Entomology Exam 1

approximately _ species of insects have been described, distributed among _ orders

1 million; 28 orders

insects have _ pair of antennae, how many sets of mouthparts and legs?

1 pair antennae, 3 sets of mouth parts, 3 pairs of walking legs

5 reasons why insects are conducive to scientific study

1. Easily cultured in lab 2. high turnover rates for population 3. less ethical concerns than vertebrates 4. small size 5. easily available

3 reasons for popularity of entomology in 18th century?

1. improved optics 2. gentlemen naturalists 3. spread of rationalism

5 ways that insects are essential to ecosystem functions?

1. nutrient cycling (leaf litter, wood degradation, disposal of carrion/dung) 2. Food for insectivorous animals 3. Plant propagation via pollination and seed disp. 4. maintenance of plant community composition and structure via herbivory 5. maintenance of animal community structure through disease, parasitism, and predation.

Diplura diversity? body size and basic features (body, eyes, mouthparts, antennae)

1000 species in 10 families (smaller than collembola which have 8000 species, 30 families). range usually from 2-5 mm but can be up to 50 mm in size. They are weakly sclerotized and therefore have soft bodies, they have no eyes, and their mouthparts, like collembola are entognathous! Antennae are moniliform (beads on a string)

What is the length of time for ephermeroptera development?

16 days to 1 yr depending on the species. This is hemimetabolous and is comprised of 12-44 instars.

the modern study of entomology dates back to the _ century

18th

there are approximately 1 million formally described species of insects, but extrapolations put the number undiscovered anywhere from _-_. However, estimates based on samples place this number between _ and _

2 to 80 million; Based on samples: 2-6 million species

How many beetle species in north america

20,000

How many orders of insects? to which class do they belong?

28-30 orders, depending on how you count. They are a member of the hexapods.

Species diversity of mayflies

3000 species 40 families

Species diversity of archaeognatha, usual size? development?

500 species and 2 families, also 6-25 mm in size. Development is ametabolous and molting is continuous throughout life

Species diversity of odonata? general size? are there varieties?

6000 species, 2 to greater than 15 cm. The two main types are dragonflies and damselfies

Species diversity of collembola? Body size?

8000 species in 30 families, 2-3 mm in length. They are ecologically common.

what is a keystone species and how does this apply to insects/example

A keystone species is the species whose loss may lead to ecosystem collapse, this can be the case with certain insects, for example termites convert cellulose in tropical soils into other organic materials to support life

This order of insects is also known as the bristletails, is one of the two most primitive insect orders and is primitively wingless, has ametabolous development and continuous molting

Archaeognatha

This primitively wingless order of insects has both cerci and an epiproct. It is usually nocturnal, has a hunched thorax and styles on the ventral side of its abdomen. It is not very species rich, having only 500 identified species and 2 families. It is characterized by ametabolous metamorphosis and molts continuously.

Archaeognatha (bristle tail)

2 ways insects are unuseful, three ways important (to our survival)

Bad 1. pests of crops. adverse effect on ag 2. can damage our health and that of animals\ good 1. provide food (lots of biomass) 2. pollinators 3. can do pest control 4. provide useful chemicals like silk

what is the penultimate instar? For ephemeroptera, what is this instar like?

Called the subimago (adult= imago). The subimago of the ephemeroptera is fully winged, has no gills, can fly although it does not feed and is shortlived. It emerges, mates, lays an egg, and dies.

what is the most diverse order of insects? how many species

Coleoptera (beetles); 350,000

High levels of undescribed species are likely to exist in what four orders

Coleoptera, Diptera, the parasitic (usually wasps) Hymenoptera, and Lepidoptera

All of the non insect arthropods have a thorax hardly differentiable from the abdomen except...

Collembola

What is interesting about collembola legs? Protura?

Collembola have 2 subcoxal segments on their legs. Protura have anterior legs which are held forward and fulfill much of their sensory function (recall they have no eyes or antennae)

ecologically common 2-3mm long soft-bodied non-insect arthropods w/ very little cuticle.

