ENTM010 exam 2

Male reproductive organs (spermatophores)

• Testes: produce sperm

• Accessory glands: contains nutritional value for female’s egg development “sperm package”

• Aedeagus: for mating (copulation)

Female reproductive organs

• Ovaries: produce eggs

• Spermatheca: stores sperm

• Accessory glands: produces ootheca (egg sac)

Reproduction

the formation of new individuals

Mating

the pairing of opposite-sex organisms for the purpose of sexual reproduction

Parthenogenetic

females who reproduce by themselves, ex: Aphids

Insects that reproduce without mating (w/o the fertilization of eggs)

• pros: great reproductive potential, no risk of losing fitness by mating (e.g., predation and mating with “inferior” males)

• cons: little mixing of genetic material

Genetic recombination

major benefit of mating, that allows for phenotypic variation which is unique offspring that can cope with different niches or environments

Why mate?

to produce new combinations of genetic variation

Mate choice

insects are extremely choosy when selecting mate because mating can be costly, is a major component of sexual selection, is one of the modes of natural selection, only 50% of organisms reproduce, and they only pass on 50% of their genes, and because there is the chance of harmful genes

Sexual dimorphism

substantial difference in size and/or appearance between adult males and females of the same species resulting in advantages of those with body size (where large males result in male-male competition because of female’s preference and large females result in female’s fecundity)

Sexual selection

is mode of natural selection in which some individuals out-reproduce others of a population because they are better at securing mates, it occurs through “choices made between sexes” and “competition within same sex” and results in difference in the ability to acquire mates and therefore the differential transmission of certain characteristics (or genes) to the next generation

Combat

part of sexual selection, contest competition in male stag beetles

“Good genes”

part of sexual selection, melanized wing patches in male damselflies and males with prominent melanized wing patches are preferred by females, and production of melanized wing patches involves a physiological process shared with an insect immune system

Nuptial gifts

part of sexual selection, scorpion fly with prey item or salivary secretions and recently-mated female katydid (spermatophore attached)

Fertilization without copulation

includes springtails (collembola); which is a small hexapod, not an insect, and firebrat and silverfish (zygentoma), it is indirect sperm transfer, involves:

• tug of war: drag female over sperm packets

• sperm rings: surround female with a ring of spermatophore

• love gardens: deposit sperm packets throughout an area in hope of female coming through

Ephemeroptera (Mayflies)

mass emergence, short lifespan (<few days), occurs near water body

Termites

swarming triggered by one or more environmental cues

Behavior and scent

part of courtship, the queen butterfly, in-flight seduction: “hair-penciling”, male organs called hair-pencils play an important role in courtship, and aphrodisiacs/tranquilizers to females as well as repellents to other males of same species

Mate guarding

part of courtship, damselfly and dragonfly, ensure paternity

Males attracting females

through sound, females evaluate signal intensity, complexity or persistence of a male’s signal to gain information about the quality of the sender

Males holding territories

male competition for access to females, create resources of interest to females such as oviposition sites, foraging or feeding sites, emergence sites, and non-food resources, and by landmarks

Emergence sites (nesting)

male bees can detect emerging female bee underground based on scents ex: “digger bees” mating

Non-food resource

is an advantageous habitat, males hold and defend sunspots (small patches of sunlight in the forest) territories, they sit and wait for a chance to mate with a passing female ex: speckled wood,

Landmarks

includes prominent landscape features like “hill-topping”, lek; where an aggregation of males that engage in competitive displays that may entice visiting females who are surveying prospective partners for mating, ex: male leaf-cutting ants lek above the desert floor awaiting virgin queens who fly into the swarm to mate

Females attracting males

through pheromones and light patterns, ex: wingless female flow worm will flash species-specific patterns to attract males

Exploitation of sexual communication (false advertising)

• parasitoids: male field crickets attract both mates and parasitoids when calling

• predators: female Photuris fireflies lure males of other species by mimicking flash patterns

• pollination: orchid flower mimics female bee and tricks male bee into pollinating

Subphylum Hexapoda

divided into two groups: Entognatha (Collembola, Protura, Diplura) and Insecta

Entognatha

ento = inside, gnatha = jaw, because their mouth parts are entognathous, and they are ametabolous, wingless, and have indirect sperm transfer

Collembola: Springtails

• have primitive compound eyes and one pair of antennae

• they live in moist soil, under bark, freshwater ponds, that occur in dense populations, and consist of furcula; which is for jumping

• they have a unique “hit or miss” reproduction strategy of indirect sperm transfer where male deposits a spermatophore in front of the female and the female immediately picks it up

