and is typically the oldest termite in the colony. Termite queens can live 25 to 50 years, with peak egg production for up to 10 years. When the queen dies and the pheromone she uses to block reproductives’ development is no longer produced, a new queen will develop in the colony.
What is the purpose of fireflies producing light?
Signals to opposite sex and species recognition (each species has a unique flash pattern)
What is the specialized egg-laying organ of a female insect called?
Ovipositor
What is Mullerian Mimicry?
Mullerian mimcry is a form of mimicry in which two or more harmful or unpalatable animals develop similar appearances as a shared protective device e.g. Acraea butterflies and Monarch butterflies
What are the characteristics of invertebrates?
Animals that do not have a back-bone and may or may not have an exoskeleton and do not necessarily have legs either
What is an instar?
A phase between two periods of moulting in the development of an insect larva or other invertebrate animal.
What are the different body divisions of insects?
Head, thorax and abdomen
What are the different lifecyles found in insects?
Ametabolic; hemimetabolic; and holometabolic
What are the stages of an hemimetabolic lifecyle and give 2 examples of insects that have this lifecyle?
Egg > Nymph > Adult. Nymphs resemble adults (mostly). With each moult (ecdysis) they develop more adult characteristics e.g. dragonflies; crickets
What are the 4 termite families?
Termitidae - Fungus Growers Rhinotermitidae - Snouted Termites Hodotermitidae - Harvester Termites Kalotermitidae - Dry Wood Termites
Where do mosquitoes breed?
In water as the larval stage are aquatic
How do fireflies produce light?
Light producing organs situated on the underside of the abdomen, towards the back (last two segments)
Chemical reaction involving the oxidation of a substance Luciferin in the presence of an enzyme Luciferase
Specialised cells in underside of abdomen filled with tiny urate crystals used as reflectors
What defence mechansim do processionary caterpillars employ?
They will congregate in long continuous lines giving the impression that they are a much bigger animal than they actually are.
What are Elytra?
These are the hardened forewings (especially evident in beetles) that cover the hind-wings when at rest. They are not used in flight and provide protection and in some species have fused if flight is no longer required.
What are the stages of an holometabolic lifecyle and give 2 examples of insects that have this lifecyle?
Egg > Larva > Pupa > Adult. Larval stage does not resemble adult (grubs and caterpillars). Pupate in order to take on adult form e.g. Butterflies & Moths
Are glow worms male or female?
“Glow-worms” are actually flightless females of the genus Lampyris (larva-like) – give off a steady glow; not flashing.
What do adult Antlions resemble? Describe their flight pattern.
The adults superficially resemble dragonflies; although the antlion antennae protrude visibly; being longer and club-like. They are clumsy fliers with a characteristic slow; flapping flight pattern.
What are the differences between Exopterygota and Endopterygota?
The first (Exopterygotes) have a simple or incomplete metamorphosis with the immature stage as a nymph; while the latter (Endopterygotes) have a more complex; complete metamorphosis with larval; pupal and adult stages.
How many eggs per day does a termite queen lay on average?
30 000 eggs
How many Orders of Insecta are there in South Africa?
25
Name the different Classes of the Phylum Arthropoda
- Insecta
- Arachnida
- Crustacea
- Chilopoda
- Diplopoda
Which part of the body are the wings of an insect attached to?
Thorax
What are the stages of an ametabolic lifecyle and give 2 examples of insects that have this lifecyle?
Egg > Young > Adult. Young are miniature versions of adults and only moult a few times e.g. Silverfish; Bristle-tails
What are the 5 different castes that make up a termite colony?
- Queen
- King
- Workers
- Reproductives
- Soldiers
What is the difference between termites & ants?
- Ants have bent antennae that look sort of like an elbow. Termite’s antennae are straight or slightly curved, but never bent like an elbow
- Ants are thinner in the middle section than that of termites.
- Another distinguishing characteristic of termites is that it has larger wings and they are always similar in size and shape, meaning they all look alike. The wings of a flying ant are far more random and do not look alike in size and shape.
What is an arthropod?
An invertebrate animal having an exoskeleton, a segmented body, and paired jointed appendages.
What temperature is a termite mound kept at and how is this achieved?
