Insects On My Mind

The air is crisp. There is a faint but shrill, pulsating but monotonous call of the Indian house cricket somewhere in the corner of my house. It is too cold for insects to be out and about. He is the only one singing. Since last few monsoons, tiny little insects are hibernating somewhere in folders carefully stored away. Every winter, as and when time permits, I set to bring a few out. The usual ritual in getting to know them is to be able to photograph them from all angles possible, cataloguing them so that you know where they were and what they were doing when you found them, and ultimately – this sometimes takes the longest – sitting down to getting to know them.

Some of these are quite a handful, and there is no shortage of them. They are either rare or they are so special in their habit – such as leading a highly secretive, parasitic life, tucked away under someone’s abdomen or in someone’s nest. I liken them to some of the secretive, nocturnal mammals, they are just so specific in their habit that for the longest time we thought they were rare. Or habitat – such as those which are highly ephemeral, arising from their watery or earthen cradle only for a few hours or days in specific areas before dying out. I liken them to migratory birds, you only have a small window to observe them in a particular space at a particular time, once that moment is lost you have to wait for their next return.

Insect identification is as much art as it is science. It takes more than a scientific eye to observe the very shape of an insect, the shape and number of flagellomeres of its antennae, the type of mouthparts, each and every furrow or bump or spine on the body, the segments of abdomen, the shape and length of the femur, the setae on its head and legs – the way these hairs are oriented, the shape of its genitalia. Insects don’t have fingerprints, but they have wing venations that are a give-away to their identity. You may have to squint your eyes a little – and if you haven’t collected a specimen, a photograph is good enough to identify the morphospecies which in itself is good enough for ecological studies.

When I come back to my base, especially during winters, I sit down and bring them out from my hard-drive where a virtual copy of them rests. These photo-copies may not serve as good specimens as the dead samples, but it is not in me to always capture and bottle a living lifeform, especially if it is uncommon – this is perhaps a downfall for the taxonomist in me, but the ecologist in me only wants to come close to its actual name. Insects might be extremely diverse, but knowing an insect for its role in an ecosystem is much more crucial for an ecologist than its species or sub-species which seldom if ever hints at its niche in an ecosystem. However, when it comes to insects, the debate always starts with what’s good or bad – that is where naming them is crucial. You do not want to pick up a pest which is morphologically similar-looking to its nemesis, and culture it instead to be used as a biological pest controller! You cannot sidestep taxonomy, but, given the resources available for any ecological study on insects (and spiders), taxonomy takes up a large chunk of funds and the ever-so scarce time.

Some insects are downright ridiculous. They’re not ugly or scary, they’re just so weird that it takes some time to get to know them. When this happens, I usually pack them away in a folder till the time that I can look at them again with a fresh mind.

The bunny-ear wasp

Among these ridiculous ones are some that I have an inordinate fascination for, like the wingless wasps. Imagine a group of insects who took to the skies millions of years ago, but the females thought flying was not for them, instead specialising in the arts of assassins who stalk on nimble feet, while their counterparts still fly trying to find their non-winged mates. Everywhere I go I try to see if there are any about.

One monsoon evening, just after a heavy downpour, I stumbled upon an ant – or I thought was one. It had emerged from a pile of tiles, scampering quickly outwards and into the grass a few feet away. I got off my feet to block its path, realising that it is not an ant but a wingless wasp, and caught her in a small container (only later to be released). I took her to my bed because that was the only well-lit place with a white background where I could take decent, uncluttered photographs. This was an exciting find, because I had no clue of what it was. After a few days of trying, I finally closed the file on this insect and moved on to better things.

On came winter, the season of reminiscence. I went back to this wasp, and got my first hint looking at its unusually short wings – wingless wasps are mostly devoid of any wings. This led me to a group of wasps known from Madagascar and parts of southern Africa, central and west Asia – Heterogynaidae – a slip of tongue – or fingers, and you might end up looking at moths in the family Heterogynidae. The Hetrogynan wasps typically show reduced wings called brachypterous wings, a feature not-so-common among wasps but can be seen in many mantids, grasshoppers and crickets.

