Order Hemiptera Auchenorrhyncha & (old orders) Heteroptera Homoptera Sternorrhyncha Sub-order Heteroptera Auchenorrhyncha Sternorrhyncha Families Seed bugs, Cicadas, Psyllids, Hemiptera 2 shield bugs, spittle bugs, whitefly, capsids, bed leafhoppers, aphids, bugs, water planthoppers coccids bugs, etc. Formerly known as the Homoptera RPB 2009; hemiptera2 v. 2.6 Why were they separated? Common diagnostic features Major differences for the ‘Homoptera’ 1. Auchenorrhyncha Auchenorrhyncha / Sternorrhyncha Cicadas and hoppers ¾ Forewings are uniform in texture ¾ Short, bristle like antennae; 3 segmented tarsi; ¾ Wings held roof-like over the abdomen at rest ovipositor well developed; good fliers or jumpers; ¾ Rostrum arises from posterior of head ¾ Evolved towards increased wing development; jumping capacity and acoustic communication (hypognathous) 2. Sternorrhyncha Psyllids, aphids, whiteflies, scales and mealybugs ¾ Longer, filiform antennae; 1-2 segmented tarsi; ovipositor reduced; often relatively inactive (except psyllids) ¾ Evolved towards reduction in structural complexity; Cicadidae increased biological complexity; nymphal sessility and protective devices (e.g. scales and galls) 1. Auchenorrhyncha: 2 super-families Sound production A. Cicadomorph families Cicadidae - the cicadas Males produce characteristic Large long-lived bugs ‘song’ (tymbals Eggs laid in bark on twigs of trees or shrubs on abdomen) Nymphs feed underground on roots and have massive front legs for tunnelling Periodical cicadas have prime number breeding cycles (13-17 years) - avoidance of predators http://www.landcareresearch.co.nz 1 Auchenorrhyncha: Membracidae Cicadetta montana - the tree-hoppers In UK: subject to major conservation efforts (in New Forest), now probably extinct may be spectacular (pronotum) Centrotus cornutus some economic species (minor) Auchenorrhyncha: Cercopidae Sugarcane froghopper: - the froghoppers Aeneolamia varia saccharina Small, hopping adults Cercopid causes “blight” of sugar cane in Trinidad (since 1863) Nymphs feed within • Pest may reduce yields by up to frothy fluid (hence also 30% in Trinidad known as spittlebugs or Nymphs (5 instars) envelop cuckoo spit) themselves in frothy spittle Feeding may cause - difficult to control stunting or necrosis Biological controls invest -igated since 1916, entomo- pathogenic fungi most promising Auchenorrhyncha: Cicadellidae Many important Cicadellid pests (=Jassidae) - the leafhoppers Empoasca spp on potato and cotton Feed principally on leaves Nephotettix spp on rice (virus vectors Saliva causes stunting (and - e.g. tungro disease) “hopperburn” in some crops) Homalodisca coagulata Some species transmit plant - “glassy winged sharpshooter” photo: IRRI diseases - Californian vines (vector of bacterial Pierce’s disease) Graphocephala fennahi http://bss.sfsu.edu 2 B. Auchenorrhyncha: 3 major economic families of Fulgoromorpha Pyrops: SE Asia Auchenorrhyncha: hind legs Fulgoridae (lantern flies - all tropical) photo: E. Rundell E. photo: Froghopper Leafhopper Planthopper Cercopidae Cicadellidae Delphacidae photo: HC Evans Fulgora sp. (S. American Cicadomorpha Fulgoromorpha lantern or alligator bugs) Auchenorrhyncha: Delphacidae - the planthoppers Planthopper pests Damage crops by feeding and as disease vectors Distinguished by moveable spur on hind tibia Family Delphacidae has 300 genera and > 2,000 The major pest of tropical rice is the brown species planthopper, Nilaparvata lugens (also the white- Exist on every continent except Antarctica and in all backed planthopper: Sogatella furcifera) major biomes Perkinsiella spp Phloem feeders, especially on monocots (sugar cane) Strong tendency to monophagy (74% single plant host) Peregrinus maidis (cereal crops) Basic facts about the brown BPH, Nilaparvata lugens (continued) planthopper (BPH) Nilaparvata lugens Pest status and damage levels of BPH 300-600 eggs per female have been enhanced by misuse of broad- Up to 12 generations per year in spectrum insecticides (suppression of SE Asia natural enemies) and some modern Environmental cues (crowding, agricultural practices (N fertiliser & high host quality) and genetics alter the proportions of macropterous yielding varieties improve host quality) (winged) and brachypterous Modern thinking involves IPM (reduced wings) forms in time and space ¾ host plant resistance, Long distance (>750 km) ¾ limited and judicious use of migrations occur regularly insecticides to conserve … (aerial plankton) ¾ natural enemies e.g. spiders and Ability to exploit patchy habitat Cyrtorhinus lividipennis (Miridae) 3 Auchenorrhyncha: Fulgoromorpha Two Fulgoromorph palm pests 20 families (some more with pest status) Tropiduchidae Dubas Bug e.g. Cixiidae, Flatidae, Ricaniidae, (dates): Ommatissus lybicus