On Insect cocks

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Cock. Penis. Dick. Wang. Whatever you call the male appendage, this is an area of insect physiology where things get pretty wild. Or perhaps more accurately, wilder than the usual.

But let’s start scientifically-correct: in the insect world the closest thing to the human penis is more properly known as the aedeagus. But ‘closest thing’ does not in any way imply great similarity. It’s actually part of the insect abdomen, and the external part of the male’s sexual weaponry is a phallus of extremely various flaps, hairs and hooks. Still with this? Good.

When it comes to shape, describing the situation as complex doesn’t get anywhere near to doing it justice. Menno Schilthuizen’s account of genital evolution is a comprehensive overview (far more so than can be included here), highlighting a wonderfully alien world of ‘prongs’, ‘pegs’, ‘springs’ and ‘titillators’. If insects are purely in it for the passing of genes, they could’ve fooled us.

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Amazing aphid dicks: from Wieczorek et al, 2011 

There’s so much to say about the morphology of aphid appendages alone that the main journal paper on the matter comes in two parts. For relatively small insects, aphids come with a significant package – “relatively large and discernible under a hand lens or even with the naked eye”. The paper includes such descriptive gems as “a few circular pits distributed mostly in its medial part. Sclerotized arms with distal part rather long and thin, and proximal part shorter and wider. Aedeagus long, inverted question mark-shaped.” And that’s just the aphid Drepanosiphumplatanoidis. Big name, big aedeagus.

Smutty jokes aside (but not for long), in insect taxonomy, male sexual organs can be extremely helpful in establishing exactly what species you’re dealing with. In fact, it can often be the only way of making a certain identification. So far, so useful, to us as well as them. But how do insects actually, you know, do it? Again, this is no simple matter.

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Normal for dragonflies: from Miller, 1991

The ‘lock and key hypothesis’ is an idea that has persisted in entomology – and, naturally,
argued over. It asserts that male and female sexual organs of an insect species, whatever wacky shape and size they are, have evolved to only be the exact ‘fit’ for each other. The theory, however, has been largely discredited over the years.

What’s abundantly clear is that sex is rarely anything straightforward in the insect world – there’s little by way of proxy for missionary. Dragonflies are a good go-to example for the messiness of it all – so much so that their sexual antics inspired a New York Times article, in which the slaty skimmer (Libellula incesta) is described as having a “fairly rococo penis”. Sex begins with what constitutes foreplay – the male grabbing the female at the back of the head – while dragonfly dongs are not just about depositing sperm, they’re also about removing that of rivals. Naturally, females are tooled up to stop that happening, if at all possible.

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Brutal bruchid beetle bell-end: Wikimedia Commons

The mealworm beetle (Tenebrio molitor) also has a dick geared up to dispatch the genes of its rivals. In the words of this paper on the matter, it “comprises a central shaft enclosed within a flexible sheath covered with chitinous spines. As the shaft extends within the female’s copulatory bursa the sheath and its covering of spines rolls back producing a `scouring’ effect.” Lovely.

With schlongs often more resembling torture implements, things can get even more brutal. Males of the bruchid beetle (Callosobruchus maculatus) actually damage the female’s reproductive tract during sex, and females, understandably, kick them for it. If she doesn’t kick, injuries tend to be worse after a longer sex session. Yet according to this paper, the carnage is not a deliberate act of destruction by the males, just an unfortunate by-product of them evolving weapons that are literally weapons. Why, it’s not yet known, but the theory is its all about being able to cling tightly to their ‘loved’ one.

If this blog puts insects in danger of being adopted by the alt-right as beacons of ultra- masculinity, hold that thought right there. Transgression of gender norms is happening in Brazilian caves, don’t you know. In the louse genus Neotrogla, it’s the females with the penis-like protrusion, and the guys with a chamber comparable to a vagina. A very niche re-definition of ‘wearing the trousers’ for sure, and in marked contrast to the species of beetles and dragonflies using their phallus to screw over their rivals with a bit of sperm scooping, our ‘macho’ cave-based females are using theirs to collect it up. Through all the kink and horror, life finds a way.

So there, a piece about insect nobs has been published on the Entomology MSc blog. I can only hope this comes up in the exams in March, making things a little less hard. Too much smut? Probably.

 

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Britain’s Next Top Pest

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Our Entomology MSc gang have just had two weeks hearing from some of the key players in the biological control industry. While there were many invasive insect pests mentioned that are currently giving UK growers cold sweats in the middle of the night, a few names kept cropping up.

Without further ado, here’s a run-down of just a few of the headline crop-hungry taxa posing new threats on these shores.

