The Fort Worth Press - Climate, big agriculture slashing insect populations 'by half'

USD -
AED 3.672974
AFN 71.467862
ALL 91.374972
AMD 391.159852
ANG 1.790208
AOA 916.99999
ARS 1072.796802
AUD 1.59738
AWG 1.8025
AZN 1.699222
BAM 1.811219
BBD 2.018475
BDT 121.482648
BGN 1.801199
BHD 0.376971
BIF 2926
BMD 1
BND 1.343366
BOB 6.907601
BRL 5.666296
BSD 0.999699
BTN 85.449031
BWP 13.836501
BYN 3.271549
BYR 19600
BZD 2.008011
CAD 1.424395
CDF 2871.000269
CHF 0.877785
CLF 0.024908
CLP 955.840257
CNY 7.268099
CNH 7.32665
COP 4151.25
CRC 502.211006
CUC 1
CUP 26.5
CVE 102.050275
CZK 22.900974
DJF 177.719787
DKK 6.85017
DOP 63.325024
DZD 134.017044
EGP 50.5842
ERN 15
ETB 129.85013
EUR 0.918105
FJD 2.32785
FKP 0.773835
GBP 0.767135
GEL 2.760097
GGP 0.773835
GHS 15.509726
GIP 0.773835
GMD 71.498917
GNF 8655.000325
GTQ 7.712361
GYD 209.774732
HKD 7.78445
HNL 25.755019
HRK 6.910601
HTG 131.01197
HUF 368.340121
IDR 16745.85
ILS 3.700289
IMP 0.773835
INR 85.65165
IQD 1310
IRR 42112.509086
ISK 132.110442
JEP 0.773835
JMD 157.858912
JOD 0.708978
JPY 148.062988
KES 129.495264
KGS 86.770498
KHR 3959.999612
KMF 453.49364
KPW 900.019816
KRW 1469.750201
KWD 0.30813
KYD 0.833098
KZT 503.1093
LAK 21664.999533
LBP 89600.000341
LKR 295.853495
LRD 199.849684
LSL 18.479641
LTL 2.95274
LVL 0.60489
LYD 4.830096
MAD 9.586497
MDL 17.928831
MGA 4664.999743
MKD 56.691557
MMK 2099.510008
MNT 3481.383862
MOP 8.014354
MRU 39.850258
MUR 45.7503
MVR 15.410067
MWK 1736.000132
MXN 20.270498
MYR 4.4675
MZN 63.900609
NAD 18.480191
NGN 1537.22005
NIO 36.749936
NOK 10.411485
NPR 136.71845
NZD 1.74756
OMR 0.384936
PAB 0.999699
PEN 3.676986
PGK 4.038496
PHP 57.074972
PKR 280.197632
PLN 3.837961
PYG 8003.148658
QAR 3.64075
RON 4.569098
RSD 107.587006
RUB 84.248805
RWF 1415
SAR 3.751198
SBD 8.326764
SCR 14.351739
SDG 600.515731
SEK 9.87528
SGD 1.347155
SHP 0.785843
SLE 22.829842
SLL 20969.501083
SOS 571.499354
SRD 36.599498
STD 20697.981008
SVC 8.746788
SYP 13002.468687
SZL 18.480143
THB 34.360248
TJS 10.911398
TMT 3.51
TND 3.097499
TOP 2.342099
TRY 37.960199
TTD 6.782581
TWD 33.250501
TZS 2639.957983
UAH 41.341606
UGX 3645.961151
UYU 42.127197
UZS 12935.000068
VES 69.92661
VND 25630
VUV 123.375609
WST 2.83707
XAF 607.466025
XAG 0.029678
XAU 0.000317
XCD 2.70255
XDR 0.755479
XOF 606.516576
XPF 110.349823
YER 245.650464
ZAR 18.953355
ZMK 9001.203963
ZMW 27.865626
ZWL 321.999592
  • RBGPF

