Drymaplaneta semivitta
In 3 days ~20% in a week ~30%
Drymaplaneta semivitta is a species of cockroach native to Australia and introduced to New Zealand. In New Zealand, it is known as the Gisborne cockroach, after the city of Gisborne where it was first discovered in the country. It has also been claimed to have first appeared in Tauranga in 1954, probably arriving on a log shipment.
One of the larger cockroaches, Drymaplaneta semivitta is about 20–45mm long and 12–15mm wide. It is a glossy dark brown, with distinctive tan or white coloured translucent stripes along each side of its head. Unlike many cockroaches, it has no vestigial wings.
In males, the third and fourth maxillary palps are enlarged, and the hind tibiae are flattened and expanded. Drymaplaneta semivitta is often found in wood material, such as timber or bark chips. It feeds off organic material but does not normally infest food. In cold weather, it can be found in roof cavities and the empty spaces between walls. D. semivitta is generally regarded as harmless.
Hex-2-enal is present in the defensive secretions of D. semivitta. This chemical also occurs in some other species of Drymaplaneta. Drymaplaneta... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Abel Tasman National Park | 🇳🇿 New Zealand |
More parks will be added in future updates.
With luck
About 10% of wildlife watchers report a Gisborne Cockroach sighting in Melbourne on a given day, based on 97 verified sightings from GBIF citizen-science data. It is the 143rd most-seen of the 875 insects we can rate there. Over three days the chance rises to about 20%, and over a week to about 30%, if each day is a fresh chance.
February, April–May and July–September
In those months about 10% of wildlife watchers report a Gisborne Cockroach in Melbourne on a given day, against under 5% in March, June and October–January, the lowest months.
Between 6 and 9 pm
Across all the parks we cover, that three-hour window holds the most Gisborne Cockroach sightings with a recorded time, and nearly all of them come between 6 pm and 6 am: it is mostly seen at night.
Among the best
Of the 4 cities where we can rate Gisborne Cockroach sightings, Melbourne ranks 3rd at about 10%, level with the leaders once rounded. The best odds are in Auckland (New Zealand, about 10%) and Perth (Australia, about 10%).
GBIF citizen-science records
It is estimated from how often the Gisborne Cockroach is recorded against all the insects logged in Melbourne (97 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.
