Subject: Please don’t be a Budworm
Geographic location of the bug: Mount Washington, Los Angeles, CA
Date: 09/10/2017
Time: 05:56 PM EDT
Dear Bugman,
Today while inspecting my medical marijuana plants, I discovered this caterpillar. I also discovered some brown buds. Is this a dreaded Budworm?
How you want your letter signed: Constant Gardener
Dear Constant Gardener,
This does appear to be a Tobacco Budworm, Heliothis virescens. According to Rollitup: “The tobacco budworm varies greatly in appearance so it can easily be confused with other species. Making an accurate ID of your attacker can be important because some species have built up resistances to certain treatments. Luckily for us growers, if you find a caterpillar on your plants you can be 99% sure its a tobacco budworm. If you live in Africa, Europe, New Zealand, Australia or Asia its going to be the species Helicoverpa armigera. If you live anywhere else its going to be the species Heliothis virescens. The distinction between these two species is not important however since they can both be treated using the same methods. Most people find the larval form (caterpillar) on their plants so I won’t spend much time describing the adult moth. The caterpillars are initially pale green and often have black dots covering their body. Thin dark lines run down the length of the abdomen and tend to be darker around the second and third segments. As the larva ages (progresses in instars) the black dots may develop a red border around them. The abdomen is also covered with numerous microspines that give the caterpillar a rough feel. The head capsule is nearly always a light brown color. Again I wouldn’t worry too much if this description doesn’t completely match up with the caterpillar you find. There is great phenotypic variation in the tobacco budworm so there can be different colors and designs.” According to Featured Creatures: “Tobacco budworm is principally a field crop pest, attacking such crops as alfalfa, clover, cotton, flax, soybean, and tobacco. However, it sometimes attacks such vegetables as cabbage, cantaloupe, lettuce, pea, pepper, pigeon pea, squash, and tomato, especially when cotton or other favored crops are abundant. Tobacco budworm is a common pest of geranium and other flower crops such as ageratum, bird of paradise, chrysanthemum, gardenia, geranium, petunia, mallow, marigold, petunia, snapdragon, strawflower, verbena, and zinnia.” No mention is made of Cannabis being a host plant. When we searched that BugGuide, we found an image very similar to your own, and according to BugGuide the food plants include “Cotton, tobacco, roses, ground cherries, soybean, and many others.”