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Megaloblatta

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  1. They look like female G. portentosa to me. Have you got a photo of an adult male?
  2. Megaloblatta

    How to identify cockroaches

    I saw a good comparison someone did some time ago, but now can't find it. It's annoying how images on internet forums disappear..
  3. Megaloblatta

    How to identify cockroaches

    I am not 100% convinced that those species do hybidize, but they might - especially given that the male genitalia of hissers is similar or identical between species (so the 'lock and key' mechanism preventing hybridisation wouldn't prevent mating). The thing is that there is so much confusion about how to identify hisser species that some people are calling specimens Princisia when they are simply a dark form of G. protentosa. It would therefore not be surprising if they found that these dark individuals successfuly mated with a light form of portentosa... I think that well documented scientific studies need to be done to prove (or disprove) hybridisation - e.g. put one male and one female nymph each of different species together and rear them to adulthood and see whether the female produces young. Rear these young for one or two generations and preserve (in 80% pure ethanol) all the adults (including the original parents) for future study. Do you know whether anyone has ever done this? PS. Although the three species you mentioned may (possibly) interbreed in captivity, in Madagascar they are geographically separated and don't seem to overlap. Wild-caught individuals are easily identifiable to species - so I would still regard them to be 'good species'. It is possible that the lack of overlap in the geographical ranges of the species has meant they haven't evolved barriers to mating.
  4. *How to identify cockroaches* By George Beccaloni (Curator of cockroaches and other orthopteroid insects at London's Natural History Museum), 2016 Identifying cockroaches is often difficult, even for experts, especially if it is a dull coloured species with no distinctive markings which belongs to a group of very similar looking dull species with no distinctive markings and little variation in size or shape... Male genitalia may have to be used to provide a definitive identification, although genitalia are not useful for some groups e.g. hissing cockroaches (Gromphadorhini), as there is little or no variation between the species of the group. Specimens bred in captivity may be more difficult to identify than wild-caught specimens, since their colour and markings may be 'abnormal' due to artificial selection or genetic drift. Note that it is often very useful to know where the specimen or culture stock came from in the first place as this can narrow down the list of possible species - see below. It is also useful to know what family or subfamily the cockroach is before starting to try and narrow it down to genus or species. If there are no books to the cockroaches to the region the species is from ("A Guide to the Cockroaches of Australia" by David Rentz is one of the few available), then try the following: If you don't have a knowledgeable neighbourhood cockroach expert who can help (and you're not really likely to as there are only a handful of such people in the world!), then post a good clear close-up image of it on one or both of the following Facebook Groups: https://www.facebook.com/groups/blattodea/ and https://www.facebook.com/groups/621091044683934/ These groups have members who are expert cockroach taxonomists, so it is possible that they may recognise it. If this draws a blank, and if you have some entomological/taxonomic knowledge, then you could try the following: 1) Go to the online world catalogue of cockroaches i.e. the Cockroach Species File (http://cockroach.speciesfile.org/HomePage/Cockroach/HomePage.aspx). 2) Click "Search" at the top, then click "Complex Search" 3) Type the name of the country (e.g. "England"), state or island (e.g. "Borneo") where the specimen was collected into the box labelled "Place name from geographic hierarchy" and then click "Find Place". If the place is found it will appear in the "Geographical Levels" below. Now click the "Submit" button at the bottom of the screen and all the cockroach species currently known to occur in that area will be listed. Click on one of these names to go to the record for that species. Note that this search only works for islands, countries, states and provinces (of large countries such as Brazil) - so don't enter anything more specific e.g. "Sydney". 4) If you are lucky there will be a photo of one or more specimens of the species, which you can then use to compare your specimen with. Use the back button of your Web Browser to return to the species list you generated for the place name you entered, and check the records for the other species too. 5) If there are no specimen images then you may have to then try and obtain the original research articles in which the listed species were named, as these will contain descriptions and hopefully illustrations of the species in question. Many of these publications (especially older ones) are now available as pdfs on the Web. Here is a good way to find them: Go to the record for a species and you will see a list of "Citations" to research articles about the species in question. The citation at the top of the list (the oldest one) will contain the original description of the species. The default view of references in the CSF does not display the titles. To see them click on "Taxon hierarchy - Change items displayed" near the top of the screen and then select Yes for "Use long form display (titles and unabbreviated journal names for cited references, also differences in other places)". Next click on "Apply the specifications listed above" and the titles of the papers will now be displayed. Next, select all or part of the title of the article at the top of the citation list and paste it into Google Search, putting quotes around it to make the search results more specific (e.g. "On some Orthoptera from Porto Rico, Culebra and Vieques Islands"). Hopefully you will now be able to find and download a pdf of the article. The geographical search can be used to produce lists of the cockroaches found in regions such as West Africa, which can be extremely useful when trying to identify species. For example, if you have a blaberid cockroach from Nigeria, it may not have been recorded from this country in the literature, but it may have been recorded from a nearby country. It would be tedious to have to go through species lists for each country in the region individually, but you don't have to - simply select the continent in "Geographical Level 1" (in this case "Africa"); then select the general region in "Geographical Level 2" (in this case "West Tropical Africa"). Then click the Submit button and you'll get a list of the cockroach species recorded from that region. You can restrict the search to a particular family etc. by using the "Scope of search" function at the top. This will enable you to (for example) get a list of just the Blaberidae known to occur in Africa. Please note however, that the "Scope" function currently has a bug in it which means it works the first time, but it then gets 'stuck'..... Good luck!
  5. Megaloblatta