Diplura: Forked tails

• the Greek words: dipl = two, ura = tail

• have a narrow and elongated body that is usually colorless

• no eyes

• 2 abdominal cerci

• an indirect sperm transfer

Protura: Cone heads

• Proto = first/original, ura = tail, the name implies they have primitive physical features

• are microscopic very small about 1 mm long

• they lack antennae so they use their first pair of legs as sensory appendages

• no eyes

• they live in most soil and feed on dead organic matters (detritivores)

Apterygota

a = no, ptera = wings, they are wingless, ametabolous development, subclass pterygote which are descendants of winged insects, and have long-paired abdominal cerci and a single median, tail-like caudal filament, with compound eyes, consisting of Order Zygentoma (silverfish and firebrats) and Order Archaeognatha (jumping bristletails)

Order Zygentoma (silverfish and firebrats)

• are found in decaying vegetation but can also be household pests on paper (which is a matter that contains polysaccharides) with starch contents and dextrins in adhesives

• have indirect sperm transfer, complex courtship behavior, and they live inside of ant nests because they scavenge the seeds collected by ants

• their feeding habit is paper

Order Archaeognatha (jumping bristletails)

archaeo = ancient, gnatha = jaw, they have large compound eyes that meet at the top of their head, an arched back, and have a wide range of habits such as algae, lichen, etc.

Hemimetabolous Orders

all have hemimetabolous development which means they have no pupal stage, it includes: Ephermeroptera, Odonata, Plecoptera, Dermaptera, Phasmida, Orthoptera, and Locust swarm

Ephermeroptera

ephemera = existing for a short time, pteron = wing, mayflies, adults do not feed, only dispense because they are short living, so they; mate, lay eggs, and die, they have large triangular front wings, 1 median caudal filament, and two long cerci, the adults are terrestrial and nymphs are aquatic (they respire through abdominal gills), their life cycle is relatively long as they live as nymphs for months to years, they molt from subimago to sexually mature adult, and they emerge in large swarm once adults which is very important in food webs

Odonata

“toothed jaw”, includes (anisoptera) dragonflies and (zygoptera) damselflies, they have large many-veined wing, chewing mouthparts in adults and nymphs, male cerci’s function as claspers during mating, they have aquatic habitats as nymphs with rectal gill pads, draining or altering their wetlands can negatively impact them, they sometimes leave to search for prey, they have terrestrial habitats as adults, dragon fly nymphs have no external gills, while damselfly nymphs do, they have intra-male sperm translocation where nymphs have extensible modified labium for prey capture and males deposit sperm into a pouch on their abdomen located near the thorax, and the female receives the sperm from the pouch

Plecoptera

plekein = “to fold”, are stoneflies, the nymphs have tracheal gills, and are aquatic since they prefer clean, cold, fast-moving water, are grazers or predators, nymphs are generally sensitive to water pollution, so their presence is a reliable indicator of excellent water quality, males drum substrates with their abdomen by vibrations to attract their mates

Dermaptera

derma = “skin”, are earwigs, have chewing mouthparts, short leathery forewings, large cerci on abdomen, they like oil so they feed on many different things like leaves, fruits, and bird droppings, they are nocturnal, and have maternal brood care so they clean and repile the eggs, this tending increases their survival rate since they are not cooperative, and have defensive compound from abdomen

Phasmida

phasma = “planton or cryptic ghost”, walking sticks and leaf insects, have chewing mouthparts, are experts at crypsis, they are herbivores, some with chemical defense (aposematic coloration), they have capitulum which is a swollen, fatty extension of the stick insect off, their function being to be carried by ants and stored underground for protection dispersal

Orthoptera

ortho = “straight”, includes grasshoppers, katydids, crickets, their front wing is tegmina, they have a short or long antennae, and saltatorial hind legs, the katydids and crickets are Ensifera which means they have elongated, thread-like antennae while grasshoppers and locusts are Caelifera which means they have short antennae, they also have frequently cryptic sometimes aposematic coloration, and they make sound which is generally important in courtship, they have distinct songs by species, they all make round by “stridulation” which is rubbing their body parts together, grasshoppers rub their hind legs and wings against the edge of closed wings, while katydids and crickets only rub their wings where a sharp edge or “scraper” on the lower wing is rubbed against a “file” on the underside of the other wing

locust swarm

the swarming phase of some grasshoppers, they normally first start being solitary, then overcrowding occurs, then the transition phase, overcrowding again, to finally the locust swarms that includes two phases, solitary where there is low density, low reproduction rate, have short flights, and are lighter green in color, and the gregarious phase where they have high density, high reproductive rate, they fly far, are darker in color (e.g., mormon crickets in the U.S. that are actually katydids not crickets) this makes them easy to access for food

