UK Butterflies
Building a Community of Responsible Butterfly Enthusiasts in Britain & Ireland
Building a Community of Responsible Butterfly Enthusiasts in Britain & Ireland
Wingspan
♂ 24 - 27 mm, ♀ 25 - 28 mm
Checklist Number
57.007
The Lulworth Skipper was first discovered in 1832 on a stretch of coast around the village of Lulworth in Dorset. This species forms discrete colonies, some of which can be very large, containing many thousands of individuals. The female is quite recognisable from the pale orange crescent on her forewings, which is either lacking or very feint in the male. The male is darker in colour, and has a sex brand on each forewing made up of a very fine line of scent scales. As its name suggests, this distribution of this species is centred around Lulworth in Dorset, between Weymouth and the Isle of Purbeck. It is absent from the Channel Islands. In Britain, this species is at the northern limit of its range, and is rarely found more than 5 miles from the coast. However, this is not a maritime species, except in Britain.
| Family: | Hesperiidae | Latreille, 1809 |
| Subfamily: | Hesperiinae | Latreille, 1809 |
| Tribe: | ||
| Genus: | Thymelicus | Hübner, [1819] |
| Subgenus: | ||
| Species: | acteon | (Rottemburg, 1775) |
Description to be completed.
The distribution data (2000-2009) has been made available through the generosity of Butterfly Conservation and any subspecies distribution is taken from Riley (2007). Click here to see the distribution of this species together with site information overlaid.
Although the status of this butterfly is relatively stable in the British Isles, it is considered a priority species for conservation efforts due to the losses being seen in continental Europe.
The table below shows the occurrence (distribution) and abundance (population) trends, using information from The State of the UK's Butterflies 2015 (Fox, 2015). Any UK BAP status is taken from the UK Biodiversity Action Plan (UK BAP) (2007 review).
1976-2014 (%) | 1976-2014 (%) | 2005-2014 (%) | 2005-2014 (%) | Click here to access the Biodiversity Action Plan (BAP). |  -78 | -76 |  +23 | +39 |
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There is one generation each year with an extremely protracted flight period that extends from the end of May through to early September and is very site-dependent. Earliest sightings are typically from the Lulworth Cove colony. This is a species that has responded dramatically to climate change, with many books showing flight periods that no longer apply.
Like many other skippers, the rapid flight of this butterfly makes it difficult to track when darting between flowers, favourite nectar sources including Thistles and Marjoram. Sunny conditions are needed to see this butterfly, since the species is inactive in dull weather. When egg-laying, the female will alight on a stem of flowering Tor-grass, and then move backwards down the stem, probing the sheath as she moves. There is a preference for taller plants. When a suitable opening in the furled sheath is found, she will lay up to 15 eggs inside, with 5 or 6 being typical.
Adults feed primarily on Common Bird's-foot-trefoil (Lotus corniculatus), Greater Knapweed (Centaurea scabiosa), thistles (Carduus spp. and Cirsium spp.) and Wild Marjoram (Origanum vulgare).
The egg stage lasts approximately 3 weeks.
"Eggs laid August 8th, 1892, hatched August 31st, the egg state lasting twenty-three days. Several eggs laid in captivity during the first week of August, 1912, all deposited in the sheaths of the flower-stems of grasses, similar to those of thaumas [sylvestris, Small Skipper], but some not so well concealed, being laid in rather more opened sheaths, and a few laid on the terminal sheath-blade partly rolled up. As many as fifteen were laid in one sheath. The egg measures 1.6 mm. long, of an elongated oval shape, being half as long again as broad; one side is usually concave; it is considerably compressed, with a central dorsal depression; the base is concave. The surface is finely reticulated with an irregular network pattern, giving the egg a slight granular appearance. The reticulations are more pronounced in some specimens than in others, also some have the side more concave. When first laid the egg is pearly-white, with a faint yellowish tinge, and semi-opaque. It gradually becomes deeper in colour and when a week old it is light straw-yellow; when a fortnight old it is opaque creamy-buff, with a dark grey spot in the centre, which deepens into dark purplish-grey on the following day, and the rest of the egg a pale cream colour. When twenty days old the larva plainly shows through the shell; it then remains unchanged until hatching on the twenty-third day, but during the last three days the larva frequently changes its position, sometimes the head appears in the centre, sometimes at one end, and again at the other." - Frohawk (1924)
On hatching, the larva immediately spins a cocoon on the site of the remains of the eggshell, within the grass sheath, in which it overwinters. In April, the larva emerges from the sheath and moves to a grass blade, where it forms a protective tube by spinning the edges of the leaf blade together. The larva feeds at night, eating the leaf both above and below the tube. The larva moves to new leaf blades, forming new tubes, as needed. There are 5 instars in total.
