BULLETIN DE L ' INSTITUT ROYA L DES SC IENCES NATURELLES DE BELGIQUE SU PPLEMENT, 70: 23-25, 2000 BULLETIN VAN 1-IET KONINKLIJK BELGISC l-I INSTITUUT VOOR NATUU RWETENSC l-I A PPEN SUPPLEMENT. 70: 23-25, 2000

Invertebrate research overview: 1. Terrestrial by Leon BAERT

Despite greatly outnumbering the vertebrates, both in beetle and families. Interesting results have al­ number of species and in population densities, the terres­ ready been obtained on the Hogna lycosid spider, the trial invertebrates of Galapagos have never aroused the Ca /oso111a ground beetle, and th e Nesaecrepidia chry­ same interest and attention as that given to their verte­ somelid beetle. It is worth noting that El Nino events brate neighboms, which made the archipelago world­ may play an important role in this kind of speciation famous. on Galapagos. In addition to its value in population This situation changed significantly, however, during genetics, the ecological and biological data that is being the 1980s when three independent, long-term study pro­ gathered can be of great use in formulating the manage­ grammes were undertaken on the systematics and evolu­ ment policies of the Galapagos National Park and for tionary ecology of the terrestrial artlu·opods of the archi­ studies of fauna! changes occurring due to human activ­ pelago. The teams carrying out these programmes have ities. coordinated their research projects so that they now com­ plement each other. They are as follows: I) Since 1982, the Belgian team of the Royal Belgian Biodiversity of the terrestrial arthropods of Institute for Natural Sciences, in Brussels, focusing Galapagos on araclrnids (L. Baert, J-P. Maelfait), carabid (K. Desender) and chrysomelid (P. Verdyck) beetles, Before the Belgian team's studi es started in 1982, only 70 and isopods; spider species and less than 900 insect species were 2) Since 1985, the Canadian team of Carleton Univer­ known. Thanks to the collecting efforts of the three teams sity, Ottawa, comprising Professor Stewart Peck and mentioned above, aided by newly developed caph1re several of his colleagues, focusing on several artlu·o­ techniques such as pitfall, malaise, and flight interception pod groups, especially beetles; traps, the number of terrestrial species has 3) Since 1985, the Austrian team of the University of more than doubled (see Table I). Innsbruck, comprising Heinrich and Irene Schatz, A great many of the known arthropod species cer­ focusing on oribatoid mites and tenebrionid bee­ tainly colonized the archipelago by nah1ral means, but tl es. it is obvious that a number have been introduced since The primary goal of these studies was to compile an man discovered and settled in the islands. It is, how­ inventory of the species of terrestrial arthropods living in ever, often difficult to determine whether a species that the archipelago. To that end, for example, the Belgian is not recognized as an endemic one has achially been team has sampled more than 500 different localities from introduced by man or not. (No doubts exist in the case th e coastlines up to the top of all major islands and of man-dependent immigrants or anthropogenic spe­ volcanoes. A database has been constructed containing cies.) the most important data usable in analyses and syntheses As a result of our work done in the 1980s we now of ecological, biogeographical, and evolutionary patterns know more or less the actual in sect and spider fauna of in the composition, structure, dynamics, distribution, and Galapagos very well. In the course of each visit by the origins of the faunas. Belgian team to Galapagos they monitor on Santa Cruz Possible cases of parapatric speciation were found Island, regardless of the duration of th eir stay, a north­ in sister species of carabid beetles and lycosid south transect along the road to Baltra and a transect with adjacent ranges but without obvious ecological or along the Bellavista-Cerro Crocker trail by means of geographic barriers between them. This persuaded the pitfall trapping. This enables them to follow on a long­ Belgian team in 1996 to start molecular biological term basis the evolution of the populations of common studies (allozyrne electrophoresis and DNA-sequencing) species, and even detect new introductions, as is shown in to investigate the population genetics of these particular the following overview. 24 Leon BAERT

Table I - Number of species of the most important terrestrial arthropod groups (from LINS LEY & U SING ER , 1966; Rom & CRAIG, 1970; LINSLEY , 19 77 ; P EC K, 1991; B AERT et al., 1995; and P EC K, 1996).

