11 July 2016 - Spot the Difference

(Eudonia mercurella)

Last Thursday we had one of the most productive traps since I arrived. An impressive 45 species including Clay, Agapeta hamana, Aethes rubiferana, Dark Arches, Green Pug, and the majestic Garden Tiger were captured. This made a stark contrast to the night before, where the only notable finding was a Purple Clay. A good number of Barred Straw, Udea Olivalis, Silver Y, and Silver-ground Carpet were fluttering about upsetting all the others, so we might have lost a couple species before they could be identified.

Garden Tiger Moth (Arctia caja)

A series of coincidences led to my cousin unearthing a Burberry 2013 F/W design that I could swear was a tribute to the Garden Tiger. Recalling Valentino’s “Camubutterfly” line in 2014, I wondered if it could be another bout of Lepidoptera invasion of the fashion industry. The official claim, however, let us down in saying that they took their print from giraffes – Giraffes! Our moth’s association with other animals does not stop there. Its scientific name Arctia caja is derived from ‘arktos’, meaning a bear, named for the hairy appearance of its larva. Caja is the female form of the Roman name Caius, as in Caius Julius Caesar.

Red Barred Tortrix (Ditula augustiorana)

The Red-barred Tortrix (Ditula augustiorana) has been recorded once before in 2012 but not properly photographed. This moth is so energetic and loves to dart around so much that even today’s photograph had to be taken with extra caution. It is one of the few micros listed as “Grade 1” on Flying Tonight, meaning it is easily identifiable even to inexperienced observers. The characteristic bold, viewfinder-like spot on its dorsum gives it away, as does the reddish-brown cross-band halfway down the body.

Marbled Orchard Tortrix (Hedya nubiferana)

Plum Tortrix (Hedya pruniana)

We were also presented with some tricky, spot-the-difference type of exercises. Suspecting they might be different species, I submitted the following pairs to Charlie Fletcher, who confirmed that they are indeed different. Out of the two Hedya’s, one is a pruniana (Plum Tortrix) and the other possibly a nubiferana (Marbled Orchard Tortrix). The latter is usually longer-winged, but the rest of the markings are hard to tell apart. The other pair (lucky I checked) turned out to be from different genera: one is a Scoparia pyralella and the other a Eudonia mercurella. The two are of similar size and shape, but the S. pyralella has a orange-brown tint that is absent in the E. mercurella. The latter supposedly has a broad X in between the termen and the second cross-line, which I failed to see.

(Scoparia pyralella)

Post : Tung Chau (UPenn)