Mutualistic relationships between the shield ant, Meranoplus bicolor (Guérin–Méneville) (Hymenoptera: Formicidae) and honeydew–producing hemipterans in guava plantation

摘要

ABSTRACT – Mutualistic relationship between the shield ant, Meranoplus bicolor (Guérin–Méneville), and two species of hemipteran, Aphis gossypii Glover and Ferrisia virgata (Cockerell), was investigated in an unsprayed guava plot at Kamphaeng Saen, Nakhon Pathom, Thailand. The reciprocal benefits were observed in both field and laboratory studies. M. bicolor activity coincided with peak seasonal activity of both hemipterans during June–August. We indicate two sets of support evidence in M. bicolor honeydew preference: (i) statistically higher value of adjusted honeydew weight collected by ant worker from A. gossypii compared with that from F. virgata ( p –value = .005), and (ii) the higher value of the strength of effect (h 2 = .62) in the total variance of multi-species association. We used two–group, ant–tended and ant–excluded, between–subject multivariate analysis of variance (MANOVA) in order to show hemipteran benefits. Both hemipteran populations increased in the ant–tended treatment, together with lesser amounts of two species of coccinellids, Menochilus sexmaculatus (Fabricius) and Coccinella transversalis Fabricius, and one species of syrphid fly, Pseudodorus clavatus (Fabricius), compared with the ant exclusion treatment ( p –value &.0005). The facultative mutualistic relationships of M. bicolor and the two hemipteran species were evaluated.