Brachyplatys vahlii ( Fabricius , 1787 ) , an introduced bug from Asia : first report in the Western Hemisphere ( Hemiptera : Plataspidae : Brachyplatidinae )

Brachyplatys vahlii (Fabricius, 1787) (Hemiptera: Plataspidae) was first detected in Panama in 2012. It represents the second introduction of the Plataspidae into the New World, its first report from the Neotropics, and the first introduction of the genus Brachyplatys into the New World. The bug was identified using morphological characters and confirmed using molecular techniques. This bug poses a potentially serious threat to several important crops in Panama, including the popular Cajanus cajan, known locally as guandú, and peach palm/pixbae palm (Bactris gasipaes), widely cultivated throughout the Neotropics.


Introduction
Invasive species are among the greatest threats to native biodiversity worldwide (Mooney and Hobbs 2000).Since life began, organisms have found ways to travel and settle in new territories, but the magnitude of these movements in modern times is unprecedented.Increasing human travel and ever-expanding world commerce are providing easy and rapid transportation for vastly more non-native species to invade new areas at unprecedented rates, often with dire consequences for local communities and human agriculture.Famous insect examples include the "red imported fire ant" (Solenopsis invicta Buren, 1972, Formicidae), which has caused agricultural and medical misery in the southern United States since the early 1900s (Ascunce et al. 2011); the Brown Marmorated Stink Bug (Halyomorpha halys Stål, 1855, Pentatomidae), which pierces and sucks juices from orchard fruits (Hoebeke and Carter 2003); and the Bagrada Bug [Bagrada hilaris (Burmeister, 1835), Pentatomidae)], a major pest of Brassica oleracea (Brassicaceae) (Bundy et al. 2012).
In 1999, a small brown-speckled bug, Megacopta cribraria (Fabricius, 1798) (Hemiptera: Plataspidae), native to Japan, somehow reached the southeastern US and established itself in the state of Georgia, where it began attacking the Kudzu vine (Pueraria montana (Lour.)Merr., Fabaceae), itself an Old World invader (Suiter et al. 2010) that grows rapidly and covers anything in its path, including buildings and tracts of forest.Though any form of Kudzu control could be considered a positive event, Megacopta also began attacking the soy crop (Glycine max (L.) Merr., Fabaceae) which is an undesirable side effect.So far, no effective control measures have been found, and the bug has spread throughout the southern states, as far west as Louisiana, and as far north as Washington D.C. (Jenkins and Eaton 2011;McConnaughey 2015).The arrival of Megacopta in the New World also marked the first and only New World appearance of the exclusively Old World family Plataspidae.Though the family name Plataspididae has been argued to be the correct spelling (e.g., Ghahari et al. 2014), we have been advised to follow the most recent catalog of Palearctic Heteroptera (Davidová-Vilímová 2006) and checklist of Chinese plataspids (Liu and Zheng 2006), and are using the family name Plataspidae.
The genus Brachyplatys Boisduval, 1835 (Plataspidae) is native to Asia.We recently found Brachyplatys vahlii (Fabricius, 1787) in the Republic of Panama on both the eastern and western sides of the Panama Canal, on five plant species at four localities (Table 1, Figure 1 Like Megacopta, Brachyplatys has an obligate relationship with a bacterial endosymbiont that enables it to feed on legumes (Fabaceae) (Hosokawa et al. 2006), giving it the potential to become an agricultural pest of legume crops.Early detection can help prevent biological introductions from turning into invasions that develop into serious agricultural pests or present medical threats.Here we document this introduction, confirming our identification using both morphological and molecular techniques.

