1. ENT 561 – Insects affecting human and animal health Introduction … continued

2. Peripheral Damage Quarantine and Restrictions Medical treatment problems (incorrect, treatment avoidance, etc.) Contamination –Blood Donations –Food Contamination Societal Costs –Associated with damage –Associate with damage prevention measures

3. In many cases, man has worsened problem Transportation of arthropods Transportation of pathogens Transportation of pathogens in humans Transportation of pathogens in livestock, insects, other animals Justinian created the first plague: “Without the empire, the bread dole, the huge shipments of grain and cloth from Africa, it is difficult to imagine how the First Pandemic could ever have erupted.” Orent, 2004

4. In many cases, man has worsened problem Increased population densities Expansion into new areas Environmental Modification Artificial Selection

5. Survey Results: Class Make up

6. Survey Results: Major

7. Survey Results: Level of Entomological Understanding

8. Introduction to the Insects

9. The oldest known insect -- Rhyniognatha hirsti – known from a single fossil, 400 million years old. This is shortly after plants colonize land and this appears to be a herbivore.

10. Introduction to the Insects

11. Life on earth as a speciescape: About 1 million of the 1.1 million animal species are insects Estimates range from 5 to 80 million insect species are currently in existence.

12. Insect Species Composition

13. Reasons for insect success Small size -there are many more niches for small organisms than for large organisms. For instance, one insect could live solely on and in the seeds of a specific plant. Short life cycle - this allows many generations within a given time for selection and evolution to take place. Large reproductive ability - large numbers of offspring support a large variation for selection and evolution to act upon. Variation in the life style of different stages in an insect's life (e.g. caterpillar versus butterfly) reduces competition for resources within the species. Wings-the ability to fly is relatively rare outside insects and has allowed them to colonize freely. Sensory sophistication - the sensory capabilities of insects surpasses most other organisms. Evolutionary interactions with other organisms - coevolution leads to greater specialization and speciation. Adaptation of appendages - mouthparts, wings and legs have often become highly specialized.

14. Insects just are They are neither good nor bad They are not here to serve a purpose – They evolved here in response to selective pressures Only man thinks of insects as “beneficial” or “detrimental”.

15. Some benefits of insects Plant pollination - Pollination by animals is more effective than by wind. Most higher plants are pollinated by animals, usually insects such as bees, wasps, flies and beetles. Production of products - honey, bees wax and royal jelly, silk (produced by the caterpillar, Bombyx mori), shellac (a varnish produced by a plant bug), cochineal (red food coloring produced by a plant bug) and 'Spanish fly' (a beetle and supposed aphrodisiac). Nutrient recycling - by detritus and dung feeders and particularly in Australia by termites. Maintenance of an ecological food chain in many systems. Human food - over 500 species of insects are used as food by humans -usually crickets, grasshoppers, beetle and moth larvae and termites. Miscellaneous - Indigenous peoples (e.g. from PNG) often used butterflies and brightly colored beetles as head or body decoration. Insect collecting is a common Western hobby and there is a small industry in arthropod pets.

16. Detrimental effects of insects Destruction or spoilage of food (both fresh and stored) and crops (including forests) Damage to goods - leather, paper, textiles, (by beetles, cockroaches, silverfish or moths), timber & structures (by termites, some ants, different sorts of borers) Direct disease of humans or livestock Disease vectors Venoms, allergies, urticating hairs Nuisance value - flies, ants Phobias - such as arachnophobia

17. Classification of insects

18. Common Names of Insects Very commonly used by scientists and laymen alike. Often more descriptive than the scientific names e.g. “Yellow Fever Mosquito” No scientific validity. For Insects, most names are set by the Entomological Society of America

19. Features of Arthropods Exoskeleton - a hard protective covering around the outside of the body (divided by sutures into plates called sclerites) Segmented body - that allows movement Jointed limbs and jointed mouthparts - that allow extensive specialisation Bilateral symmetry - whereby a central line can divide the body into two identical halves, left and right Ventral nerve chord - as opposed to a vertebrate nerve chord which is dorsal Dorsal blood vessel