To confirm my finding, I wrote an amazing expert from WaspWeb.org, an online knowledge repository on wasps of the Afrotropical region. He informed me that it could be a Hetrogyna, and kindly forwarded my email to another amazing expert who suggested that it is an extremely rare wasp not recorded from India before – belonging to a small family with a mouthful name Rhopalosomatidae, in the genus Olixon. 
Olixon sp. (Rhopalosomatidae) from Kanha - or as I like to call her, the bunny-ear wasp

This genus is known from the New World (the Americas), the Afrotropics, and Australia – it was so far missing in south Asia until this little wasp strode out from a pile of tiles. I was directed to a 1999 masters’ thesis “Systematics of little known parasitic wasps of the family Rhopalosomatidae (Hymenoptera: Vespoidea)” by Dr Antonia Elena Guidotti, where Dr Guidotti mentions “Olixon species also occur in most of these areas except for Southeast Asia (excluding one record from India) and is also found in Australia.” There is one single specimen sitting in the National History Museum (London), collected in 1979 and identified by a certain M. Day as Olixon nr. majus TOWNES. He mentioned that it might be the same specimen Dr Guidotti is referring to.

So maybe my wasp is not the first record after all, but it may be a new species. This wasp is intriguing because very little is known about its life history. They are ectoparasitoids of crickets (see Guidotti, 1999), lurking beneath rocks and crevasses where crickets take cover in the day. An infected cricket looks like it is carrying a bag stuck near its abdomen (see this BugGuide image). I am not sure if they are nocturnal, but I encountered it, quite surprisingly, again in the day at a chai shop in Bandhavgarh the previous monsoon as it scampered from underneath the counter and into a gap in the shop shutter. Like crickets, these wasps are also crepuscular and nocturnal, and are likely to be found where crickets dwell. On disturbance they jump a little – probably using their bunny-ear wings to create some momentum to get away from harm, but they cannot fly.

The webspinner hunter

A year before this Rhopalosomatid, another ant-like creature captured my attention. While scouring tree trunks in Kanha, I saw a very unusual ant scouting the same trunk – on a closer look, it turned out to be a wingless wasp! This was also like nothing I had seen before. I had considered Olixon to be similar to this one at first, but the bunny-ear wings suggested otherwise.

After scouring the tree trunk, I started to scour the internet. It took me another winter to finally reopen the case of this mysterious insect, and wrote to an expert of Embioptera – the webspinners. She very kindly assured that my doubt was correct, it was a parasitoid of the webspinners – a not-so-uncommon group of insects found across India’s forests. And this wasp’s name is a mouthful too: Sclerogibbidae. A paper by Kurian and Mathen published in 1961 considers Sclerogibbidae to be “a very rate and poorly known group.” This 1961 paper is the only record of Sclerogibbidae from India as far as I know. It is likely that the wasp from Kanha is also the species these authors described, Mystrocnemus madrasensis, however I cannot be sure and it could also be a new species.
Mystrocnemus cf. madrasensis, a Sclerogibbid from Kanha

This species is also a specialist parasitoid, capturing adult webspinners from their webbed-lairs on tree trunks, where this parasitoid can be found, and lays an egg on them – this could be the reason why it has distinctly robust front pair of legs. And just like former, Mystrocnemus larva feeds on its host as it goes about its business as usual, ultimately spinning a cocoon once the host is dead and emerging as another wingless assassin.

The mega-winged bug

It is not always that you have to wander out to find the unusual, sometimes they visit you. One monsoon night after a ‘good session’ of insect photography in the backyard I retired to my room in Kanha. Once you see insects, you see them everywhere, in every shape, shadow, or just plain illusion. My attention went towards a small black blob just under the fluorescent light, enamouring me by just sitting there. I pulled myself up to take a closer look, and it looked just like an ordinary bug.

Come January of 2017, with the book on Insects and Spiders of Kanha already published, I took a look at this particular individual again. I wrote to another amazing expert in aquatic ecology, who had in the same year that I found this fellow published on the first record of the same insect from Thailand – the Alderfly – a member of Sialidae family of the order Megaloptera – the same mega as in Megalodon for “large”, but here it means large ptera (or wings) – a new record of the order for Madhya Pradesh.