Order Matodea (soothsayer)

mantids that have large raptorial front leg, triangular heads, large compound eyes, chewing mouthparts, are master of camaflouge, ambush predators, have unusual mating, produce ootheca, commit sexual cannibalism, and have male coercion and female injury

Order Blattodea: cockroaches

have a flattened body, long antennae that is cetaceous, tegmina, and cursorial legs, there are around 4,4k species, that are primarily herbivores/scavengers, yet only around 30 associated with humans, about a dozen species are considered pests, and they produce ootheca (egg case)

Infraorder Isoptera: termites

iso = “equal”, 2 pairs of similarly sized wings (winged reproductives only), abdomen broadly joined to thorax, differential caste morphology, winged-”allate”, they form huge social colonies, which is extremely important in natural systems as recyclers and food for other animals, they have a caste system of workers, soldiers (nasute and mandibulate), and reproductives (king and queen), they feed on dead plant materials (sources of cellulose: leaves, twigs, wood, lumber, feces), mutualistic relationship with gut symbionts (help digest cellulose), some maintain a specific fungus garden and feed on the fungus, their mound architecture is biomimicry and ventilation

dry wood termites

are part of termite’s economic importance and is the main colony in wood because they produce holes where fecal pellets are pushed out from wood, so you see small piles on the floor

subterranean termites

are part of the economic importance of termites and is the main colony in soil, and feed on wood in contact with soil, they construct tubes for shelter as they travel between their underground colonies and the structure

Thysanoptera (fringe wing): trips

thysano = “fringe”, they have short legs, narrow wins with long fringe of hairs, they are very small that are about 1 mm long (earwigs are bigger), they have asymmetrical mouthparts where only their left mandible is involved in forming a stylet “rasping-sucking” mouthpart along with maxillae (their right mandible is reduced and non-functional) leaving damage on leaf and fruit surfaces, they are occasionally parthenogenetic, they have a unique metamorphosis where they have 2 feeding nymphal stages (on plant) following this they usually drop to the ground and hide, 2 additional non-feeding nymphal stages (off plant), and winged adult stage

order Hemiptera “true bugs”

have 4 suborders, there are around 50-80k species, they have sucking mouthparts (proboscis), and have mandible + maxiliae inside trough-shaped (modified) labium to form a proboscis, and separates excess fluid from plant sap for rapid removal of honeydew, and is located in anterior, front part of midgut

suborder auchenorrhyncha

includes cicadas, leafhoppers, treehoppers, plant hoppers, and froghoppers, which have piercing-sucking mouthparts, short antennae, 2 pr wings-held roof-like usually, exclusively plant-feeing (phytophagous) and has over 30 families

Cicadidae (cicadas)

they have tymbals that produce very loud sounds, fossorial front legs in nymphs, include periodical cicadas in North America, and have a synchronous emergence where only male cicadas make sounds, are part of suborder auchenorrhyncha

Membracidae (treehoppers)

they feed on plant saps, have enlarged pronotum (dorsal side of prothorax), crypsis, and gregarious nymphs, part of suborder auchenorrhyncha

cicadellidae (leafhoppers and sharpshooters)

can be very damaging to some plants, they feed on plant sap, are colorful, disease transmission of pierce’s disease through oleander grapes, and have excessive honeydew production, and extraordinary jumping due to gear-like mechanism in hind legs

suborder sternorrhyncha

includes aphids, whitefly, and scale insect, have piercing-sucking mouthparts, wings-variable where held roof-like or flat or absent, some are serious crop pests, and excessive amount of honeydew that becomes sooty mold

Aphididae (aphids family)

are wingless during cloning phase, have alates which means they have winged reproductives during sexual reproduction phase, they transmit plant diseases, and have ant-aphid mutualism where both partners benefit, but aphids gain protection and ants gain carbohydrate-rich resource

Aleyrodidae

whiteflies, are small <2 mm, covered in white, waxy powder, and have several serious agricultural pests

Coccoidea (superfamily)

scale inserts and mealy bugs, that are less mobile as mature, nymphs and females are covered in wax, pests, and have ant-scale mealy bug mutualism

Dactylopiidae

cochineals, sessile parasites on cacti in the genus Opuntia and are source of a natural dye carmine

