Paraneoptera

1. Paraneoptera Lecture 6

2. Some major characteristics of Hexapoda: • Maxillary plate present • 3 body parts (head, thorax, abdomen) • 3 thoracic segments each bearing a pair of legs • Legs composed of 6 segments • 11 maximum abdominal segments • Trachea • Some major characteristics of Insecta: • External mouthparts • Malpighian tubules • Annulated antennae • 2 pretarsal claws articulated with tarsus • Johnston’s organ • Ovipositor • Posterior tentorial arms fused

3. Paraneoptera • Psocodea, Thysanoptera, Hemiptera • Slender, elongate maxillary lacinia separated from the stipes • Swollen postclypeus containing an enlarged cibarium (sucking pump) • Reduction of tarsomere number to three or less • Parasitic lice, bark lice, book lice, thrips, true bugs, plant bugs, cicadas, planthopper, aphids, scale insects, etc.

4. Psocodea(psokosmeaning rubbed or gnawed) • Seven suborders • Formerly “Psocoptera” (non-parasitic lice, bark lice and book lice) and “Phthiraptera” (parasitic lice, chewing lice and sucking lice) • Phylogenetic analyses show paraphyleticPsocoptera and Phthiraptera, thus a new classification is adopted.

5. “Psocoptera” • Small, soft-bodied insects • Winged or wingless • Long antennae • Mandibulate mouthparts • Large and swollen clypeus • Booklice and barklice, but free-living

6. “Psocoptera” diversity • 5 super orders • 85 genera and 340 species known from North America • Feed on algae, lichens, molds, dead insects, pollen, papers

7. “Phthiraptera” • Wingless ectoparasites of birds and mammals • Formerly divided into two groups Anoplura (sucking lice) and Mallophaga (chewing lice), but recent phylogenetic studies show that Mallophaga are paraphyletic. • Four suborders of parasitic lice now include: Anoplura, Rhynchophthirina, Ischnocera, and Amblycera

8. Diversity of parasitic lice Anoplura: parasites of mammal Rhynchophthirina: parasites of elephants and wart hogs Amblycera: parasites of birds and mammals Ischnocera: parasites of birds and some mammals

9. Obligate parasitic lice of humans • Head louse: Pediculushumanuscapitis • Body louse: Pediculushumanushumanus • Pubic louse: Pthirus pubis

10. Genetic relationships between head louse and body (clothing louse) help infer the origin of human clothing Toups et al. 2011 (MBE)

11. Origin of pubic louse leads to an interesting inference about human biology Reed et al. 2007 BMC Biology

12. Coevolution between primates and lice • Complex history of cospeciation, parasite duplication, parasite extinction, andhost switching

13. Thysanoptera(thysano, fridge; ptera, wings) • Common name: thrips • Minute, slender-bodied (0.5 to 5 mm) • Wings present or absent • When fully winged, four wings are long and narrow fringed with long hairs • Sucking mouthpart (stout, conical, asymmetrical) • http://youtu.be/Tjkuh8e07NE

14. Mouthpart modification • Labrum forms front of proboscis • Basal portion of maxillae form the sides • Labium forms the rear • Only one mandible (the left one; right mandible vestigial) • “punch and suck” mouthparts

15. Diversity • Two suborders: Terebrantia and Tubulifera • 9 families, ~6000 species • Predaceous, herbivorous • Some species are serious pests and vector of plant diseases

16. Phylogeny of Thysanoptera based on molecular data • Two suborders monophyletic, but internal relationships are still questionable Buckman et al. 2013 (Syst. Ent.)

17. Hemiptera(hemi, half; ptera, wings) • Large and diverse group of insects • True bugs, cicadas, hoppers, psyllids, whiteflies, aphids and scale insects • Piercing-sucking mouthparts (stylet with two canals, one for saliva another for fluid) • No maxillary and labial palps • No cerci

19. Dynamic classification • Formerly Heteroptera and “Homoptera” • “Homoptera” paraphyletic grade • Four suborders: Sternorrhyncha (aphids, psyllids, scale insects, whiteflies), Auchenorrhyncha (cicadas, planthoppers, treehoppers, leafhoppers, lantern flies), Coleorrhyncha (moss bugs), Heteroptera (true bugs)

20. Sternorrhyncha • Relatively inactive insects • Tarsi one or two segmented • Long and filiform antennae • Many pest species • Aphids (Aphididae), psyllids (Psyllidae), scale insect (Coccidae and many families), whiteflies (Aleyrodidae)

21. Complex life cycle • Rosy apple aphid (Dysaphisplantaginea)

22. Auchenorrhyncha • Active insects • Good fliers or jumpers • Tarsi three-segmented • Short and bristle-like antennae • Males often produce sound • Cicadas (Cicadidae), treehoppers (Membracidae), spittlebugs (Cercopidae), leafhoppers (Cicadellidae), lanternflies (Fulgoridae)

23. Periodical cicadas (Magicicadasp.) • 13-year and 17-year • Several species • Brood: all periodical cicadas of the same life cycle type that emerge in a given year • http://youtu.be/ICDdTBgqYt0

26. Prud’homme et al. 2011 (Nature) • Membracidaepronotum modification (helmet) is actually an appendage, a wing serial homologue • Helmet arose by escaping ancestral repression of wing formation in the first thoracic segment by homeotic gene • Possibly because new innovation is not prohibitive (no interference to flight) • Developmental evidence

27. Detailed morphological analysis reveals that the Nature study was based on misinterpretation of morphological characters

28. Heteroptera • Antennae slender with 4-5 segments • Proboscis 3-4 segmented, arising from front of head and curving below body when not in use • Pronotum usually large, trapezoidal or rounded • Triangular scutellum present behind pronotum • Front wings with basal half leathery and apical half membranous (hemelytra). Wings lie flat on the back at rest, forming an "X". • Tarsi 2- or 3-segmented

30. Diversity • ~73 families, ~50,000 species worldwide • Diverse diet and life histories • Plant bugs (Miridae), seed bugs (Lygaeidae), stink bugs (Pentatomidae), leaffooted bugs (Coreidae), assassin bugs (Reduviidae), water striders (Gerridae), giant water bugs (Belostomatidae), water boatmen (Corixidae) and many more.