Orchid Hunter

Early Marsh Orchid, Dactylorhiza incarnata

Wild orchids are a treat to behold, their cascade of flowers boldly proclaiming their uniqueness with only c. 28 species present in the wild in Ireland (1). And yet, as is becoming increasingly the case with many species, their numbers are decreasing, dramatically in the case of some of the rarer species. The reasons for this are manifold and complex but are all due to habitat destruction of one form or another.

Early Marsh Orchid, Dactylorhiza incarnata, with emerging flowers

However they are not so scarce as to require treks deep into uncharted territory to view examples of the commoner species. It is rather embarrassing to admit but I had never before seen a wild orchid in Ireland. A combination of bad timing and lethargy has thwarted me over the years so it was with great joy that I found a number of Early Marsh Orchids (Dactylorhiza incarnata) on Galley Head on the south west coast. Their cascade of purple flowers, held aloft above the surrounding grasses was quite the show. Even here, however, they were confined to areas where the vegetation was at its lowest. A 28 year survey of D. incarnata in northern Germany confirmed this observation with populations on meadows enjoying a resurgence with the reintroduction of mowing of meadows (2). While D. incarnata showed some shade tolerance, in vegetation over 150 cm plants were unable to survive. Introduction of such mowing methods in places with surviving populations of D. incarnata would certainly help increase numbers.

Early Marsh Orchid, Dactylorhiza incarnata

Marsh Orchids, the genus Dactylorhiza, are a taxonomically confusing group with many species readily hybridising to give a plethora of morphological variations (1). D. incarnata is no exception, with five subspecies being recorded in Ireland (3).

Early Marsh Orchid, Dactylorhiza incarnata

References:

1. O'Mahony, 2009. Wildflowers of Cork City and County pp. 296-312
2. Schrautzer et al., 2011. Flora 206 pp. 622-630
3. Stace, 1997. New Flora of the British Isles

The Bluffing Buff

Buff Ermine Moth, Spilosoma lutea

Even though the rain is doing its best to deny us the pleasure of it, it is summer, making the apparel of the Buff Ermine moth (Spilosoma lutea) seem a little incongruous. With what looks like a miniature scarf draped over its wings, maybe it knows the Irish summers better than we do. S. lutea is common throughout Europe and much of the temperate belt of Asia at this time of year in a variety of habitats and will continue to be so until August (1). The brown tufted larvae are polyphagous, feeding on quite a variety of plant species.
 

White Ermine Moth, Spilosoma lubricipeda

Being the colour that it is, S. lutea should be an easy target for predators. Yet it is this very colour that saves it from being so. S. lutea is actually a mimic of its close relative the White Ermine moth (S. lubricipeda) (2), a moth that is unpalatable to predators due to its high levels of pyrrolizidine alkaloids (3).

References:

1. Hammond, 2008. The Wildlife Trusts Handbook of Garden Wildlife p. 49
2. Rothschild, 1963. Proceedings of the Royal Entomological Society of London. Series A, General Entomology 38 pp. 159-164
3. Rothschild et al., 1979. Biological Journal of the Linnean Society 12 pp. 305-326

Orange Tip Egg

Orange Tip Butterfly egg (Anthocharis cardamines) on Cuckoo Flower (Cardamine pratensis)

An Orange Tip female (Anthocharis cardamines) lays a single egg on a Cuckoo Flower (Cardamine pratensis), the egg turning orange as it matures. As stated previously, only one egg is laid per plant as cannibalism is common in Orange Tip larvae. This is not a rare occurance as many lepidopteran larvae engage in cannibalism, either of eggs or of other, smaller larvae (1). This is often due to the larvae living in a confined space. Not so with the Orange Tip that actively predates its own type (2).

Orange Tip Butterfly egg (Anthocharis cardamines)

References:

1. Whitman et al., 1994. Carnivory in phytophagous insects, p. 161-205. In: Functional dynamics of phytophagous insects (Ananthakrisnan (Ed))
2. Zago-Braga and Zucoloto, 2004. Revista Brasileira de Entomologia 48(3): 415-420

Plant, Clean Thyself!

Marsh Cinquefoil, Comarum palustre

I have always found the flower of the Marsh Cinquefoil (Comarum palustre) most beguiling. The sepals, petals and stamens all seem to combine to form a purplish-star that frames the black-spiked carpels. As its common name suggests, it is found in a variety of wetlands like fens, moors, bogs, wet heathlands and, or course, marshes (1). It is common in such habitats, but the their destruction means that it is becoming far less widespread in Ireland than it once was (2).