Spotted wing drosophila (Drosophila suzukii)

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Not the most appetizing plum, thanks to D. suzukii (photo: Martin Hauser/ Wikimedia Commons)

Despite its catchy name, nobody hopes to catch this fruit fly on their crop. Originally from South East Asia, it’s been rapidly expanding its range in Europe, and was first seen in the UK in August 2012. Unlike like other Drosophila, which tend to go in for decaying and rotten fruit, D. suzukii uses its serrated ovipositor to lay its eggs through the skins of otherwise undamaged fruit. A neat evolutionary advantage for it, really bad news for growers of soft fruit.

The pest control industry is very much all over trying to get the better of this species, though there is no perfect formula. Research has suggested that using biological methods, in this case entomopathic nematodes and fungi, can reduce population development, but can’t stop outbreaks.

South American tomato moth (Tuta absoluta)

Another great name, another insect to strike fear into growers. Unsurprisingly, it’s massively into tomatoes, and can do enormous damage to crops when left unchecked – to the point when they can finish off the lot. Although numbers of outbreaks in the UK are still relatively small, the potential to penetrate all parts of the tomato plant means that any arrivals, such as in imports of Spanish tomatoes, must be taken very seriously indeed.

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The tomato isn’t looking great either (Photo: TNAU Agritech Portal)

Full development from egg to adult has been seen in a wide range of temperatures, and a 2013 study concluded that Tuta is “well able to develop under temperatures that would commonly be experienced in UK glasshouses”.

Other research has highlighted the potential of natural enemies to counter this tomato-loving moth, with Macrolophus and Nesidiocoris tenuis, two Hemipteran egg predators, now seen as having the best potential to make inroads into populations. The problem with this approach is that sometimes a beneficial insect can become a pest, and in this case, the biocontrols have been known to do plant damage themselves. Nothing is ever completely straightforward in the world of pest management, it seems.

Diamondback moth (Plutella xylostella)

There have been recent spikes in numbers of this lover of cabbage and cauliflowers, sparking natural concern among growers. Evidence is mounting that it’s surviving winter here, as well as resistant to pesticides.1280px-Plutella_xylostella1

The fight is by no means over, however. Intercropping – growing a different crop in proximity to the main one – looks like a promising tactic in taking on the pest. A 2010 study showed that planting onion, tomato or pepper with cabbage was as effective as spraying.

Melon thrips (Thrips palmi)

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Photo: Forestry Images/ Wikimedia Commons

Although this thrips species can’t survive the British winter, it can establish with protected crops, and is extremely unfussy in its choice of meal. As such, it’s as much a threat to growers of ornamental plants as it is to those in the fruit and veg business.

What’s more, it’s another insect known for being highly pesticide resistant, so effective biological controls are certainly what’s called for here. It seems likely that a mix of entomopathic nematodes and fungi may well be the dream team for tackling both the larval and adult stages.

 

Is that it?

Far, far from it. The insects featured here are certainly not the only ones that could potentially do significant harm in UK agriculture, should they both get the chance to arrive and find a way to consolidate their numbers here.

DEFRA’s top six of the very latest potentially damaging pests and diseases features a pair of longhorn beetles from the east, while the UK Plant Health Risk Register is a fascinating and somewhat frightening source of information about potential threats to the flora of this island. Currently listing 1,024 pests (not just insects, however), it serves to highlight that amidst the great advantages to global trade come some pretty serious pitfalls.

The prizes for pests that manage to establish themselves in the UK’s famously un-tropical climes are significant – and in an agricultural environment of reducing pesticide effectiveness and use, controlling their proliferation is a multi-faceted and often complex game.

Successful pest management has to take into account factors like the temperatures insects operate in, where they operate in the crop canopy, the need to tackle both adult and juvenile stages, and compatibility of biological control methods with insecticides and fungicides. It also needs to factor in a comprehensive clean-up after the pest has been beaten, to prevent an immediate repeat of the nightmare all over again.

While there are plenty of checks in place to try and prevent invasive pests getting the chance to test their resolve against the UK climate, it’s practically impossible to prevent every insect of potential harm making it past the border. The prerogative is that when they do show up, they are reported quickly, and expert advice sought when needed. If the last fortnight’s lecturers were anything to go by, there certainly is the expertise out there to nip most comers in the bud before scares become crises.

In defence of common names

In our Dipteran discussions on Tuesday last week, the idea of doing away with all insect common names was mooted. While this may have had some support from MSc colleagues in the room, I think the majority were probably with me in internally screaming “NOOOOOOOO!”.