A little more digging around revealed that a similar-looking specimen was collected from Puducherry (year unknown), and described as Indosialis indicus in 2008 by Liu, Flint, and Yang. The individual from Kanha, based on the morphological descriptions by the authors, is Indosialis indicus. This discovery is interesting because Megaloptera is considered to be a relatively unknown group of insects in spite of being a rather small Order in comparison to most other insect orders. The Wikipedia entry for Megaloptera mentions short lifespan, nocturnal and crepuscular habits, and their larva’s tolerance to pollution as the reasons.
Indosialis cf indicus, an Alderfly from Kanha

Megaloptera of India are understudied – their distribution is mostly along the North-Eastern high-altitude areas. The record of Indosialis from Puducherry and Madhya Pradesh are perhaps the only records from peninsular India as far as I know, making them sort of a treasure to find if you’re into entomology. These aquatic insects – a large number of them preferring colder waters – spend a large time in waters as predatory nymphs, emerging only for mating purposes during monsoons. The likelihood of finding them therefore is always around still or flowing waterbodies – just put a light out and they will visit you.

The fly of paradise

Not all insects are fond of monsoon. One hot summer night, one curious insect came flying into my bathroom. I welcome insects whenever they arrive, except a few places when they surprise by suddenly buzzing while you’re minding your own business. This one appeared to have extremely long legs dangling from its frail body as it flew about. Only once it settled did I realise that this is not your ordinary Cranefly with long legs. Its wings were sort-of a give away to what order it belonged, the lacewings.

A little more digging around revealed it to be a thread-winged antlion, Croce filipennis, belonging to Nemopteridae. The textbook of entomology, written by A. D. Imms in 1925, describes them as “striking and beautiful insects flying with a curious up-and-down motion after the manner of Ephemerids, with the long hind-wings streaming in the air” – and indeed they are the Paradise Flycatchers of the insect world.
Croce filipennis, the thread-winged antlion from Kanha

Although recorded in central India from different localities, they are quite uncommon. Their larva – which appear much like the doodlebugs (antlion larva), live in “dust and refuse on floors” in and around well-wooded houses, feeding on small invertebrates such as Psocids (book lice). Their presence indicates that they are eating up your dust mites and book lice, but their uncommonness adds to their beauty.

The sneaky little one

I usually set out to check around lights just before the onset of monsoon – one must start a few days before the monsoon rains properly set in because the intense humidity prior to the rains is a trigger for insects to come out of hiding. The nights are sultry, but after a long quiescence the insects begin to stir again – you may be in for a rare treat during this small window. One such sultry night of June in 2016, I came across an unusual – they’re always unusual if you don’t know them – insect which I thought was, based on its appearance, a caddisfly. Caddisflies are something of an enigma themselves, and India is severely lacking in understanding their diversity as well as their role as indicators of the health of our aquatic ecosystems. I photographed this obscure-looking downy brown insect only to keep a photographic record and like others stored it away.

I don’t know if it was curiosity that brought me back to this insect. I was sort-of sure it was ‘just another’ caddisfly, which I have knowingly ignored for the longest so far, but there was a little doubt that made me want to know more about this individual. The way it perched, its back arched upwards, its long, outward-facing antennae, and its peculiar hunched posture of wings, did hint at something I had familiarity with: the Neuropterans!

And it was one, a member of the family Berothidae that Aspock said “have accountably been neglected up to now and of which our knowledge is rather unsatisfactory” in 1986. The same remains true today. This family is considered to be the oldest within Neuroptera – an order that itself is one of the oldest among many insect orders.
Beaded lacewing of family Berothidae, from Kanha

Commonly called Beaded Lacewings, Aspock very disappointingly reiterates that very little is known about them. “No one has any idea of how or where the adults of most species live, as they have almost exclusively been collected at light.” In general, members of this family are believed to be associated with termites. At least a few species are termitophiles. “Their larvae live freely among termites in their galleries without being attacked. The mobile first and third instar larvae produce an aggressive allomone which they spray by waving their abdomen, paralysing and killing termite workers, soldiers and reproductives” – Aspock mentions this as a unique behaviour among Neuropterans which are largely generalist predators, adding a caution that this should “by no means be uncritically generalized.”

As long as we don’t know what the Berothids of central India are up to, I think it is safe to assume that they, too, are in some ways associated with termites since their time of emergence matches exactly with that of alate termites as they prepare for their nuptial flights at the onset of monsoon. The best time to see them is the first two to three weeks in the month of June when they congregate on lights around homes in well-wooded areas.

A bulked-up mosquito?

If there are insects that are so common that you brush them aside without a second look, it is flies. While scouring, like always, some brambles behind my house one summer day I stumbled upon a fly that appears like something but is something else!