Marsh Cinquefoil, Comarum palustre

Growing in such wet, muddy conditions, C. palustre has to deal with the possibility of reduced photosynthetic activity due to dirt and debris from the surrounding waters getting on its leaves. And deal with it it does, in a most effective way. The leaves of C. palustre have a convex relief and are covered with ribbon shaped epicutlicular wax crystals. The roughness caused by these ribbon shapes and the hydrophobic properties of the wax gives the plant an excellent water repellency. Additionally, any particulate matter landing on the leaves will in turn be carried away with water droplets making them anti-adhesive with respect to such contamination. Of course such self cleaning ability is not purely the preserve of C. palustre. A great number of plants exbit such a capacity, many of which originate from habitats with conditions similar to the marshy home of C. plaustre. Probably the most famously in the Lotus blossom (Nelumbo spp.) which has lent the name “the Lotus effect” to the phenomenon.

References:

1. Phillips, 1977. Wild Flowers of Britain p. 106
2. O'Sullivan, 2007. Proceedings of the Royal Irish Academy 107 pp. 147-203
3. Neinhuis and Barthlott, 1997. Annals of Botany 79 pp. 667-677

Return of the Lily Beetle

Red Lily Beetle, Liloceris lilii

A little later than last year, but the Red Lily Beetle (Liloceris lilii) has made an unwelcome return to the suburban garden in Cork city. Their vibrant red colour makes these beetles easy to see and therefore easy to pick off any lily (or fritillary) plants, but failure to control them will result in decimation of any host plants in a garden. So far, 6 individuals have been seen, far less than the near-infestation last year.

Tough Little Creeper

Yellow Pimpernel, Lysimachia nemorum

Creeping amongst hedgebanks and shady woodlands, the Yellow Pimpernel (also Wood Loosestrife, Lysimachia nemorum) is putting forth its xanthous, star shaped flowers. These are born on slender stalks, with the whole plant having a delicate appearance. This belies the tenacity of the plant, however. In areas where the soil is subjected to compaction, where other species will not survive, L. nemorum will be unaffected (1). Indeed in areas where heathlands have been replaced by woodland, L. nemorum is one of the few plants that will remain (2). Even the plant featured above was growing plentifully in rough limestone chips along a forest path.

Yellow Pimpernel, Lysimachia nemorum

References:

1. Godefroid and Koedam, 2004. Biological Conservation 119 pp. 207–217
2. Gardiner and Vaughan, 2008. Conservation Evidence 5 pp. 95-100

Nomadic, Parasitic, Enigmatic and Endangered

Goode's Nomad Bee, Nomada goodeniana

Bees should be busy. Busy and industrious. Honey bees are often used as an example of how a society should operate, self sacrifice for the greater good and all that. And bumble bees are seen as grouchy and clumsy, visiting flowers as noisily as they like, hardworking to the last to provide for their larvae. Yet of the 102 bee species in Ireland, 80 of them are solitary bees (1) who do not adhere to this busy stereotype at all. Males and females mate, lay eggs in a nest and die off with the coming winter. The resultant offspring emerge in the spring to fend for themselves. Many solitary bees don't even look like the common idea of a bee and resemble more a wasp. This is certainly the case for pretty Goode's Nomad Bee (Nomada goodeniana) with its bold yellow and black striped abdomen. Unlike pollen gathering bees, N. goodeniana lacks hairs on its body, another things it has in common with smooth bodied wasps. Nomad bees like N. goodeniana lay their eggs in the nests of other bees (2). The hatching grubs will feed on the larvae of the hosts, which has caused them to be also called cuckoo bees. Unfortunately N. goodeniana is an endangered species in Ireland (1), a situation which is exacerbated by the lack of information on the bee. More research into the habitat requirements and host-parasite ecology of N. goodeniana in Ireland to put in place policies to help this species (3).

Goode's Nomad Bee, Nomada goodeniana

References:

1. Fitzpatrick et al., 2006. Regional Red List of Irish Bees
2. Chinery, 2004. Collins Gen Insects p. 242
3. Fitzpatrick et al., 2007. Conservation Biology 21 pp. 1324-1332