Help Desk Article, June/July 2020
By Kathy Love
Well over 50% of calls to the BCMGA Help Desk are tree and lawn concerns, but the runner-up to those two issues is insects, most generally insect identification.
In June and July, the desk has logged 9 contacts from citizens concerned they have seen the recently publicized Asian Giant (Murder) Hornet (AGH) Vespa mandarinia. In all but one instance we were able to assure the concerned citizens they were seeing either the Eastern Cicada Killer Sphecius speciosus (7 calls), the Western Cicada Killer Sphecius grandis (1) or in 1 case a bald faced hornet Dolichovespula maculata. To help assure our concerned citizens that they are not being invaded by the AGH we refer them to a May 2020 blog by Dr. Michael Merchant, Professor and Extension Urban Entomologist https://citybugs.tamu.edu/2020/05/05/giant-hornets/.
In this blog post Dr. Merchant explains “The bottom-line is that the chance of Asian giant hornets invading Texas soon is slim, given that at the moment only a few wasps have been found in only one county in the far northwest corner of the U.S.” He goes on to address the issue of the pest being transported by humans to other areas as unlikely since they are social insects and a lone hornet transported in a container, etc. cannot survive away from its nest. Likewise the possibility of an entire nest being transported undetected is unlikely. He explains that the most likely scenario for transport by humans would be a mated queen going to sleep in the winter by burrowing into a potted plant and coming to Texas — so take care when unpotting your plants in 2021!
When we identify cicada killers, we ask folks not to kill them as they are not aggressive and generally do not bother people. They are beneficial as they provide control of the cicada population. The female uses her stinger to sting and paralyze the cicada which she takes back to her nest, lays her egg and the larvae feed on the cicada. The male does not have a stinger and may be aggressive around the nest but he can’t pop you! The adults feed on flower nectar.
Then there is the flatid planthopper! Yeah, that’s it’s common name the Flatid Planthopper Metcalfa pruinose. Our first contact with this interesting little non-pest was on June 3rd on a boxwood shrub (see photo). We identified it as the nymph phase of Metcalfa although we thought we could also make out some adults when enlarging the photo. Dr. Merchant has also blogged on Metcalfa at https://citybugs.tamu.edu/2017/06/15/citrus-flatid-planthopper/. Since this was our first encounter with this fella we submitted our photo to Dr. Merchant who confirmed we got it right.
Adult planthoppers insert their eggs into the bark, and then the nymphs feed on plant sap with their piercing, sucking mouthparts. As they feed they secrete a protective white waxy substance that covers their body and the surrounding stem. This fluffy white substance may look unsightly but does not harm plants. Nymphs can jump 12-18″ which is why they are called planthoppers. They do not generally cause significant harm at any stage of their life but if you don’t like the look, they can be washed off with a stream of water or use insecticidal soap or horticultural oil to remove them.
They only have one generation a year and it seems at least in our area, they are more numerous in some years than others. After this initial case, we saw them two more times in the following weeks, in one case on member Teri Marceau’s plants.
Finally, every year I have worked the help desk someone brings in the biggest, ugliest bug imaginable! It is the adult stage of the hardwood stump borer beetle Mallodon dasytomus. https://www.insectidentification.org/insect-description.asp?identification=Hardwood-Stump-Borer-Beetle
These have come to the help desk collected from one citizen’s wooden deck and from pecan and elm trees. It is the larval stage of this big guy that does the damage as it eats through the wood surface and the adults make a sizeable hole when they emerge. The larvae can take 3 to 4 years to reach the adult stage. We tell citizens to let the adult stage carry on unless the larvae are causing significant damage to trees, deck, lawn furniture, etc. and you need to disrupt the life cycle. If I had a dead or dying tree and found these guys, I’d keep them around as one of their favorite foods is ants, like fire ants!
Finally, just a reminder to keep your eye out for any sightings of the Emerald Ash borer. It has not been found in Bell or any of our surrounding counties but has been found as near as Tarrant and in May of this year, Denton counties. We have had calls about possible sightings but so far what we have seen have been green longhorn beetles and green tiger beetles. This link to Dr. Merchant’s Insects in the City blog will give you more information on this exotic pest https://citybugs.tamu.edu/2020/05/18/emerald-ash-borer-in-denton/.
If you are not already signed up for Dr. Merchant’s blog, you should consider doing to as he is certainly a wealth of entomology knowledge and stays on top of new topics, like the Asian Giant Hornet, etc.
BCMGA Mission Statement
The Bell County Master Gardeners Association assists the Texas A&M AgriLife Extension Service in providing high quality, relevant, research-based horticultural education and service to the residents of Bell County and the state of Texas through outreach, teaching, and demonstration projects.
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