Species Account

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Distribution


 
 

Summary Data


Season (Adult / Immature):

National Status: Local

Local Status: Scarce and very local resident.

Local Record: Grade 3   See here for explanation

Flight time: One generation, Jun-Jul.

Forewing: 15-17mm.

Foodplant: Unknown.

Regional breakdown:

 VC61VC62VC64VC65
Year first recorded1940197519002013
Year last recorded2011201120142013
Number of records1199151
Number of individuals1342111
Unique positions147101
Unique locations14771
Adult records1119141
Immature records0000

For the county, we have a total of 144 records from 29 sites. First recorded in 1900.
 

Photos


2124 Fen Square-spot 01
© Andrew Rhodes

Species Account


Sutton & Beaumont, 1989: In many parts of Britain it is almost impossible to tell this species from D. rubi (Vieweg) since they may look very similar and both are univoltine in some areas and bivoltine in others. In Yorkshire, however, D. florida is generally single brooded, appearing in July whereas D. rubi is double brooded, appearing mainly in June and August. Also there tend to be visual differences in size and colour so we can be sure that this species does occur, although it may well be under-recorded due to general confusion and some overlap in flight times. The records suggest it is very local on low, damp ground, and P.Q. Winter notes that some VC61 records are from arable areas where only small patches of habitat exist in the form of ditches and roadside verges.

2012 (CHF): This species and Small Square-spot appear to be in the process of evolutionary separation and there is some confusion in identification. Fen Square-spot is thought to be univoltine across the country (not bivoltine in some areas as stated above) whereas Small Square-spot is bivoltine except for northern Scotland, so Fen Square-spot in Yorkshire flies in late June and throughout July, ie between the two broods of Small Square-spot. The two are not easy to tell apart but Fen Square-spot is larger, paler and brighter and likes fens and acid bogs. It is also reputed to fly later at night and rarely appears before midnight. Wing markings are identical. The genitalia are similar but subtle yet distinct differences have been noted. Most Yorkshire records come from the east of VC61 and 62 and there were three records in 2011 after a gap of four years. There are several old records from Askham Bog and Skipwith Common but it has not been seen at either site for many years.

Argus 69, 2013:
65. Foxglove Covert, 19.7.2013 (CHF, JCW, AJW). NEW VICE-COUNTY RECORD.
 

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