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Pests of Guava :: Major Pests :: Spiraling whitefly


 

6. Spiraling whitefly: Aleurodicus dispersus (Aleyrodidae: Hemiptera)

 

 

Distribution and status
           
It is an introduced polyphagous pest of vegetables, fruit trees, ornamentals and shade trees. It is native of the Caribbean Islands and Central America. It is widely distributed in almost all countries due to rapid dispersal and adaptability.

 

Host range

It is found on 128 plants including guava, cassava, cotton, chillies, tomato, brinjal, bhendi, papaya, crotons and weeds such as Euphorbia, Corchorus, Eclipta, Vernonia, Vicoa, Acalypha, Alternanthra, Amaranthus, Convolvulus, Abutilonetc.

 

Bionomics

Adults are larger than many of the whitefly species and white in colour with waxy coating on the body. Eyes are dark reddish brown. Fore wings are with three characteristic spots. Eggs are laid in a spiraling pattern (concentric circles) on the undersurface of leaves. Egg period lasts for 5-8 days. Nymphal period is 22-30 days. Adult longevity is for 13-21 days. Total life cycle is completed in 40-50 days.

Adults and nymphs congregate heavily on the lower surface of leaf, suck the sap and cause pre-mature leaf drop, chlorosis, yellow speckling, crinkling and curling. Honey dew secretion also leads to the development of sooty mould fungus. The copious white, waxy flocculent material secreted by all the stages of the pest is readily spread by wind and thus cause public nuisance. It is also a suspected vector of mycoplasma disease, lethal yellowing in coconut.

 

Integrated Pest Management

      • Remove and destroy damaged leaves along with life stages.
      • Remove and destroy weed plants like Abutilon, Acalypha, Euphorbia, etc., in the nearby vicinity as these plants are alternate hosts.
      • Use yellow sticky traps at 15/ha to attract and kill the adults
      • Release Chrysoperla carnea predators at 10000/ha to kill all life stages
      • Encourage the activity of predators such as Encarsia and Coccinellids, Chilocorus nigrita, Chilomenus sexmaculatus, etc.
      • Spray Fish oil rosin soap (FORS) 25g/L or NSKE 5% or neem oil 0.03% 1ml/l or phosalone 35 EC 3 L or triazophos 40 EC 3 L or  acephate 75 SP 1.5 kg in 1500 -2000 L per ha., two to three times based on the incidence.
      • Avoid using synthetic pyrethroids and extending crop growth.
      • Conserve spiraling whitefly parasitoids, Encarsia haitiensis and E. guadeloupae.