1980 1991 1997 111/roduced 5pecies* Insecta 883 1592 1748 2 12+ Scorpiones 2 2 2 Pedipalpi I l Sc hi zo mida I l 1 Solifugae I l Pseudoscorpiones 16 18 Opiliones l I Araneae 70 15 2 154 ? (> 1990:2) Acari 38 192 248+ Amphipoda 4 4 Isopoda 17 17 7 Other Crustacea 17 Chil opoda 10 13 13 5 Diplopoda 2 9 9 8 Symphyla I l l Onychophora l l TOTAL 1005 200 1 2236+

... from PECK , 1996

Overview of recent arthropod introductions in the Crn z, in 1958). The spi der, £. pa/Iida, is found on San past ten years Cristobal. Anyphaenoides octodentata is found on Sierra Negra vo lca no, lsabel a Island. 1987. Introduction of the wasp Polistes versico/or in 1997. The black fl y is fo und on Santiago. Floreana followed by its quick dispersal over most of the I 998. Population explosion of the cockroach Anop/ec­ islands (AB EDRABBO, l 991 ). ta /at ern/is, the diplopod Asio111 01pha coarcla/a, and the 1988. Was111a1111ia a11mpu11cla/a (the Iittl e fire ant) is little fire ant Was111a 1111ia auropunctata on Santa Cruz. All reported from (BAERT et al. , field trip report, are very co mmon from the coast up to the pampa zo ne. unpubli shed, 1988). Asio111 01pha coarctata is fo und in the highlands of San­ 1989. A spider, Anyphaenoides octodentata, is intro­ tiago. duced in Sa n Cristoba l. Our monitoring reveals its pre­ It seems clear that many introductions by humans are sence in Santa Cruz in 1990. This species probably com­ associated wi th transport of merchandise by boat and petes with the endem ic species A. pacijica. The black fl y, aircraft from the mainland of Ecuado r. Food products Si111uliu111 bipu11 ctatu111 , is introduced in Sa n Cri stobal. such as fruit and vegetables are ve ry likely to carry l 992 . Our monitoring of Santa Cru z reveals the pre­ unwanted invertebrates. The nonch alant manner in which sence of two new introductions in the agricultural zone: a ca rgo is unloaded needs to be radically changed, with nesticid sp ider, Eid111a11e//a pa/Iida, and a small brown such activities subj ect to much ti ghter control and super­ cockroach Anoplecta latemlis. In the following years vision. All goods should if necessary be treated so as to both species spread throughout the other vegetation ensure that they are free of ali en spec ies . Until there is zones. Anyphaenoides octodentata is fo und in Floreana. better control of the coming and goi ng of merchandise the 1994. Introduction of the wasp, Brnchygastm /echu­ danger of potential new introductions will remain. guana, in Santa Cru z (A11onymous, l 994). Tourism also has an adverse effect on the local fauna 1996. Population explosion of the introduced cottony and flora . Travel between islands gives a helping hand to cushion sca le, !ce1ya purchasi (first seen on San Cristobal th e spread of we ll established isolated populations of in 1982) which has invaded at least nine islands, where it closely related taxa, thu s causing "genetic pollution". attacks or kills more than 20 pl ant species. Also a popula­ The li ghts of tourist or other boa ts anchored in shallow tion explosion of the introduced diplopod, Asio111orpha bays close to the coast while spending the ni ght between coarctata, at an altitude of between 350 and 600 metres island visits can attract large numbers of flying insects (thi s species was first recorded in Academy Bay, San ta including moths, ants, flies , etc. A recent study revealed Terrestrial arthropods 25 th at flying insects were much less attracted to yellow Eradication programme for the fire ant Wasnw nnia on neon light than white li ght. The use of such li ghting Marchena island. should therefore be compulsory on every boat navigating Monitoring programme fo r th e bl ack fly (Simulidae) in the waters of Galapagos. on Santiago and San Cri stobal. I would like to emphasize the possible importance ofEI Long-term monitoring of the Santa Cru z vegetation N ino events in the colonization processes. They may zones to observe eventual new introductions, and increase th e number of poss ible colonization events, such long-term monitoring ofVolcan Alcedo in the frame­ as rafting of vegetation islets from mainland Ecuador work of the goat eradication programme. toward s Galapagos due to in creased rainfall on th e main­ Museum development. land, but also enable a quick and firm establishment of But