hexapod ecology

Hexapod Ecology

By Nigel Detablan

Photo obtained from: https://www.thinglink.com/scene/754022537674883074

Hexapoda Ecology Subtopics

- Coevolution both exerts selective pressures on each otherand evolves in response to each other

- Coevolution of plants and insects is exhibited in herbivoryand pollination

- In herbivory, plant evolves defenses and the insectresponds with counter offensives.

ApiaceaePhoto obtained from: http://www.interhomeopathy.org/sumbulus-moschatus-keeping-perfect-control

Photo obtained from: http://www.epharmacognosy.com/2012/04/biosynthesis-of-coumarin-and.html

Carrot worm

A female black swallowtail butterfly, Papilio polynexes, is attracted by these chemicals

Photo obtained from: http://ohioplants.org/families-apiaceae/

Photo obtained from: http://www.arbico-organics.com/product/celery-worm/problem-solver-guide

Photo obtained from: http://www.epharmacognosy.com/2012/04/biosynthesis-of-coumarin-and.html

- The great diversity of floral structure largely reflects adaptationsfor facilitating pollination

- In pollination, both participants evolve to maximize benefitsand minimize costs

- Adaptations include colors, odors, and nectars that attractinsects – some have high specificity

Photo obtained from: http://www.washington.edu/news/2014/06/26/foul-fumes-derail-dinner-for-hungry-moths/

Moth hovers over a flower

Monarch butterfly feeding on flower nectar

Photo obtained from: http://magnusonkimball.photoshelter.com/image/I0000x6OmLKtjxCw/

• Insects are capable of parasitic nutrition.

• Parasitism is common and has evolved manytimes.

• Juvenile or adult is parasitic so that differentstages exploit different food resources andhabitat

Adult – Parasitic Juvenile – Conventional methods

Adult flea feeding on a cat

Photo obtained from: https://extension.entm.purdue.edu/publichealth/insects/flea.html /

Larva feeding on fecal blood

GIF obtained from: http://fleascience.com/flea-encyclopedia/life-cycle-of-fleas/flea-larvae/what-do-flea-larvae-eat/

Adult – Conventional methods Juvenile – Parasitic

Screwworm fly feeding on nectar

Photo obtained from: https://en.wikipedia.org/wiki/Cochliomyia

Myiasis

Photo obtained from: http://www.monsterparent.com/wp-content/uploads/2014/12/b90b7980-547c-097f-cc8d-9bf568e12efc.jpg

• There are some that spend their entire life cycle on the host

Lice

Photo obtained from: http://www.medicinenet.com/head_lice/article.htm

• Parasitoidism combines features of parasitism and predation.

• Parasitoids are smaller than their hosts and remain incontact with them over long periods, but theyeventually kill and consume the host

• Hyperparasitoids are parasitoids that attackparasitoids

Three very large families of insects that aredominantly parasitoids

Braconidae (Family)Hymenoptera (Order)

Ichneumonidae (Family)Hymenoptera (Order)

Tachinidae(Family)Diptera (Order)

Braconid wasp parasitoidizing a tomato hornworm

Photo obtained from:http://bugs.bio.usyd.edu.au/learning/resources/Entomology/internalAnatomy/imagePages/parasitoidWaspLarvae.html

• Hexapods use chemical, tactile, visual, andauditory signals to communicate

• Communication is important to find mates,give warnings about danger, tell about foodsources and etc.

• Pheromones are chemicals used to signal conspecifics.They are used to attract one sex to the other.

Adult female gypsy moth Adult male gypsy moth

Photo obtained from: https://en.wikipedia.org/wiki/File:Lymantria_dispar_8-8-2006_19-20-14.JPG

Photo obtained from: https://en.wikipedia.org/wiki/File:Lymantria_dispar_MHNT_Fronton_Male.jpg

• Pheromones also mark trails or territories insome species.

Ants

Photo obtained from: http://mute-net.sourceforge.net/howAnts.shtml

Photo obtained from: http://pestworldforkids.org/pest-guide/ants/

• Bioluminescent flashings of fireflies, which function in sexualattraction, is a visual signal

Photinus

Photo obtained from: https://en.wikipedia.org/wiki/Photinus_pyralis

PyrePlies.mp4

PyrePlies.mp4

• Sound can be produced by stridulation or the vibration of a membrane. Instridulation, a rough, rasplike scraper is rubbed over a file to produce soundand is a characteristic of grasshoppers, katydids, and crickets.

• Function in sexual attraction and aggression

• Allomone is a compound released by a source organism that has anadverse effect on the target organism.

• E.g. Lacewing larvae release a gas that subdues the prey, and mostHymenoptera produce venom to kill or immobilize the prey

• Social organization, or eusociality, the highest development ofcolonial organization, has evolved in only two taxa of insects:

Isoptera Hymenoptera

Termites Ants Bees

Eusocial societies are recognizable by three chief characteristics:

1. Members of the society cooperate in caring for the juveniles

2. There is a reproductive division of labor, sterile individuals performing the physical labor while fertile is for reproduction

3. All eusocial insects exhibit some degree of polymorphism, and the different types of individuals in a colony are termed castes

Diversity of Hexapoda

Springtails

Collembola

Silverfishes

Zygentoma

Mayflies

Ephemeroptera

Dragonflies

Odonata

Grasshoppers, Katydids, Crickets, Locusts

Orthoptera

Termites

Isoptera

True bugs

Hemiptera

Stinkbugs, Squash bugs, Water striders

Heteroptera

Beetles

Coleoptera

Sawflies, ants, bees, and wasps

Hymenoptera

Butterflies, moths

Lepidoptera

True flies

Diptera

hexapod ecology

Science