Insect Biology Opportunity 2

What are 6 examples of mechanical stimuli?

touch, body stretching and stress, position, pressure, gravity, and vibrations

What are the 4 major classifications of mechanical stimuli?

tactile mechanoreception, position mechanoreception (proprioceptors), sound reception (tympanal and non-tympanal), and sound production

List the 4 kinds of tactile receptors.

multicellular spine, acanthae, microtrichia, and setae

_ are considered proprioceptors that give continuous sensory output at a frequency that varies with the position of the hair. Often form a bed of grouped small hairs, a hair plate at joints or at the neck, in contact with the cuticle of an adjacent body part to monitor the relative positions of different body parts.

trichoid sensillum

_ comprise internal proprioceptors associated with muscles such as those of the abdominal and gut walls. They monitor bodily functions such as abdominal or gut distension, or ventilation rate.

stretch receptors

Insects are _, meaning they lack the ability to maintain homeothermy, or a constant body temperature independent of fluctuations in their environment.

poikilothermic

Although the temperature of an inactive insect tends to track with ambient temperature, many insects can alter their temperature somewhat by what two ways:

behavioral mechanisms (ectothermy) and physiological mechanisms (endothermy)

Security from predation, maximum utilization of scarce food, overcoming of host resistance, cohesion of social insects, and increasing the changes of mating are all potential benefits provided by _?

aggregation pheromones

Social insects, like honey bees, utilize _, which are volatile, non-persistent compounds that readily disperse for defense.

alarm pheromones

_ detection is important for butterflies (to locate healthy host plants), social insects (nest regulation), and female mosquitos (to locate a blood-meal).

carbon dioxide

_ or chemical odors, are important in interspecific and intraspecific communication. One example is found in insects like butterflies, involving the use of chemicals called _, which are substances that are secreted to the outside by one individual and received by a second individual of the same species.

semiochemicals, pheromones

Communication chemicals utilized between different species are called _ and are grouped according to the benefits they provide to the producer and receiver. _ benefit the receiver but disadvantage the producer; _ benefit the producer by modifying the behavior of the receiver while having a neutral effect; and _ benefit both the producer and the receiver.

allelochemicals, kairomones, allomones, synomones

_ have many _ that provide visual coverage of 360 degrees.

compound eyes, ommatidia

Basic components needed for vision are _ to focus light onto photoreceptors and a nervous system complex enough to process visual information. The _ is the photoreceptive structure comprised of several adjacent retinula (nerve) cells consisting of close-packed microvilli.

lens, rhabdom

_ are found in clusters on the head and focus light to an extended retina which receives a _ image. These structures function as ‘horizon detectors’ for flight.

ocelli, pixelated

Diagram 1

List 4 reasons that insects have been successful in terms of sensory systems and behavior.

sense and interpret their surroundings, respond selectively to cues from a heterogeneous environment, differentiate between hosts, respond to microclimatic factors

What senses do night-active insect species rely on more?

smell and hearing

What are position mechanoreceptors are called?

proprioceptors

Trichoid sensilla are flexible, hair-like projections that arise from an innervated socket, list four properties.

develop from epidermal cells, fulfill tactile functions, respond to movement of the hair, some sensitive enough to detect vibrations of air caused by noise

Sub-cuticular mechanoreceptors that are specialized sensory organs that receive vibrations are called _, which consist of _.

chordotonal organs, scolopidia

_ comprised of a central cap or peg surrounded by a raised circle of cuticle and with a single neuron per sensillum, located on joins.

campaniform sensilla

A _ are a type of non-tympanal organ that detects substrate vibration located in the proximal tibia of each leg and responds to _.

subgenual organs, substrate-borne sounds

Non-tympanal sound reception consists of _ and _.

detection of substrate-borne signals, near-field sound perception

A _ is a _ that responds to distant sound transmitted by airborne vibration and are linked to chordotonal organs and are associated with air-filled sacs, especially modified trachea, that enhance sound reception. This structure is located on _.

tympanum, membrane, various parts of insect bodies depending on order

What are two ways Tiger Moths (Arctiidae) use their metathoracic tymbals? What can Diptera wing beats be used to identify by other Dipterans?

intraspecific communication and detection of bat (predator) ultrasounds; species and sex, the males higher in tone

Some blind cave insects respond to light due to sensory receptors below the body cuticle via _.

dermal detection

Most studied insects sense temperature with their _.

antennae

In Leafcutter ants, thermosensitive peg-in-pit _ are clustered in the apical antennal flagellomere and respond to changes in air temperature and radiant heat.

sensilla coeloconica

What extreme form of temperature detection is seen in Jewel Beetles (Buprestidae)? Why do they have this ability and how does it work?

forest fire detection, oviposit in smoldering pine trunks, infrared radiation detection in pit organs

