Pesticide induced resurgence
, often shortened to
resurgence
in pest management contexts, can be described as a constraint of
pesticide
use, by which they fail to control
pests
such as insects and
spider mites
: instead ‘flaring up’ populations that may have been of minor importance. Although there are more than one mechanisms by which this takes place, mortality of
natural enemies
following the use of broad-spectrum insecticides and
acaricides
is often implicated. This is sometimes called the “pesticide treadmill”: a term coined by
Robert van den Bosch
to describe a self-reinforcing over-dependence on agrochemicals and inimical to natural
biological controls
. Notable examples include the flare-up of rice
brown planthopper
populations, following over-use of broad-spectrum inscticides.
[1]
Causes and mitigation
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]
With an increasing population, world food production has been subject to
intensification
and since the 1950s, the use of chemical
pesticides
. Examples are included below, but because of its importance to rice, outbreaks of the
brown planthopper
were intensively studied. The differential mortality of the pests and their natural enemies (spiders,
parasitoids
, predatory
bugs
,
etc.
) was a major factor causing outbreaks. However, there were other resurgence factors such as increased pest fecundity due to increased protein content of the rice
phloem
, on which the insects feed.
[1]
Sustainable intensification encompasses
Integrated pest management
(IPM) practices, which are widely recognised as an appropriate strategy for, not only reducing financial costs to farmers and growers, but also managing technical constraints associated with
pesticide resistance
, resurgence and the risks of high crop
residues
. An obvious solution is to reduce or eliminate pesticide use, but where pest pressure is high (
e.g.
with many tropical crops), this is not always feasible: but various measures can be taken, including better timing,
application
and the use of less deleterious products such as
biopesticides
.
[2]
Examples
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]
- Cottony cushion scale
Icerya purchasi
Management of
Icerya purchasi
populations is a well-known early success for classical
biological control
, after introduction of the
vedalia ladybird
in the late 19th century. However, crop spraying with
DDT
and
organophosphate
insecticides in the 1950s, resulted in high vedalia mortality and cottony cushion scale resurgence; this was especially caused by drift of
malathion
or DDT applied by airplane during the early spring months.
[3]
- Spider mites
First generation insecticides such as DDT were often replaced by
synthetic pyrethroids
for agricultural and horticultural use by the end of the 1970s, due to their relatively low persistence and mammalian toxicity. However, their broad spectrum of activity varies for both spider mite control, and their ability to invoke resurgences of different spider mite species on various plants. Pesticides may be both lethal and repellent to
Phytoseiids
and other spider mite predators. After synthetic pyrethroids applications, spider mite development is shortened, the sex ratio can becomes more biased towards females and onset of winter diapause is possibly delayed.
[4]
References
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- ^
a
b
Chelliah, S; Heinrichs, EA (1980).
"Factors Affecting Insecticide-Induced Resurgence of the Brown Planthopper,
Nilaparvata lugens
on Rice"
.
Environmental Entomology
.
9
(6): 773?777.
doi
:
10.1093/ee/9.6.773
.
- ^
Bateman RP (2003) Rational Pesticide Use: spatially and temporally targeted application of specific products. In:
Optimising Pesticide Use
Ed. M. Wilson, Publ. John Wiley & Sons Ltd, Chichester, UK; pp. 129-157.
- ^
Bartlett BR, Lagace CF (1960) Interference with the biological control of cottony-cushion scale by insecticides and attempts to re-establish a favorable natural balance.
Journal of Economic Entomology
,
53 [6]
1055?1058.
- ^
Gerson U, Cohen E (1989) Resurgences of spider mites (Acari: Tetranychidae) induced by synthetic pyrethroids.
Experimental and Applied Acarology
6: 29?46.