Biology and functional response of the predator, Dortus primarius (Distant) (Hemiptera: Miridae) preying on Frankliniella schultzei (Trybom) (Thysanoptera: Thripidae)

Abstract

Background: Dortus primarius (Distant) (Hemiptera: Miridae) is a general predator reported from the oriental region. This bug is naturally found in many crop ecosystems where it feeds on thrips, aphids, insect eggs and other soft-bodied insects. Although, the rearing protocol of this predatory mirid has been developed, the efficiency of this predator as a biocontrol agent is limited and needs to be investigated. The thrips, Frankliniella schultzei (Trybom) (Thysanoptera: Thripidae), is a polyphagous pest that attacks many crops in polyhouse in India. Therefore, in the present study, biology and functional response of this predator to different densities of F. schultzei larvae in the laboratory was investigated. Results: The mirid predator was able to develop from egg to adulthood on tomato infested plant with F. schultzei larvae in 23–24 days with 15 and 11.76% mortality of 4th and 5th instar nymphs, respectively. Both 5th instar and female adults exhibited a type III functional response. At highest prey density (40) both 5th instar and female adults consumed 21.6 and 28.6 thrips larvae per day, respectively. Functional response parameters, viz. attack rate, handling time, a/Th and T/Th showed the potency of this predator against F. schultzei. Conclusion: Based on the high fecundity, predation rate and density dependent behaviour, it is predicted that D. primarius might be an efficient and potential predator. However, further research is needed to assess its release rate and other ecological studies in the field situation.