The Bagrada Bug

California and Arizona have an immigration problem. No, not those immigrants; I am referring to an insect known as the Bagrada Bug, Bagrada hilaris. This member of the stink bug family Pentatomidae is native to Africa but has found its way to the U.S. where it has quickly become a crop pest. It is also known as the "Painted Bug."

The Bagrada Bug has not been here long. It was first detected in June of 2008 in Los Angeles County, but is now found abundantly throughout southern California and adjacent southern Arizona, eastward through southern New Mexico and into Texas. It had previously established itself in Italy, Malta, and southern Asia.

This insect is frequently mistaken for the native “Harlequin Bug,” Murgantia histrionic, but the Bagrada Bug is about half the size of its native cousin, adults measuring a mere 5-7 millimeters.

Murgantia histrionica, the "Harlequin Bug"

The nymphs of B. hilaris are occasionally dismissed as beneficial lady beetles due to their bright red and black markings. There are five nymphal instars, an “instar” being the interval between molts.

Bagrada hilaris nymph

What makes the Bagrada Bug problematic is its appetite for plants in the cabbage and mustard family (Brassicaceae in today’s classification, Cruciferae of previous eras). So, kale, turnips, broccoli, radishes, and related vegetables are all on its menu. It doesn’t end there, either. The bug is also known to feed on potato, sorghum, cotton, papaya, maize, various legumes, and other crops. Ornamental plants like sweet alyssum and candytuft are also vulnerable.

The appearance of this pest in the U.S. caught everyone off guard, including entomologists. Its biology and natural enemies are barely known, so few control methods can be applied, let alone biocontrol agents like parasites and predators. We don’t even know exactly how fast the Bagrada Bug is spreading.

You can help improve our understanding of the distribution of B. hilaris by keeping an eye out for it and reporting your observations to your state department of agriculture. Having images to back up your identification can help immensely.

Almost all information on the Bagrada Bug in the U.S. is found online because the species is such a recent introduction here. The most trusted resources are websites with URL addresses ending in “.edu” or “.gov.” Commercial sources are often less accurate.

Sources: Arakelian, Gevork. 2013. “Bagrada Bug,” Center for Invasive Species Research, University of California, Riverside.
Flint, Mary Louise, et al. 2013. “Pest Alert! Bagrada Bug,” UC IPM Online, University of California.
Wisch, Hartmut, et al. 2012. “Species Bagrada hilaris - Bagrada Bug,” Bugguide.net.

Spider Sunday: Foreign Spider Now in Florida

Surprise, surprise, surprise, yet another exotic invader has recently been discovered in the Sunshine State. When you have pythons, tegu lizards, and other alien animals roaming free and reproducing in the swamps, a tiny arachnid might seem to be no big deal. Still, it is symptomatic of greater problems in protecting our native ecology that extend beyond lax regulation of the pet trade. This particular species, Cithaeron praedonius, is native to the Old World, from western Africa (Gambia), to Greece, Libya, and Malaysia. It is an accidental introduction to Australia and Brazil (Carvalho, et al., 2007). The first report of this species in the U.S. came from Port Richey in Pasco County, Florida, in February, 2011.

© "MrWheeler" via Bugguide.net

The manner in which the Florida record was revealed reflects the importance of citizen scientists and the power of the internet. A member of the Arachnoboards online community posted images of a spider he had found and that he was having trouble identifying. He then enlisted the help of Florida arachnologist G.B. Edwards. The mystery was solved in part when another Arachnoboards member located in Italy suggested the species. Specimens subsequently sent to Edwards allowed him to confirm the identification conclusively (Edwards & Stiles, 2011).

Whether this was an isolated incident of introduction seems to have been answered with a “no,” as another record was reported this last week on Bugguide.net, another influential internet resource for identifying North American insects and other arthropods. The location this time is Winter Springs, a suburb of Orlando, in Seminole County, Florida.

Cithaeron praedonius is a spider that hunts “on foot,” rather than spinning a web and waiting for prey to be intercepted by the silken snare. In fact, this species may be a specialized predator of other spiders. Observations have shown that in the first Florida case, the live specimens in captivity readily fed on native cobweb weavers, as well as juvenile Brown Widow spiders. Given its nomadic nature, perhaps the species has already spread to neighboring counties from the Port Richey location.

© "MrWheeler" via Bugguide.net

The spider is clearly reproducing, as flat, round egg sacs were found at the Pasco County location. Spiders of different ages were also observed. Each spider creates a silken “nest” in which to molt, and perhaps rest when it is not actively hunting. Otherwise, the spider dispenses with silk in its daily life.

These are small spiders, mature females averaging about 5 millimeters in body length, males about 3 millimeters. The compact arrangement of the eyes might fool one into thinking they might be juvenile males of the Southern House Spider, Kukulcania hibernalis. Worse yet, they could be mistaken for young recluse spiders (Loxosceles sp.).

© "MrWheeler" via Bugguide.net

If you have seen Cithaeron praedonius, or any other unfamiliar spider, consider taking clear images and submitting them to Bugguide, or Project Noah, or another community where scientists and the public interact. Securing specimens and preserving them in ethyl alcohol, along with a label noting the date and location of capture (plus the collector’s name), is tremendously important in confirming identifications later.

Our invasive species have many points of origin and many avenues of access to new territories thanks to unregulated (free?) trade, our internationally mobile society, and our fascination with organisms both floral and faunal, from foreign soils. Perhaps we should be more satisfied with the life that lives here already, and how we can better protect it from exotic competition.

Sources: Carvalho, Leonardo S., Alexandre B. Bonaldo, and Antonio D. Brescovit. 2007. “The first record of the family Cithaeronidae (Araneae, Gnaphosoidea) to the new world,” Revista Brasileira de Zoologica 24(2): 512-514.
Edwards, G.B. and Joe T. Stiles. 2011. “The first North American records of the synanthropic spider Cithaeron praedonius O.P.-Cambridge (Araneae: Gnaphosoidea: Cithaeronidae), with notes on its biology,” Insecta Mundi 0187: 1-7.