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

Forestry Management for Caddisfly Biodiversity

Philopotamus montanus

With around 8% of Ireland under commercial forests (1), correct management of these sites is essential to maintain biodiversity in a variety of habitats throughout the country. Most commercially forested sites are in uplands, where the nature of the soils make them unsuitable for dairy or beef production. Being in upland areas they will inevitably have streams near or often running through them. The vast majority of these commercial forests in Ireland are coniferous which have been shown to directly influence the ecology of forest streams through hydrological, chemical and energetic pathways (2), so the layout of the forests upon planting is very important.

Philopotamus montanus

An engaging little caddisfly that is often found associated with coniferous forest streams is Philopotamus montanus. The larvae live in fast moving streams, spinning long, tubular, bag-like nets on the undersides of rocks which they use to catch diatoms and detritus (3). The clumsy, slow flying adults rarely venture far from these streams and are on the wing from May to August (however the individuals pictured were photographed in April). However the occurrence of P. montanus in forest streams is very much dependent on its management. Specifically, it requires small rocky streams with hard margins (2). Therefore it is essential to take these needs into account when laying out commercial forests near streams if we are to keep these little brown and yellow winged wonders for the future.

Philopotamus montanus

References:

1. www.coilte.ie
2. Weatherley et al., 1993. Biological Conservation 63 171-176
3. Gibbons, 2010. Insects of Britain and Europe p. 143

Vomitous Mould

Fuligo septica

The Dog Vomit Fungus (Fuligo septica) is not a fungus, and is certainly not vomit, be it dog or other. It is a myxomycete, a type of slime mould that will feed on microbial communities on rotting vegetation. F. septica grows vegetatively as a mass of plasmodium which moves by amoeboid locomotion and feeding is achieved by phagocytosis (1). Historical references to F. septica as a fungus arose due to its fungus-like habit if producing fruiting bodies under unfavourable conditions. While these can be quite ornate in some species, F. septica produces a simple aethalium, a large, spore containing sack.

References:

1. Chapman et al., 1982. Experimental Mycology 6 195-199

A Puddle of Tadpoles

Rana temporaria tadpole

There is a forest, about 10 miles from Cork city. Its a commercially planted one, Sitka Spruce and Japanese Larch, with a border of Beech. The forest is bisected by a walkway, which acted as an access road when part of the forest was harvested some two years ago. The heavy machinery used in the harvest left depressions in the road which the recent rain has turned into dirty, shallow puddles – puddles that are home to a cloud of tadpoles.

A puddle of tadpoles

The puddles were at most 20 cm at their deepest parts, but the Common Frog (Rana temporaria) tadpoles were most visible at depths of 5 cm or less. It does seem odd that adult frogs would spawn in such shallow, temporary water source but not at all uncommon (as reported last year on this blog, for example) and can often lead to catastrophic losses (1). However the tadpoles are able to respond to this stress by speeding up their development, metamorphising faster when posed with the problem of pond (or in this case puddle) drying (1).

Rana temporaria tadpole

References:

1. Laurila and Kujasalo, 1999. Journal of Animal Ecology 68 pp. 1123–1132

A Bugle Call Against Colitis

Bugle, Fulgio septica

The wild Bugle (Ajuga reptans) is such a bewitching plant it has become a popular addition to many suburban herbaceous borders. Its cascade of violet-blue flowers are arranged in a glorious pyramid that normally stands proud at 20-30 cm, but can reach 50 cm in some places (1). Found in pastures and woodlands throughout Europe, it grows vegetatively using stolons and often forms dense aggregates of flowers (2).
Chemically, A. reptans is a terribly complex plant producing a spectrum of chemicals that act as insect anitfeedants (3) and producing anthocyanins which can be used as natural food dyes (4) to name but a couple. It even produces a compound that has been shown to reduce colitis in rats. While the aetologies of inflammatory bowel diseases such as colitis remain unclear, it is thought that they result from an uncontrolled immune response to normal gut flora (5). Administering a phenylpropanoid glucoside called teupolioside (5) produced by A. reptans to rats subjected to colitis reduced significantly the appearance of diarrhoea and the loss of body weight.

References:

1. Phillips, 1978. Wild Flowers of Britain p. 28
2. Dong et al., 2002. Flora 197 pp. 37–46
3. Bremner et al., 1998. Phytochemistry 47 pp. 1227-1232
4. Terahara et al., 2001. Phytochemistry 58 pp. 493–500
5. Di Paola et al., 2009. Biochemical Pharmacology 77 pp. 845– 857

Safe from the Harlequin

Cream Spot Ladybird, Calvia quatuordecimguttata

The threat to native Irish ladybird species from the invasive Harlequin Ladybird (Harmonia axyridis) has been outlined before in this blog, as has the presence of H. axyridis breeding sites in Ireland. Larvae of the Harlequin are voracious feeders and will readily consume the eggs of other coccinellids (1). However they will stop short when it comes to the eggs of the Cream Spot Ladybird (Calvia quatuordecimguttata), which are overwhelmingly rejected by Harlequin larvae when presented as a food source (2). The eggs are coated with a complex mixture of hydrocarbons, acid and alkenes that deter predation. Eggs treated with hexane to remove the coating immediately became more susceptible to attack.

