Currently viewing the tag: "What’s on my Woody Plant?"
Gardeners are frequent contributors to our site because of concerns they have differentiating beneficial insects from injurious species. With more and more gardeners attempting to cultivate Cannabis, we started noticing more identification requests from growers. We hope we are offering a public service by responding to our readers’ questions without sensationalizing or taking sides surrounding the legalization of marijuana.

Subject:  Is this Japanese Beetle going to eat my medical marijuana?
Geographic location of the bug:  Ohio
Date: 07/28/2021
Time: 12:28 PM EDT
Your letter to the bugman:  Dear Bugman,
The Japanese Beetles were terrible this year.  They ate all the leaves off my neighbor’s ornamental plum tree.  They decimated the roses, and at times they seem to want to eat everything in sight.  They ate my friend’s hawthorn.  I keep finding one or two when I inspect the medical marijuana I just started growing this year, but they don’t seem to be eating the plants.  I have tried to research Japanese Beetles and marijuana and I was thrilled with your section on Insects and Cannabis called What’s on my Woody Plant?
So I expect my girls to start producing buds soon.  Do I need to fear the Japanese Beetles eating my marijuana?
How you want your letter signed:  Paranoid Pot Grower

Japanese Beetle on medical Marijuana

Dear Paranoid Pot Grower,
Time may be on your side, especially since the Japanese Beetles you are finding do not appear to be eating the leaves on your plants.  According to BugGuide:  “Larvae feed on roots of many plants. adults feed on more than 350 different species of plants, but are especially fond of roses, grapes, smartweed, soybeans, corn silks, flowers of all kinds, and overripe fruit.”   Your buds are flowers, so they might be attractive to the beetles if there is no other preferred food to be eaten.  BugGuide also states Japanese Beetles are active “mostly: June-Sept” and we suspect your harvest will be after late September, so you shouldn’t have to worry about loosing your entire crop.  According to Holy Moly Seeds, Japanese Beetles eat:  “Mainly roses, grapes, cannabis, beans, strawberries, tomatoes, peppers, grapes, hops, cherries, plums, pears, peaches, berries, corn, peas, and many more. They feed on the foliage of the plant, eating the material in between veins.”  According to Medical Marijuana (Cannabis sativa x indica)
:  “Japanese beetles will eat the entire leaf. Just like home gardens a population of Japanese beetles can kill a whole plant by destroying its leaves so badly it cannot photosynthesize enough to support itself” but you do not seem to be experiencing that.  Medical Marijuana Cannabis Pests says nothing about leaves and buds, but it does state:  “The most serious root pests are flea beetle grubs (Psylliodes attenuata) and white root grubs — Japanese beetles (Popillia japonica) and chafers (Melolontha hippocastani and M. melolontha).”  Please give us an update if you do find the Japanese Beetles are eating your buds.

Subject:  Sunflower Fruit Fly and immature California Mantis on Cannabis
Geographic location of the bug:  Mount Washington, Los Angeles, California
Date: 07/15/2021
Time: 09:39 AM EDT
Your letter to the bugman:  Dear Bugman,
As you know, we are having muggy weather in Los Angeles and the humidity seems to bring out more bugs.  My “girls” of 2021 are starting to show their stigmas and they are beginning to attract new insects.  I don’t have any identification requests for you today, but I wanted to submit a new photo of the pretty Fruit Fly you identified as Paracantha cultaris in 2019.  It is on a first generation plant (a genie) from a seed that I found on the Kernal Kush I grew last year.  The flies really like my Cannabis, and you assured me they will not harm my plants, and that they actually are associated with sunflowers which are always growing near the Cannabis.  I think it is sad that this pretty fly doesn’t have a common name and I would like to suggest Sunflower Fruit Fly.
I also eagerly await the appearance of immature California Mantids on my plants and I’m including an image of an inch long individual on my favorite strain Woodhead, and this is the fifth year I have grown plants descended from the original Woodhead I grew in 2017.  Once again, it is so nice to see you posting again.
How you want your letter signed:  Constant Gardener

Sunflower Fruit Fly

Dear Constant Gardener,
Thanks for your kind words.  It is curious that this distinctive fly does not have a common name and Sunflower Fruit Fly does seem very appropriate in light of BugGuide’s comment:  “breeds in
Helianthus annuus” which is identified on CalScape as simply Sunflower.  Also, thanks for being so conscious of native insects in your horticultural endeavors.

Immature California Mantid

Subject: Budworm
Geographic location of the bug:  Mount Washington, Los Angeles, California
Date: 06/21/2021
Time: 05:46 PM PDT
Your letter to the bugman:  I found a bud worm on a sprout indoors under lights????
How you want your letter signed: Mel Frank

Tobacco Budworm eats Cannabis sprout

Dear Mel,
Thanks so much for your submission of a Tobacco Budworm caterpillar,
Chloridea virescens.  We are honored to get this important documentation from such a distinguished expert.  BugGuide also has documentation of a Tobacco Budworms feeding on marijuana.


Subject:  Glassy Winged Sharpshooter on my herb
Geographic location of the bug:  Mount Washington, Los Angeles, California
Date: 06/18/2021
Time: 04:20 PM EDT
Your letter to the bugman:  Dear Bugman,
I missed you last growing season.  I noticed a recent comment from Peter about Glassy Winged Sharpshooters on budding marijuana. I sent in a photo two years ago of a Green Lynx Spider eating a Glassy Winged Sharpshooter on one of my plants, but I have to do manual hunting of this unwanted visitor.  I don’t like to use pesticides on my plants, so I catch the litter buggers and just squash them. They can be very difficult to catch though.  Seems they have an uncanny ability to move to the other side of the stem when they are threatened.
How you want your letter signed:  Constant Gardener

Glassy Winged Sharpshooter

Dear Constant Gardener,
Thanks for sharing your tips to the manual control of unwanted insects on your crops.  We are also thrilled to learn you do not use pesticides which can often kill beneficial insects as well as the targeted “pest” species.

Glassy Winged Sharpshooter

Subject:  Immature Mantis Patrolling my 2020 Crop
Geographic location of the bug:  Mount Washington, Los Angeles, California
Date: 06/16/2020
Time: 12:35 AM EDT
Your letter to the bugman:  Welcome Back Bugman
I really missed you during the early days of COVID-19 and I’m glad you have returned to making postings.  I don’t have an identification.  I just wanted you to see the young Mantis I recently discovered patrolling for prey on one of my 2020 plants, Purple Jane
How you want your letter signe:  Constant Gardener

Young Mantis on Young Cannabis

Dear Constant Gardener,
We are happy to be back as well.  That Mantis is really well camouflaged on your healthy looking plant.

Subject:  Unknown insect
Geographic location of the bug:  Ottawa Ontario Canada
Date: 02/06/2020
Time: 12:41 PM EDT
Your letter to the bugman:  Not sure if these are thrips or aphids? any help identifying and eradicating these would be appreciated. This is my third indoor crop over winter that has been infested over this winter so far 🙁
Thank you very much!
How you want your letter signed:  Thank you

Aphids on Cannabis

Dear Dave,
These appear to be Aphids, and they appear to be on a
Cannabis leaflet, so we are assuming you are growing Marijuana indoors.  This article on Canna Connection might have some helpful information for you as does Royal Queen Seeds.  Because female Aphids are able to give birth asexually, they do not require mating and populations of Aphids can increase quite rapidly.  Indoor growing has its own set of challenges, and keeping plants pest-free is often difficult.

Excellent! Thank you so much for the references.. I’ll do my best to eradicate these tiny pests.. you’ve been most helpful!
Take good care my friend!