For thermoregulation and temperature detection, Leafcutter Ants have _; some Jewel Beetles have _; Tenebrionidae beetles are _; Beclouded cicadas are _; and the behavior by the swift setwing when they perch with wings spread is called _.

sensilla coeloconica, IR detection by pit organs, dark, two-toned dorsoventrally, basking

_ trap chemical molecules, which are transferred to a site for recognition, where they specifically depolarize a membrane and stimulate a nerve impulse; they typically have _ with one or more pores.

chemoreceptors, sensilla

Two examples of the use of insect _ include the Bola Spider, which lures insect prey with these chemicals into a sticky trap and the Queen Butterfly, which is thought to generate these chemicals from ingesting Mistflower.

sex pheromones

What are two ways insects use hearing?

intraspecific communication, detection of predators

All stridulating Orthopterans enhance their sound using the _, or modified forewings.

tegmina

_ is the most common method of sound production and involves the _ rubbing against the _.

stridulation, scraper, file

A method of sound production involves alternate muscular distortion and relaxation of a specialized area of elastic cuticle, the _, to give individual clicks or variably modulated pulses of sound, as heard in male cicadas. On cicadas, they are located _.

tymbal, dorsolaterally on the first abdominal segment

Light emissions in fireflies and fungus gnat cave-dwellers derive from _.

luciferase

What is the main factor required for successful mating?

male and female in the same place and same time

_ are identified by visual markers and are usually species-specific. Predominantly male, allows for more effective mate finding and limits inbreeding.

swarming sites

Conspecific male and female insects must be together to reproduce sexually, which occurs by _, in which _ typically gather. This increases _, decreases _.

swarming, males, predation upon breeders, inbreeding

_ defend a territory against conspecific males and court arriving females.

substrate-based aggregations

_ refers to when poorly developed larva hatches and feeds orally from accessory (“milk”) gland secretions within the “uterus” of the mother’s reproductive system. The full-grown larva is deposited and pupariates immediately.

adenotrophic viviparity

A _ occurs when males hold territories that contain no resources of importance to females and exhibit male-male aggression plus courtship of females.

lek mating system

_ the male courts a prospective mate by offering a prey item.

nupital gift

What are the four categories of courtship?

visual displays, tactile stimulation, acoustic courtship, nupital gifts

Most insects are diploid with _ (female) and _ (male). Lepidoptera have a different sex-determination system, in which females have two different kinds of chromosomes: _, and the males have two of the same kind of chromosome _.

XX, XO, ZW, ZZ

_ occurs when sexes may meet via attraction to a common resource like rotting fruit, animal dung, or a specific host species, which may be the best place for offspring needs.

common resource site mating

What is a possible outcome due to insects being so conspicuous when synchronizing the time and place for mating?

predation through prediction or luring

Describe courting and mating in Mecoptera Harpobittacus australis (Bittacidae):

Nupital gift is offered, male touches female abdomen while she inspects gift, if she rejects she lowers herself until she hangs head downwards suspended by her terminilia.

_ refers to eggs incubated inside the reproductive tract of the female and eggs hatch immediately after being laid.

ovoviviparity

Hemimetabolous insects oviposit at a _, while holometabolous insects oviposit at _.

habitat utilized by adults, habitats that different from adult habitats

What are two examples of ornaments used in male-to-male combat?

“antlers” of phytalmia, eyestalks

What does the “Sexy Son” hypothesis entail?

selection driving the development of elaborate male displays

_ refers to initiation of egg development taking place within the mother, which thus gives birth to live young.

viviparous

Intraspecific competition for mates (insect fight-club), male–male interactions where the female chooses the winner, male adorned secondary sexual characteristics, long-distance sexual calling, and discrimination between the sperm of different male are all examples that lead to _.

sexual selection of genetic expression

What is the “Candymaker” hypothesis?

Using a spermatophylax to prolong mating and preventing removal of the ampulla.

Extrusion of the male _ during copulation includes extension from the abdomen and the organ is everted or extended to produce a structure capable of depositing semen deep within the female reproductive tract. In many insects the male terminalia have _, which lock with specific parts of the female terminalia to maintain connection.

adeagus, modified claspers

Do Collembola, Diplura, and apterygote insects use indirect or direct fertilization?

indirect

A gene called _ is found in Honey Bees and is the primary switch in sex-determination. If two versions of this gene are inherited, the bee becomes _, while an unfertilized (haploid) egg with a single copy of the gene becomes _.

complementary sex determiner (CSP), female, male

_ refers to groups of male butterflies gathering at a site and drinking large amounts of liquid to gain _ for transfer to their offspring in the form of a nupital gift.

puddling, sodium and nitrogen

_ occurs in all female members of the Strepsiptera where unlike males, females remain within the host throughout their life.

neoteny

_ is the development from an unfertilized egg containing half of the female chromosome complement following meiosis, which is exemplified by Honey Bees. Female Honey Bees develop from _ eggs, while males develop from _eggs.