Issidae, Tropiduchidae Issidae Coconut leafhopper Zophiuma lobulata (associated with Finschlafen's palm disorder) Cixius sp. Photo: Benoit Benoit Photo: ToLweb Martha, Flatid nymph Ricania sp. Diagrammatic cross section of part of a 2. Sternorrhyncha leaf showing the tissues from which Aphidiae - true aphids siphuncles various plant-sucking insects feed Often complex life cycles ¾ Polymorphism ¾ Viviparity Photo: Wikipedia ¾ Cyclical parthenogenesis Very important pests of many major crops ¾ feeding damage ¾ vectors of disease ¾ e.g. Mysus persicae, Aphis fabae, Brevicoryne brassicae Sternorrhyncha: Adelgidae Sternorrhyncha: Phylloxeridae - conifer woolly aphids - phyloxerans, “root aphids” Differ from true aphids Autoecious (whole life cycle as all parthenogenetic within one individual plant) morphs are oviparous and they have no Form leaf and root galls siphunculi Root feeding by the vine Host alternating 2-year phyloxeran, Viteus vitifolii, cycle with Picea spp as was a serious problem in primary host and other Europe until the use of conifers as secondary American rootstocks hosts 4 Sternorrhyncha: Psyllidae Psyllid pests Middle ranking pests of fruit trees - jumping plant lice ¾ Psylla mali on apples (right) ¾ Psylla pyricola on pears Asian Citrus Psyllid, Diaphorina Psyllids are small (similar size of aphids) citri, vector of citrus greening with strong jumping (especially hind) legs bacterium Liberibacter asiaticum Incapable of sustained flight Leucaena leucocephala, is a fast growing, nitrogen-fixing tree native Nymphs often produce white waxy secretion to Mexico & C. America Characteristic, simple wing venation, with a ¾ The psyllid Heteropsylla cubana is also native to Mexico and C. striking principal basal vein America ¾ Present in small numbers throughout its natural range and causes little damage ¾ Invasive pest species to new Leucaena plantings in Asia & Africa ¾ …so classical biological control appropriate? http://www.fao.org/forestry/49410/en/ken/ J D Ward, USDA Forest Service, www.bugwood.org Psyllid for biological control of Impact of Aphalara itadori Japanese knotweed Aphalara itadori (nymphs) photos: courtesy R. Shaw Photo: R. Shaw Sternorrhyncha: Aleyroididae Some basic facts about whiteflies - whiteflies 1,200 described species, 15 of Very small adults with wings covered in which are serious pests waxy white powder Traditionally found in the tropics, Active 1st instar nymph, later nymphs but now in temperate zone sessile and scale-like Most monophagous, but most Very important pests: important pest species are ¾ Bemisia tabaci on cotton, tobacco etc. (>300 polyphagous hosts) Pests of annual, perennial and ¾ Trialeuroides vaporariorum in glasshouses protected crops ¾ Aleyrodes proletella, cabbage whitefly on Damage is direct via feeding crucifers and honeydew contamination ¾ Aleurocanthus woglumi, citrus blackfly and also indirect as vectors of disease 5 Life cycle of a glasshouse whitefly More basic facts about whiteflies and its parasitoid Adults v. small, moth like with waxy dusting. 6 life stages: egg, 1st instar nymph (crawler), 2 sessile nymphal stages, a 4th instar (pupa) and adult > 200 eggs per female 3 week life cycle Pest status enhanced by overuse of pesticides Modern controls include more selective chemicals, parasitoid natural enemies (Encarsia formosa), entomopathogenic fungi, predatory beetles and bugs and plant resistance Sternorrhyncha: Coccidae Pseudococcidea - mealybugs - the soft scales Relatively mobile compared with Coccoidea Usually covered by copious waxy filaments Females are apterous May cause damage by toxic saliva or disease spread (e.g. cocoa swollen shoot virus by Scale-like and often Planococcoides spp.); cosmetic damage to parthenogenetic. ornamentals Important pests include Coccus spp on fruit trees Milviscutulus mangiferae www.fsca-dpi.org/FloridaInsectGallery/hemiptera.htm Some facts about scales & mealybugs Diaspididae - armoured scales Hosts are mainly woody plants e.g. citrus and Scale not attached to body coffee (unlike soft scales) Lifestages of Important secondary resurgence pests and Females lack legs and the oystershell most stages difficult to kill with insecticides scale antennae Most highly modified of all plant bugs Males winged but rare or ¾ Females oviparous or viviparous, often obscurely absent segmented with atrophied appendages, scale like body with waxy or powdery coating. 50 - 400 eggs Many important pests in laid under scale. orchards e.g.: ¾ Males often 2 winged (no hind-wings) and in some ¾ San Jose Scale (first pest to species never recorded or rare. be recorded as resistant to ¾ Dispersive (crawler) first instars pesticides in 1908) ¾ Mussel Scale & oystershell scales 6 Sternorrhyncha: Margarodidae Classical biological control and -