Let’s be frank from the start: yes, our good old Anglicised common names are mostly easier to remember than scientific names, unless you’re a fluent Greek or Latin speaker. But that’s not why I’m here to stick up for the commoner.

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It’s well worth first acknowledging that there are problems with common names. Many are seemingly endless variations on a pretty loose theme (see the myriad ground beetles or hoverflies), and they can be different at national and even local level, de-standardising what is an internationally-agreed nomenclature and even muddying the waters of the body of research on given species.

But it’s not like the waters aren’t muddy enough in the first place. It’s arguable that things haven’t changed that much since 1942, when the Journal of Economic Entomology published an editorial stating:

With the scientific names of insects in perpetual chaos, due to the application of the law of priority, the splitting of species and generic concepts, and the endless shuffling of species from one genus to another, common names have come to have much more significance and importance than formerly.”

Common names have a tendency to cut through the noisy clanging of taxonomic debates – but they can do more than that: evoke, romanticise, or simply tell it like it is. On the latter, common names can tell you what an insect feeds on (pollen beetle, currant aphid, fungus gnat, dog tick), give you a crystal clear idea what an insect looks like (scorpionfly, giraffe weevil, orchid mantis, violin beetle), and let you know where it likes to hang out (larder beetle, house fly, museum beetle, bedbug).

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Devil’s coach horse beetle – Ocypus olens (Wikimedia Commons)

They can also simply bring a bit of fun to what can seem to outsiders like a dry discipline. Science is not forever vanquished by the simple admission that talk of fairyflies, ugly nest caterpillar moths, assassin bugs, beautiful demoiselle darters and bombardier beetles makes the world a slightly lighter, more wonder-filled place.

Common names can even reveal a bit about our culture. Why on earth shouldn’t Britain, a country steeped in existential angst and the occult, have brought its language to bear on the death’s head hawk moth, devil’s coach horse and deathwatch beetles?

As if to prove the joy of an apt common name, when Tuesday turned to Wednesday and we were introduced to the Lepidoptera via a photo of the Picasso moth, there was a notable instant improvement in the mood of the room, previously somewhat tense ahead of the afternoon’s assessed practical.

The power to evoke should not be underestimated in the communication of science. From a personal perspective, a life-long love of beetles would have been far less likely sparked by Lucanus cervus than stag beetle. The public are not a bunch to be sneered at for their failure to appreciate scientific correctness – and what’s more, need to be brought along as the pivotal role of insects in supporting human life becomes ever clearer.

Picasso moth M Greeshma

Picasso moth – Baorissa hieroglyphica (photo: M. Greeshma)

I agree wholeheartedly with Michael J. Samways, who in his 2005 book Insect Diversity Conservation urged experts not to shy away from charismatic ‘icon’ species and to use their common names, “so as to give the conservation mission warmth and familiarity”.

In case I haven’t made myself quite clear, I’m not just trying to make life more difficult for Giannis, Cyprus’s representative on the course, who’s been sitting through the Hellenic-monikered species being reeled off as part of our Biology and Taxonomy of Insects module with a distinct air of ‘heard it all before’.

And all of this is absolutely no argument against scientific names per se. Of course, they will always have primacy – but they shouldn’t sit on their own, or they might just find themselves in sparse company.

Behind the Moth Meme

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Unless you’ve digitally cleansed your life recently, you’ll probably be aware that moth memes have taken over the internet – so much so that there is now, inevitably, a Reddit page dedicated to this unique sub-group of social media fodder.

The focus of this frenzy of meme-making has been moths’ famed love of artificial light. But here at Mastering Entomology, we’ve decided to delve a little deeper.

First and foremost, though, it’s worth pointing out that there are plenty of moths that fly during the day – so aren’t the types to be suckered into the seductive glow of a lamp. A study by Florida Museum of Natural History suggested that 15-25% of all Lepidoptera are day-flyers, while Butterfly Conservation has helpfully produced an overview of the UK’s non-nocturnal moths.

But of the nocturnal species, is there really a deep craving driving moth orientation towards our light sources? The fun-killing simple answer is probably no. The expert consensus seems to be that it’s all a misunderstanding; that they’re actually looking to orient themselves by the moon, and they’re simply drawn to alternatives because they’re brighter. As they move closer, their ability to triangulate is thrown off kilter, resulting in them returning to the light repeatedly.

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But given the distraction, as opposed to attraction, our light sources bring, are all moths equally likely to zone in on the bright lights, and are all electric lighting types equally likely to bring lepidopterans into their glow? That’s another no and no.

