DEFENSIVE BEHAVIOUR OF THE LONGTAILED MEALYBUG PSEUDOCOCCUS LONGISPINUS (TARGIONI TOZZETTI) (HEMIPTERA: PSEUDOCOCCIDAE) AGAINST THE BROWN LACEWING SYMPHEROBIUS FALLAX NAVAS (NEUROPTERA: HEMEROBIIDAE).

Abstract

DEFENSIVE BEHAVIOUR OF THE LONGTAILED MEALYBUG PSEUDOCOCCUS LONGISPINUS (TARGIONI TOZZETTI) (HEMIPTERA: PSEUDOCOCCIDAE) AGAINST THE BROWN LACEWING SYMPHEROBIUS FALLAX NAVAS (NEUROPTERA: HEMEROBIIDAE).

The defensive tactics of 2nd- and 3rd-instar nymphal and adult Pseudococcus longispinus (Targioni Tozzetti) against larval Sympherobius fallax Navas were studied. When attacked by 1st- and 2nd-instar predators, these three mealybug stages were able to secrete ostiolar fluids which spread and hardened on the mouthparts of the predators; 1st-instar mealybugs appeared to be unable to secrete ostiolar fluids. Adult mealybugs also successfully defended themselves against 1st-instar predators by simply pushing them away with their cerarial wax fringe. Of the lacewing stages, 3rd-instar S. fallax larvae were the most successful at overcoming the defense tactics of P. longispinus.

Key words: lacewings, Chrysopidae, Chrysoperla carnea, behavioural defence, morphological defence, potato sprouts, haemolymph.