Subject: What’s in the eggplant patch?
Geographic location of the bug: Brisbane, Australia (inner city)
Time: 01:41 AM EDT
Your letter to the bugman: Hi Bugman,
These bugs have been in my eggplant patch for some time now. I am still getting eggplants so they don’t seem too harmful, but no one knows what they are! They can fly, but they seem to prefer walking. I once counted 30 in the patch.
Location: Brisbane, Australia. Time: Summer. Maybe relevant this is in a fifth floor balcony garden. There are plenty of bugs in the garden overall, but these ones seem to have a monopoly on the eggplant.
How you want your letter signed: The Curious Eggplant Grower
Dear Curious Eggplant Grower,
You had us with your subject line: What’s in the eggplant patch?
These are Scarab Beetles and we are inclined to speculate they are in the Fruit and Flower Chafer subfamily Cetoniinae. We are continuing research; we just wanted you to know where to begin your own research.
There seems to be a considerable amount of variation in color and markings on the Mango Flower Beetle, Protaetia fusca, pictured on the Brisbane Insect site, but though none exactly matches the warm golden-bronze color of the individuals you submitted, we nonetheless believe that species is correct.
Based on the images and the statement “Elytra of male with apical spines, female lacking spines” posted on the Hawaiian Scarab ID site, the individual on the right in your image, with the spines on the posterior ends of the elytra or wing covers, is a male. The site also states: “In Australia, both adults and larvae are found throughout the year. Females deposit as many as 147 eggs in humus during their 6–7 month adult lifespans. Larvae feed on organic materials within the soil rather than live plant roots and reached maturity in roughly 50 days. Natural enemies include wasps (Scolia spp.) that attack larvae, a variety of birds, and Aspergillus fIavus (a fungus that sometimes infects adults).”
We have been getting numerous comments lately from Australia regarding the Blue Flower Wasp, an Australian Scoliid Wasp, indicating they have plentiful prey, the larvae of Scarab Beetles.