The tendency to head for the light could be greater for moths from areas with little light pollution. Altermatt and Ebert (2016) found that in the case of the small ermine moth (Yponomeuta cagnagella), ‘city moths’ from populations that had experienced high amounts of artificial light were less likely to fly to light under lab conditions than those from ‘dark sky’ populations. It has been suggested by several studies that natural selection should favour those less drawn to artificial light – pretty logical stuff – and this research provides some evidence that such selection may indeed be happening.

Altermatt and Ebert have serious form when it comes to advancing knowledge on moths and light. In their 2009 study with Adrian Baumeyer, male Yponomeuta cagnagella and Ligdia adustata were seen to be 1.6 times more likely to make a beeline for an artificial light source than females. A good argument to settle the ‘smarter sex’ debate, perhaps.

A PhD study in Exeter has recently shed further light (pardon the pun) on the type of illumination most attractive to larger moths, finding that short wave lighting attracts both greater numbers of species and individuals than long wave.

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The interplay of moths and light is, alas, not all online laughs and levity. There is growing evidence that artificial light may be having deeper effects on moth numbers than simply the deletion of those flying at speed towards the lamp. While the fact they are drawn to light is firmly established, there is evidence that it could be reducing moths’ attraction to each other.

A 2015 study in the Netherlands by van Geffen et al looked at the mating habits of Operophtera brumata, a member of the Geometridae family, when tree trunks were lit with different-coloured LED lighting. What the first phase of the research discovered was two-fold, and fascinating: a significant reduction in females on the illuminated trunks, again suggesting a sex bias in light attraction, and an inhibition of mating when they were under the lights. A side note, though: perhaps appropriately for this sexy moth discussion, more females caught on trunks lit with red light had mated than those with green or white light.

Mating is not the only matter that will pique concern amongst conservationists. Other research has found links between feeding and artificial light (they appeared to do less when subjected to it) and caterpillar development (they reached lower mass under white light and pupated earlier under green and white).

There is clearly multi-faceted interplay between moths and light, and a sense that we’re only beginning to understand the mechanics and effects of it. The ability of species to coexist with increasingly dense human habitation is a hot topic, so knowledge in this area is only set to grow in the coming years. Far from every aspect of this issue has been covered in this blog, but in the interests of brevity, it might be best to wrap up (although most of those readers who came for the memes have probably gone already).

Final note: this week and next we’re doing the taught elements of Biology and Taxonomy of Insects, the second module of the Entomology Masters here at Harper. Next Wednesday we’ll be looking at Lepidoptera, increasing our knowledge of these complex yet internet content-friendly insects.

Meet the new ento-blogging team

New year, new team of aspirant entomologists writing for Mastering Entomology – and this time around there’s four of us. With no further ado, let’s introduce the team…

Ant lion

Here’s an antlion Sam found earlier

The antlion fanatic

Hey, I’m Sam. I’m actually a fairly recent convert to the ento crowd. My undergrad was in zoology, where I was considering going into conservation or behavioural research. As the leader of the course was an entomologist I did learn a lot about insects, but my passion wasn’t really ignited until a trip to Africa in my final year. In a place where monkeys and hippos are the norm, I found greater fascination in the intricate pitfall traps formed by the antlions that surrounded our hostel. That trip cemented in me a desire to understand the behaviour of insects and its evolution. Which is exactly why I’m here at Harper Adams. I’ll try my best to share all the interesting behaviours that I come across in my studies.

The future curator

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…and a death’s head hawkmoth Dom photographed earlier

Hi, I’m Dominic. I chose to study Entomology as I am very passionate about the subject and want to improve my knowledge and understanding of Insects. Ultimately, I wish to work as an Entomological curator where I can look after the important collections held within museums, educate the public on insects and hopefully conduct my own research to help the conservation of entomofauna and the habitats they reside in. My main interests in Entomology are Lepidoptera and Coleoptera (predominantly Moths and Scarabaeidae). I am fascinated with the way that Insects interact with and influence other organisms as well as looking at their roles in various ecosystems, I am also intrigued with how Insects have impacted human culture. In this blog I hope to write about insect behaviour, interactions, historical importance, environmental impacts and any other Entomology facts I find interesting.