    Why "undescribed" species stay that way?

    The reason why undescribed cockroach species often stay that way for a long time is that there are very few active cockroach taxonomists in the world. There are simply not enough knowledgable people and the few there are don't have the time to name all the many new species that are in museum collections - or indeed which still need to be collected. One estimate ts that there are about 15,000 unnamed cockroach species 'out there' and I can believe it.
  6. Megaloblatta

    American Cockroach Society

    Hi Peter, Is the quarterly newsletter/journal of the American Cockroach Society entirely devoted to roaches, or does it cover invertebrates in general? What is the name of this publication? What issue number is it up to? Cheers, George
  7. Megaloblatta

    Key for roaches?

    Blattodea Culture Group membership pays for two issues of the full colour journal Cockroach Studies. The membership fee is realistic for Britain & Europe, but will seem more costly to Americans because of currently unfavourable exchange rates. The BCG Committee is looking into reducing the cost of printing Cockroach Studies and if we can reduce these then the price will obviously come down (The BCG is non-profit making). Best wishes, George Beccaloni
  8. Megaloblatta

    The study of cockroaches..?

    Yes, that is what I would call it - and did call it in something I wrote once.
  9. Megaloblatta

    Gromphadorhina portentosa ?

    Hi Matt, No one to my knowledge has tried to hybridize hissing roaches. It would be a a very interesting thing to do, however! You would need to separate females of each of the species you wanted to hybridize from any males when the females were still large nymphs. You would then need to rear them to adulthood, introduce males of the 'other' species you wanted to cross with them, and see if any nymphs appeared in a few month's time. Cheers, George
  10. Megaloblatta

    Gromphadorhina portentosa ?

    Your Gromphadorhina looks a lot like portentosa, but I have never seen a black form with redish markings on the sides of the meso- and metanota. The thing to do would be to examine the labrum under a low powered microscope and see whether it is 'hairy'. If you don't have a microscope I would be happy to examine a dead dried specimen for you when one dies. You should send it to me at the following address: Dr George Beccaloni Curator of Orthopteroidea Entomology Department The Natural History Museum Cromwell Road South Kensington London SW7 5BD, UK It would be worth trying to track down the origin of this culture. Cheers, George
  11. If you have tried to join the BCG recently and have sent payment to the Membership Secretary Roland Dusi by PayPal then please read on…. The email address which was listed on the BCG Website and elsewhere as the one to use to send your PayPal payment to (i.e. Roland.Dusi@aol.com) was incorrect. The correct address is RolandDusi@aol.com Please check your PayPal account to see what the status of your payment is. If it is “pending” then please cancel it and resend it to the correct address. Thanks, and sorry for the unfortunate mistake! Full details of how to subscribe to the BCG can be found here: http://blattodea-culture-group.org/node/804
  12. Megaloblatta

