Main predators of insect pests: screening and evaluation through comprehensive indices.
BACKGROUND
Predatory natural enemies play key functional roles in integrated pest management. However, the screening and evaluation of the main predators of insect pests has seldom been reported in the field. Here, we employed comprehensive indices for evaluating the predation of a common pest (Ectropis obliqua) by nine common spider species in Chinese tea plantations.


RESULTS
We established the relative dominance of the spider species and their phenological overlap with the pest species, and analyzed DNA from the nine spider species using targeted real-time quantitative polymerase chain reaction to identify the residual DNA of E. obliqua. The predation rates and predation numbers per predator were estimated by the positive rates of target fragments and the residual minimum number of E. obliqua in predators' guts, respectively. The results showed that only four spider species preyed on E. obliqua, and the order of potential of the spiders to control E. obliqua from greatest to smallest was Neoscona mellotteei, Xysticus ephippiatus, Evarcha albaria and Coleosoma octomaculatum by the Z-score method.


CONCLUSION
The orb-weaving spider N. mellotteei has the maximum potential as a biological control agent of E. obliqua in an integrated pest management strategy. An approach of screening and evaluating main predators of insect pests through comprehensive indices was preliminarily established. © 2017 Society of Chemical Industry.
['Yang|Tingbang|T|http://orcid.org/0000-0002-6685-1209', 'Liu|Jie|J|', 'Yuan|Longyu|L|', 'Zhang|Yang|Y|', 'Peng|Yu|Y|', 'Li|Daiqin|D|', 'Chen|Jian|J|']
D000818:Animals D028241:Camellia sinensis D002681:China D020387:Food Chain D007300:Insect Control D007814:Larva D009036:Moths D010572:Pest Control, Biological D011235:Predatory Behavior D013112:Spiders
predation comprehensive indices Ectropis obliqua spiders molecular gut analysis real-time quantitative PCR