 

Entomologists on wrekin

Gary (L) on a collecting mission with fellow members of the Harper ento crowd

The outlier

I’m Gary. You could certainly argue that I’m not the typical Entomology MSc student, having spent the last decade-plus in writing, communications and journalism. The love of insects has always been there, mind – just, it’s fair to say, lying somewhat dormant for a spell. Heavily influencing my taking of this somewhat tangential turn was time spent in the Prespa National Park in Greece, Albania and the Republic of Macedonia, where, similarly to Sam, I spent much of my time staring in awe at the biodiversity on the floor rather than looking out for bears, wolves or the magnificent array of bird species. Though I’m not exactly relishing the statistics that are to come as we work towards our final research projects, an insect-collecting trip up the Wrekin last week with some of my fellow Ento postgrads firmly fixed in my mind that I’ve made the right, albeit slightly curious, decision. Twitter: @garyfromleeds

Niahs aphid

Niah’s pet aphid mama

The pest patroller

Hi, I’m Niah, the token Integrated Pest Management student on this blog. I come from a science background, having just completed my Bachelor’s in Biological Science, but I knew next to nothing about entomology until my interest was sparked on a placement at the Warwick Crop Centre. Having spent a summer emptying traps, carrying out pesticide trials, and compiling citizen science moth counts into a report, I decided that pest management was the way forward! As well as singing the praises of biological control, I am especially interested in social insects, months, vectors of human disease and, of course, aphids. It’s quite a mixed bag but I’m looking forward to including some of them in this blog!

We’re aspiring to bring you some blog content that’s as diverse and intriguing as the world of our favourite arthropods. If we can get even remotely near, we’ll have done a pretty good job.

The larvae emerge…

It’s that time of year again when a new cohort of enthusiastic entomologists begin their journeys at Harper Adams, which of course means new authorship of Mastering Entomology. So, this short post is going to introduce us as the new authors and let you know what you can expect from us across the next year.

We’ve written short pieces introducing ourselves:

Hi guys! My name is Aqib Ali and I am one of two curators of this blog, for this academic year. I’ve had an interest in “creepy crawlies” from a very young age. It began with a childish, albeit slightly morbid, curiosity (yes, I was one of those pulling-off-legs and offering-sacrificial-larvae-to-spider-overlords kind of kids). Although, this interest faded slightly as I moved through the mundane secondary school system, my love for life sciences remained constant and it led to me doing a BSc (Hons) Zoology degree at the University of Derby. As I passed through my undergraduate course, my passion for all things insect was slowly reignited. I did several modules with entomological content, one of which was “Applied Entomology”, taught by the likes of Professor Karim Vahed- a leading expert in the field of sexual selection and insects. With my interests piqued, I decided to do a dissertation on an aspect of sexual selection, namely intrasexual selection (male competition). I looked at whether weapon size affects the outcome of aggressive encounters in a cricket species (Platygryllus primiformis). I also sought out volunteering, such as a research assistant for forensic entomologist Dr. Kate Barnes, to broaden my entomological interests. By the end of my undergraduate degree my heart and head were both set on carrying on down the entomological path. Deciding what my next step would be was a no brainer: the MSc Entomology course at Harper Adams University. What attracted me to this course was its range of modules which cover a variety of topics, the excellent teaching quality and facilities, and that it’s quite literally one of a kind.

My entomological interests at this stage are broad and I am open to the many aspects of this diverse subject. Entering this course open-minded will allow me to fully experience and consider my options before I find my specialism. This journey has started with a bang with the Biology and Taxonomy module! In the short time, I’ve been here I’ve learnt so much! I hope to carry on learning new things, acquiring invaluable skills, amassing great experiences and most importantly, loving what I do.”- Aqib Ali

 

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The new cohort, learning some practical skills in Biology and Taxonomy of Insects (Photo by Aqib)

 

Hi I’m Linzi and I’m a graduate from Keele University studying Applied Environmental Science with Physical Geography. My interest in entomology began when we used aquatic insects as indicator species during a field trip to Cwm Idwal. This developed further throughout more field trips around Staffordshire and into France. When it came to my final year I selected modules that would allow me to focus my interests more and decided to base my dissertation on insects.

After hours of scouring news articles and journal articles I decided to investigate pesticide contamination in honey, particularly neonicotinoids. Although by the end of my experimental work I ended up looking for 91 different pesticides across five honey samples. I loved my dissertation and really wanted to take it further, this is what really set my mind on entomology. Hours and hours of reading articles about honey bees, and other beneficial pollinators had me captivated and after a short google search, my heart was set on Harper.

I have been lucky to be given the opportunity to study at Harper, and since arriving only three weeks ago I’ve already learnt so much and my interests have greatly broadened! I’m excited to keep broadening my interests and eventually find the area that I will  have a career in.Linzi Jay Thompson

So…that’s us! We will be publishing a variety of articles covering; our course, our interests and more. We aim to publish as regularly as possible (schedule permitting) so check back to see which exciting article we have posted. You can expect up to three articles per month covering a variety of topics, meanwhile, please follow us on twitter @EntoMasters for the latest updates, and follow our personal twitter accounts too @EntoAqib and @Apis_Linzi.