Collembola or springtails

This hexapod order has ocelli, are small and soft bodied, their legs feature 2 subcoxal segments, have sensory organs behind their antennae, and have entognathus mouthparts, as members of the group entognatha. They jump with their furcula, and also have a collophore for salt exchange and retaining hook called a retinaculum

Collembola- the Springtails

How many species for: Each of the entognathans, and archaeognatha, one of the two primitively wingless insect orders? What order is nocturnal, hunchbacked, has compound eyes and ocelli, molts continuously and is usually 6-25 mm in length?

Collembola: 8000 sp. Diplura: 1000 sp Protura: 800 sp (poorly studied) Archeognatha: 500 sp. Archaeognatha

Ephemeroptera: eyes, mouthparts, antennae, wings?

Compound eyes and 3 ocelli, have reduced mouthparts, filliform antennae, and large triangular forewings with smaller hindwings

Omnivorous non insect hexapods, display some social behavior, 2-5mm in length though can be up to 50. Have cerci and maniliform antennae, and display some social behaviors/care for young. They molt continuously.

Diplura

This non insect hexapod order is distinct from the other non insect hexapods in that its thorax hardly differs from its abdomen and they also have cerci which range from long and philoform to short and pincer like

Diplura

non insect hexapods with no eyes, 2-5 mm in length (but can be up to 50mm), soft-bodied, unpigmented and weakly scleerotized, and have cerci

Diplura

what are the three entognathous orders?

Diplura, Protura, Collembola

The mayflies are part of what order of stream dwelling insects?

Ephemeroptera

This order of insects has reduced mouth parts, 12-44 instars in its hemimetabolous development which can range from 16 days to 1 year depending on the species, of which there are 3000. They are excellent bioindicators for streams, have filliform antennae, compound eyes and 3 ocelli, and have aquatic algae feeding nymphs.

Ephemeroptera

true/false: Archaeognatha and Zygentoma are both primitively wingless, but archaeognatha have compound eyes while zygentoma have ocelli. Both have epiprocts.

False! All true except that archaeognatha have both compound eyes and ocelli.

Where do proturans live?

Found exclusively in soil, moss, and leaf litter

What is the difference between a Furca, retinaculum, and epiproct?

Furca is the tail of the springtail or collembola, allows it to jump. Retinaculum is also a part of the collembola, it is a retaining hook. The epiproct is a part of Archaeognathan anatomy, and along with the cerci gives it the appearance for which it is called a bristletail.

Zygentoma mouthparts, legs, eyes, cerci?

Hypognathous mouthparts, large coxae, 1-3 ocelli, no compound eyes, and have cerci (plus epiproct)

Zygentoma reproduction? where do they live? how related to ants/termites?

Indirect fertilization via spermatophore placed on the ground. They live in mammal burrows, in caves, leaf litter, deserts, and under bark. Can be commensal with ants and termites.

What is interesting about the archaeognatha thorax? Abdomen?

Its thorax is humped, giving it a hunched over appearance. The abdomen is segmented and has small muscle containing styles on its ventral surface

Ametabolous development

Little or no change between molts, an ancient condition that occurs in primitively wingless insects

Where do collembola usually live and why? relation to termites?

Live in moist soil or leaf litter, consume decaying vegetation, can be commensal with termites or ants.

what does the term mating flights have to do with?

Mayfly (ephemeroptera) males have elongate legs used to seize females during mating flights

what order of hemimetabolous insects has long lived adults that travel in a basket conformation, can be up to 15 cm in length, has aquatic nymphs and 20 instars, can be divided into two major suborders, has mandibulate mouthparts and short bristlelike antennae?

Odonata

What order of insects features 6000 species, has long lived adults who fly with their legs in basket conformation, 2 main types, aquatic nymphs, 20 instars and extensible grapsing labium?

Odonata (dragonflies and damselflies)

Coleoptera, Diptera, Hymenoptera, Lepidoptera: what relates these four

Of undiscovered insect species, most are likely to be members of these four orders

Protura diversity, general size, and body type?