Suborder Heteroptera

includes shield bugs, seed bugs, assassin bugs, flower bugs, bed bugs, and water bugs, they feed on liquid food with diverse habitats, long antennae, and have proboscis which indicates they take liquid diets, have piercing-sucking mouthparts proboscis, labium-folds function as sheath, wings are folded flat over abdomen and are hemelytra (membraneous half)

family gerridae

family of suborder Heteroptera, aquatic group, known as water striders, they have tarsal modifications that allow them to walk on water, they can be found in marine habitats, and they have raptorial front legs that make them predatory

family corixidae

family of suborder Heteroptera, aquatic group, known as water boatmen, are freshwater aquatic, they lack gills, so they carry air bubble down into the water to take oxygen from water, they have natatorial legs and are mostly herbivores

family belostomatidae

family of suborder Heteroptera, aquatic group, known as giant water bugs, they have 2 breathing tubes at the tip of abdomen, they have large raptorial front legs, and have large sit-and-wait predators of insects, snails, tadpoles, and fish

family miridae

family of suborder Heteroptera, terrestrial group, known as plant bugs, they are mostly plant-feeding, few are predators (phytophagous), some are agricultural pests, but some are serious pests like Lygus bugs

family reduviidae

family of suborder Heteroptera, terrestrial group, known as assassin bugs and kissing bugs (subfamily Triatominae), they have raptorial front legs, the assassin bugs are ambush predators and stalkers, and the kissing bugs are blood-feeders that transmit Chagas disease vector, they are nocturnal, and use heat and order to locate hosts

family cimicidae

family of suborder Heteroptera, terrestrial group, known as bed bugs, they are wingless, blood-feeders, and are parasitic

family pentatomidae

family of suborder Heteroptera, terrestrial group, known as stink bugs and shield bugs, they have a distinct angular shape, some are brightly colored, they have a noxious odor from their defensive alarm compound, and some are agricultural pests

Heteroptera

are not colorful

Auchenorrhyncha

are colorful

order psocodea

includes bark lice, book lice, and true lice, psokhos means gnawed or rubbed

suborder psocoptera (booklice and bark lice)

feed on fungi, algae, lichen, organic debris in nature also starch containing items like grain, wallpaper glue, and hook bindings, and they generally prefer humid conditions

suborder phthiraptera (“true” lice)

have a ectoparasitic lifestyle of mammals and birds, they have scansorial legs for clinging, includes chewing lice and sucking lice, and are wingless

Mallophaga (chewing lice)

feeds on dead skin cells, hair, and feather, over 90% of them feed on birds, and their head is wider than the prothorax

Anoplura (sucking lice)

feed on blood, some being vectors of human disease, they host exclusively on mammals, and their head is narrower than the prothorax, includes head lice where eggs (nits) are laid on hair shaft, adults staying on the head, hygiene is not a factor in likelihood of getting them, and body lice where eggs are laid on clothes, adults stay in the clothing when not feeding and hygiene does affect the likelihood of getting them because they develop off human body causing intense itching and rash, crab lice is found in the pubic region, and hosts defend against them with dust baths, grooming, and preening “nit-picking”

Epidemic typhus fever

transmission of disease by human body lice caused by the bacteria rickettsia

transmission mechanism

louse obtains the bacteria by blood meal from a patient and then the bacteria grows in the louse’s gut and is excreted in its feces, for the human to then stretch the itchy louse bite which rubs the feces in the wood

historical impact of true lice

occurs in conditions like overcrowding and poor hygiene like prisons and refugee camps and was extremely common in concentration camps during WWII

treatment and prevention of true lice

antibiotics like doxycycline, vaccines that are not currently available but was once developed, DDT-hand spraying equipment, and lice removal clinics

homometabolous order

neuroptera, trichoptera, mecoptera are examples of insect groups that undergo complete metamorphosis, transitioning through egg, larva, pupa, and adult stages, they have gradual changes, have extensive reorganization of body structures during the pupal stage and nymphs often resemble the adult but lack wings and functional reproductive organs, while larva bares no resemblance to form of adult

Neuroptera

neum = “nerve”, have numerous cross veins, it includes lacewings, dobsonflies, antlions, and mantidflies, and are family chrysopidae

Lacewings

part of the holometabolous order; neuroptera, they have eggs on stalks, their pupation is in cocoons, the larvae are predatory, they have their tympanal organ (auditory organ) near the basis of forewings, they act as a biological control agent because as larvae they feed on small insects and mites with sickle-shaped mouthparts ingest liquified body contents, and they respond to ultrasound produced by avoidance

