Families of economic importance of Homoptera

A. Cicadellidae: (Jassidae): Jassids or leaf hoppers

• Slender, usually tapering, posteriorly, wedge shaped insects usually rest in a position ready for jumping.
• When disturbed they leap often several feet.
• Antennae minute, bristle like, 3 segmented
• One or two rows of small spines are present on hind tibia which is most important feature
• Both young ones and adults have the characteristic habit of running sideward or diagonally
• These are very important vectors of viral diseases.
• Ovipositor well developed and adopted for lacerating plant tissues for egg laying.
• Many excrete honeydew through anus.
• Forewings are somewhat thickened and often brightly coloured
• Anal veins 1A and 2A do not unite to form ‘Y’ shaped vein. Eg: Cotton leafhopper –Amrasca biguttula biguttula Paddy leafhopper –Nephotettix virescens – Mango hoppers – Amritodes atkinsoni,Ideoscopus clypealis

B. Delphacide Plant hoppers

• This is the largest family among the plant hoppers
• Most of the species are small with reduced wings
• The characteristic feature of this family is the presence of large mobile apical spur on hind tibiae
• Costal cell is absent in the winged forms
• Alary polymorphism is very common winged, wingless and brachypterous
• Forms occur in the some species. Eg Brown plant hopper of paddy (BPH)-Nilaparvata lugens
• White backed plant hopper on rice (WBPH) –Sogatella furcifera

C. Aphididae : Aphids or plant lice

• This family constitute a large group of small soft bodied, pear shaped, fragile phytophagous insects that are frequently found in large numbers sucking the sap from various parts of plants
• Antennae fairly long
• Rostrum usually long and well developed
• The characteristic feature of aphids is the presence of a pair of cornicles on the dorsal surface of 5th or 6th abdominal segments (It is believed that they produce waxy substances)
• Winged / Wingless. Alary polymorphism is prevalent. When winged, hind wings are much smaller with fewer veins. At rest the wings are generally held vertically above the body.
• Tarsus – 3 segmented with a pair of claws
• Nine pairs of lateral spiracles present
• Excrete honeydew through anus (honey dew consists of excess sap, excess sugars and waste materials) to which ants are attracted,
• Associated phenomenon in reproduction are parthenogenesis, oviparity and viviparity
• Occurrence of alternation of generations. The sexes are unequally developed, males often being rare. Eg: Myzus persicae – Tobacco aphid, Aphis gossypi – Cotton aphid, Aphis craccivora – Groundnut aphid

D. Pseudococcidae Mealy bugs

• Females are wingless, elongate oval with distinct segmentation.
• Body covered with powdery wax or filamentous waxy secreations.
• Legs well developed. No instar is sessile. All the insect stages are able to move because of legs
• Eggs are placed in a loose cottony waxy material
• Eg: Brinjal mealy bug – Planococcus insolitus Citrus mealy bug –Planococcus citri Sugarcane mealy bug –Saccharicoccus sacchari

E. Coccidae Scale insects (Soft scales):

• The females in this group are flattened, elongate oval insects with obscure segmentation and hard smooth exoskeleton or covered with wax or tough scales.
• They are wingless, legs present or absent and the antennae absent or much reduced.
• Males are active, 1st pair of wings well developed, 2nd pair reduced to halters.
• Tarsus if present 1 – segmented with a single claw.
• Metamorphosis complex. 1st instar nymph has legs & antennae and active known as crawlers after 1^st moult, become sessile a waxy or scale like covering is secreted.
• In males last instar preceeding adult is queicent and called pupa. Females have one less instar than males.
• Oviparous, ovoviviparous
• Excrete honey dew like aphids Eg: Pulvinaria psidi – Guava scale, Icerya purchasi – cottony cushion scale

F. Aleurodidae E.g. White flies

• E.g.: Sugarcane whitefly – Aleurolobus barodensis Cotton whitefly –Bemisia tabaci Castor whitefly –Trialeurodes.