The feeding behaviour exhibited hy the different subfamilies or Reduviidae is distinctly correlated with the specific prey types involved. Important adaptive modifications arc seen associated with their methods of prey capture and feeding. Based on the analyses of feeding behaviour, reduviids may be grouped as (i) 'blood feeding' type, (ii) 'sticky-trap' type, (iii) 'raptorial' type. (iv) 'wait and grab' type, (v) 'pin and jab' type and (vi) 'chase and pounce' type. The oviposition methods are highly varied in Reduviidae and it is possible to assign group characteristics. but the ultrastructure of the eggs, particularly those of chorionic collar extensions and thc operculum. indicate subfamily resemblance. The usefulncss of fi:cdin,l! and reproductive behaviours and the egg ultrastructure in the biosystcmatics of Reduviidae are discussed.

The pin and jab type of predatory behaviour of Rhinocoris marqinatus Fabricius is distinctly different from the feeding behaviour of other subfamilies known so far. The thin long legs, tibial pads, long slender rostrum capable of more than 90°forward extension, slow gait of this predator are ideally suited for efficient capture of soft-bodied prey types, particularly caterpillars. As in other predatory reduviids, visual stimuli provided by the moving prey, elicit feeding responses in Rhinocoris marqinatus and this is augumented by other sensory systems, including olfactory. The predatory feeding behaviour of Rhinocoris margin atus consists of disinct stimuli-response mediated sequences of events and based on these the feeding behaviour model for this insect is depicted.

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Prickly acacia (Vachellia nilotica subsp. indica), a native of the Indian subcontinent, is a serious weed of the grazing areas of northern Australia and is a target for classical biological control. Native range surveys in India identified a leaf webber, Phycita sp. (Lepidoptera: Pyralidae) as a prospective biological control agent for prickly acacia. In this study, we report the life cycle and host-specificity test results Phycita sp. and highlight the contradictory results between the no-choice tests in India and Australia and the field host range in India. In no-choice tests in India and Australia, Phycita sp. completed development on two of 11 and 16 of 27 non-target test plant species, respectively. Although Phycita sp. fed and completed development on two non-target test plant species (Vachellia planifrons and V. leucophloea) in no-choice tests in India, there was no evidence of the insect on the two non-target test plant species in the field. Our contention is that oviposition behaviour could be the key mechanism in host selection of Phycita sp., resulting in its incidence only on prickly acacia in India. This is supported by paired oviposition choice tests involving three test plant species (Acacia baileyana, A. mearnsii and A. deanei) in quarantine in Australia, where eggs were laid only on prickly acacia. However, in paired oviposition choice trials, only few eggs were laid, making the results unreliable. Although oviposition choice tests suggest that prickly acacia is the most preferred and natural host, difficulties in conducting choice oviposition tests with fully grown trees under quarantine conditions in Australia and the logistic difficulties of conducting open-field tests with fully grown native Australian plants in India have led to rejection of Phycita sp. as a potential biological control agent for prickly acacia in Australia.

Ecobehavioural and biological aspects of two species of seed,infesting thrips, viz Chirothrips mexicanus Crawford and Chiridothrips indicus Ramk. and Marg. are discussed with particular reference to their reproductive biology, population dynamics on different host plants and their damage potential to seed production of their primary host plants.