Photos 1-2: Adult male specimen 1
Photos 2-4: Adult male specimen 2
A large population of bagworms was found in a decorative town garden. The host plant, unidentified as all the leaves had been eaten, was covered in cocoons, some of which were quite old. Two adult moths were found, freshly hatched.
The moths have been identified as part of the Amatissa genus, though their species is unknown. I have raised moths in this genus before:
(link) Unfortunately, the specimen experienced wing damage.
Photos 4-6: Cocoon comparison between the two adult males
The cocoons themselves are simple, tube-shaped sacks with minimal decoration. Large chunks of chewed leaves found around the cocoon's centre, with smaller chunks of vegetation covering both silky openings. During larval development, the bottom of the cocoon is twisted/folded shut.
Photos 6-8: Larvae feeding on a new host plant next to the old
Larval appearance mirrors that of many different Psychidae genera, having a beige head capsule covered in brown speckles.
It's also worth noting, that psychids from multiple genera share similar cocoon designs. Therefore, cocoon design (when it comes to these simple cigar-shaped cocoons) may not be adequate for identification.
In the Wet Tropics (FNQ), these bagworms are common. Often times I find them feeding on garden plants (such as here).
Photo 9: Green ants (Oecophylla smaragdina) removing pupal case from cocoon (already hatched pupa, not live pupa)
Other insects, such as ants, were beginning to damage and reuse materials from the other hatched cocoons. Though I can't say for sure when this bagworm community started, I do recall seeing them in this area months (perhaps even years) prior.
With the caterpillars moving on to their next foodplant, it certainly seems this population won't die off just yet (unless they're sprayed of course). I'll keep my eye on this area to see how things go.
Unidentified, genus Amatissa
08/08/23