Identification
The domed, smooth, and slightly square appearance of the bugs brought to us from Bethania were reminiscent of Megacopta cribraria which one of us had chanced to see specimens of several years earlier.That memory led to an online search for images of the family Plataspidae, and hence to the genus Brachyplatys, a tentative identification that later was verified and expanded to species level by a molecular study.Brachyplatys vahlii bugs are quite small, 5 mm long and 4 mm wide, shiny black, with a rust-colored border (Figure 2), and they emit a typical unpleasant stink-bug odor when handled.At first glance they resemble beetles, but closer inspection reveals that they have sucking mouthparts, with which they pierce the stems of the host to feed on plant juices.They occur in large numbers and gradually kill the plant.The only eggs we have seen are similar to those of Megacopta (as shown in Poplin and Hodges 2012, 2013) in that they were laid in two rows (Figure 2) and are barrel-shaped with a crown of small projections at the apical end.They differ from the eggs of Megacopta in being shorter and proportionately wider and in having the crown projections much more numerous and distinctly shorter.They also have a double wing-like structure on one side that is not seen in the photographs of Megacopta eggs in Poplin andHodges (2012, 2013).Information on the native range of Brachyplatys vahlii can be found in Azhar et al. (1984), Liu and Zheng (2006), Ramakrishna (1920), Ruberson et al. (2012), and Takara (1957) (see Table 2).Genomic DNA was extracted from three whole bugs, from the Bethania location, using a DNeasy Blood and Tissue kit (Qiagen).The insect mitochondrial COI and 16s loci were amplified using the primer pairs LCO1490-HCO2140 (Folmer et al. 1994) and 16sA1-16sB1 (Hosokawa et al. 2006) respectively.PCRs were conducted using Qiagen Taq with a thermal cycling profile of 94 C for 3 min, 30 cycles of 94 C for 1 min, 50 C for 1 min, and 72 C for 2 min, followed by a final extension at 72 C for 5 min.Products were cleaned using gelase and sequenced on an ABI 3500XL using BigDye chemistry.Sequences were aligned and corrected using Sequencer 5.1 and a GenBank BLASTn search was done to determine similarity with sequence in the database.
An 832 bp fragment was detected at the 16s locus (GenBank No. KT447151) and 623 bp at COI (GenBank No, KT447152).Both fragments were identical in all three individuals.At the 16s locus, the sequence showed a 99% similarity to a Brachyplatys vahlii (Fabricius, 1787) specimen collected in Onna, Okinawa (GenBank No. AB240167), differing at only 4 positions.The next closest match was to Brachyplatys subaeneus (Westwood, 1837) (GenBank No, AB240167), to which it showed only an 85% similarity.While COI was less definitive, the sequence showed 83-86% similarity to other members of the infraorder Pentatomorpha at the COI locus.
Mounted vouchers of the bugs collected in Panama City have been deposited in the collections of the Smithsonian Tropical Research Institute, Panama (STRI) (five specimens, Symbiota database numbers STRI-ENT 0124178-0124182), and the Museo de Invertebrados "G.B.Fairchild," Universi-dad de Panamá, República de Panamá (MIUP) (two specimens).Additional specimens will be deposited in the National Museum of Natural History, Smithsonian Institution, Washington, D.C. (USNM) once the paperwork has been completed.

Plant associations
At least eleven species of Brachyplatys are found across Asia where they have been reported feeding on 56 plant species belonging to 30 genera and 9 families (Rider 2014) (Table 3) and often are considered as pests (Tauthong et al. 1979(Tauthong et al. -1980;;Waterhouse 1997;Shine et al. 2003).The plants most attractive to them belong to the bean family, Fabaceae, which, in addition to guandú and soy, includes other widely cultivated beans (Phaseolus L. spp.): lima beans, green or string beans, red beans, kidney beans, black beans, and black-eyed peas.Another plant family preferred by some species of Brachyplatys is the grass family, Poaceae, which includes corn (Zea mays L.), rice (Oryza sativa L.), and sugar cane (Saccharum officinarum L.).Ramakrishna (1920) provided the earliest published host association for B. vahlii, on Sesbania Scop.(Fabaceae) in India: "The black oval shining Pentatomid, Brachyplatys vahlii, is often found in numbers in company with the common Coptosoma cribraria on agathi (Sesbania)."Since then it has been reported as an occasional pest on cocoa, Theobroma cacao L. (Malvaceae; formerly Sterculiaceae), in Malaysia (Azhar et al. 1984).
As of this report, host plants of B. vahlii in Panama include Cajanus cajan, cultivated across the country; Schefflera actinophylla, an ornamental tree; Leptolobium panamense a Neotropical tree used in agroforestry, rural construction, and traditional medicine; and Bactris gasipaes, the most important domesticated palm in the Neotropics, native to and widely cultivated throughout South and Central America for its nutritious fruits and heart of palm (palmito) (Graefe et al. 2013).

Conclusion
Brachyplatys vahlii is already established on both sides of the Panama Canal, on a variety of plants, and has the potential to spread into areas of the country with agricultural activity and present a serious threat to several valued crops.Continued surveillance to determine the extent of its distribution and possible spread is needed, as is research on the efficacy of various control measures.
).It was first detected in 2012 in Vacamonte, Arraiján District, Panama Oeste Province on pigeon peas/guandú plants (Cajanus cajan (L.) Millsp., Fabaceae) and peach palm/pixbae palm (Bactris gasipaes Kunth, Arecaceae) in a residential backyard.It was found a second time (photographed only) in 2013 in the Cucaracha section near to Paraiso, Ancon, Panama Province, on a tree, Leptolobium panamense, (Benth.)Sch.Rodr.and A.M.G. (Fabaceae) and still was there on that tree in June of 2015.In 2014, it was found again in Vacamonte, this time on umbrella tree (Schefflera actinophylla (Endl.)Harms, Araliaceae).The fourth detection was in 2015 in the Bethania section of Panama City, where large aggregations (Figure 2) fed on the stems of guandú plants in a residential backyard; the plants that had bugs feeding on them, died.It was seen a fifth time, and photographed, in mid-February 2015 on a hand rail at the InterContinental Playa Bonita Resort and Spa, Arraiján District, Panama Oeste Province.

Table 1 .
Chronology of Brachyplatys vahlii (Plataspidae) encounters in the Republic of Panama*.These encounters were opportunistic -no formal surveys of the distribution have been undertaken.Since this manuscript was accepted, a thriving colony of Brachyplatys vahlii has been reported by Juan Ignacio Pérez, on Cajanus cajan (Guandú) in Panama (11 November 2015): La Chorrera (8.879833, -79.751194), several miles farther west than reported herein.