Dobsonflies

family corydalidae, as larvae they are aquatic called hellgrammites, are voracious predators, and are used a bait for fishing, they pupate in soil near water

antlions

part of the holometabolous order; neuroptera, family mrymeleontidae, as larvae they have sickle-like mandible with teeth, adults can fly well, the larvae are sit-and-wait predators with pit-fall trap, and they prefer fine, sandy soil for their habitat

convergent evolution (with antlions)

independent evolution of similar features in species of different lineages, examples include worm lions (which are order diptera “fly”) and ant lions (order neuroptera) which have the habit of pit-fall trap hunting and mantids (order mantodea) and mantidfly (order neuroptera) which have raptorial forelegs

mantidflies

part of holometabolous order; neuroptera, family mantisphidae, as adults they have raptorial forelegs, they prey on small insects, their eggs are on short stalks, and as larvae they are parasitic in spider egg sacs

tricoptera: caddisflies

tricho = “hair”, are closely related to butterflies and moths (which are order Lepidoptera), as larvae they are aquatic with tracheal gills, they use various types of materials to build their case, and most of them feed on algae (periphyton)

mecoptera: scorpion flies

males have “scorpion-like” tail enlarged genitalia, they have nuptial gift, and hanging fly are mecoptera (while crane fly are diptera) and female lacks “scorpion” tail

order Coleoptera (sheath wings): beetles

is the largest order of insects including about 400k specifies described, 40% of all insects being beetles, and 25% of all species are beetles, as larval stage they are adapted for feeding, and as pupae their population generally occurs in some types of substrates, their morphology includes chewing mouthparts and elytra (Koleon - “sheath”)

J.S. Haldane

said the creators had “an inordinate fondness for beetles”

elytra

its function is for armor, retention of water, wing protection, stabilization during flight, and its modifications are fused elytra for darkling beetle which are flightless and shortened elytra for rove beetle which can fly, its leg morphologies includes corsorial, fossorial (digging), natatorial, and saltatorial, for most beetles, elytra covers the entire mesothorax, metathorax, and abdomen

life history and ecological niche

larvae are “eating machines”, they often live in similar habitats and eat similar types of food (or prey), they have a diverse diet where beetles specialize in predators, herbivores, wood borers, and scavengers (which is dead body organisms and organic matters)

predators

usually adults and larvae in Suborder Adephaga (“greedy”) are predators, mouthparts are often saber-like in adults and larvae, ground beetles (Family Carbide) are “caterpillar hunters” not letting them go once acquired

defensive strategy of bombardier beetles

chemical weapon that is the secret to their success, they secrete hot, noxious gas/liquid to deter predators, their reaction Is highly exothermic, it involves hydroquinone + hydrogen peroxide to benzo quinone + peroxidase + catalase (mixing chamber)

tiger beetles (family cicindelidae)

some are brightly colored, they are fast runners that run up to 5.6 mph, as larvae they hide in the vertical burrow throw and throws its head backward to grab nearby prey with its sickle-shaped jaws and pulls down the prey into the burrow to eat it, they are sit and wait hunter, they pupate in soil and they have hooks located on the back of their abdomen as an anchor while they subdue large prey

predaceous diving beetles (family dytiscidae)

“able to dive”, adults and larva are predaceous, the larvas pupate in mud, and carry air bubbles for underwater gaseous exchange as adults and have natatorial legs to apart to the aquatic lifestyle

whirligig beetles (family gyrinidae)

“two pairs” of eyes above and underwater, they are gregarious aquatic beetles, larvae and adults are predacious, good fliers as adults, and their respiration is by taking air bubble under elytra

lady bird beetles (family coccinellidae)

as larvae they are spotted or bonded with minute spines and as adults they have oval body shapes with bright coloration, they feed on small plant pest insects like aphids, scales, and mealybugs, their aposematic coloration and active secrete reflex bleeding (hemolymph) containing distasteful alkaloids signals to their predators, and they migrate to hibernate when cold weather starts because their aphid meal disappears (overwintering)

scarab beetles (superfamily scarabaeoidea)

are scavengers as immatures, some are brightly colored/metallic, as adults they have a distinctive lamellate antennae with layers of thin plate

dung beetles (family scarabaeidae)

adults eat soft dung, includes rollers, tunnelers, and dwellers, dung as provision for developing larvae, they are important because they provide ecological services by removing dung produced by larger animals (are important recyclers), and they have cultural importance in ancient Egypt, people called the dung beetle (scarab) “Kheper” associating it with Re, the sun God

rhinoceros beetles (hercules beetle)

large beetles (2+ inches), male competition for females using horns