Clepsis persicana
In 3 days ~10% in a week ~30%
Clepsis persicana, the white triangle tortrix or the green needleworm, is a species of moth of the family Tortricidae. It is found in North America, where it has been recorded from Alaska and British Columbia to Newfoundland and south to Virginia and west to California. The habitat consists of coniferous and mixed coniferous forests.
The larva is slender and very active, with yellow head and wide, indistinct greyish stripes on the body. In Ontario, larvae have been collected in late May and June. Measures to control green needleworms have not been needed. The length of the forewings is 8.5-10.5 mm for males and 10–11 mm for females. The forewings are orange basally, becoming darker and purplish towards the termen, which is pale. Adults are on wing from June to August in one generation per year.
The larvae have been recorded feeding on a wide range of deciduous and coniferous trees, including Acer (including Acer negundo), Osmorhiza, Solidago, Alnus (including Alnus viridis, Alnus incana), Betula (Betula papyrifera, Betula nana), Corylus, Cornus canadensis, Rhododendron canadense, Vaccinium, Frasera (including Frasera fastigiata), Ribes, Maianthemum canadense, Comptonia peregrina, Fraxinus, Abies (including Abies balsamea, Abies concolor, Abies lasiocarpa), Larix (Larix occidentalis), Picea (including Picea glauca, Picea engelmannii), Pinus (including Pinus banksiana), Pseudotsuga (including Pseudotsuga menziesii), Ceanothus, Malus pumila, Prunus (including Prunus virginiana, Prunus persica), Rosa, Rubus, Populus (including Populus tremuloides, Populus balsamifera), Salix and Ulmus. They web the leaves of their host plant and feed in the calyx. Young larvae lower themselves on a silk thread and search for abandoned shelters of other Tortricidae species. If no such shelter is found, the larvae will feed on cover plants on the ground. The species overwinters as a mid-instar larva. Pupation takes place under the bark of their host plant or in amongst fallen leaves at the base of a tree. The larvae have a yellowish-green or greyish-green body and a yellowish-brown head. They can be found from April to June. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Acadia National Park | 🇺🇸 United States | |
| 2 | Great Bear Rainforest | 🇨🇦 Canada |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Edmonton | 🇨🇦 Canada |
With luck
About 10% of wildlife watchers report a White Triangle Tortrix sighting in Great Bear Rainforest on a given day, based on 10 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 150th most-seen of the 235 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
June
In that month about 10% of wildlife watchers report a White Triangle Tortrix in Great Bear Rainforest on a given day, against under 5% in July to May, the lowest months. That is one of Great Bear Rainforest's driest months, with about 150 mm of rain against 480 mm in November.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most White Triangle Tortrix sightings with a recorded time, and about half of them come between 6 pm and 6 am: it is most active around dawn and dusk.
Among the best
Of the 2 parks where we can rate White Triangle Tortrix sightings, Great Bear Rainforest ranks 2nd at about 10%, level with the leaders once rounded. The best odds are in Acadia National Park (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the White Triangle Tortrix is recorded against all the insects logged in Great Bear Rainforest (10 verified sightings from 2019 to 2026), 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.