The primary larval foodplant is Tor-grass (Brachypodium rupestre).
"Directly after emergence the larva measures 2.12 mm. long. It is stoutest at the middle, gradually tapering anteriorly and more so posteriorly. The head is intensely black, with a granulated surface, and beset with a few whitish hairs. On the first segment is a transverse olive-brown, chitinous, dorsal band with a granular surface. The segments have five sub-divisions, the first on each segment being the widest. On each side above the spiracles are three rows of tiny white club-shaped hairs; the dorsal series is composed of one on the first sub-division of each segment, the second series is sub-dorsal, one on the third division, and the third is placed just above the spiracle, and below the spiracle are two slender pointed hairs and others on the claspers. The hairs on the anal segment are much longer and slightly curved. The spiracles are very inconspicuous. The entire colouring of the body, legs and claspers is bright straw-yellow, with a granular surface. Although the young larva of acteon is very similar in all respects to that of thaumas [sylvestris, Small Skipper], there is a marked difference in the colour of the head. That of the latter is pale olive-ochreous, while in action it is of an intense black, and the granulations are smaller. The colour of the body in action is a richer yellow. Almost at once after hatching, without attempting to feed, the larvae spin themselves up in little neat, compact, pearl-coloured cocoons; usually the ends are spun together and sometimes overlapping each other, and often spun over the empty egg-shells, as the larvae do not move from where they hatch; in these dense tough coverings within the rolled-up sheath, the larvae are perfectly protected for their long winter's sleep, as they undergo complete hibernation for a period of eight months. About the third week of April the larva awakens from hibernation and eats its way out of the tubular grass sheath, making a small hole through the side; when a sheath contains a number of larvae the exit holes resemble numerous pin pricks. Directly after leaving the sheath the little larva is very active and rapidly crawls about in search of a young tender blade of grass, which it soon starts to feed upon, eating little notches out of the edge. It then spins two or three strands of silk from edge to edge of the blade, which draws them partly together, and increases the number daily until as many as nine or ten cords are spun at almost an equal distance apart, which brings the edges nearer together; in this shelter the larva rests after each meal off the edge of the blade, a short distance above the abode. After hibernation it is of a much paler colour than just after hatching from the egg, being of a pale straw-yellow. The head is smoother than that of thaumas [sylvestris, Small Skipper], having a more shining surface. Before first moult it measures 4 mm. long; the colour is a very pale greenish-yellow or pale primrose-yellow." - Frohawk (1924)
"After the first moult the head is olive-black, granular, and beset with tiny whitish hairs. The colouring of the head in this stage is very distinct from that of thaumas [sylvestris, Small Skipper], which is ochreous in its second stage. The body of acteon is a pale greenish-yellow, with a medio-dorsal darker green line. It is sprinkled with minute black stud-like processes and minute white hairs along the lateral region, which are considerably longer round the anal segment. There is no dorsal collar on the first segment." - Frohawk (1924)
"After the second moult (shortly before third) it measures 7.5 mm. long. The head is buff with a very slight greenish tinge, and a faint whitish stripe on each lobe of the crown continuous with the sub-dorsal whitish body stripes; the surface is finely granulated, and sprinkled with minute black points over the crown, and white bristles in front. The body is rather tapering at both ends, of a pale ochreous-green, longitudinally striped as in the subsequent stages, but less defined. The whole surface is sprinkled with minute black studs, each bearing a tiny, shining black knob with a shank set on a little circular disc; these become more elongated on the anterior and posterior segments in the form of clubs, and the anal flap is fringed with fine white projecting hairs." - Frohawk (1924)
"After the third moult it is 12.7 mm. long. The stripes on the head are pale yellowish, otherwise it is similar to previous stage in all respects, but the entire colouring and markings are more clearly defined. The ground colour is a pale glaucous-green with a darker green medio-dorsal stripe, intersected by a pale central line and bordered on either side by a pale yellowish line, and a similar sub-dorsal line and a broader whitish lateral stripe." - Frohawk (1924)
