A remarkably high diversity of the wingless long-horned beetles in the mountains of northern Borneo is reported by three Czech researchers from the Palacký University, Olomouc, Czech Republic. Apart from the genera and species new to science, the entomologists report the first case of reproduction by live birth in this rarely collected group of beetles. The study was published in the open access journal ZooKeys.
Generally, insects are oviparous, which means that their females lay eggs and the embryonic development occurs outside the female's body. On the other hand, ovoviviparous species retain their eggs in their genital tracts until the larvae are ready to hatch. Such mode of reproduction is a relatively rare phenomenon in insects and even rarer within beetles, where it has been reported for a few unrelated families only.
The long-horned beetles are a family, called Cerambycidae, comprising about 35,000 known species and forming one of the largest beetle groups.
"We studied the diversity of the rarely collected wingless long-horned beetles from Borneo, which is one of the major biodiversity hotspots in the world," says main author and PhD student Radim Gabriš. "The mountains of northern Borneo, in particular, host a large number of endemic organisms."
The scientists focused on the group which nobody had studied in detail for more than 60 years. They found surprisingly high morphological diversity in this lineage, which resulted in the descriptions of three genera and four species new to science.
"During a dissection of female genitalia in specimens belonging to the one of the newly described genera, named Borneostyrax, we found out that two females contained large larvae inside their bodies," recalls Radim Gabriš. "This phenomenon have been known in a few lineages of the related leaf beetles, but this is the first case for the long-horned beetles."
However, according to the authors, the modes of reproduction remain unknown for many beetle lineages besides Cerambycidae, so the ovoviviparity might be, in fact, much more common. Further detailed studies are needed for better understanding of the reproductive strategy in this group.
Gabriš R, Kundrata R, Trnka F (2016) Review of Dolichostyrax Aurivillius (Cerambycidae, Lamiinae) in Borneo, with descriptions of three new genera and the first case of (ovo)viviparity in the long-horned beetles. ZooKeys 587: 49-75. doi: 10.3897/zookeys.587.7961
Uwezekano mkubwa wa kuonekana kwa aina mbalimbali za vipepeo wenye pembe ndefu katika maeneo ya kaskazini mwa Borneo, umethibitishwa na watafiti watatu wa Chuo Kikuu cha Palacky, Olomouc, Jamhuri ya Czech. Mbali na jamii na spishi mpya kwa sayansi, wataalamu wa wadudu wanaripoti kisa cha kwanza cha uzazi wa kuishi katika kundi hili la wadudu ambao hawajapatikana mara nyingi. Utafiti huo ulichapishwa katika jarida la wazi la ZooKeys. Kwa kawaida, wadudu huzaana mayai, yaani, wanawake wao hutaga mayai na kiinitete huendelea nje ya mwili wa mwanamke. Kwa upande mwingine, spishi za ovoviviparous huhifadhi mayai yao katika viungo vya uzazi hadi mabuu yanapokuwa tayari kuanguliwa. Njia hii ya kuzaliana ni nadra sana kwa wadudu na hata ni nadra zaidi kwa vipepeo, ambapo imeripotiwa kwa familia chache tu zisizo na uhusiano. Kwa mfano, aina ya beetle ya pembe ndefu (Cerambycidae) ina aina 35,000 za aina mbalimbali, na ni mojawapo ya makundi makubwa zaidi ya beetle. "Tumechunguza utofauti wa wadudu wa aina ya longhorned ambao hawapati mabawa na ambao hupatikana mara chache sana katika eneo la Borneo, ambalo ni mojawapo ya maeneo yenye viumbe wengi duniani,"" anasema Radim Gabriš, mwandishi mkuu na mwanafunzi wa PhD." "Makali ya kaskazini mwa Borneo, hasa, yana idadi kubwa ya viumbe wa kiasili". Wataalamu hao walichunguza kundi hilo ambalo halikuwa limechunguzwa kwa undani kwa zaidi ya miaka 60. Uwezekano wa kugundua tofauti za kimaumbile katika mzao huo ulisababisha kuelezwa kwa jamii tatu na spishi nne mpya kwa sayansi. "Wakati wa kuchunguza viungo vya uzazi vya wanawake katika sampuli za moja ya jamii mpya zilizoelezwa, Borneostyrax, tuligundua kwamba wanawake wawili walikuwa na mabuu makubwa ndani ya miili yao, ""Radim Gabriš anakumbuka." "Hii ni jambo ambalo limetambuliwa katika jamii chache za mbawakawa wa majani, lakini hii ni mara ya kwanza kwa mbawakawa wenye pembe ndefu". Hata hivyo, kulingana na waandishi, njia za uzazi bado haijulikani kwa ajili ya mimea mingi ya beetle mbali na Cerambycidae, hivyo ovoviviparity inaweza kuwa, kwa kweli, zaidi ya kawaida. Uchunguzi zaidi wa kina unahitajika kwa uelewa bora wa mkakati wa uzazi katika kundi hili. Gabriš R, Kundrata R, Trnka F (2016) Mapitio ya Dolichostyrax aurivillius (Cerambycidae, Lamiinae) katika Borneo, na maelezo ya jamii tatu mpya na kesi ya kwanza ya (ovo) viviparity katika beetles ndefu-horned. Zookeeper: (Kichwa cha Mnyama) (Kichwa cha Mnyama) (Kichwa cha Mnyama)