The Pacific Cockroach, Euthyrrhapha pacifica (Coquebert, 1804)
Our kids got got an inexpensive metal detector for Christmas this year, and it has turned out to be maybe my favorite thing that Santa brought. It wasn’t my idea, so don’t start accusing me of gifting stuff based on what I deem to be fun rather than what my kids actually want – although, I must admit, I am a little guilty of this to a certain extent with other presents. (Exhibit A: The Fridgezoo Penguin. This was a Christmas gift for the kids that I brought back from a recent trip to Japan, and it was probably my second most favorite gift after the metal detector. You put it in the refrigerator, and whenever you open the fridge it says hello, and if you leave the fridge open, it starts talking to you in Japanese. I think it is really cool, but the rest of my family finds it annoying.)
So anyway, last week we took the metal detector out to Lanikai to hunt for some treasures. It was a lot of fun, the kids found an old key, some kind of luggage tag thing, some bottle caps, and some other random metal objects; however, for me, the greatest treasure was found on the beach access path as we were walking back to the van – a pacific cockroach! In all my time in Hawaii, I have only seen this lovely roach, Euthyrrhapha pacifica (Couebert, 1804), on one other occasion (Barbers Point), so it was a real treat. Even though I was wrangling my sandy three-year-old at the time I spied it, I was still able to scoop it up from amongst some beach naupaka (Scaevola sericea) leaves, and put it in a plastic sandwich bag. The next day at work I snapped some photos of it during my lunch break before releasing back into the landscape.
Despite its designation as the Pacific cockroach, Euthyrrhapha pacifica is considered an immigrant to Hawaii. According to Zimmerman (1948), it was first recorded from Hawaii by Bormans in 1882. It is supposedly common on many of the pacific islands and throughout the tropics (Fullaway and Krauss 1945, Zimmerman 1948). The Catalogue of the specimens of Blattaria in the collection of the British Museum lists Brazil, Madagascar, and Polynesia as its distribution (Walker and Gray 1868).
I found very little information on this roach within the references that were immediately available to me at work and on the internet. The most descriptive account that I found was in “Common Insects of Hawawii” (Fullaway and Kraus 1945): “Euthyrrhapha pacifica (Coq.) Familiy BLATTIDAE. This pretty little insect is probably the most attractive member of the roach family in Hawaii. The two distinctive orange spots on the wing cases make this species easily recognizable. It is of wide distribution in the tropics and occurs on many of the Pacific islands. Found both indoors and out, it breeds in neglected cupboards, rubbish in houses and beneath dead leaves and debris. The young nymphs emerge from the egg capsule through a hole which they gnaw out. They are rather dull in appearance in contrast to the adults. The roaches are active both during the day and at night and may be seen running about in an erratic manner.” Zimmerman (1948) adds that “it is not infrequently confused with the beetles by laymen.”
I was able to track down a couple of references in the Proceedings of the Hawaiian Entomological Society. In Volume 2, number 4 of the Proceedings (1912) it is written that “Mr. Terry exhibited a specimen of the small roach, Euthyrrhapha pacifica, and one of its egg capsules from which the young had emerged. He called special attention to the fact that instead of emerging in the usual way for roaches the young of this species gnaw a hole through the capsule resembling that made by parasites, for which it might be mistaken. Later, in Volume 12, Krauss (1945) reports the first record E. pacifica on the island of Hawaii.
There are a few random internet references. On the “Ask a Bishop Museum Scientist” site David Preston identifies a Pacific cockroach for a someone and provides some info. You can find a really good of photo of E. pacifica here on Flickr. And finally, a Facebooker humorously thinks E. pacifica is named after Steven Colbert , rather than French entomologist Jean Antoine Coquebert being the author.
Fullaway, D. T. and N. L. H. Krauss. 1945. Common Insects of Hawaii. Tongg Publishing Company, Honolulu, Hawaii.
Kruass, H. L. H. 1945. Proc. Haw. Ent. Soc. 12(2):309.
Terry, F. W. 1912. Proc. Haw. Ent. Soc. 2(4):145.