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 .
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.
7.
8.
9.
10. 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.
11.
12.
13. The effects of resurgence
An increase in injury to the crop and potential losses in crop production
An 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
14. 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
16. 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)
17. 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)
18. 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)
19. 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)