A fungus-growing termite nest sits 1 m below the ground. It is kept at a constant temperature of 31 degrees centigrade by a spiralled mound which emits hot stale air through tiny holes in its walls which in turn allow cold fresh air in. This then circulates around a network of tunnels
Name 4 methods of communication in insects
- Colour
- Light
- Sound
- Scent - phermones
What is hypermetamorphosis and give an example of an insect that has this lifecycle?
This is a complex metamorphosis involving various forms of the larval stage:
- Eggs laid in soil
- First stage larvae emerge and actively seek out grasshopper eggs (some species attach themselves to bees and are carried to the hive)
- If successful they will then moult into inactive grubs and feed off the grasshopper eggs (or bee larvae) - In some cases there is a further “dormant” grub stage
- Grub then pupates
- Adult emerges after a number of weeks
e.g. Blister Beetles
What insect uses tymbals to produce sound?
Cicadas produce amplified “clicks” using tymbals (membranes) on the underside of abdomen by pulling these membranes in then releasing them again akin to pressing down the lid of a tin repeatedly to produce a sound.
What is the exoskeleton of an arthropod made of?
Chitin
How do termites build mounds?
Fungus-growing termites work individually using a process called swarm intelligence to build complex temperature controlled mounds with specialist chambers and fungal gardens. There is no central blueprint or coordinator for this outstanding piece of engineering. The fungus-growing termites build large mounds which are typically 2 to 3 metres high. The mounds; known as termitaria; are made with a mixture of soil; saliva and faeces which dry as hard as concrete. These structures can withstand being used as a rubbing post by elephants.
What would you look out for when looking for Antlion larvae in the field and explain their method of capturing prey?
Larvae move backwards; and have long; elongated mouthparts modified for sucking out the body fluids of their prey
What is a haemocoel?
This is the body cavity of an arthropod
Name 5 different chemical defence mechanisms employed by insects with an example of each
- Stings - bees & wasps
- Irritant hairs - Certain caterpillars
- Toxic secretions - Blister beetles
- Squirting acid - Ground beetles (formic acid)
- Repugnatorial excretions - Stink bugs
What is cantharadin?
Cantharidin is an odorless; colorless fatty substance of the terpenoid class; which is secreted by many species of blister beetles. … In its natural form; cantharidin is secreted by the male blister beetle and given to the female as a copulatory gift during mating.
Give an example of a beetle that practices Batesian mimicry
Meloid-mimicking Jewel Beetle mimics the Blister/CMR Beetle
What are the body fluids of arthropods called?
Haemolymph
What are the differences between butterflies and moths?
Butterflies
- Wings generally held together vertically when at rest i.e. closed
- Antennae usually “clubbed”
- Usually active during the day
Moths
- Wings typically folded “roof-like” over abdomen at rest i.e open
- Antennae either “feathery” (males) or straight
- Usually active at night
What are the differences between dragonflies and damselflies?
Dragonflies
- Broader hindwing
- Wings held open when at rest
- Eyes touching each other at the top of the head (except Gomphids)
- Overall body shape appears more robust
Damselflies
- Fore- and hindwings equal size
- Wings held together over abdomen when at rest
- Eyes widely separated (“bulbous” on the side of the head)
- Overall body shape appears more slender
Dragonflies Damselflies Broader hindwing Fore and hindwings equal size Wings held open when at rest; Wings held together over abdomen when at rest Eyes touching each other at the top of the head (except Gomphids) Eyes widely separated (“bulbous” on the side of the head) Overall body shape appears more robust Overall body shape appears more slender
Name the different insects
- Owl-fly
- Antlion
- Dragonfly
- Damselfly
- Antlion
What is this and what insect made it?
It is a Prey Mantis egg case called an Ootheca
What are the two subfamilies of mosquitoes?
- Culicinae – rest with bodies parallel to surface
- Anophelinae – rest with bodies tilted at 45 degrees
What genus of mosquitoes carries the parasite reponsible for causing malaria?
Anopheles
What are the 4 strains of malaria?
- Plasmodium vivax (mildest form)
- Plasmodium falciparum (“cerebral malaria”) – most serious
- Plasmodium malariae
- Plasmodium ovale (similar symptoms to P. vivax)
What moths are Horn-Borer moths related to?
Clothes Moths
What do Horn-Borer moths digest on the horn?
They digest the keratin that the horn is made up of. This is the larval stage of the moth lifecycle
Where do Matabele ants get their name from?