"After fourth moult, fully grown, it measures from 22 mm. to 25 mm. The head is somewhat oblong, with a granular surface, and sprinkled with minute white hairs. The eye spots are black and mouth parts brown; the clypeus is outlined with white; a whitish streak extends over two-thirds of each lobe of the crown. The body is attenuated at each end. The first segment is very small; each succeeding segment increases in size to the middle and then decreases posteriorly, the anal one terminating in a round projecting flap; the segments have seven sub-divisions. The ground colour varies from a pale yellowish-green to a glaucous or bluish-whitish-green; in all examples the dorsal surface is the palest; a darker bluish-green medio-dorsal longitudinal band runs the entire length of the body, which is intersected by a very fine central yellowish line, and bordered on either side by a yellowish-white stripe, a sub-dorsal finer line of the same yellowish-white colour. Along the lateral surface the ground colour increases in depth to the ventral surface. The whitish spiracles are situated on a faint, fine, yellowish line, below which is a broad and conspicuous lateral stripe; on each clasper is a crescentic whitish mark. The whole surface is studded with extremely minute white bristles, which have black wart-like bases over the thoracic segments. The legs are whitish and claspers green. Between the ninth-tenth and tenth-eleventh segments on the ventral surface are white waxy patches similar to those of other Hesperidae larvae. They mostly live in a tubular abode made of one or more blades of grass spun together. When they live in this way they feed below their retreat, eating the whole portion of the blade away for 25 mm. or more, excepting the midrib, and when that part of the tube in which they rest becomes too small, or rather too short, they crawl down the remaining rib and form a fresh dwelling. But in some cases the large larvae rested on the broad blades of grass (Brachypodium sylvaticum) in a straight position without further protection and fed at the apex of the blades. In captivity they readily feed on various grasses, Poa annua, Phleum pratense, Holcus mollis and Brachypodium sylvaticum. Like other Hesperidae larvae acteon is provided with an anal comb for the ejectment of the excreta. The comb consists of twenty or twenty-two teeth, otherwise it is similar in formation and functional character to that of sylvanus. On July 10th, 1912, a larva was watched through the act of pupation; from the first splitting of the larval skin down the centre of the thorax to the time the larval skin was actually cast was three and a half minutes. It shed the skin by a series of writhings, and it then immediately decurved the anal segment to enable the cremaster to reach over the crumpled-up skin; at the same instant it writhed and twisted in order to hook the cremaster to the silk pad. After resting a short time it writhed again, and repeated the writhings at intervals, after a short rest each time, until it was firmly secured." - Frohawk (1924)
The fully-grown larva forms a loose tent of grass blades, drawn together with silk at the base of the foodplant, within which it pupates. The pupa is secured by a silk girdle and the cremaster. The pupal stage lasts approximately 2 weeks.
"The pupa averages about 17 mm. long; it is very similar to that of thaumas [sylvestris, Small Skipper], but acteon has a much longer head horn, being about twice the length of thaumas [sylvestris, Small Skipper], and the thorax is less curved in acteon. In all other respects it is similar. It is slender and gradually tapering to the anal segment. Dorsal view: The head with a long frontal tapering horn, beset with a few minute bristles; the eyes large and prominent; the thorax is slightly swollen across the base of wings; otherwise the outline is even to the anal segment, which terminates in a long cremaster, provided with a bunch of whitish hooks—not orange as in thaumas [sylvestris, Small Skipper]. Lateral view: The head horn projecting straight in front, but slightly decurved. Head sloping to the thorax, which is gently curved and runs almost in a straight line with the abdomen, which is tapering; the cremaster is slightly decurved, flattened and concave ventrally; the tongue case reaches to the middle of the eighth abdominal segment and is free from the apex of the wings. The ventral outline is almost straight to the head, which is rounded to the base of the horn. Colouring: At first the thorax, head and wings are a brilliant translucent green, and the abdomen light yellow-green; it is striped longitudinally with white, similar in pattern to the larva. Gradually it becomes paler and of a whiter green over the head and wings, while the thorax remains a bright green, the abdomen remaining unchanged, but the whole colouring more opaque. On the eleventh day the development of the imago begins to show: the limbs, antenna and wings become opaque whitish; the head point and eyes pinkish; the latter gradually changing to a bright rose-pink, and finally through purple to blackish. The wings and limbs gradually turn deep amber colour, the thorax paler, and blending into the yellowish abdomen, which still shows the dorsal stripes; finally the whole pupa becomes dark, the wings dark olive-brown, the remainder a smoky black, the abdomen dull greenish-ochreous ventrally, the segmental divisions whitish and the antennae orange. It is attached by a cincture round the middle and by the cremastral hooks to a carpet of silk spun along the surface of the blades; generally several blades are spun together so that the pupa lies partly concealed between them; the dorsal stripes, which are retained until just before emergence, harmonize with the grass blades, rendering the pupa very inconspicuous." - Frohawk (1924)
The following links provide additional information on this butterfly.
