Insect collections and the questions they create

ALLRIGHT!!!! I have been inspired by grading insect collections. Yes, inspired by insect collections. You may ask why or you may not (because you know me that well)!

So, Popillia japonica Newman, Japanese beetle (Order Coleoptera, Family Scarabaeidae).

P. japonica is the most destructive scarab beetles in North America particularly to agronomic and horticultural crops. Here is an example of some of their damage; picture and more information here

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It was accidentally introduced into the US in New Jersey in 1916. Since it's introduction it has spread to all states east of the Mississippi River and into portions of Canada such as Quebec. Populations have been discovered in California but they were effectively eradicated there.

P. japonica was detected in Kansas in North Topeka in 1992. Since then Kansas entomologists routinely place Japanese beetle traps in high-risk areas such as landscape nurseries to detect the presence of this pest. These traps may be baited with eugenol and phenethyl propionate. I found a website with more information about organic trapping; the homemade mixture looks interesting! ;)

P. japonica is often confused with Euphoria spp (Fabricius), green June beetles. However, P. japonica can easily be told apart by looking for their white tufts of hair along the abdominal segments and they are smaller than green June beetles.

I found this lovely Japanese Beetle picture here

I found this Green June Beetle picture, here.

Now, that you have seen them do you think you could tell them apart?

I found this comparison picture, here. I'm sure that now you can definitely tell them apart.

Typical Life Cycle:

I found this beautiful life-cycle image here. In other words, larvae emerge from the soil in the spring. Pupation occurs during late May to early June. The adults begin emerging in late June and are active though September. The females will lay eggs in the soil during late September. The eggs hatch within 14 days. The larvae will feed until the onset of cold and then tunnel deeper into the ground where they will eat and grow until spring. In most places they are univoltine (one generation per year) however where the cold is really extreme thy may take two years to produce one generation.

So, now that you know a little bit about P. japonica, you may be wondering why seeing this insect in a collection made me want to blog about it. Well, I was curious about the current range in Kansas since this specimen was “collected” in Riley County which does not contain Northern Topeka. MMM???

Today, I wandered into the local extension agents office and I asked, "Is the Japanese beetle present in Riley county?" This lead to many questions such as "Why do you ask specifically about Riley County?" Where was it found? What time was it found? What was it doing? Were there more than one specimen in that location?

Of course, I could only answer the first question which was that a student turned it in and I wanted to know if it was possible to find them here in Riley county. The extension agent knows me well so this wasn't surprising for him but he did thank me for my vigilance. Apparently, Japanese beetles can be found in Riley county but are rare; they tend to be located in more metropolitan areas such as KC, Wichita, Lawrence, Topeka, and Salina. Recently, someone found one in Hays. For those of you unfamiliar with Kansas, I have found a map for you to look at so just click on Kansas and see the map.

The difficult part (because I wanted to encourage cooperation not fear of retribution) was to collect the rest of the information from the student. She did respond multiple times with plenty of information and stated that she thought it was cool that we were so interested in getting more information because of its pest status. She said she found the P. japonica at Marlott Memorial Park ("on top of the world"), on October 4th, in the evening (around 6pm), on some yellow flowers, and it was the only one found. I will be turning this information over to my extension agent friend and let him go from there.

I guess, you never really know what I'm going to blog about.

Book References Used:

Pedigo, L.A., & Rice, M.E. 2006. Entomology and Pest Management, 5^th Ed. Pearson Prentice Hall, Upper Saddle River, New Jersey, US. Pg. 113, 322, 489

Salsbury, G. A., & White, S.C. 2000. Insects in Kansas. Kansas Department of Agriculture. Pg. 185 and 187.