`GPB PPT

AGRICULTURE

1. Welcome

2. Presentation topic-Resurgence of mites Presentation by MANTESH.SM PALM 7018

3. Resurgence According to De Bach increasing in the pest populations fallowed by the applications of insecticides which kill some pests and their natural enemies . The residual activity of the insecticide then expires and the pest population is able to increase more rapidly and to a higher abundance when natural enemies are absent .

4. Types of resurgence 1) primary pest resurgence 2) secondary pest resurgence

5. Primary pest resurgence Pest populations which were initially suppressed by the applications of pesticides bounce back to excessive levels within short time. Primary pest resurgence occurs when the target mite population responds to an acaricide treatment by increasing to a level at least as higher than the population level observed before the treatment .

6. Secondary pest resurgence The type of resurgence where minor pests developing into major pests. Development of secondary pest resurgence occurs when an acaricide treatment controls the primary pest and destroy natural enemies of minor pests elevating the secondary pest to primary pest status. The successful control of one primary pest can lead to an outbreak of a second primary pest when the two pest species feed on the same plant part. A secondary pest was in such small numbers previous to pesticide application that it was not a significant pest. It became an economic pest after the insecticide application as minor pest population numbers shoot up and become major pest.

7. The effects of resurgence An increase in injury to the crop and potential losses in crop production A n increase in management costs for additional chemical controls to prevent further injury In perennial crops, an increase in the pest abundance that carries over to the next growing season

8. Resurgence management Avoid Hormoligosis Spraying of recommended insecticides at proper intervals Cultural practices which enhance natural enemies Alternation of pesticides , by using selective pesticides the natural enemies can be saved Monitoring of pest population through traps should be done to determine proper time for insecticide applications Recommended spacing should be followed to avoid favourable environmental conditions for multiplication of pests

9. Case Studies On Resurgence Of Mites

10. Neonicotinoid Insecticide Imidacloprid Causes Outbreaks of Spider Mites Laboratory experiments provide evidence that imidacloprid debilitates insect predators of spider mites suggesting that relaxation of top-down regulation combined with enhanced reproduction promoted a non-target herbivore to pest status . Jan P. Nyrop , et al (2011 )

11. Resurgences of spider mites ( Acari : Tetranychidae ) induced by synthetic pyrethroids These pesticides are lethal as well as repellent to phytoseiids and other predators that prey on spider mites, may inhibit fungi which attack the latter, and affect phytophagous competitors.  Uri   Gerson et.al(2009)

12. Ecology and Control of Eriophyid Mites Injurious to Fruit Trees in Japan  A marked resurgence in  A. fockeui  populations occurs after synthetic pyrethroids are sprayed, because they have no effect on  A. fockeui  but are harmful to the predators, such as phytoseiid mites . Wataru Ashihara et al (2014)

13. The Ecological Approach to the Management of the Citrus Rust Mite Phyllocoptruta oleivorus ( Ashin .) The pest was formerly of minor importance with apparently having been held in check by natural enemies,. yet with the increase use of organic phosphorus pesticides,like phosolone and diethion , it becomes a noxious pest Aly H .(2006)