At a glance, this fly looks like a mosquito on steroids – a beefed up bloodsucker with stout and sharp needle-like proboscis you’d not want buzzing around you. To my relief this fellow was calmly perched on the inflorescence of fennel.

I carry a list of species of insects I want to see, a large chunk of them is filled with flies. And this was one of them! Although it looks like a large, muscular mosquito, it was a beefly in the family Bombyliidae – in the genus Toxophora.
Toxophora sp. from Kanha

If there is one family of flies in the order Diptera that is diverse in its form, it is Bombyliidae. While most flies appear like bees, some appear like dragonflies, and some like teddy bears, but they all have a common beginning, they are parasitoids of insects such as bees and wasps, spiders, and grasshoppers. Eggs are laid into nests of these animals or directly on egg pods. The larva, according to Yeates (1997), “consume the host when it is in a quiescent stage such as the mature larva, prepupa or pupa”. As adults they are voracious feeders – not of blood, fortunately – it is one of the largest families of flies which feeds on flowers for nectar and in turn pollinates many species, including several of our crops such as carrots and onion.

Only one species in genus Toxophora has been recorded in India so far, Toxophora iavana, from the states of Tamil Nadu, Uttar Pradesh and West Bengal – making this individual from Kanha a first for Madhya Pradesh. Toxophora lay eggs in nests of potter wasps – but they are not as common as the latter, and are more likely to be found around forest clearings feeding on flowers. It is generally believed that Toxophora is a hyperparasitoid – insects which are parasitoids of other parasitic insects. Like dream within a dream. In other words, they are sort-of like a thief stealing from a thief who stole from you. However, Yeates says that this is not true for Bombyliids. He writes, “All bombyliids recorded as hyperparasitoids do not appear to have evolved in any close association with the primary host, and are best termed pseudohyperparasitoids.” This term is a little tricky to understand. There are three players here: a secondary parasitoid, a primary parasitoid, and the host. For a hyperparasitoid (the secondary parasitoid), the primary parasitoid is its host. However, in pseudoparasitoidism, the secondary parasitoid does not attack the primary parasitoid until it has completed feeding on its host (the third player), the secondary parasitoid only then attacks the primary parasitoid’s pupa. In other words, the secondary parasitoid’s life does not directly depend on the third player – the host of the primary parasitoid. So that’s what some Bombyliids, including Toxophora, are supposed to be: complicated little creatures.

It's a trap!

Then there are those who surprise you when you least expect them. A few months ago, I came across an ant I never thought I would lay eyes upon in central India. It was also on my list for the longest time, and saw it at Valparai in 2017. On contacting the amazing myrmecologist from India, it was identified as Anochetus madaraszi, a rather widely distributed trap-jaw ant found in Jammu and Kashmir, Arunachal Pradesh, Manipur, Mizoram, Sikkim, Assam, West Bengal, Orissa, Uttar Pradesh, and Karnataka. However, for the longest time I thought trap-jaw ants (in the genus Anochetus and Odontomachus) preferred wetter forests until I saw one in northern central India.
Inset: Photograph of Anochetus madaraszi; map from antmaps (see here), for more on antmaps visit here.
The map shows records of A. madaraszi for south Asia, the star (added later) indicates new record for Madhya Pradesh.

Trap-jaw ants have specialised, long mandibles which are held open widely as they go foraging for food. They have small sensory hairs along the mouth which, upon sensing something, trap shut with blinding speed. Now, these ants are very tiny, barely half-a-centimeter across, but active hunters of even smaller invertebrates. Unlike most ants, they are solitary foragers and prefer living in small colonies making them that much harder to find. They nest in the ground, but the nest opening is only a small hole, hence you may miss it (I still haven’t located their nest). It is no surprise this species remained in the shadows of tigers for this long in central India.

After my tryst with these creatures, one thing became clear. If it weren’t for these amazing taxonomists and experts, I’d have never been able to get to know these fascinating insects that live among us. When you name something, not only are we giving them a chance to become known to the world, we are also setting in motion the wheels of ecology, the questions that come after a name is given: what is their status? what are their functions? – and the bane of them all, how are they beneficial to humans? A Sclerogibba or a Rhopalosomatid is perhaps of little importance to humans, their roles are hidden away much deeper in the ground for humans who have their heads up in the skies, but here they are, such specialised masters of what they do. A Sclerogibba does what a Sclerogibba does for no one else can do it.

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