    Unidentified roaches from the Grenadines

    I've had a look at the photos and can identify one, and possibly a second. Going from left to right the species are as follows:- Colapteroblatta nigra (Brunner von Wattenwyl, 1892) - Epilamprinae Possibly Euthlastoblatta near absimilis (Gurney, 1937) - Blattellidae Blattellidae Epilamprinae The following species are recorded as being found in the Grenadines according to the Blattodea Species File:- Hemiblabera brunneri Saussure 1869 (Blaberidae, Blaberinae) Colapteroblatta nigra Brunner von Wattenwyl 1892 (Blaberidae, Epilamprinae) Epilampra abdomennigrum De Geer 1773 (Blaberidae, Epilamprinae) Homalopteryx laminata Brunner von Wattenwyl 1892 (Blaberidae, Epilamprinae) Chromatonotus notatus Brunner von Wattenwyl 1893 (Blattellidae, Blattellinae) Cariblatta spinicauda Hebard 1929 (Blattellidae, Pseudophyllodromiinae) Chorisoneura barbadensis Rehn & Hebard 1927 (Blattellidae, Pseudophyllodromiinae) Euphyllodromia albinervis Brunner von Wattenwyl 1893 (Blattellidae, Pseudophyllodromiinae) Euphyllodromia lineolata Dalman 1823 (Blattellidae, Pseudophyllodromiinae) Nahublattella laodamia Rehn & Hebard 1927 (Blattellidae, Pseudophyllodromiinae) Riatia bipunctulata Brunner von Wattenwyl 1892 (Blattellidae, Pseudophyllodromiinae) Latindia castanea Brunner von Wattenwyl 1893 (Polyphagidae, Latindiinae) Henicotyle antillarum Brunner von Wattenwyl 1892 (Blattidae, Blattinae) Pelmatosilpha marginalis Brunner von Wattenwyl 1893 (Blattidae, Blattinae) Cheers, George
  13. Megaloblatta

    Beetle mimics

    I should clarify: Prosoplecta are actually found in the Philippines, Malaysia and Indonesia (see my cockroach catalogue http://blattodea.speciesfile.org/HomePage.aspx), but most of the best mimics seem to come from the Philippines. The only Philippine islands they seem to have been recorded from are Mindanao and Luzon, although they are almost certainly found on others too.
  14. Megaloblatta

    Beetle mimics

    The very best beetle mimicking roaches are Prosoplecta from the Philippines. These are excellent mimics of distasteful ladybird beetles (Coccinellidae). Illustrations of some of the species can be found on pages 22 and 23 of issue 1 of Cockroach Studies. A pdf is available to download free from here:- http://www.blattodea-culture-group.org/node/802 I have been trying off and on for years to obtain livestock of Prosoplecta, with no luck so far! I don't know anyone who has ever kept them in captivity. George Beccaloni
  15. Megaloblatta

    Aquatic roaches

    There are dozens (if not hundreds) of species of aquatic roaches, all of which belong to the Blaberidae subfamily Epilamprinae. They are found throughout the tropics in rainforest habitats and I have personally collected them in Ecuador (from water-filled bromeliads), and in Papua New Guinea, Madagascar and Malaysia (under stones beside forest streams). Some species are more aquatic than others e.g. Epilampra abdomennigrum from Costa Rica actively swims and dives below the surface of water, whilst Stictolampra trilineata from Papua New Guinea climbs over submerged rocks (probably because it lives in fast flowing streams and would be swept away if it tried to swim). For more information about aquatic roaches see the excellent recently published book on cockroaches by Bell, Roth & Nalepa (http://www.amazon.com/Cockroaches-Ecology-Behavior-Natural-History/dp/0801886163). George Beccaloni
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