Hawkmoths are Sphingidae and one of the most amazing insects to arrive at the purpose-built moth wall in REGUA’s garden at night. They are bulky and fly like nitro-fuelled rockets in what seems parabolas bashing themselves in the process coming to land under lamps. Lepidopterists say that they are guided by stars and perhaps they believe they have landed just by one of the billions out in the sky at night.
Curiously, wet evenings are best for the moth wall at REGUA, and it’s hard to see the stars at such times. These moths are important pollinating species for many tree species of the Atlantic Rainforest, but their preferences remain to be researched.
This is an example of Eumorpha labruscae and left Alan Martin author of REGUA publication, Guide to the Hawkmoths of Serra do Orgaos green with envy as he hasn’t seen it. Alan’s book says this is a widespread species and March was a good time to see it on the wall, so hopefully he will catch up with it on a future visit.
Dr Adrian Spalding, president of the British Entomological and Natural History Society in company of Devon’s Marsland reserve director Gary Pilkington visited REGUA in search of insects and birds last October. The weather was not helpful being hot and dry, so together with Jorge, REGUA’s resident lepidopterist, we headed for a night’s “moth trapping” at Bel Miller’s house in nearby Macae de Cima.
The weather at that point changed and a light drizzle started. Bel had mentioned that the weather had also been dry so the rain was most welcome. Before dinner, Gary set up the light and whilst we had our meal, we could see the moths homing in. Dr Adrian was up and down and taking photographs of species that converged by the light. Jorge patiently placed examples of Hawkmoths for identification and send mouth-watering photos to Alan Martin, co-writer of REGUA’s publication “A Guide to the Hawkmoth of the Serra dos Orgaos, South-eastern Brazil”.
A multitude of Silkmoths, Tiger moths, Hawkmoths and other micro moths as well as other insects attracted by the light and humid weather came in droves and Adrian said that this must be “the best night EVER I have mothed!” Gary was similarly delighted, his head covered in moths busy taking photos.
A superb Giant Silkmoth visited, Rothschildia hesperus (Linnaeus, 1758). Occurring from Argentina to South USA, this is a canopy rainforest species found from sea level to 1400m. It has a wingspan of 10-12 cm and the male is larger bearing transparent triangular windows in each wing. Females have more rounded wings than males. The adults do not feed, for after mating and laying eggs, and their life’s function is fulfilled.
Dr. Adrian and Gary were in their element. Who wouldn’t be, covered in moths !!
One of the two most common species of hawkmoth found at REGUA is Xylophanes porcus continentalis which is found from Central America to southern Brazil. At least that is what we thought until a new paper was recently published in the European Entomologist by Jean Haxaire and Carlos Mielke. Their paper describes two new species that occur in south and south-east Brazil, and suggests that the entire X. porcus family needs further investigation.
Since 2001 there have been 74 species of hawkmoth (Sphingidae) found at REGUA, from the 110 or so that have been recorded in the Serra dos Órgãos mountains. Arguably one of the nicest is Oryba kadeni which has a distinctive shape and colouring.
Widespread throughout Central and South America, this is this was my first sighting, though it has been recorded at REGUA twice before, once by Nicholas at his house and once by his father Robert Locke. To be more precise, Robert found the unmistakable wings of this moth by his front door, the remains of a meal for a large bat.
Walking the 50km of trails at REGUA is fascinating for birders and naturalists alike. Altitudinal range spans 30 – 2000m and there is a richness of invertebrates and plants to match the diversity of birds that draws the majority of visitors to REGUA. All classes of arthropod are present in abundance and there are many interesting patterns of distribution waiting to be identified and investigated.
REGUA’s lodge garden has a roofed, whitewashed wall complete with mercury vapour lamp generating many new records of moths for the Reserve and for Rio State. The wall often reveals a wealth of other interesting invertebrates such as this Dobsonfly (Corydalidae). Many of these creatures are difficult to see in the forest probably because they are residents of the tree canopy.
In the forest there are chance encounters with exciting species such as the White Witch Moth (Thysania agripina) Noctuidae with a huge wingspan.
December to Febuary is the Brazilian summer and usually a hot rainy season and time of maximum plant growth. This is, of course, an excellent time for all insects and amphibians. Whilst August to November is the Brazilian Spring and busy for birdwatching, it is also good for insects. Only March to July are a little quieter.
There is a profusion of wonderful butterflies. Some, like the 88, (Diaethria clymena) are very common. The most famous neotropical butterflies belong to the Genus Heliconia, with their distinctive strap-shaped wings and bright colours. These insects were shown to have co-evolved with their food plant, the different species of passion-vine (Passiflora). The vines put out new shoots irregularly and the butterflies must live a long time to be able to search out new growth and lay a full complement of eggs.
Another spectacular group of insect are the various species of huge Morpho butterflies which flit through the forest under-storey.
Diptera are interesting and diverse. There are three common sources of food that can provide for a profusion of flies: dung, carrion and some species of freshly emerged fungus. Parasitoid ichneumonids and tachinids search out the larvae of butterflies and moths whose living tissues they will feed on until they finally cause their death.
Ants are predators, roaming leaf and shoot for opportunities or different species will farm leaves with the help of fungus.
Spiders must guard against predatory wasps and some of these are very large indeed.
Beneath the placid exterior of the forest, termites work to undo the conversion of CO2 to sugar; every now and then a crash is heard acr
oss the forest as another giant tree succumbs to their tiny jaws.
There is much work to do to find out how many species of arthropod exist in these rich habitats. We are only in the earliest of stages investigating how all these myriad species interact in Mata Atlântica.