Attraction Of Predatory Ladybeetles,Coccinella Septempunctata And Harmonia Axyridis By Floral Volatiles From Vegetable Fields And Orchards Fields

With the increasing demand on green and non-pollution fruits,traditional chemical control measures for diseases and insect pests,which cause environmental pollution and make the pests and pathogens become resistence to pesticides and fungicide,can not meet the need for contemporary fruit industries.The green prevention and control technology based on the chemical communication relationship between plant-pest-natural enemies has become a research hotspot at home and abroad.Effective protection and utilization of natural enemies is an important part of green prevention and control technology.It could improve the control efficiency of pests to develope natural enemy attractant combined with sex pheromone traps technology,which can retain andexpand propagation natural enemies in the habitat.Hence,the development of effective natural enemy attractants has important significance in the biological control.The Coccinella septempunctata and Harmonia axyridis are important predatory natural enemies,which can control the pests such as aphids,whiteflies and scale insects in the open vegetable garden and orchard due to large appetite,rapid reproduction,and strong flight and survivability.Flowering plants can provide nutrients to natural enemies to prolong their life,reduce mortality during diapause,improve their flight and predation ability,and thus affect the adaptability of natural enemies in the field.Therefore,the attraction of aroma volatiles from flowers in gardens and orchards to the Coccinella septempunctata and Harmonia axyridis under laboratory and field trial were investigated.The main contents and contributions of this work are summarized as follows:1.Selection preferences of Coccinella septempunctata and Harmonia axyridis on volatiles of peach and pear flowers:Coccinella septempunctata and Harmonia axyridis feed on pollen,nectar and other sugar-rich foods on peach blossoms and pear blossoms in early spring.Therefore,firstly,the attraction of volatiles of peach blossoms and pear blossoms to Coccinella septempunctata and Harmonia axyridis was determined.14 and 16 compounds were identified from peach and pear flowers by headspace dynamic adsorption/gas chromatography-mass spectrometry,respectively.With the Y-type olfactometer and wind tunnel behavior test,it was found that the Coccinella septempunctata had obvious selectivity preference for furfural,terpinene and methylheptenone,and Harmonia axyridis had a clear preference for 1.4-diethylbenzene and terpinene at 1 ?g/mL.2.Selection preferences of the Coccinella septempunctata and Harmonia axyridis on the flowering plants in the vegetable garden and orchard habitat:In order to obtain more active compounds,the group of 58 aroma volatiles from flowers in the fruit and vegetable habitats was constructed through literature review.The attracting effects of these compounds on the Coccinella septempunctata and Harmonia axyridis were evaluated by Y-tube olfactometer and wind tunnel behavior test.Finally,it was found that Coccinella septempunctata adults had strong tendency to 12 kinds of compounds such as cis-3-hexene-1-alcohol and trans-3-hexene-1-alcohol.Adults of Harmonia axyridis showed strong tendency to 14 kinds of compounds such as cis-3?hexene-1-alcohol and n-nonane.3.In laboratory and field screening of ladybug attractant formulas:Among the compounds screened above,a formula with good attracting activity to Coccinella septempunctata and Harmonia axyridis was obtained by mixing above compounds in the wind tunnel.In order to improve the stability of the formula,the compounds with attracting activity in part 2 were added to it.Finally,formula C1-1,C2-1,C1-2.C2-2,C2-5,C1-9,C2-9,C1-11 and C2-11 showed good attraction effect to ladybusis in the field.