arrhenotoky, fertilized, unfertilized

The vast majority of female insects lay eggs, which is called

oviparous

_ occurs in the example of some gall midges that have eggs hatch internally and the larvae may consume the body of the mother before leaving to feed on the surrounding fungal medium.

hemocoelous viviparity

In damselflies, males and females mate for a long period of time. What does the male spend most of the time doing?

scraping competing male’s sperm out

What are the two main types of sexually selected adaptations in males that increase certainty of paternity?

displacing ejaculate from previously mated males, reducing the effectiveness or occurrence of subsequent inseminations

What are four mechanisms that aid males to successfully pass on their genetics?

mating plugs, prolonged copulation, guarding of females, structures for gripping the female

Seminal fluid chemicals may elicit post-mating responses in the female insect as fluid enters her hemolymph and acts on her nervous and/or endocrine system. These include: _ and _.

induction of oviposition, repression of sexual receptivity

_ refers to the example where some gall midges have embryos formed in the hemocoel of a paedogenetic mother-pupa, termed a hemipupa, which destroys the mother-pupa from within and has evolved to allow maximum use of locally abundant but ephemeral larval habitats.

pupal paedogenesis

_ is the expulsion of eggs from ovary into the oviducts. _ is egg laying.

ovulation, oviposition

Sperm are received by the female’s copulatory pouch or directly into a spermatheca. A _ is the means of sperm transfer in most orders of insects; only some insects deposit unpackaged sperm.

spermatophore

True or False: Internal genitalia of female insects show less diagnostic variability than the internal structures of the males; external genitalia of both sexes are much more sclerotized than the internal genitalia.

false

How can occurrence of re-mating under natural conditions be determined?

observation or dissection

_ refers to when females may produce parthenogenetically only female eggs from a nuclear genetic basis or by parthenogenesis-inducing bacteria such as _.

thelytoky, Wolbachia sp.

Katydids males give females elaborate spermatophores that consists of a large, proteinaceous, sperm-free portion, the _, which is eaten by the female after mating, and a _, eaten later.

spermatophylax, sperm ampulla

What is the term for the shedding of an old cuticle?

ecdysis

_ refers to the numbers of generations per year, with _ referring to 1 generation per year, _ two generations per year, _ more than two generations per year, and _ insects have generation time in excess than one year.

voltinism, univoltine, bivoltine, multivoltine, semivoltine

Increment in size occurring between one instar and the next of a sclerotized body part.

molt increment

Instar duration; time between two successive ecdyses.

stadium

Following emergence from the pupal cuticle, many holometabolous insects void a fecal fluid called _, which represents the metabolic wastes that have accumulated during the pupal stadium.

meconium

Refers to the act of an insect emerging from its pupal case or hatching from its egg as a larva.

eclosion

The magnitude of both molt increments and stadium periods may be affected by what five factors?

food supply, temperature, larval density, physical damage, sex

Reproductively mature final instar, called the _ or _.

adult, imaginal instar

Ephemeroptera have what unique phase between nymph and imago?

subimago

The developmental history of an organism from egg to adult.

ontogeny

Hatchling emerges from egg in a form resembling a miniature adult, lacking only genitalia.

ametaboly

_: partial or incomplete metamorphosis, _: external wing pad development.

hemimetaboly exopterygote, holometaboly endopterygote

True or false: in Collembolans, Diplurans and apterygote insects, growth is indeterminate and they will continue to molt until they die.

true

Inactive phytophagous legged larvae; lack abdominal prolegs but have functional thoracic legs; lack true legs, worm or maggot-like

polypod, oligopod, apod

What looks like a pupa actually often is a fully developed adult within the pupal cuticle, referred to as _.

pharate adult

_: Appendages are not closely appressed to the body, articulated mandibles (_); pharate adult uses to cut the cocoon, or non-articulated mandibles (_); adult sheds the pupal cuticle.

exarate, decticous, adecticous

_ insects tend to be small and fast-developing, using evenly available resources; _ utilizes seasonally restricted resources; _ insects include those that develop slowly on evenly spread resources and those that track a bimodally distributed factor.

multivoltine, univoltine, bivoltine

The _ egg stage begins as soon as the female deposits the mature egg and begins the estimated age of the egg.

embryonic phase

_: epidermis separates from the cuticle of the previous stage; new instar comes into existence

apolysis

Many univoltine and some bivoltine species enter _ at some stage, awaiting suitable conditions before completing their life cycle.

diapause

_ occurs when insects track resources in space by directed movement which is persistent movement away from an original home range.

migration

_: from ecdysis to ecdysis

instar

_ occurs at a fixed time, regardless of environmental conditions, whereas _ is optional and occurs in insects in which diapause occurs only in the generation that must survive the unfavorable conditions.

obligatory diapause, facultative diapause

_ is significant in diapause because changed day length predicts much about future seasonal environmental conditions.

photoperiod