Cream Spot Ladybird, Calvia quatuordecimguttata

Adult Cream Spots are quite different from other ladybird species in Ireland, having no black markings and orangish-brown elytra with 14 cream spots (3). They are found on a variety of plant species and are generalist feeders, feeding on both aphids and psyllids (4). However, their preferred food are pysllids and females feeding on these produced more than 4 times as many eggs than those feeding on aphids (5).

References:

1. Pell et al., 2008. BioControl 53 pp. 147-168
2. Ware et al., 2008. BioControl 53 pp. 189-200
3. McGavin, 2010. Pocket Nature Insects and Spiders p. 107
4. Hodeck et al., 2012. Ecology and Behaviour of the Ladybird Beetles (Coccinellidae) p. 154
5. Sem'yanov, 1980. Journal Entomologicheskoe Obozrenie 59 pp. 757-763

30,000 Year Old Campion

Red Campion, Silene dioica

Campions are plants of the genera Lychnis and Silene and produce some of the prettiest flowers in the Irish countryside, so much so that many, such as the Red Campion (Silene dioica) are very popular cultivated plants. Seven Campion species are recorded in Ireland, five of which are native (1). Of these, four are Silene species, but this low number belies the size of the genus. Some 700 species exist, mostly in the Northern Hemisphere (2).
 

Sea Campion, Silene maritima

Species of Silene produce between 5 and 100 seeds, which are reddish to gray or black in colour and reniform to globose in shape with the embryo peripheral (2). They are a source of food for many animals and it is for this reason that a number of seeds of the Silene species, Silene stenophylla, were found deep in the permafrost of Siberia. The seeds were found in the ancient burrows of a ground squirrel (Geomys, subgenus Urocitellus) that are now some 38 metres beneath the present day surface (3). Radiocarbon dating of the seeds puts them at 31,800 ± 300 years old, placing there origin back in the Late Pleistocene. The location of the seeds in the permafrost meant that hey were exposed to a constant, stable temperature of -7°C for millenia and this fact, along with surprisingly low levels of ground γ radiation damage for plant material of that age, meant that the seeds were excellently preserved: so well preserved in fact that whole fertile plants were regenerated from the placental tissue of the seed using tissue culture techniques (4). The revived 30,000 year old plants that grew were initially identical to their modern S. stenophylla forebearers, but as they grew they showed different, longer petals than the flowers blooming wild today. The Russian scientists who carried out this back-from-the-dead feat suggest that permafrost can act as a depository for an ancient gene pool (4).

References:

1. Phillips, 1978. Wild Flowers of Britain
2. Jürgens, 2004. Biochemical Systematics and Ecology 32 pp. 841–859
3. Başli et al., 2009. Anadolu University Journal of Science and Technology 10 pp. 161–167
4. Yashina et al., 2012. Proceedings of the National Academy of Sciences USA. doi:10.1073/pnas.1118386109

Rejection: Courtship Behaviour in the Orange Tip Butterfly

Male Orange Tip Butterfly, Anthocharis cardamines

With the flowering of the Cuckoo Flower (Cardamine pratensis), so one of its main grazers follows suit and take to flight. The larvae of the Orange Tip butterfly (Anthocharis cardamines) feed on a variety of brassicaceous plants, but have a distinct preference for C. pratensis and Garlic Mustard (Alliaria petiolata). Since these food plants have differing habitats –  hedgerows and tracks in arable woodland (C. pratensis) and wet pastures and woodlands (A. petiolata) – A. cardamines is a widespread butterfly, but occurs in low densities (1).

Female Orange Tip Butterfly, Anthocharis cardamines

Mating and courtship is pretty low-key for the Orange Tip, with females accepting a mate within seconds of courtship. However, one notable display is evident, that of the rejection dance of the female. Females who have already mated and want to shoo away the persistent males will flatten their wings against their perch and elevate their abdomen. This is followed by an opening of the genital valve, purportedly to release anti-aphrodisiac hormones to discourage the males (2). This behaviour was observed in the pair pictured, a female in flight that perched upon pursuit by a male and proceeded to display her abdomen on two separate occasions, after which the male left without mating.

Orange Tip Butterfly pair, Anthocharis cardamines. The female (left) is in the process of rejecting the male (right) by using the raised abdomen display.

Oddly, this very same rejection dance is also used by virgin females just prior to mating. It is thought that the differences between the two occasions is that virgin females release aphrodisiac hormones from the genital opening to attract the males (2).

Female Orange Tip Butterfly, Anthocharis cardamines, in raised abdomen display

Females will lay their eggs at the base of the flowers of the host plants, after which the larvae will feed on the flowers. Only one eggs is deposited per flower as cannibalism is frequent among larvae (1).

References:

1. Dempster, 1997. Oecologia 111 pp. 549-556
2. Wiklund and Forsberg, 1986. Animal Behaviour pp. 328-332