SCIENCE-GOSSIP. 



199 



DACTYLOPIUS OR MEALY-BUGS. 



With a New Species. 

 By T. D. a. Cockerell. 



'T^HE interesting creatures known to horticul- 

 turists as mealy-bugs, a genus of Coccidas, 

 ha%'e not received the study they deserve in 

 Europe. While Mr. Maskell has been carefully 

 describing the numerous species found in Australia 

 and New Zealand, those of Europe, left in a rather 

 unsatisfactory condition by Signoret, have been let 

 alone until quite recently. As a result of this 

 neglect, j\lr. Newstead, of the Grosvenor Museum, 

 Chester, has been able to describe new species 

 from England, Ireland and Wales, and no doubt 

 there are others to be found. The first of these, 

 Dadylopius walkeri, Newst., was made known in 

 June, 1891, from specimens found on Agrostis 

 vulgaris, at Manley, Cheshire. The second, D. 

 hibernicus, Newst., published in July, 

 1895, ^^s found by Miss Tomlin, on 

 grass at Ballintoy, Co. Antrim, Ire- 

 land. The third, D. radicum, Newst., 

 published October, 1895, is from Puffin 

 Island, Anglesea, on Arineria vulgaris. 

 All the descriptions, with figures, will 

 be found in the " Entomologist's 

 Monthly Magazine " for the dates men- 

 tioned. If these discoveries are not 

 enough to stimulate the British micro- 

 scopists to activity, it may be added 

 that recent researches have brought to 

 light new British Coccidae of several 

 genera other than Dadylopius. Only the other 

 day I received from Mr. E. Ernest Green speci- 

 mens of Rhizococcus devoniensis, Green MS., n.sp., 

 found at Budleigh Salterton, Devon, on Erica 

 dnerea. 



Not only may native species be studied in 

 England, but our hothouses are very frequently the 

 abode of exotic coccids. There are ten species of 

 Dadylopius which were described from specimens 

 found in Europe on hothouse and garden plants, 

 their native habitat being still unknown or un- 

 certain. So during the winter the entomologist 

 who will turn his attention to these little-known 

 creatures will not fail to find material for study in 

 hothouses, with every prospect of interesting dis- 

 coveries before him. 



Unfortunately there is no work existing which 

 will enable the student to readily determine his 

 coccids. For the English reader, the most con- 

 venient guide to the subject is Maskell's little book 

 on the scale insects of New Zealand, published by 

 the New Zealand Government, in 1887. A check- 

 list of the species of Coccidae known up to the 

 present time (about 800) may be obtained from 



January, 1S97.— No. 32, Vol. 3. 



Dactylopius lich- 



tensioides 



in sac on twig of 



Artemisia. 



Professor S. A. Forbes, State Laboratory of Natural 

 History, Urbana, Illinois, U.S.A. However, the 

 present unsatisfactory condition of things is not 

 to last very long. Mr. R. Newstead has in pre- 

 paration a fully illustrated monograph of British 

 Coccidae, which, I believe, is to be shortly pub- 

 lished by the Ray Society. It will include not 

 only the native species, but those found in hot- 

 houses, and will doubtless contain an immense 

 amount of new and valuable information. 



The typical female Dadylopius is a small elongate 

 oval creature of a yellowish or brownish colour, 

 more or less besprinkled with a mealy secretion, 

 possessing six legs and antennas of eight joints, of 

 which the last is conspicuously longer than those 

 immediately before it. The body ter- 

 minates in the two rounded lobes, which 

 are not produced or cylindrical ; from 

 them arise setae, which are sometimes 

 covered with the mealy secretion, so 

 that the insect has two white tails. The 

 sides of the body often show a lot of 

 little mealy tufts. All these characters 

 should be observed with a lens in the 

 living insect, which must then be boiled 

 in a solution of caustic soda or potash 

 until it is clear, and examined by 

 transmitted light under the compound 

 microscope for the minute details of 

 the legs, antennae, etc. 



The genus Dadylopius, however, has been made 

 to contain a number of curious forms differing very 

 materially from the above description. This year, 

 Maskell has separated three such under a new 

 generic name, Laclinodius, giving excellent reasons 

 for so doing. Doubtless, other genera will have to 

 be erected, but the time is, perhaps, hardly ripe for 

 a new generic classification of the Dactylopiine 

 series. 



One of the aberrant forms reached me a few 

 weeks ago, and when I saw it I thought it was a 

 new Lidiicnsia, belonging to a group entirely 

 different from the mealy-bugs. As it has not 

 been published, I will give the description of it 

 here. 



Dactylopius lichtexsioides, n.sp. 



Female, purple-black, slightly mealy, covered by 

 a firm globular white sac, about 3 mm. long and 

 high, like a Lidiiensia ; general form of insect, oval ; 

 when boiled in caustic soda, it stains the liquid 

 dark purple-black. Legs and antennje very minute, 

 pale brownish. Antennae moderately slender, of 

 about equal width from second to seventh joint ; 