Only 800 species (diplura have 1000 and collembola have 8000), 7 families (half in one genus), less than 2 mm in size (smallest non insect hexapod). Delicate and mostly unsclerotized elongate body, in which the thorax and abdomen are hardly differentiated. They are also almost entirely lacking in pigment

contrary to early molecular studies, what two groups, which share segmentation and appendages w/ arthropods, and are sometimes grouped w/ arhtropods

Onychophora (velvet worms) and Tardigrada

who was Karl Stephan?

Originally from germany, nonprofessional beetle collector in Lattimer County, Oklahoma, collected over 2000 diff species, a little over 10% of the beetle diversity in north america, right in his backyard. He sent to UF's insect collection, and ID'd insects via a primitive microscope.

the most poorly studied of the entognathans?

Protura! Little is known about its biology

Order of non insect hexapods with the smallest number of species is...? how many?

Protura! Only 800 species (7 families and half are in one genus)

This non insect arthropod is soft bodied and lacking greatly in sclderotization. It is nearly transparent and lives in moist soil or leaf litter. It lacks eyes, antennae, cerci, and uses its anterior facing legs and pseudocolus organ to fulfill much of its sensory functions. It is the least studied of the three entognathans, and has the smallest species diversity, with only 800 species and 7 families

Protura.

Springtails are the ___? Bristletails?

Springtails are the order Collembola. Bristle tails are Archaeognatha.

What is entomophagy?

The practice of eating insects.

what is interesting about the mouthparts of aquatic nymphs of odonata?

They are extensible labium for grasping.

Where do archaeognatha typically live, what do they eat, what is their movement like?

They are nocturnal, live beneath bark or leaf litter during the day, they eat litter, detritus, algae, lichens, moss. They can run fact and jump considerable distances.

Are collembola insects? what is their common name?

They are non insect hexapods. Their common name is springtails.

How does dipluran diet differ from collembola

They are omnivores, while collembola are herbivorous/feed on decaying plant matter in leaf litter and moist soil

Do diplurans have eyes? Cerci? How does their body type differ from Collembola?

They do not have eyes, they do have cerci, and their body is more enlongate with a thorax and abdomen that are hardy differentiated from eachother

what is interesting about how ephemeroptera emerge from streams? how can you tell mayfly nymphs from other aquatic insects

They emerge synchronously in a swarm. easy to identify due to the 3 pronged tail (epiproct + cerci)

Besides anterior facing legs, how else do proturans sense their environment?

They have a sensory organ called a pseudoculus.

What are the three special features of Collembola? What are they for?

They have a ventral tube for salt exchange (also called collophore), a retaining hook called a retinaculum, and a forked jumping organ called a furca/furcula

describe the sensory system of Collembola

They have no compound eyes, only ocelli, as they spend much of their time buried in the soil. Behind their antennae is a pair of sensory organs not usually seen in other hexapods.

What is diplura development like? Do they display social behavior?

They molt continuosly throughout their life, incomplete metamorphosis. they do display some social behaviors (gregarious) and females tend young/eggs,

Archaeognatha reproduction? are they diurnal?

They reproduce indirectly via sperm droplets placed on the ground. they are usually nocturnal.

describe the general appearance of Collembola- what is their cuticle like, etc?

Very little cuticle, they are extremely small, mostly membranous and soft-bodied. Also wingless and legs have 2 subcoxal segments.

Are there non insect hexapods? If yes, how many?

Yes. There are three orders of hexapods which are not considered insects.

This primitively wingless order of insects is dorsoventrally flattened has large coxae, can lives in caves, deserts and mammal dwellings, can be comensal with ants or termites, uses indirect fertilization, can be 5-13 mm in length and only has 600 species. They also have cerci and a long caudal appendage called an epiproct

Zygentoma

This order of insects is primitively wingless, has only 600 species, can be 5-13 mm in length, has no compound eyes but 1-3 ocelli, has characteristic silver scales and is dorsoventrally flattened

Zygentoma (silverfish)

why does the archaeognatha appear to have three tails?

because it has cerci plus a caudal extension that is longer than the cerci

besides being important to our survival, why else are insects useful

can be good model organisms to study, such as drosophila in genetics!

