Lily Moth (Polytela gloriosae), family Noctuidae, Sri Lanka

photograph by Žilvinas Pūtys

Pond frog as predator of hornet workers: High tolerance to venomous stings

Shinji Sugiura

ABSTRACT

Some animals use stingers to repel attackers, and some predators have evolved tolerance to such stings, enabling them to consume venomous prey.

For example, social wasps, such as hornets, use modified ovipositors as venomous stingers to inject venom, which can cause intense pain in humans.

The world’s largest hornet, Vespa mandarinia (Hymenoptera: Vespidae), stores huge amounts of venom in its abdomen, which can kill mammals.

Although some animals are known to prey on adult hornets, it remains unclear whether these predators can avoid or tolerate their venomous stings.

Adult hornets have been found in the stomach contents of some amphibian predators, including the pond frog Pelophylax nigromaculatus (Anura: Ranidae), suggesting that they can successfully attack and consume hornets.

To examine whether frogs avoid or tolerate hornet stings, the pond frog P. nigromaculatus was experimentally presented with stinging females (workers) of three Japanese hornet (Vespa) species—V. simillima, V. analis, and V. mandarinia—under laboratory conditions.

Almost all frogs attacked the hornets, and the hornets were observed stinging the frogs during these attacks. However, 93%, 87%, and 79% of the frogs ultimately consumed V. simillima, V. analis, and V. mandarinia, respectively. Hornet stings neither killed nor harmed the frogs.

These results suggest a high tolerance of pond frogs to the venomous and painful stings of giant hornets. Frogs may serve as useful model organisms for investigating the physiological mechanisms underlying the intense pain and lethal effects of hornet stings in vertebrates.

Read the paper here:

https://esajournals.onlinelibrary.wiley.com/doi/10.1002/ecs2.70457

Imperial Sunstreak (Arcas imperialis), family Lycaenidae, Peru

photograph by Gavin Leung

Tailed Blue Metalmarks!!!

The Periander Metalmark (Rhetus periander), family Riodonidae, was one of my target species, and one I’ve wated to see for quite awhile… and I managed to see two! (bttm 3 photos)

I also managed to see another member of the genus Rhetus, the Blue Doctor (Rhetus dysonii), at a cloud forest lodge nearby. (top image)

If i had to rate a favorite butterfly sighting, in a lifetime of watching butterflies, these 3 individuals were the top 3!

photographs by Paxon Kale CC

Orchid Bees (tribe Euglossini, family Apidae)

Manu Biological Station, Madre de Dios, Peru

One of my favorite insect encounters at Manu was with orchid bees! The volunteer coordinator, who is also an entomologist, showed me their method for attracting and surveying them.

They pin squares of cardboard to a tree, and dab on scents (which are usually essential oils or extracts). The male bees show up and “gather the scents” which helps them to attract females (so its win-win for the bees and the entomologists).

Here we see 4 species of orchid bee:

Euglossa analis (shiny blue/purple)

Euglossa sp. (smaller shiny green)

Knob-fronted Cuckoo-Orchid Bee, Exaerete frontalis
(large black-winged shiny green)

Eulaema sp. (Black front, yellow/black/red abdomen)

photographs by Paxon Kale CC

Orthoptera of Manu Biological Station,
Madre de Dios, Peru

photographs by Paxon Kale CC

Iridicolor Geometer Moth (Iotaphora iridicolor), family Geometridae, Thailand

photograph by Antonio Giudici

Wasp-mimic Moth (Tyrictaca sp.), family Sesiidae, Malaysia

photographs by Timmy Wong

Broad-bordered Bee Moth (Hemaris fuciformis), family Sphingidae, Czech Republic

• Diurnal moth.

photograph by Ivo Carvan