    0.0000

    68

    0%

  • CMSC

    0.0600

    22.5

    +0.27%

  • NGG

    0.0000

    65.78

    0%

  • RIO

    -0.3300

    59.9

    -0.55%

  • RELX

    0.3100

    50.98

    +0.61%

  • CMSD

    0.0100

    22.83

    +0.04%

  • SCS

    0.1400

    11.46

    +1.22%

  • BCC

    3.1600

    102.07

    +3.1%

  • BCE

    -0.9600

    21.82

    -4.4%

  • RYCEF

    -0.2700

    9.78

    -2.76%

  • BTI

    -0.8500

    40.25

    -2.11%

  • JRI

    0.0600

    13.04

    +0.46%

  • VOD

    -0.1500

    9.12

    -1.64%

  • GSK

    -0.2300

    37.64

    -0.61%

  • AZN

    -0.3800

    72.22

    -0.53%

  • BP

    0.0000

    33.81

    0%

Climate, big agriculture slashing insect populations 'by half'
Climate, big agriculture slashing insect populations 'by half' / Photo: © AFP/File

Climate, big agriculture slashing insect populations 'by half'

A warming world and intensive agriculture are causing insect populations to plummet by nearly half compared to areas less affected by temperature rises and industrial farming, researchers said Wednesday.

Text size:

The researchers measured both insect abundance and number of species in areas across the world and compared that to insects in more pristine habitats.

The study published in Nature found that the double whammy of global warming and shrinking habitats has not just hit population numbers, but also provoked a 27 percent drop in the diversity of species.

"The reductions are greatest in the tropics," lead author Charlie Outhwaite, a macroecologist at University College London's Centre for Biodiversity and Environmental Research, told AFP.

But less data from tropical regions, which are richest in biodiversity, means the global decline in insects is likely worse than the study's headline figures suggest, she said.

The calculations may also be too conservative because areas used to benchmark change -- while the most pristine on the planet -- have already been degraded to some extent by human activity.

While in line with earlier estimates of insect decline, the new findings are based on different methodologies.

Covering 18,000 species from beetles to butterflies to bees, the study drew from 750,000 data points collected from 1992 to 2012 at 6,000 locations.

"Previous studies have been carried out at the small scale on a limited number of species or species groups," Outhwaite said.

The consequences of insect decline are significant.

Some three-quarters of 115 top global food crops depend on animal pollination, including cocoa, coffee, almonds and cherries.

Some insects are also crucial for pest control -- especially of other bugs.

Ladybugs, praying mantis, ground beetles, wasps and spiders all play crucial roles in keeping pest insects in check, from aphids and fleas to cutworms and caterpillars.

Insects are also crucial for decomposing waste and nutrient cycling.

- 'A catastrophic outcome' -

The study is the first to look at the combined impact of rising temperatures and industrial agriculture, including the widespread use of insecticides.

"We often only consider one driver of change, such as land use, whereas in reality a lot of drivers will be impacting the same space," Outhwaite said.

The interaction between these drivers, the study shows, is worse than if they had acted independently.

Even without climate change, converting a tropical forest into agricultural land leads to drier hotter areas due to the removal of vegetation that provides shade and retains moisture in the air and soil.

Add a degree or two of warming, and these regions become even hotter and drier, pushing certain species of insects up to or beyond their limits.

In some regions, insects are now experiencing extended periods in which temperatures exceed the highest extremes of less than a century before.

Up to now, intensive agriculture and habitat loss have been the major driver of insect decline.

Earlier research, for example, estimates the number of flying insects across Europe has dropped 80 percent on average, causing bird populations to shrink by more than 400 million in three decades.

"We know that you can't just keep losing species without, ultimately, causing a catastrophic outcome," said Tom Oliver, a professor of applied ecology at the University of Reading.

"You cannot keep removing rivets from an aeroplane without it eventually falling out of the sky."

- Farming hope -

The new study points to a strategy that could extend a lifeline to threatened insects.

Areas practising low-intensity agriculture -- fewer chemicals, less monoculture -- that were surrounded by at least 75 percent natural habitat saw only a seven percent decline in insect abundance.

But if the density of surrounding natural habitat dropped below 25 percent, insect population declined by nearly two-thirds.

"I think this finding gives us hope that we can successfully design landscapes to produce food where biodiversity can thrive," Jane Hill, a professor of Ecology at the University of York, told the Science Media Centre.

Insects comprise about two-thirds of all terrestrial species, and have been the foundation of key ecosystems since emerging almost 400 million years ago.

Moles, hedgehogs, anteaters, lizards, amphibians, most bats, many birds and fish all feed on insects.

S.Rocha--TFWP