A window in a sunny corner of my bedroom lets in bugs. The metal frame is warped in such a way that the sliding mesh never closes all the way, leaving a gap three inches wide and four feet high, which is, of course, an open invitation for all sorts of small visitors.
While many of these visitors are unwelcome (roaches, mosquitoes, and houseflies), and some are alarming (honeybees, hornets, and carpenter bees), several are fascinating overnight guests.
An emerald beetle, shiny and bright,
I see it sparkle in the sunlight
With a metallic sheen
On figs, it’s often seen
A jewel of nature, pure delight!
Photo L. Shyamal, CC BY-SA 3.0
Cover photo: Stick insect eggs often resemble seeds. Some females lay eggs in hidden or hard-to-get-to places, while others drop them one by one on the ground at different places, making it difficult for predators to find them. Photo: Hayath Mohammed
Bumbling beetles
Amongst these guests, we often host emerald-coloured beetles. These large beetles (about an inch in length) are a species of scarab beetle named (Heterorhina elegans) found in India and Sri Lanka. They have a black spot near the end of each wing case. I’d often seen these beetles feeding on the ripe figs of the Ficus racemosa tree, whose spreading branches overshadowed my window.
During hot, humid July afternoons, the ripe figs give off a sweet-sour odour that these beetles seem to love – many would dive headfirst into the fermenting fruits and stay there for hours. When they’d finally emerge in the cool of the evening, gloriously drunk, they’d fly in erratic swoops and swirls and collide with the window or enter our room, buzz around the tube light, and finally perch on the window’s wire mesh. A night’s rest to recover from their afternoon’s alcoholic orgy, and then off early in the morning.
The beetles’ pre-flight preparation is always charming to watch. After thoroughly cleaning their antennae, they toddle round and round and rear up to flail their first pair of legs in the air while opening up their elytra (colourful, tough, shiny wing cases covering their delicate wings). Watching the thin wings spring open and stretch always made me wonder how such frail-looking things could support the beetles’ squat bodies in flight. With wings spread, a lumbering leap would cause the beetle to be airborne with a loud buzzing sound.
An interesting fact about their iridescence is that it is not entirely created by pigments (like those found in butterfly wings) but rather due to the structural properties of their armour-like exoskeletons. While a layer of pigment gives them their base colour (green, in the case of Heterorhina elegans), the layering of plate-like cells on the exoskeleton twist, bend, and scatter light like the liquid crystal displays of some televisions. Scientists believe that understanding the light-reflecting properties of beetles’ exoskeletons could provide insights into developing superior reflective paints. Humans have been so fascinated with beetles’ shiny colours that, in the past, the elytra have been used to embellish jewellery and even textiles!
My room was visited by a potter wasp small
In mud she crafted a nesting hall
With diligence keen
And on a strict routine
She created mud-sterpieces on my bedroom wall!
Photo: Jithesh Pai
A purposeful potter wasp
On another day, a muted buzzing drew my attention. This time, it was a potter wasp, most likely of the species Phimenes flavopictus, striped yellow and black, carrying a ball of mud.
As I watched, she landed on a corner of the wall next to the window and began spreading the mud ball there. In a few hours, with multiple little mud balls, she had created a neat globular nest reminiscent of a matka, a round-bottomed earthen pot. She then disappeared for a few hours, returning with a limp, green caterpillar as long as her own body. With quick jabs of her feet and the stinger in her abdomen, she managed to coil the paralysed caterpillar and stuff it into the nest. Finally, she sealed the nest’s entry with more mud and began constructing and provisioning another pot adjacent to the first one.
Over three days, she built five mud chambers and stocked each with a variety of caterpillars. Although adult potter wasps are chaste nectar feeders, their larvae are voracious carnivores that feed on the caterpillars entombed inside the nests.
Despite the macabre way these wasps feed their brood, they are important biological pest-control agents as they prey on several economically important pests. Even more amazing is that some potter wasps use chemicals, released by the plants caterpillars chew on, to home in on their prey.
On my wall sits a spider hairy
Frankly, she looks quite scary
With eight eyes agleam
In the moonlight’s beam,
For prey, she waits patiently.
Photo: Jithesh Pai
The jaunty jumping spider
A few days after the potter wasp finished stocking and sealing her nests, I spied another visitor. A brown, black, and white jumping spider, which I discovered to be a female of the species Carrhotus viduus; she was orange with yellow and orange markings along the abdomen.
Carrhotus viduus spiders seem to be very daring. They tend to nest and hunt near ant colonies, which is something most spiders avoid, as ants can be highly aggressive towards them. These spiders are considered useful biological pest-control agents in crops such as brinjal, where they prey on aphids, mosquitoes, treehoppers, and other insects, while several house-dwelling species prey on mosquitoes.
Although most people lump spiders into the same category as insects or “bugs”, spiders are not insects. They belong to the class Arachnida (which includes scorpions, daddy-long-legs, ticks, and mites). Despite their somewhat menacing appearance, some spider species are social and may have distinct personalities. Research shows that in Stegodyphus sarasinorum spiders, which form communal webs, individual spiders vary in boldness and aggressiveness, and these may affect task partitioning in the colony.
Here is a stinkbug morose
And although he can cut quite a pose
He gives off these scents
That are not quite heaven-sent
And frankly, very offensive to the nose
Photo: Jithesh Pai
The solitary stink bug
After the spider visit, we hosted a less-than-welcome visitor. A patchy dark-and-light brown shield-shaped insect with a pungent odour and appropriately named stink bug. While many sources identified this insect as the brown marmorated stink bug (Halyomorpha halys), one study points out that this may be a misidentification of a very similar species (Halyomorpha picus). While the former originated in East Asia and is an invasive pest on many crops in Europe and the USA, the latter is a minor native pest in India.
Whichever species it was, it smelled like rotting coriander. The smell is attributed to the chemicals trans-2-decenal and trans-2-octenal, which stink bugs use as a defence against predator birds. However, research shows that these compounds are multifunctional as they also act as antibacterial agents.
Coexisting with bugs
Besides these visitors, my room has had a succession of interesting interlopers, including dragonflies, moths, butterflies, caterpillars, honeybees, carpenter bees, praying mantises, grasshoppers, crickets, and katydids. While I welcomed many of these and spent hours studying them, home invasions by bugs are no joke. Using pesticides to keep insects away from homes is also not a viable long-term option, as many insects develop resistance to common insecticides. Worse, insecticides often poison the insect’s predators and travel up the food chain to affect other animals, such as birds.
The problems arising from the swarms of pesky mosquitoes invading my room every evening finally forced me to get the warped window fixed. While I no longer need my trusty mosquito zapper, I do sometimes miss the other interesting little guests I used to receive.
About the contributor
Anusha Krishnan
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