Matabele ants are named after the Matabele Warriors who advanced through south and central Africa in the 1850s; wiping out villages as they went. They were an off-shoot of the Zulu nation under the leadership of one of Shaka’s lieutenants; Mzilikazi (whose name means “The Path of Blood”) their marauding armies crushing African villages; destroying and killing everything in their paths
What do Matabele ants feed on?
They almost exclusivley feed on termites
Describe a Matabele Ant raid
Well organized raids initiated by a lone “scout” who lays a pheromone trail behind her once a termite nest has been located. Foraging termites or termite dwellings are located by the detection of chemicals in the soil sheeting built by the termites. The raiding party follow the pheromone trail directly back to the termite colony. They enter the termite colony; stinging and paralyzing their prey and stacking them around the entry points. At the end of the raid the termites are carried back in bundles in the jaws of the major workers
How many insect species are there in the world?
Estimated between 6 - 30 million species
What percentage of world species are insects?
55% of all known species on Earth are insects. Estimated that for every living person there are 2 million insects.
How many species of insects are there in Southern Africa?
80 000 species
Which orignated first dinosaurs or insects?
Insects. They originated about 300 million years ago and dinosaurs only about 230 million years ago!
What is the traditional use of Blister Beetles?
True Spanish fly is made from blister beetles, specifically the substance produced by the beetles called cantharidin. The insect’s name is not for nothing; contact with cantharidin blisters skin.
Its use dates way back, and some of its many infamous fans included:
- a Roman empress who used cantharidin to encourage sexual behavior worthy of blackmailing her family with
- Roman gladiators who used it for orgies
- queens who used it on their kings and those kings on their mistresses to spice things up
Dried beetles would be crushed and be mixed with drinks or sweets — not always to the receiver’s knowledge — and consumed to promote feelings of warmth throughout the body and swelling of the genitals. But these warm fuzzies are due to inflammation, not attraction
In the name CMR Beetles, what does the “CMR” stand for and why?
Cape Mounted Riflemen - A group that had uniforms with black and yellow bands
Certain insects form a beneficial relationship involving ants, employing the efficient and aggressive nature of these ants to provide them with protection and/or food – What is the term given for such a relationship (involving ants) and give an example of an insect that makes use of such a relationship?
Myrmecophilous relationships e.g. Paussids -> Ant Nest Beetle
A myrmecophile is an organism that lives in association with ants.
What does sequester refer to in reference to arthropods?
Animals may acquire toxicity by absorbing toxic compounds from their food, e.g. from plants or other animals. Sequestration and accumulation of toxins may provide protection from predators, which learn to avoid this prey because of unpleasant experiences such as bitter taste
Name a beetle that is known to spray formic acid in self-defence?
Ground Beetles
Describe the appearance of an adult antlion?
It has a long slender body with big eyes and long wings
What is an alate?
A winged reproductive caste from a social insect colony in its winged form.
What do the dwellings of “Harvester” termites look like?
They excavate nests up to 6m deep in the soil forming spherical hives
Can termites digest cellulose?
No but they have tiny organisms living inside their digestive systems called protozoa that break down the ingested cellulose except for Macrotermes that use fungus gardens in their termitaries to break down the cellulose for them to later consume.
What does a “nuptial flight” mean?
The nuptial flight occurs after heavy summer rain and the alates from the termitaria are let out and will fly to find a mate from a different termitary
What is “Termitomyces” and where does it grow?
Termitomyces is a genus of fungi that rely totally on termites of the subfamily macrotermes for survival. They grow in the fungus gardens established within the termitary.
Your guest describes having seen an insect that looked like a wasp but had no wings – it was a deep metallic brown/purple with a few white spots. What might this insect have been?
Velvet Ant
Explain the life-cycle of a “fig” wasp?
Female wasp finds a suitable fig and lays her eggs in a floret within the syconium. The males hatch before females and impregnate females. Males burrow their way out of fig wall. Females hatch and use the tunnels made by the males to exit the fig and complete the life cycle.
Discuss the small pipe-like structures that may be found on the horns of dead animals; what is unique about the species that is responsible for these?
These are created by Horn-Borer moth larvae. The tubes are reinforced with the larvae’s excrement as it gnaws its way through the keratinous horn material. The larvae eat keratin via a process called keratophagia. They will pupate after +-2 years
How might one be able to distinguish between males and females of adult moths?
