Published online by Cambridge University Press: 09 March 2007
Predatory ants are omnipresent year-round in upland (dryland) rice fields in the Philippines. At least 14 species were identified of which the very aggressive Solenopsis geminata (Fabricius) and also Tapinoma sp. nr indicum Forel usually predominated. Some highly aggressive species, notably Pheidolegeton spp. and Bothriomyrmex dalyi Forel were localized. Solenopsis geminata flourished within many fields, not only during the crop season but also throughout dry season fallows where they remained aggressively predatory. Rice plants infested with brown planthopper Nilaparvata lugens (Stål) were usually found within a few hours and S. geminata workers were quickly recruited to N. lugens aggregates. Predation was usually incomplete and workers began to solicit the few remaining late instar or adult N. lugens survivors. These oviposited but no second generation nymphs appeared. There was a surge of recruited ants at the time of N. lugens egg hatch when surviving adults were also killed. Initially, S. geminata alone killed N. lugens aggregates less quickly than with the whole predator complex but ultimately its sole effect was as great as that of the complex. Scattered N. lugens adults, corresponding to numbers that initially colonize rice plants, were eliminated as quickly by S. geminata alone as by the predator complex. Tapinoma indicum occurring separately or with S. geminata on the same plant contributed to predation of N. lugens especially on young nymphs. Solenopsis geminata attacked other insects on rice notably leaffolders of which 97% mortality was recorded when they were exposed throughout egg and larval stages. The role of S. geminata as a predator of upland rice pests is discussed in the context of known biological control of pests of non-rice dryland crops in the tropics and sub-tropics by S. geminata and other Solenopsis spp.
To send this article to your Kindle, first ensure no-reply@cambridge.org is added to your Approved Personal Document E-mail List under your Personal Document Settings on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part of your Kindle email address below. Find out more about sending to your Kindle. Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations. ‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi. ‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Find out more about the Kindle Personal Document Service.
To save this article to your Dropbox account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Dropbox account. Find out more about saving content to Dropbox.
To save this article to your Google Drive account, please select one or more formats and confirm that you agree to abide by our usage policies. If this is the first time you used this feature, you will be asked to authorise Cambridge Core to connect with your Google Drive account. Find out more about saving content to Google Drive.