Ecological Control On Tea Insect Pests In Xiangfeng Tea Plantation

In this paper the background of the ecological control on tea pests was reviewed. Ecological control on tea pests is a new strategy of pest management. Its peculiarity, principles and methods were discussed. It is posit that ecological control of pests is a piece of systematic works, and the pest is just one element of the ecological system in tea garden. We should study all the main factors in this system carefully and acquire much enough about the structure and functions of this system, and then take steps to control them correspondingly. Ecological control on tea insect pests in Xiangfeng tea plantation was done according to above idea and practice, which obtained from the former research. Followings are the main studies in this paper.1. Investigation of insect community. There are 90 Species of insect and mite pests from 43 Familias, 11 Ordos, and 2 Classes in the plantation. Leaf-feeders (Lepidoptera: Lymantriidae, Psychidae, Limacodidiae) are the major ones ,32 species, 35.55% of the insect pests community. Leaf-suckers (Homoptera) are the second ones ,19species, 21.11% of the insect pests community, and insect pests of Coleoptera are the third ones, 12 species, 13.33% of the insect pests community. There are over 60 Species of natural enemy from 30 Familias, 10 Ordos, and 2 Classes. Predatory ladybirds and Carabidae, parasitic wasps, spiders are the dominant species.2. Dynamics of insect pests community. The seasonal pattern of the community is divided into 4 phase, one is from October -December the year before to January ~ March, the second one is April ~ May, the third one is June ~ July, the fourth one is August ~ September. Some parameters of the community show that species richness of April -September is the highest, diversity index of April - May is the smallest, evenness of April - September is the smallest, dominant indices of April to September is the highest. So, the phase from April to September is the phase of the number of the community increased and decreased greatly, also, it is the key phase for management. Results ofprincipal component analysis show that E. pseudoconspersa Strand T. aurantii Boyer et Fonscolombe, E. vitis (Gothe) et al occurrence mainly from April to May, E. obligue hypulina Wehrli, O. chinensis (Thunberg), A. theae (Watt) et al occurrence mainly from June to September.3. Test of Acta against Empoasca vitis (Gothe). Applied Acta against E. vitis (Gothe) during its peak occurrence period show that Acta exert excellent control effect against E. vitis (Gothe), the results of plot trial show that Acta 10000 times diluting solution, 12000 times diluting solution and 15000 times diluting solution obtain control effect of population reduce 63.87%, 60.29%, 53.13% in Id, 92.63%, 90.43%, 83.82% in 3d, 96.43%, 94.63%, 89.02% in 5d and over 90% in 7d respectively. The results of applied Acta 12000 times diluting solution against E. vitis (Gothe) show that the population reduce is 59.47% in Id, 89.21% in 3d, 95.13% in5d,96.01% in7d and 98.96% in lOd respectively.4. Analysis of the vertical distribution of main insect pests and their natural enemies. The vertical distribution pattern of main insect pests is divided into 3 part, insect pests mainly concentrate on the upsides, about 30cm high from the top of the vegetation, there are dangerous leaf-feeders and suckers (e.g. E. vitis (Gothe), T. aurantii Boyer et Fonscolombe, E. spseudoconspersa Strand, C. minuscula Butler, E. obligue hypulina Wehrli and so on )in here. Niche breadth and overlap between T. aurantii Boyer et Fonscolombe and its natural enemies is calculated, so it does with E. vitis (Gothe) and its natural enemies.5. Sex pheromone trap of tea tussock moth. Pheromone of tea tussock moth, Euproctis speudoconspersa is applied to trap the moth, the results show that there are 372 male moth trapped in field trial, 5.3 moth per basin per night. Control effect amount to the treatment of man power and pesticide.