# Rearing soapberry bugs

[EcoEvoDevoLab](https://hackmd.io/@EcoEvoDevoLab/AngeliniLab)

Updated 24 September 2021


> Photo by Dave Angelini, [Flickr](https://live.staticflickr.com/65535/47624606181_c18a2e5b12_c_d.jpg)

## General information

The red-shouldered soapberry bug, *Jadera haematoloma* is a scentless plant bug (order Heteroptera; family Rhopalidae). Rhopalids are mostly tropical bugs. Species of the genus *Jadera* live in the New World tropics where they feed on plants of the soapberry family ([Sapindaceae](https://en.wikipedia.org/wiki/Sapindaceae)). The only other common rhopalid in the United States is the [box elder bug, *Boisea trivittata*](https://en.wikipedia.org/wiki/Boxelder_bug), which feeds on box elder or maple seeds.

*Jadera haematoloma* is a native of south Florida old growth, hardwood dry forests—what the locals call "[hammock](https://en.wikipedia.org/wiki/Hammock_(ecology))". This environment once covered the Florida Keys and areas in and around the Everglades, and it can still be found in some locations. Here *Jadera* feed on balloon vine ([*Cardiospermum* ssp.](https://en.wikipedia.org/wiki/Cardiospermum)), which grows on other plants in clearings, empty lots, and along roadsides where light is good.

*Jadera* has been a favorite example of rapid adaptive evolution. In the early 20th century, the goldenrain tree ([*Koelreuteria* ssp.](https://en.wikipedia.org/wiki/Koelreuteria)) was introduced from China as an ornamental tree. *Jadera* made a host-shift to this new plant, which is also a sapind. However, the new food source imposed new selection pressures and by the 1990s, populations of these bugs had adapted to the new tree with a reduction in the length of their beak, an increase in their egg production, and other changes.

This species of bug is also interesting because individuals can develop with either long or short wings as adults. Macropters (adults with long wings) can fly and exploit new sites. Brachypters (adults with short wings) cannot fly and lack flight muscles in the thorax, however these females are able to produce more eggs than macropterous females. This [polyphenism](https://bugsinourbackyard.org/whats-polyphenism/) is determined in part by genetics and in part by juvenile nutrition. Our lab is working out how all this happens!

:::warning
**Soapberry bug care is based on [milkweed bug care](https://hackmd.io/@EcoEvoDevoLab/rearingmilkweedbugs)**, so please read the protocol for that species first, even if you’re focusing on research with *Jadera*. If something isn’t explained here, assume that the procedures for milkweed bugs apply. The specific needs of *Jadera* are described below.
:::

## Bug stocks

- **Labeling** is especially important for *J. haematoloma*. Populations can be easily confused. Be sure to keep the appropriate labels with bugs during cage cleaning. For experiments, always record the population of bugs you are using.
- Seperating eggs from cages with adults is an important way to keep soapberry bugs healthy. Hatchlings can survive in cages with adults, but wrangling is much easier if small juveniles are not mixed in with larger bugs.


Mass rearing cages can be set-up as for *Oncopeltus*, with a few important differences:

- **Extra water**: In addition to a flask of spring water, soapberry bugs survive better if the cage contains a small (4-cm) Petri dish bottom or top with a soaked piece of paper towel. Fold the paper towel so to fits inside the dish. Check the cages every 1-2 days and keep this paper towel wet. You can just squirt water onto the dish.
- **Seeds** for this species depend on the population, and are placed in a small (4-cm) Petri dish bottom/top. Go easy on these seeds—they’re not as easy to get as sunflower seeds!
- **GRT seeds** feed the "derived" / short-beaked populations. GRT stands for the Chinese goldenrain tree (*Koelreuteria paniculata* or *K. elegans*). Available from [F.W. Schumacher Co.](https://treeshrubseeds.com/) and [Sheffield's Seed Co.](https://sheffields.com/seed_genus_species_lot/Koelreuteria/paniculata/090122/////)
- **BV seeds** feed the "ancestral" / long-beaked populations from the Florida Keys and Everglades. BV stands for the balloon vine, *Cardiospermum*. In the wild, in south Florida the bugs feed on *C. corundum*. We are limited to supplies of *C. halicacabum* from [outsidepride.com](https://www.outsidepride.com/), but the bugs seem to do just fine on these.


- A peice of **cardboard egg carton**, at least 10 cm^2^, is necessary for soapberry bugs. This helps them molt, as it's a place for them to grab onto with better grip than the glass or plastic elsewhere in the cage. They also like to hide underneath it.
- No cotton balls are needed for *Jadera*. Females will drop eggs everywhere, but especially in the seed dish.
- Temperature for *Jadera* should be warmer than normal room temperature. They like 26-28˚C, so an **incubator** is necessary.
- **Humidity** should be kept high by placing a large container of water in the incubator.
- **Lights** in the incubator should be set to a 14/10 light/dark cycle. Be sure it doesn’t get too hot near the light if it’s a jury-rigged set-up. (Cages have melted!)

:::warning
To prevent the spread of pests, including mites and booklice, dishes can be kept in the incubator on a tray sprinkled with [diatomaceous earth](https://en.wikipedia.org/wiki/Diatomaceous_earth).
:::

## Nursery dishes

A special nursery should be used to hatch eggs to minimize hatchling mortality and cannibalism. This can be done whenever adults have laid several dozen eggs in an old cage.


- The seed dish should be removed from the old cage. There may be scattered eggs on the bottom of the cage, water flask, and hiding in the cardboard. Gather all the eggs into a Petri dish (Fig. A)
- Using forceps, remove the old seeds and dead bugs (Fig. B-C). Old seeds can go back into the old cage, in a new seed dish.
- Mix the eggs with some dried cracked seeds and into a larger (10-cm diameter) deep Petri dish. It's important that the cracked seeds have been dried in a drying oven, otherwise they will mold quickly.
- Add a small piece of egg carton (~2 cm^2^). It should sit up on its corners to allow hatchlings to hide beneath it.
- Add a 1.5 mL microcentrifuge tube filled with spring water and plugged with a cotton ball. The tube can lay on its side, and the cotton should be damp, but water should not run freely out of the tube.
- Cover the dish with two layers of KimWipe to prevent hatchlings from squeezing out under the lid of the enclosure.

These conditions (Fig. D) should encourage new hatchlings to eat the seed fragments and drink water, rather than [exsanguinating](https://en.wikipedia.org/wiki/Exsanguination) their unhatched siblings. If cannibalism is a problem, you can watch the dish daily and remove new hatchlings to a separate dish, allowing other eggs to hatch unharmed.

Keep hatchlings in the nursery until most have molted to the second instar, then move the opened nursery dish into a new standard mass-rearing cage. Welcome home!

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