Males have more feathery looking antennae as these are used to aid in finding a female by “smelling” the pheremones produced by the female.
How would one easily distinguish between a dragonfly and a damselfly?
- Dragonflies have hind wings that broaden at the base which makes them larger than the front set of wings.
- Damselflies have wings that are the same size and shape for both sets and they also taper down as they join the body becoming quite narrow as they connect.
- Damselflies rest with their wings closed, and dragonflies with their wings open
- If you are fortunate enough to get an up close view of dragons and damsels, then you will notice that dragonflies have very large eyes that are close together, whereas damselflies have, though still large, smaller eyes with a gap in between.
What insect constructs a larval case from Acacia thorns or other material? Give a traditional belief involving these insects.
Bagworms
In Zambia, the Nkoya believe that the bagworm is female and that the male is a small snake person (7; pp. 166–172). The bagworms are considered dangerous because snakes are always in the neighbourhood. When treading upon a case and crushing it, the snake will attack and bite the person. In Zambia (Lozi), I was told that when bagworms are given to the husband in his food, he will remain loyal to his wife. In Kenya (Kamba), it was mentioned that when an uncircumcised boy loses cows, it is a serious matter and the boy then collects a bagworm and forces the caterpillar to come out. The direction to which it points when it comes out indicates that is where the lost cows can be found.
Explain the reproductive (courtship) process of the African monarch butterfly?
The male Monarch has a secretory gland on his hindwing which he inserts a pair of protrusions from his abdomen. He will then brush the powder over the females antennae to induce a “relaxed state” which will allow him to mate with her.
Give the names of ten butterfly species found in the lowveld.
Some examples:
- Bushveld Purple Tip
- Bushveld Orange Tip
- Common Orange Tip
- Broad-bordered Grass Yellow
- Common Grass Yellow
- Wandering Donkey
- Citrus Swallowtail
- Brown Veined White
- Yellow Pansy
- Blue Pansy
- Guineafowl
What species of moth is the Mopane Worm the larval stage of?
Gonimbrasia belina is a species of emperor moth which is native to the warmer parts of southern Africa. Its large edible caterpillar, known as the madora or mopane worm or amacimbi,masontja, feeds primarily but not exclusively on mopane tree leaves. Mopane worms are an important source of protein for millions in the region.
What 4 types of dung beetles are there and how do they use dung differently?
- Endocoprids
- Live inside the pile of dung and eat and lay eggs inside it
- Paracoprids
- Make tunnels below pile of dung for eggs
- Telecoprids
- Roll balls of dung away from original site for food and eggs
- Kleptocoprids
- Steal balls from Telecoprids for their own use
What animals feed on the larvae of Dung Beetles?
Civet & Baboons
Approximately how many species of dung beetle occur in southern Africa?
780 Species
What is malaria and how is it transmitted?
Malaria is a serious and fatal disease caused by infection by protozoan parasites. It is transmitted by the bite of female mosquitoes.
What insect is the main vector of Yellow fever?
Mosquito Aedes aegypti
Which insect is responsible for transmitting “Sleeping sickness”?
Tsetse fly
What is another name for “Trypanosomiasis”?
African Sleeping Sickness
What is “Nagana”?
African Sleeping Sickness
Which two species of insects are responsible for the galls on Silver Cluster-leaf trees?
Gall wasps & Midges
Answer the following:
- longest insect
- Heaviest insect
- Smallest insect
- Longest living insect
- Shortest living insect
- Fastest insect
- Insect with the longest migration
- Stickinsect
- Heaviest adult insect - Giant Weta
- Larval stage of Goliath Beetle is heaviest insect
- Fairyfly
- Termite Queen
- Dot Mayfly
- Dragonflies
- Wandering Glider dragonfly
What insect gives the “Rain tree” and the “Weeping wattle” their common names? Describe this insect’s life cycle and how it gets its common name.
The Spittle Bug has a hemimetabolic lifecyle. They pierce plant stems and feed on plant juices. As they feed they defecate at the same rate of feeding producing a foam like substance that drips from their anus.
Discuss the Weevil/Cycad relationship?
Female hose nose cycad weevils will use their long noses to bore into the cycad seed where they will lay their eggs. Once hatched the larvae will feed on the cycad seed. This will hollow out the seed and the larvae will pupate inside the seed and emerge as adults.