20. Distinguishing Features of Insects vs. Other Arthropods InsectsArachnidsCrustaceansCentipedesMillipedes Legs 68Variable 1 pr/bs2 pr/bs Antennae 1 pr02 pr1 pr Body Divisions 32VariableManymany Wings 2 pr0000

21. Distinguishing Features of Insects vs. Other Arthropods InsectsArachnidsCrustaceansCentipedesMillipedes Legs 68Variable 1 pr/bs2 pr/bs Antennae 1 pr02 pr1 pr Body Divisions 32VariableManymany Wings 2 pr0000

22. Head

23. Head - Mouthparts

24. Mouthparts have evolved in many ways.

25. Insect Head: Antennae Antennae are primarily chemical (& sometimes sound) receptors Three basic segments: the scape, pedicel and flagellum Flagellum made up of multiple flagellomeres

26. Many basic types of antennae Aristate - pouch-like with a lateral bristle. Eg. House flies. Capitate - abruptly clubbed at the end. Eg. Butterflies. Clavate - gradually clubbed at the end. Eg Carrion beetles Filiformis - thread-like shape. Eg. Cockroaches. Geniculate - hinged or bent like an elbow. Eg. Bees/ants. Monoliform - bead-like in shape. Eg Termites. Serrate – saw toothed shape. Eg. Click beetles Plumose - brush or feather-like shape. Eg Moths and mosquitoes. Setaceous - bristle-like shape. Eg Dragonflies.

27. Insect Body: Thorax & Abdomen Ventral = Underside Dorsal = Topside

28. Insect Legs

29. Wings Generic Mosquito Wing

30. Internal Anatomy

31. Insect Cuticle

32. Insect Life Cycles -- Ametabolous Like almost all insects, start with eggs. Immatures have the very same shape as adults Seen in the most primitive, wingless groups (not medically important)

33. Insect Life Cycles -- Hemimetabolous Start with an egg Immatures have similar shape with adults EXCEPT wings. Wings develop externally to body Immatures often live in the same habitat as adults Includes the more primitive winged groups (Bugs, Dragonflies, Grasshoppers, Roaches

34. Insect Life Cycles -- Holometabolous Start with an egg. Immatures have a very different shape from adults Body transition occurs in pupal stage. Pupal stages often double as a survival stage. Larvae and adults often inhabit different niches Includes the most advanced insects: flies, beetles, moths/butterflies, bees/ants, fleas.

35. Insect Development and Weather -- Light May control vegetation and therefore insect populations Important in orientation. Used for inflight control – especially for night-flying insects Photoperiod -stimulus for diapause initiation Many insects are nocturnal or diurnal

36. Insect Development & Weather - Temperature Body temperature of insects governs rate of growth Most insect activity and reproduction occurs between 15 -35o C Different stages may have different rates of development. Surviving extreme temperatures often requires special adaptations in physiology, behavior, etc. Understanding the relation between development & weather enables us to predict activity/threat level.

37. Insect Development & Weather - Wind Indirect effect causing evaporation, humidity and so desiccation Dispersal e.g. aphids, moths grasshoppers Often affects activity levels esp. for weak fliers. Affects distribution of olfactory stimulants for feeding, oviposition, and mating. Primarily a factor for adults.

38. Insect Development & Weather - Moisture Sometimes affects development directly. Rain important for those species that need ephemeral aquatic habitats. Humidity important as an antidessicant. Often interacts with temperature

39. When populations are too big, they must be controlled. Cultural – Habitat manipulation Mechanical/Physical – swatting/picking, exclusion, environmental manipulation, etc. Biological – Using one species to control another: Predators, parasitoids, pathogens Genetic – Applying a control on F 1 which is expressed in F 2 or later. Behavioral – Modifying the behavior Chemical – Using lethal chemicals