Grammodes stolida
In 3 days ~20% in a week ~40%
Grammodes stolida, the geometrician, is a moth of the family Erebidae. The species was first described by Johan Christian Fabricius in 1775. It is found in Africa, southern Europe, most of Asia and Australia. It migrates to central and northern Europe as far north as England, Denmark and Finland.
Forewing: basal two-thirds black brown, with basal patch, costal streak, and reniform stigma fuscous grey; crossed at middle by a pale ochreous band oblique from subcostal and widening downwards, its outer half yellowish; limited externally by a biconcave ochreous band, narrower below, followed below vein 6 by a broad brown band, on the outer edge of which are three or four irregular black patches, and above and beyond it on costa a black blotch, sharply angled externally on vein 6, these black marks forming the inner edge of a diffuse submarginal pale line; terminal area shaded with brown and fuscous, with a short black apical streak and a diffuse dark cloud below the middle; fringe grey with white base, altogether whitish round apex: hindwing olive fuscous, becoming blackish towards termen; a white band from costa at one-third to anal angle, and... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | West Coast National Park | 🇿🇦 South Africa | |
| 2 | Kgalagadi Transfrontier Park | 🇿🇦 South Africa | |
| 3 | Namib-Naukluft National Park | 🇳🇦 Namibia | |
| 4 | Kruger National Park | 🇿🇦 South Africa | |
| 5 | Addo Elephant National Park | 🇿🇦 South Africa | |
| 6 | Garden Route National Park | 🇿🇦 South Africa | |
| 7 | Table Mountain National Park | 🇿🇦 South Africa |
With luck
About 10% of wildlife watchers report a The Geometrician sighting in Johannesburg on a given day, based on 17 verified sightings from GBIF citizen-science data. It is the 95th most-seen of the 213 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 40%, if each day is a fresh chance.
January
In that month about 20% of wildlife watchers report a The Geometrician in Johannesburg on a given day, against under 5% in April–August and December, the lowest months. That is one of Johannesburg's wettest months, with about 120 mm of rain against almost none in July.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most The Geometrician sightings with a recorded time, and about 7 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
Among the best
Of the 10 cities where we can rate The Geometrician sightings, Johannesburg ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Naples (Italy, about 10%) and Pretoria (South Africa, about 10%).
GBIF citizen-science records
It is estimated from how often the The Geometrician is recorded against all the insects logged in Johannesburg (17 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