all these activities need finance for research equip­ newly arrived species in th e otherwise harsh environ­ ment; personnel; technical aid in the monitoring pro­ ments of Galapagos. They can also trigger population grammes; and for curatorial work in the museum. It is explosions of already established introduced species, as obvious that all available energy is focused on those seen above with the diplopod Asiomorpha coarc/ata. In introduced artlu·opod species which by one mea ns or thi s way such events may well have been the ca use of another (e.g. stinging people, destroying valuable plants) primordial steps in th e evolution and adaptive radiation of make their presence clear to man. But what about the many invertebrates of the archipelago. equally obvious but relatively inoffensive introduced spi ­ der species cited earli er, and the small diplopod and the cockroach? Current activities of th e Charles Darwin Research Station with regard to terrestrial arthropods References The post of staff entomologist at the CDRS was only created in 198 1. This was certainly due to the increasing problems caused by the fire ant Wasmannia aurop1111cta­ ABEDR ABBO , S. , 199 1. Nueva av ispa introducida en las islas. ta. Dr Yael Lubin, the entomologist working at that time Carla !11/'ormativa, 3 1: 4. in the islands, had to focus her research upon the bio­ ANONYMOUS. 1994. Another introduced wasp in Galapagos. economics of this pest species. Yael Lubin left the islands Galapagos Bulletin: 2. after the E l N ino of 1983 . From 1987 unti I 1993 the role BAERT, L., MAE LFAIT , J.-P. & DESEN DER, K., 1995. Di stribution of entomologist was taken over by Sandra Abedrabbo, of the species of the Orders Scorpi ones, Solifugae, who focused her research on Wasmannia and Polis/es, on Ambl ypyg i, Schi zom id a, Opiliones and Pse ud oscorpi ones in monitoring different vegetation zones of Santa Cru z, and Galapagos. Bulletin van her Koninklijk Belgisc/1 Jn stit1111t vool' in starting to organize the Museum. Na t1111n vetensc/wppen. Ento 111 ologie, 65: 5- 19. At present [Spring 1998] two scientists in the Charl es LI NSLEY, E.G ., 1977. Insects of the Galapagos (S upplement). Darwin Research Station's Department of Terrestrial Occasional Pape!'s of th e Calif'omia Acade111y a/Sciences, 125 : & Plants, Invertebrates Quarantine are concentrating on 1-50. several projects which reflect the current priorities of the Entomology Section. LI NSLEY, A.G. & USI NGER, R.L., 1966. In sects of th e Ga lapagos Island s. Proceedings o/ th e Calij'omia Academy o.f Sciences, Dr Charlotte Causton from Great Britain is responsible 33(7): 113-1 96. for: PECK, S. B., 199 1. The Galapagos Archipelago, Ec uador: With The Quarantine programme, for establishing the sys­ an emphasis on terrestrial invertebrates, especiall y insects; tem of monitoring the Agriculhire Zone and other and an outline for research. In : The unity of evoluti onary parts of the island of Santa Cru z in search of possible biol ogy. Pl'oceedings of the Fo11l'th International Congress of new introduced species. . Systematic and Evol11tionarv Biologv. Ed ited by E.C. DUD LEY. The Cottony Cushion Scale programme, including Di oscorides Press, Portland , OR., pp. 3 19-336. studying the ecology, di stribution, and effects of the PECK, S. B., 1996. Origin and development of an in sect fa un a on species in Galapagos; and preparing the ground for a remote archipela go: The Gal apagos Islands, Ecuador. In : Th e eventual biological control of this pest species by th e Ol'igin and evolution o/ Pacific Island biotas, Neiv Guinea to introduction of a coccinelid beetle or " ladybird ", Eastern Polvnesia: pattems and p!'ocesses. Allen KEA ST and Rodalia cardina!is. She has made an extensive litera­ Scott E MILL ER . SPB Academic Publishing, Amsterd am, The ture study of bi ological control and is overseeing Ne th erl ands, pp. 91-122. construction of the new hermetically-sealed labora­ Dr Leon BAERT tory for performing test experiments with the beetl e. Department of Entomolo gy Koninklijk Belgisch lnstituut Lie. Lazaro Roque from Ecuador is responsible fo r var­ voor Natuurwe tenschappen ious eradi cation and monitoring programmes, such as: Vautierstraat 29 Monitoring programme for th e introduced Po/isles B-l 000 Bru ssel and Bmchygastm wasps. Bel gium