Lecture 6 Flashcards
Order: Hemiptera
- True bugs
- Hugh order: Diverse
How many species fo hemiptera?
50-70,000 species
How many families of Hemiptera?
About 100 families
How many species of hemiptera in Ireland
About 770 species
Hemiptera characteristics
- Half winged
- 2 parts to wings (generally), forewings modified by hardening
- Mouthparts- rostrum
- Piercing/ sucking mouth parts: can be sap-sucking plat feeder, blood sucking ectoparasite or predator
Hemimetabolous
- Incomplete metamorphosis
How may sub orders?
- 2
- Based on wings
-Heteroptera
-Homoptera
Sub-order Heteroptera
- Known as true bugs
- Herbivores and carnivores
- Bed bugs, shield bugs, bugs on or in water
- 50,000 species worldwide
Shield Bugs
- Family: Acanthosomatidae
- ‘Stink bugs’ in USA
- 21 species in Ireland
- Parent shieldbug (Elasmucha grisea)
Hemiptera
- Damage done by plant-feeding species
1. Direct removal of plant nutrients
2. Injection of phytotoxic saliva (causing growth distortions)
3. Excretion of ‘honeydew’ waste- clogs plant stomata; inhibits gas exchange across leaf-lamina and inhibits photosynthesis; provides a medium for growth of sooty moulds etc- blocks light and photosynthesis
4. Transmission of plant-pathogenic viruses
‘Caspid’ or ‘mirid’ bugs
- Family: Miridae
- Brown (potato) capsis (Calocoris norwegicus)
- Green capsid (Lygocoris pabulinus)
- Causes damage to potato tops, sugar beet, tree foliage, peas
Bed bugs
- Family: Cimicidae
Sub-order: Homoptera
- Forewings same texture throughout
-Held roof wise over body rather than flat - All vegetarian
- Cicadas, leaf hoppers, aphids
Leaf-hopper
Family: Cicadellidae
Frog-hopper
Family: Delphacidae
Whiteflies
-Family: Trialuridae
- Glasshouse whitefly (Trialuroides vaporarium)
Tobacco Whitefly
- Bemisia tabaci
- Similar to glasshouse whitefly
- Found globally
- Field, vegetable and ornamental crop production
- Carrier of plant disease
- Pest of salad crops eg tomato, cucumber etc
- Carrier of plant disease eg tomato yellow lead curl
- Any found in Ireland so far has been eradicated
What is whitefly’s natural enemy?
Parasitoid wasp (Encarsia Formosa)
Superfamily: Aphidoidea
- Aphids
- 5000 species describes, 450 as pests
- Damage by removal of sap, honeydew
- Transmission of viruses
Family: Aphididae
- Aphids/greenfly/blackfly
- Females mainly perthenogenetic: nymphs borne alive (viviparous)
- Tube- like ‘cornicles’
Aphids- morphological forms
- Apterae (wingless females)
- Alatae (winged females)
- Alate nymph (developing wings
Aphid Mouthparts
Slide 37
Aphid life cycle
- Parthenogenesis
- Vivipary
Aphid structure
-Head
-Antennae
-Siphunculus (emits alarm pheromones)
-Cauda (tail)
-Rostrum (used for feeding)
-Legs
-Thorax
-Abdomen
Aphids in Ireland
-Grain aphids (Sitobion avenae)
Green spruce aphid
-Elatobium abietinum
Mealy cabbage aphid
- Brevicoryne brassicae
- On OSR in Summer
Mealy cabbage aphid
- Brevicoryne brassicae
- Brussel sprouts in winter
Aphid biocontrol
- Marmalade hoverfly
- Episyrphus balteatus
Natural Biological Control
- Fungus- infected aphids
Mummifies Aphids
- Attacked by parasitoid wasps
Scale insects
- Family: Coccidae
- Brown soft scale (coccus hesperidium)
Mealy bugs
-Family: Pseudococcidae
-Long-tailed mealybug (Pseudococcus longispinus)
Cochineal scale bugs
- Dactylopious spp
- Common on cacti
- Used for red dye
Plant Suckers
- Family: Psyllidae
- Apple psyllid (Psylla mali)
