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Tuesday, 17 January 2012

Last year's top 20 macros...

A very unscientific look at 2011 compared with the previous two years threw up some quite interesting statistics.  There are obvious drawbacks with such a small data set, and even taking into account 25% more effort through the year, the spread of trapping sites and dates was fairly consistent.  The 20 most numerous macro species were, in most cases, considerably more numerous than the average of the previous two years.

There were declines noted in 4 species, Common Quaker and Small Quaker down due to the extremely good numbers of Spring 2010; Large Yellow Underwing was well down on 2010, but similar to 2009, as was Mottled Beauty which was only fractionally down on the average. 

The next few slight increases may be accounted for mainly by the extra effort, and then there are some dramatic figures, more than doubling for Brown Silver-line, Clouded Border and Yellow-tail.  Next, Flame Shoulder, Common Footman, Dark Arches and in particular Smoky Wainscot and July Highflyer increased greatly, and the amazing numbers of Four-dotted Footman was also the third most common species which in itself is remarkable.

Taxon Vernacular 2011 2010 2009
Ave
2009/10
% change
Orthosia cerasi Common Quaker 272 530 135 333 -18.2
Noctua pronuba Large Yellow Underwing 190 283 180 232 -17.9
Orthosia cruda Small Quaker 107 201 48 125 -14.1
Alcis repandata Mottled Beauty 217 133 303 218 -0.5
Campaea margaritata Light Emerald 122 39 187 113 8.0
Pheosia gnoma Lesser Swallow Prominent 116 71 99 85 36.5
Orthosia incerta Clouded Drab 188 223 51 137 37.2
Conistra vaccinii Chestnut 107 112 22 67 59.7
Xanthorhoe montanata Silver-ground Carpet 142 81 69 75 89.3
Idaea aversata Riband Wave 124 39 89 64 93.8
Petrophora chlorosata Brown Silver-line 175 112 62 87 101.1
Oligia strigilis agg. Marbled Minor agg. 112 69 39 54 107.4
Euproctis similis Yellow-tail 131 38 88 63 107.9
Lomaspilis marginata Clouded Border 194 46 86 66 193.9
Ochropleura plecta Flame Shoulder 136 39 35 37 267.6
Eilema lurideola Common Footman 562 119 142 131 330.7
Apamea monoglypha Dark Arches 109 42 7 25 344.9
Mythimna impura Smoky Wainscot 122 24 22 23 430.4
Hydriomena furcata July Highflyer 220 23 33 28 685.7
Cybosia mesomella Four-dotted Footman 258 0 13 7 3869.2


Four-dotted Footman
The Four-dotted Footman trapped in 2011 were all in the Pilmoor area:

Pilmoor wood SE SE4672 1 07-Jun-11
Pilmoor wood NE SE4673 1 07-Jun-11
Low Wood (E), Pilmoor SE4772 5 14-Jun-11
Sessay Wood, Pilmoor SE4773 14 14-Jun-11
Pilmoor wood SE SE4672 1 dead 29-Jun-11
Sessay Wood, Pilmoor SE4773 82 02-Jul-11
Low Wood (E), Pilmoor SE4772 21 02-Jul-11
Pilmoor wood NE SE4673 84 10-Jul-11
Sessay Wood, Pilmoor SE4773 42 14-Jul-11
Pilmoor wood SE SE4672 7 21-Jul-11


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