Meet Ken Gartside, naturalist and wildlife photographer!

Ken has been a Naturalist and wildlife photographer since being a birdwatching kid. His interests are wide-ranging, but his specialisms are in Fungi, Lichens and Invertebrates in general, but especially insects such as Hoverflies (Syrphidae) and Dragonflies/Damselflies (Odonata). Long retired, he now helps with conservation work and wildlife recording generally, including with RSPB at Dovestone reserve in Oldham and the Peak District dark peak area of Saddleworth, where he lives, which are all in Watsonian VC63, South West Yorkshire.

Ken is also involved with wildlife photography, surveying and recording in many areas of Greater Manchester and Yorkshire, including as a member of Sorby NHS, based in Sheffield – and has given many illustrated talks to local societies on wildlife.

The Wildguides Hoverflies 3rd edition has some of Ken’s photographs included in it, and he has also written self-published books including ''Hoverflies of Saddleworth'' and ''Insects of Tilos & Halki'' (Dodecanese, in Greece).

Ken’s photos can be viewed on the following sites:https://www.flickr.com/photos/kenpiccs/ and https://www.flickr.com/photos/183752748@N06/

YNU The Naturalist article, December 2018: https://www.ynu.org.uk/about-the-ynu/publications/download-page/download/2-naturalist/32-naturalist-dec-2018

Ken’s account is really a tale of two species: the tiny Ichneumon Wasp Listrodomus nycthemerus and its interaction as a parasitoid with the Holly Blue Butterfly Celastrina argiolus.

Holly Blues often have a double brooded year and use Holly as the main larval food plant in spring, and in autumn use Ivy, but other bushes are known to be occasionally used for egg-laying. There are 3 mature Holly trees, male and female, in Ken’s fairly small wild garden in Saddleworth, West Yorkshire. The trees are around 20 ft high, but the Ivy grows on the stone and brick walls, so is lower and more easily accessible to watch. It is left to grow largely unrestricted and thus flowers copiously in late autumn to attract pollinators and acts as a breeding ground for the beautiful Holly Blue butterfly.

Holly Blues are using both of these habitats, but it is far easier to see and take photographs of them from August onwards when the Ivy starts to bud, which is where they lay their tiny eggs then.

Seen in autumn, Ken also has a colony of individual nests present of the solitary wasp Mellinus arvensis, a lovely black and yellow species which is around at this time too, searching for its dipteran prey to stock its nest holes in the ground.

Prior to 2018, this blog’s featured species had never been found in Yorkshire. Ken recounts its discovery: ‘Whilst photographing Mellinus hunting on 31st august 2018, I saw what I thought was one of the males, which are smaller than females, but something made me look twice – its black and yellow markings on the tail weren't quite right. I had found a Listrodomus nycthemerus amongst the Ivy buds – a Yorkshire first, confirmed by Bill Ely and put on iRecord. Since then, I have seen them in most years, but more in 2022 and 2023 than other years since 2018.’

This most likely illustrates the cycle of interaction of boom and bust for the two insects, usually considered to be around 5 years as first one, then the other, reaches its maximum breeding potential, with numbers of the other dropping off. This cyclical variation in numbers is well recorded in Holly Blues and is thought to be solely the result of the wasp activity, notwithstanding seasonal weather and other factors. The butterfly gradually recovers its population, and one assumes the wasp must also.

Listrodomus is a rare insect but is very likely under-recorded as it is hard to see in the canopy of Holly – it is only around 6-8mm long. It is also double brooded, mirroring the host butterfly. Ken has observed the wasp’s egg-laying technique on a few occasions, which is to diligently and unhurriedly go round all Ivy buds searching for larvae of Holly Blue to lay into. This lovely host specific wasp is small and inconspicuous in the tangle of Ivy leaves and buds. It uses the early instar larvae of Celastrina argiolus found on the buds as a host in a parasitoid way. This means the egg is laid in, and develops in, the host larva which is not immediately killed. The butterfly larva continues to grow and develops into a pupa, from which the wasp eventually emerges from the now-dead pupa as an adult. Parasitoid relationships result in the death of the host species, whereas a parasitic relationship does not.

Holly Blues have been spreading north for many years and were first recorded in Yorkshire in 1978 (Butterfly Conservation Yorkshire) and is now increasingly found in Scotland. It is likely that in a few years, Listrodomus will also be seen more in Scotland as it follows its host when there is a viable population, perhaps only 3 to 5 years after the butterfly itself colonises. The distribution stronghold of the wasp appears to be on the continent and Yorkshire is towards its northernmost range, but as mentioned, both species are gradually trending northwards.

There are only 230 European Listrodomus nycthemerus records and 9 UK national records, as the Yorkshire finds mentioned have not yet trickled through the system – NBN can be notoriously slow, but records can be viewed there: https://species.nbnatlas.org/species/NBNSYS0000031474. Meanwhile, the Holly Blue Celastrina argiolus is abundant, with 491K records in 2024: https://species.nbnatlas.org/species/NHMSYS0000516260. Interestingly , when Ken originally found the wasp, NBN only showed 159K Holly Blue in 2018!

These two species are inextricably linked by the desire and need of the wasp to use the butterfly as host - there appear to be no other benefits to either species. The story of these two intertwined species is a lesson in carefully watching your local patch or a particular habitat on a regular basis; you never know what you might discover!

Recording and monitoring

Let’s hope this short blog article inspires others to search and find this wasp and its butterfly host, to help inform further research and build up our knowledge of distribution and quantity by entering the record on iRecord, iNaturalist or via your regional Local Environmental Records Centre, which you can find on the map in this link: https://www.alerc.org.uk/lerc-finder.html, for which NEYEDC covers the North and East Yorkshire region.

Further information and acknowledgements

NEYEDC would like to thank Ken for his time and expertise in helping to create this blog.

The Natural History of Yorkshire in 100 Species

#79 Listrodomus nycthemerus by Ken Gartside

Recording and monitoring

Further information and acknowledgements