MONOPIS CROCICAPITELLA (CLEMENS, 1859) (LEP.: TINEIDAE): CASE-BEARING LARVAE in ENGLAND FOUND FEEDING on BAT DROPPINGS Abstract
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Ent Rec 130(5).qxp_Layout 1 14/10/2018 11:02 Page 233 Entomologist’s Rec. J. Var. 130 (2018) 233 MONOPIS CROCICAPITELLA (CLEMENS, 1859) (LEP.: TINEIDAE): CASE-BEARING LARVAE IN ENGLAND FOUND FEEDING ON BAT DROPPINGS R. J. H ECKFORD ¹ AND S. D. B EAVAN ² ¹ Department of Life Sciences, Division of Insects, Natural History Museum, Cromwell Road, London SW7 5BD (Correspondence address: 67 Newnham Road, Plympton, Plymouth, Devon PL7 4AW) ² The Hayes, Zeal Monachorum, Devon EX17 6DF Abstract An account is given, including a larval description, of Monopis crocicapitella (Clemens, 1859) being reared from case-bearing larvae found feeding on bat droppings in Devon, England. Although there have been three notes in the British literature recording the larva as a case-bearer, these appear to have been overlooked in subsequent publications. There has been no prior report of the larva feeding on bat droppings in the British Isles, nor any larval description based on British observations. We consider records made both within and outside the British Isles. Key words : Lepidoptera, Tineidae, Monopis crocicapitella , larval case, larva, description, bat droppings. Introduction On 11 September 2017 Dr M. L. Luff made one of his frequent visits to Dartington Hall Estate, Devon, England, for the purpose of studying Coleoptera. During the course of this, and in the company of Mr C. N. Wills, Site Bat Warden for the Devon Bat Group, he collected a quantity of bat droppings that had been produced by Lesser Horseshoe Bat Rhinolophus hipposideros (Bechstein, 1800) (Chiroptera), in the hope that they might harbour beetles, either adults or larvae. Unfortunately they did not but he noticed a number of larval cases which he thought might be of interest and the following month passed these to us together with the bat droppings. Later that month moths began to emerge and proved to be Monopis crocicapitella (Clemens, 1859). This was quite a surprise for two reasons. One was because we were unaware that the larva made a case and the other was because we did not know that it fed on bat droppings. Pelham-Clinton (1985: 189), in a comprehensive review of British Tineidae in The Moths and Butterflies of Great Britain and Ireland 2, states that the larva is apparently undescribed, although it had been reported to feed on a variety of materials which are listed but bat droppings are not mentioned. Moreover, later in that volume Pelham-Clinton (1985: 195) comments that the larvae of most species in the genus Tinea Linnaeus, 1758, feed from a portable case, whereas there is no suggestion in his account of the genus Monopis Hübner, [1825], that the larva of any species in that genus does so. Ent Rec 130(5).qxp_Layout 1 14/10/2018 11:02 Page 234 234 Entomologist’s Rec. J. Var. 130 (2018) In fact Bignell (1878) had recorded that the larva of Monopis crocicapitella was a case-bearer, although his note is entitled ‘Food of Tinea ferruginella ’; Tinea ferruginella is now Monopis obviella ([Denis & Schiffermüller], 1775). In 1878 Monopis crocicapitella had not been recognised as a British species, no doubt because the adult looks similar to M. obviella . M. crocicapitella was tentatively added to the British list by Richardson (1893) who described it as a new species under the name Blabophanes heringi . Walsingham (1907: 728) synonymized this with Monopis crocicapitella and subsequently Bankes (1912) stated that N. M. Richardson had ascertained that Bignell’s material was in fact Monopis crocicapitella . Bignell did not describe either the larva or the case and as far as we are aware the first description of both was provided by Căpuşe & Georgescu (1963) in a Romanian journal. There are, however, other publications, both in Britain and elsewhere, which refer to the larva being a case-bearer. Some also either state that the larva feeds on bat droppings or associate the species with bats in caves. We are not aware, however, of any larval description or records of the larva feeding on bat droppings based on British observations. Therefore later in this paper we describe, and illustrate, the larva and its case but first we review certain published records of the biology made in the British Isles and abroad. Observations on the larva made in the British Isles Bignell (1878) was apparently not only the first in the British Isles to rear the species, but possibly the first person anywhere to do this. Although he gives no larval description, importantly he refers to the fact that the larva is a case-bearer. In August 1876 he gathered a quantity of Wormwood Artemisia absinthium L., locality not stated, in order to obtain certain Macrolepidoptera larvae. He placed this in a linen bag which was hung up, presumably outside. On 21 February 1877 he searched the contents and about half a dozen ‘ Tinea ferruginella ’ flew out which he captured. As recorded in the Introduction to this paper, Bankes (1912) states that subsequently these were identified as Monopis crocicapitella. Bignell comments that ‘I then collected all the cases I could find; some were in pupa, others in the larva-state and feeding.’ Bignell sent some cases to C. G. Barrett and records that his reply was that ‘it was a welcome and startling sight to find it cleverly clearing out the seeds from every flower-head of the dry wormwood.’ Bignell concluded that the problem of what the larva eats had now been solved, as it was a seed-feeder, but wondered whether it was confined to species of Artemisia or whether it also fed on other ‘composite plants’ (namely species in the Compositae, now usually given as the Asteraceae), because the moth was known to occur where Artemisia absinthium did not. Meyrick ([1928]: 823) gives ‘Larva on seeds, woollen refuse, also probably on dried excrement, etc.’ It is likely that some of this information came from Ent Rec 130(5).qxp_Layout 1 14/10/2018 11:02 Page 235 Entomologist’s Rec. J. Var. 130 (2018) 235 sources outside the British Isles. He makes no mention of the larva inhabiting a case unlike, for example, his account of Tinea pellionella Linnaeus, 1758, at page 830. Ford (1949: 180) states, ‘On seeds, woollen refuse, refuse of birds’ nests.’ Like Meyrick ( loc. cit .) he makes no mention of the larva inhabiting a case but does so in his account of Tinea pellionella at page 184. Then Woodroffe & Southgate (1952) record the larva as being a case-bearer. This was as a result of the discovery of a considerable infestation in a block of flats at Harrow, Middlesex. A hot-water pipe was lagged along much of its length with asbestos, but beneath two flats the lagging was of felt which was covered with case-bearing larvae and in one flat the larvae were attacking the underfelt of the hall carpet. Rather surprisingly, Woodroffe & Southgate do not describe either the larva or case. Obviously unaware of Bignell’s observations, they comment that ‘the literature appears to contain no reference to the fact that the larvae are case-bearers, resembling larvae of Tinea pellionella L.’ The following year Woodroffe (1953: 745) states that ‘The larvae are case- bearers, and were found several times in some numbers in pigeons’ nests.’ In the previous sentence, however, he refers to his note jointly published with Southgate and cited in the above paragraph, and so his comment that the larvae are case-bearers does not necessarily mean that those found in pigeons’ nests were also case-bearers. Unfortunately Robinson (1979), in a detailed account of what is ‘a revision the case-making (or ‘case-bearing’) clothes-moths of the Tinea pellionella group’, was obviously unaware of the notes published by Bignell, Woodroffe & Southgate and Woodroffe because at page 58 he comments that: ‘Only a few other species of Tineidae with case-making larvae are occasionally found associated with woollen or feather products – these are free-living Monopis species and their larval ‘cases’ are not true cases but immovable sections of tunnel, the walls of which consist predominantly of frass and food particles.’ In the following year, however, Robinson (1980: 107) states that ‘Rather surprisingly, the only description of the larva of this common and widespread species seems to be that by Căpuşe & Georgescu (1963b: figs. 1–7). The larva makes a flattened, slightly ovate, fine-grained case.’ The reference to Căpuşe & Georgescu (1963b) is to their paper cited both in the Introduction to this account and later. Pelham-Clinton (1985: 189), a meticulous observer, states that the larva is apparently undescribed, and with no suggestion that the larva is a case-bearer. He records that the larva is ‘reported as feeding on a variety of materials including flour, oats, other seeds and woollen refuse’ and comments that moths are ‘sometimes common in poultry-houses and have been bred from pigeons’ Ent Rec 130(5).qxp_Layout 1 14/10/2018 11:03 Page 236 236 Entomologist’s Rec. J. Var. 130 (2018) nests.’ Although he was correct in commenting that the larva was apparently undescribed as far as the British literature was concerned, nevertheless, as already mentioned, Căpuşe & Georgescu (1963) had already described the larva, and larval case and pupa, which we consider in the next section. Later Pelham-Clinton (1988: 46) gives the larva as ‘In birds’ nests, on stored products of vegetable origin including flour, corn, felt and textiles, or on a variety of refuse of plant or animal origin.’ Again there is no mention that the larva is a case-bearer, in contrast to the comment on the following page that, with the exception of Tinea pallescentella Stainton, 1851, so far as is known all the species in the genus Tinea construct portable silken cases.