Odonata eyes, mouthparts, antennae?

compound eyes, 3 ocelli, short bristlelike antennae. Mouthparts mandibulate.

Any aspect of the study of insects, be that evolution, ecology, bahvior, anatomy, physiology, biochem, genetics

entomology

true/false: most of what we know about insect diversity today is due to scientific studies by researcher universities

false! most is due to nonprofessionals

What do ephemeroptera nymphs feed on? are they aquatic? what allows for this?

feed on algae, are aquatic, have abdominal lamellar gills!

In temperate climates, what is true sometimes of fly and beetle species?

flies (number of species) may outnumber that of beetles in some temperate climates, though coleoptera are usually taken to be the most diverse hexapods

What is a furcula? Retinaculum? collophore? what hexapod order has these features?

furcula is a forked jumping organ, retinaculum is a retaining hook, and the collophore or ventral tube is used for salt exchange. These are all features of the non insect hexapod order, collembola

the ancestral insect form has _ segments and what else

has 15 segments, 1 pair antennae.

what is odonata development like?

hemimetabolous, has 20 instars

what type of ephemeroptera forms mating swarms?

imago.

are collembola sexually dimoprhic

in some life stages, males and females take diff # of molts! Males 5, females more.

what is the zygentoma abdomen like?

it has 11 segments (primitive) and also has muscle-containing styles on the ventral side (like archaeognatha)

Ephemeroptera development

it is hemimetabolous! Nymphs are aquatic and there are 12-44 instars.

Termites in the tropics are an example of a _, because they turn cellulose into usable organic materials in the tropical soil

keystone species

multivoltine means..

multiple generations per year

Within arthropods, hexapods were thought to be most closely related to what? why?

myriapoda, since both have head capsules, and generally are morphologically similar. However, molecular phylogenetic studies have shown that hexapoda are actually closest in relation to crustaceans

are onychophora and tardigrada arthropods?

no but in some studies that are grouped with them, they have segmentation and appendages in common with arthropods.

Protura: eyes, antennae, cerci, mouthparts?

no eyes, no antennae, no cerci, and mouthparts are entognathous

dragonflies and damselflies are members of what order of insects? how do they differ from eachother and what are their proper names?

odonata. The dragonflies are anisoptera and damselflies are zygoptera. They differ in that damselflies have widely separated eyes and similar looking wings with narrow bases. Anisoptera (dragonflies) have contiguous eyes and hindwings that are broader at the base. Also, they both have aquatic nymphs but zygoptera have normal gills while anisoptera have gills in the rectum

Zygentoma diversity, size, shape?

only 600 species in 3 families, 5-13 mm in length, and are dorsoventrally flattened.

some studies indicate that insects are closest in relation to crustaceans and others still that they are _ to crustaceans

paraphyletic

Physical characteristic of zygentoma that is unique?

silvery scales

Archaeognatha mouthparts, eyes, cerci?

the mouthparts are hypognathous (facing down and back), they have large compound eyes as well as ocelli, has cerci

define entomology

the scientific study of insects, anything related to their biology

Mouthparts for collembola? Why are their legs special?

their mouthparts are entognathous, meaning contained in a pouch, this whole group is called entognatha because of this feature. their legs have 2 subcoxal segments (at the top)

What is a weird developmental feature of proturans?

their segments are added posteriorly during development.

Do ephemeroptera have cerci? epiproct? 2 other orders that have epiproct?

they have cerci and an epiproct. Zygentoma (silverfish) and Archaeognatha (bristletails) also have epiprocts.

What is interesting about male adult odonata?

they have secondary genitalia on the ventral side of the 2nd and 3rd abdominal segment

what is unique about collembola reproduction? what is their metamorphosis like?

they lay eggs like most insects though these eggs lack a substantial yolk. They use incomplete metamorphosis, with adults looking a lot like the immatures. Males reach maturity in five molts, females take longer, and there is sexual dimorphism in a number of life stages

Are there one or multiple generations per year of ephemeroptera?

this depends on location, ones in colder climates will have one generation per year and develop more slowly while others will be multivoltine, mult generations per year