2018 October 6

   Jeremy Tatum writes:   I saw about four Cabbage Whites over or near the cabbage fields at Island View Road today.

   Here is a picture of a moth that arose from a caterpillar found on Gumweed during the VNHS Butterfly Walk on September 2.   I released it today near to where the caterpillar was found at Island View Beach.  See Val’s photograph of the caterpillar on the September 2 evening posting.

Heliothis phloxiphaga Lep.: Noctuidae)  Jeremy Tatum

2018 October 5

   The Monthly Butterfly Walk is scheduled for Sunday, October  7.   The weather forecast is not great. However, being optimists, we have not cancelled the walk and Jeremy Tatum will be at the Mount Tolmie summit at 1 p.m., rain or shine.  You never know, the sun may shine long enough for a butterfly or two to appear.  If there is steady rain, however, we are unlikely to find anything.  Although  butterflies have been scarce in September, there have been some spectacular rarities, such as Monarch, American Lady, Mourning Cloak and California Tortoiseshell.  And an Orange Sulphur is not unknown at this time of year.

2018 October 4

   Jeremy Tatum writes:  Now that this site is not quite as busy as it was in mid-summer, here’s a leisurely opportunity to think about tiger swallowtail identification.  It should be easy:  The background colour of the Western Tiger Swallowtail is yellow.  That of the Pale Tiger Swallowtail is white.   Right?   My problem is that sometimes I can’t be sure whether the colour I’m seeing in yellow or white.  Perhaps the yellow of a Western has become faded with time, or something like that.

  Here, then, are two additional clues:

Western Tiger Swallowtail

Western Tiger Swallowtail

1.   The yellow and black tiger stripes at the leading edge of the forewing are approximately equal in width.
2.   The crescent-shaped spot at the base of the long hindwing tail is yellow.

Pale Tiger Swallowtail

Pale Tiger Swallowtail

   1.  The black tiger stripes at the leading edge of the forewing are broader than the white stripes.

   2.  The crescent-shaped spot at the base of the long hindwing tail is mostly orange (with maybe a little white at its tip).  (Thanks to Mike Yip, who drew my attention to this feature.

   What brought this up is that I was recently perusing some past Invert Alerts, when I came across the following picture by Kirsten Mills, May 27, which I had identified and labelled as a Western Tiger Swallowtail.

Kirsten’s photograph

   Well, maybe the background colour looks slightly yellowish, but from the above criteria you can see clearly that I had misidentified it (apologies to Kirsten!), and  it is in fact a Pale Tiger Swallowtail.  I have now relabelled it as such.

   I do not know of any feature by which I can distinguish between the caterpillars of the two species, other than foodplant, which is usually willow for the Western and alder for the Pale.

  Do they ever hybridize?  Are there some individuals that we cannot identify confidently, even if we try to use the above two features?   Let’s keep a look-out next summer.

   Of course there are other species of tiger swallowtail, such as Canadian and Eastern Tiger Swallowtails, and at the moment I don’t know how to identify them reliably.  Presumably they don’t occur on Vancouver Island – but who knows?  Let’s keep our eyes open!

  Another complication:  As with most other organisms, there have been name changes over the years.  I am not sure why some recent authors have chosen to omit the word “Tiger” from Pale Tiger Swallowtail, and call it just the Pale Swallowtail.  Maybe because real tigers aren’t white?   But the Pale one is obviously one of the tiger swallowtail group (subgenus Pterourus); the omission of “Tiger” somehow suggests that it should be set apart and doesn’t belong to this group.  That is why I usually prefer to retain the “Tiger”.

2018 October 1

    Scott Gilmore writes from Upper Lantzville:  I found a couple of really tiny [3-4 mm] beetles in some oyster fungi on Saturday. The one with the red pronotum is from the genus Triplax from the family Erotylidae; the other one is Namunaria pacifica from the family Zopheridae.

Triplax sp. (Col.: Erotylidae)   Scott Gilmore

Namunaria pacifica (Col.: Zopheridae)

Scott Gilmore

2018 September 29

   Jeremy Tatum writes:   No reports today up to 2:00pm, and I probably shan’t be at the computer again today.  I thought I’d just make the following remarks.

    The September 2 VNHS monthly Butterfly walk yielded Cabbage White, Woodland Skipper,Ringlet, Purplish Copper.  Since then, it must have seemed to most of us, individually at least, that the butterfly season was over, most of us not seeing more than an occasional Cabbage White.  Yet collectively it has been a good deal more exciting than that.  Since that September 2 Butterfly Walk, the following additional butterflies have been seen, by one enthusiast or another, in the southern Vancouver Island birdwatching area:

Monarch

Lorquin’s Admiral

Red Admiral

Painted Lady

American Lady

California Tortoiseshell

Mourning Cloak

Pine White

Grey Hairstreak

   Not a bad haul – thirteen species in September.   And still on Vancouver Island, though not in the above area, there have been sightings of Green Comma and Hoary Comma.  And of course there have been many moths, including some spectaculars such as Black Witch and Catocala, and caterpillars of Lappet and Polyphemus moths.