name:
Largus succinctus (Linnaeus 1763)
Latin
succinctus ("tightly wrapped, concise")
Largus grooming wings:
Sections included here: 1) Introduction, 2) Finding Largus Bugs, 3) Housing and Care, 4) Life Cycle, 5) Moulting, 6) Mating, 7) Observations, 8) A Few Resources
Introduction
I have reared Largus succinctus on and off for several years and through multiple generations. Largus bugs are extremely easy to raise. As a bivoltine, omnivorous, diurnal species, Largus bugs are excellent candidates for school projects examining hemimetabolism (incomplete metamorphosis) in a species of true bug.
Both in the wild and in captivity, these bugs will feed on a variety of plants, fruits, and flowers, as well as on dead insects (including conspecifics) and fecal matter. Booth (1994) provides an interesting list of numerous plant families on which Largus californicus has been observed feeding, along with the stage of the insect at the time it was observed.
These largus nymphs (fourth and fifth instar) are eating a dead Vespula squamosa:
The literature lists Largus bugs as non-flying (Booth, 1990), but I have on occasion seen these guys fly very short distances. They prefer to scurry along the ground and are quite proficient runners when they need to be. Their gentle nature, however, does allow them to be prey.
In my backyard, a Xysticus crab spider makes a meal of one:
Finding Largus bugs
In my opinion, finding Largus bugs is the only difficult step in the entire rearing process. In my case, I have them in my backyard, but I have very rarely encountered them in the natural habitats that I frequent. Based on my experience, I had assumed that these guys were somewhat synanthropic, but a quick review of the literature and the records on iNaturalist indicates that these guys can be found in a large variety of habitats.
First- and second-instar nymphs in my yard and an adult on Asclepias curassavica:
In my yard, Largus adults on Tagetes, Salvia leucantha, Verbesina virginica:
Largus nymph moulting from fourth instar to fifth instar in my yard:
According to online resources, these guys can be found on the trunks of pine trees and on various fruits (Layton, 2016) as well as on many different flowers, shrubs, and trees.
It's very easy to catch Largus bugs: you can let them crawl onto your hand and carefully cup your hand around them. When I'm in the field, I put my insects in 4"x4" clear plastic containers with a bit of vegetation to keep them comfortable.
Housing and Care
HOUSING
I recommend using large cages for Largus bugs since they enjoy running around and being active. I use a 36" x 24" x 24" butterfly habitat.
My Largus bugs are currently housed with other phytophagous bugs. This is a sample cage for Hemiptera / Orthoptera, a cage large enough to include 4-inch potted plants and food dishes:
If you are rearing Largus bugs, be very careful when you open the cage, as they will very quickly crawl out of the cage. I open the cage with caution, first just enough to poke my finger inside. Then I run my finger first along the zipper line as I unzip behind my finger to ensure that anyone in the way is moved by my finger and not by the zipper. I open the cage just enough to lean my head in to see and to reach into the back of the cage. After I've watered all the plants and changed out the food dishes, I slowly make my way out and brush off all the Largus bugs who have crawled on me in the process. They run fast and are adept at escaping through any opening, so be very careful when working inside their cage.
Beside each of my habitat cages, I keep a selection of clear containers (different sizes) with flat tops for catching bugs that I need to move or who fly out of the cage. With Largus bugs, you can just use your hands since they are easy to catch.
FOOD
Largus bugs are very easy to feed: they eat everything! So I provide one of just about everything that I feed any of my insects: organic Romaine lettuce, apple slices, carrots, sweet potato, corn kernels, pecan/walnut/almost slices, cricket powder, fish flakes, rolled oats, wheat bran, dry cat food crumbs, gecko pellets, butterfly sponges, and fresh water sponges. Of course, they also have their 4-inch potted plants, including lettuce and vegetable plants along with native flowering plants. Largus bugs most enjoy the pecan pieces, apple, lettuce, butterfly sponges, oats, and cricket powder, but I see them munching on just about anything. Since they are so often on my bee fondant outside, I sometimes offer them a bit of fondant crumbs, as well.
Here are adult Largus bugs munching on apple (with a friend):
Here's a
VIDEO of a Largus bug eating apple. The dinner guest is a Cotinis nitida.
Here are fifth-instar nymphs eating lettuce and eating apple:
Largus bugs even like corn!
And, of course, they like carrots:
Largus bugs on
bee fondant:
This is an adult on a butterfly sponge:
Life Cycle
EGG
I've seen Largus bugs lay eggs on leaves and atop soil and on miscellaneous surfaces.
Eggs are laid in clusters and are pale yellow, measuring around 1 mm each.
View through a microscope:
NYMPH (five instars)
The nymphs I raise hatch approximately 18 days after eggs are laid.
Here are new hatchlings atop their egg cluster:
And here are some just-born nymphs whose eggs were laid on newspaper:
These newly hatched nymphs are moving around for the first time, still atop their egg cluster. The second set is from eggs laid on newspaper.
