| Belidae | |
|---|---|
 | |
| Rhinotia hemistictus | |
Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Arthropoda |
| Class: | Insecta |
| Order: | Coleoptera |
| Suborder: | Polyphaga |
| Infraorder: | Cucujiformia |
| Clade: | Phytophaga |
| Superfamily: | Curculionoidea |
| Family: | Belidae Schönherr, 1826 |
| Subfamilies | |
Belinae | |
Belidae is afamily of weevils, calledbelids orprimitive weevils because they have straight antennae, unlike the "true weevils" orCurculionidae which have geniculate (elbowed) antennae. They are sometimes known as"cycad weevils", but this properly refers to a few species from thegeneraParallocorynus andRhopalotria.
The Belidae today have an essentiallyGondwanan distribution, occurring only in the Australia–New Guinea–New Zealand region up to Southeast Asia, South and Central America (barely reaching North America), some Pacific islands (notably theHawaiian Islands) and a few places in Africa. Many lineages of belids are notable for their highlyrelictual distribution; for example theAglycyderini are found in two areas on opposite sides of the Earth, with no such beetles known from anywhere in between.[1]
Belids were more widespread during theLate Jurassic toEarly Cretaceous, about161 to 100 million years ago, when they were found at least in Central Asia, Spain and Brazil.[2]Paleogene species belonging to still-livingtribes are known from Europe and North America.[1]
Members of the subfamilyBelinae are typically elongated and cylindrical. Some belines resemble other weevils, like the genusLixus of the true weevil family (Curculionidae), orbrentids. Others aremimetic and imitate less closely relatedPolyphaga beetles such asLycidae orPyrochroidae.[1]
The adults are distinguished from other ancient weevil lineages by some characteristic traits: The foretibia of belines is unusual in that it has a comb of bristles (setae) in anapical groove opposite the tarsal articulation; this is used forgrooming. Microscopically, thespermathecal gland is several times longer than thespermathecal capsule. Most also have only a few (four or fewer) setae on eachmandible (more inAglycyderini), and thepronotum is constricted at the tip (not inOxycorynus,Parallocorynus andRhopalotria).[1]
The endocarina is V-shaped. In most, the antennae have a retractable membrane at the base (not inParallocorynus andRhopalotria), and thealimentary canal hascaeca distributed all over at random (in two clean bundles inAglycyderini andMetrioxenini).[1]
Adults usually eatpollen; thelarvae feed on the wood of diseased or dying plants or on deadwood,flower buds or fruits. Though they may appear to bepests because of their association with plants dying off, belids tend to avoid healthy plants. They may occur as a secondary complication in plants already affected by some pest ordisease however. But altogether, belids (as opposed to many other weevils) are normally harmless and can be beneficial, the adults aspollinators and the larvae asindicator species for bad condition of their host plants. InFlorida for example,Rhopalotria slossoni is important in maintaining populations of the rareCoontie (Zamia pumila); indirectly, the Atala butterfly (Eumaeus atala) also depends on this beetle.
The original host plants of belids were probablyAraucariaceae,conifers which were extremely common during the time when the family evolved. Some moderngenera also feed onangiosperms, usually rather old groups likeBalanophoraceae,Myrtaceae orVitaceae, oncycads, or onpalms. The Pacific genusProterhinus has undergone a vigorousadaptive radiation on theHawaiian Islands andevolved to utilize a wide range of the limited diversity of plants found there.[1]
Thesubfamilies have each, at various times, been considered as separate families, but they are grouped together in most recent classifications. There are three main living lineages, variously considered three or, as here, two subfamilies, with thetribeAglycyderini sometimes considered a distinct subfamily. Other classifications treat theOxycoryninae as distinct family Oxycorynidae. A prehistoric subfamily only known fromMesozoicfossils are theEobelinae.[1][2]
Data related toBelidae at Wikispecies