If anyone is interested here's a list of useragents and their strings.
I haven't verified all of them to check if they are correct, but it's a start
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] ichiro', 'ichiro/2.0 (ichiro@nttr.co.jp)');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Alta Vista', 'Scooter/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Hogsearch', 'oegp v. 1.3.0');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Kraehe [Metasuche]', '-DIE-KRAEHE- META-SEARCH-ENGINE/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Yahoo', 'Yahoo! Slurp');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Google', 'Googlebot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Alexa', 'ia_archiver');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] MSN', 'msnbot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] W3C [Validator]', 'W3C_Validator');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Ask Jeeves', 'Ask Jeeves');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] TurnitinBot', 'TurnitinBot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Seekport', 'Seekbot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] IBM Research', 'ibm.com/cs/crawler');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Yahoo MMCrawler', 'Yahoo-MMCrawler/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Ocelli', 'Ocelli/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Gigabot', 'Gigabot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Majestic-12', 'MJ12bot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Google Adsense', 'Mediapartners-Google/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Walhello', 'appie 1.1 (www.walhello.com)');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Voyager', 'voyager/1.0');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] WiseNut', 'http://www.WISEnutbot.com');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Thumbshots [Capture]', 'thumbshots-de-Bot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] GeoBot', 'GeoBot/version');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] suchpad', 'http://www.suchpad.de/bot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Telekom', 'crawleradmin.t-info@telekom.de');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Insuranco', 'InsurancoBot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Xaldon [Spider]', 'Xaldon WebSpider');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] ICCenter', 'iCCrawler (');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Nutch', 'Nutch; http://lucene.apache.org/nutch/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Cosmix', 'cfetch/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Heise IT-Markt [Crawler]', 'heise-IT-Markt-Crawler');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Esperanza', 'EsperanzaBot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] EliteSys', 'EliteSys SuperBot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] NG-Search', 'http://www.ng-search.com)');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] genie', 'genieBot (');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] MP3-Bot', 'MP3-Bot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Sensis [Crawler]', 'Sensis Web Crawler');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Seoma [Crawler]', 'Seoma [SEO Crawler]');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] g2 [Crawler]', 'g2Crawler');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] OmniExplorer', 'OmniExplorer_Bot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Baidu [Spider]', 'Baiduspider+(');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] W3C [Linkcheck]', 'W3C-checklink/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Accoona', 'Accoona-AI-Agent/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] ichiro [Crawler]', 'ichiro/2');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] GBSpider [Spider]', 'GBSpider v');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] psbot [Picsearch]', 'psbot/0');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] PlantyNet', 'PlantyNet_WebRobot_V');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Twiceler', 'Twiceler www.cuill.com/robots.html');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] IPG', 'internet-provider-guenstig.de-Bot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Susie [Sync]', '!Susie (http://www.sync2it.com/susie)');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] WissenOnline', 'WissenOnline-Bot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] 24spider', '24spider-Robot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Snappy', 'Snappy/1.1 ( http://www.urltrends.com/ )');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Zerx', 'zerxbot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] LinkWalker', 'LinkWalker');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Exabot', 'Exabot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Jyxobot', 'Jyxobot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Tbot', 'Tbot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Findexa [Crawler]', 'Findexa Crawler (');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] ISC Systems', 'ISC Systems iRc Search');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] IRLbot', 'http://irl.cs.tamu.edu/crawler');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Mirago', 'HeinrichderMiragoRobot (');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Sygol', 'SygolBot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Nutch/CVS', 'NutchCVS/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] WWWeasel', 'WWWeasel Robot v');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Naver', 'nhnbot@naver.com)');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Heritrix [Crawler]', 'heritrix/1.');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] FAST Enterprise [Crawler]', 'FAST Enterprise Crawler');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Google Desktop', 'Google Desktop');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] MMSBot', 'http://www.mmsweb.at/bot.html');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] GeigerzaehlerBot', 'http://www.geigerzaehler.org/bot.html');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Vagabondo [Crawler]', 'http://webagent.wise-guys.nl/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Nimble [Crawler]', 'NimbleCrawler');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Bunnybot', 'powered by www.buncat.de');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] YahooSeeker', 'YahooSeeker/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Boitho [Crawler]', 'boitho.com-dc/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Scumbot', 'Scumbot/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Steeler [Crawler]', 'http://www.tkl.iis.u-tokyo.ac.jp/~crawler/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] FAST WebCrawler [Crawler]', 'FAST-WebCrawler/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Orbiter', 'http://www.dailyorbit.com/bot.htm');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] ASPseek [Crawler]', 'ASPseek/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Crawler Search [Crawler]', '.Crawler-Search.de');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Francis', 'http://www.neomo.de/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Online link [Validator]', 'online link validator');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Asterias', 'asterias/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Asterias [Spider]', 'http://www.singingfish.com/help/spider.html');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] NetResearchServer', 'NetResearchServer/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Orange [Spider]', 'OrangeSpider');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] MSNbot Media', 'msnbot-media/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] McSeek', 'powered by www.McSeek.de');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Webmeasurement', 'webmeasurement-bot,');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] 123spider', '123spider-Bot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Cometrics', 'cometrics-bot,');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] MSN NewsBlogs', 'msnbot-NewsBlogs/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Houxou [Crawler]', 'HouxouCrawler/');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Google Feedfetcher', 'Feedfetcher-Google');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Yacy', 'yacybot');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] Yahoo Slurp', 'Yahoo! DE Slurp');
INSERT INTO punbb_bots (bot_alias, bot_string) VALUES ('[Bot] AdsBot [Google]', 'AdsBot-Google');