VIDEO of newly hatched nymphs
VIDEO of newly hatched nymphs
These are first-instar nymphs at 2 days old and 5 days old:
And here are first-instar nymphs on lettuce:
Second-instar nymph:
Third-instar nymph:
Fourth-instar nymph:
Fifth-instar nympH:
And here's a freshly moulted adult:
Moulting
Largus bugs moult their way to adulthood through five instars. Like other insects, Largus bugs attach themselves to a surface where they can benefit from the force of gravity to help them push out of the exuvia. And as with the other insects that I rear, a failed moult is the most likely cause of premature death.
failed moult to adult:
From what I have observed with the ones that I raise, Largus bugs are more likely to abandon exuviae than to eat them. I have never witnessed one of mine eating the exuvia after moulting; however, I have occasionally seen different nymphs (not ones freshly moulted) eat abandoned exuviae.
Here's are two nymphs moulting from fourth instar to fifth instar:

and
Here's a fifth-instar nymph moulting to full adult:
Moulting to Adult series:
This freshly-moulted adult has not yet darkened:
Here's an exuvia from a fifth-instar nymph who moulted to adult:
Mating
From what I've observed, males "jump" the females by rushing up on them and attempting to mount. Females often kick them off, but if the male is successful, he will grasp the female and then turn so the two are back-to-back. The pair remain in copula for an extended period of time, and the female generally walks, leading the pair around, and feeds.
In this case, the female rejects the male after he jumps her and tries to mount:
VIDEO of female rejecting mate attempt.
The female of this mating pair is feeding on a butterfly sponge:
The female here (outdoors) is eating the last crumbs of the bee fondant I provide through winter for honey bees.
Here a fourth-instar nymph gets a lesson about making new ones from a mating pair:
In terms of the female's capacity to store sperm, Booth (1994) notes that "One female laid a clutch of 100 eggs 65 days after her last possible contact with a male, and the hatching success was 40%." Booth also observed at least two individual females mating with two different males on the same day (Booth 1994).
Parasitism by Tachinid Flies
It's quite common to see Largus bugs with Tachinid fly eggs glued to the scutellum. I have found several with the parasitoid fly eggs on them. Trichopoda pennipes is one Tachinid fly known to attack Largus species (Tachinid Fly - Trichopoda pennipes, 2022).
Because I raise bugs and not flies, I remove the eggs. Since the eggs are "cemented" to the victim, they are not easily rubbed off. I get a good hold on the bug (with Largus it's easier than with other Hemiptera because Largus have a relatively hefty build) and use toothpicks to scrape off the eggs.
Largus bug in my yard with Tachinid eggs:
And here is the bug after I removed the three eggs from the scutellum:
Observations
Largus succinctus grooming proboscis:
Largus bugs are very active and move around the cage quite a bit. They are tolerant of other species of insects and not at all shy. They enjoy a wide variety of foods, making it fun to feed them.
The bugs are fairly hardy as adults. From what I could see, the greatest number of deaths occur in first-instar nymphs, who are very delicate but also very active. It's important to provide a large habitat for these guys with plenty of space to moult and to avoid overcrowding. Overall, they do well in captivity and are quite prolific. When I raise these guys, I keep the overwintering bugs (they are in all stages of growth) and then release everyone in spring once the temperatures stabilise. From what I can see, the generations overlap considerably. In winter on mild days, I see both adults and nymphs of all stages (but more older ones) in the yard. Inside, I have all instars of nymphs and adults. I'm not aware of a diapause stage for these insects, but I believe they are capable of surviving winters as adults or as nymphs by hiding in protective spaces.
A note to teachers who might use these insects in the classroom:
Be advised that these guys will readily eat their fallen comrades, given half a chance. Depending on your audience and personal preferences, you might choose to remove dead specimens from the rearing cage.
Also, I would highly recommend that you carefully check captured bugs for Tachinid fly eggs and remove them from the bugs to avoid some rather icky situations.
Note the Largus bugs here taking advantage of some winter bee fondant (a January video):
VIDEO of honey bees and Largus bugs on bee fondant.
A Few Resources
Booth, C. L. (1990, March). Biology of Largus californicus (Hemiptera: Largidae) . https://www.jstor.org/stable/3671980
Booth, C. L. (1992, May 1). Ontogenetic Color Change and Mating Cues in Largus californicus (Hemiptera: Largidae). https://academic.oup.com/aesa/article-abstract/85/3/331/26960
Conrad, J. (2012, July 22). Largus bug, Largus succinctus. https://backyardnature.net/n/a/largus-b.htm
Eric, E. R. (2014, May 6). Livin' Largus. http://bugeric.blogspot.com/2014/05/livin-largus.html
Layton, B. (2016, September 7). Bordered plant bug, vol. 2, no. 28. http://extension.msstate.edu/newsletters/bug%E2%80%99s-eye-view/2016/bordered-plant-bug-vol-2-no-28
Texas A&M AgriLife Extension Service . (n.d.). Largus Bug. Field Guide to Common Texas Insects. Retrieved from https://texasinsects.tamu.edu/largus-bug/
References
Booth, C. L. (1990, March). Biology of Largus californicus (Hemiptera: Largidae) . Retrieved from https://www.jstor.org/stable/3671980
Tachinid Fly - Trichopoda pennipes. North American Insects & Spiders. (2022, December 3). Retrieved from https://www.cirrusimage.com/flies_trichopoda/
.