258 [April, 



It is quite possible that many insects are capable of producing sounds, but 

 these sounds may be inaudible to some of us ; for, as Dr. Carpenter observes : 

 " There is a different limit to the acuteness of the sound of -which the ear can 

 naturally take cognizance in different persons ; if the sound be so acute (high in 

 pitch) that the membrana tympani will not vibrate in unison with it, the individual 

 will not hear it, although it may be loud ; and it has been noticed that some persons 

 cannot hear the very shrill tones produced by particular insects, or even birds, which 

 are distinctly audible to others " (Ani. Phys.). — C. Or. Ham, 14, Granville Street, 

 Dover : March 6th, 1889. 



Note on Eupithecia extensaria. — Our fortunate discovery, in 1887, of ISupithecia 

 extensaria on this coast was duly followed in September by the discovery of its larva 

 feeding, as we expected, upon Artemisia maritima. It is a pretty larva of a rather 

 bright green with whitish longitudinal lines, the subdorsal and spiracular lines being 

 broad, and one along the ventral area narrow. The spiracular line is also more or 

 less edged below with pinkish-brown. Head green, with pinkish-brown mouth, legs 

 also pinkish-brown, claspers green, swollen and glossy. The entire larva is a 

 combined plan of mimicry— its body is striped precisely like the curiously grooved 

 sprays and leaf-stalks of the Artemisia, which exhibit, alternately, green skin and 

 white down, the pinkish-brown mouth and feet, drawn together when the larva is at 

 rest, exactly resemble the opening buds of the plant, and the two pairs of tumid 

 claspers at the hinder extremity resemble in an extraordinary degree the thickened, 

 rounded segments of the leaves. This last-named resemblance seems, at first sight, 

 unnecessary, but its value is demonstrated by the discovery that this larva has & 

 habit — which I have never observed in any other species — of standing, apparently, 

 upon its head, that is to say, laying hold with its thoracic feet and extending its body 

 stiffly so that its hinder extremity is in the air. This, however, is only an occasional 

 practice, and during the day time it generally remains close to the stem, twisting 

 itself among the leaves and blossoms, but, at night, feeding voraciously on both. When 

 full-fed it descends to the ground, where it makes a tough cocoon, and changes to a 

 pretty stumpy pupa of a chestnut-brown, with bright green wing cases. 



The moths emerged in June and July, almost every larva pi'oducing an imago. 

 Not a single parasite occurred among them. 



This species seems to be gregarious or excessively local in its habits, frequenting 

 sheltered clumps of the food-plant, but not extending its range very far, although 

 the Artemisia is plentiful on the coast. This excessive localism may be habitual 

 with the species, or it may be an indication that it is quite a recent immigrant to our 

 coasts, and this last view I am inclined to favour, partly from the present immunity 

 of the species from parasites, but still more from the circumstance that so acute and 

 energetic a worker as Mr. Atmore had not previously observed it. He and I think 

 it impossible that he should have so long overlooked it. I may add that from this 

 gregariousness the species might probably be easily exterminated. We do not propose 

 to effect this, and I think that we shall have the sympathy of all real Entomologists 

 in our resolve not to give any one else facilities for doing so. We are making the 

 species pretty extensively known, for this is one of our handsomest "Pugs." Larvae 

 were again secured last September, by which our friends will probably benefit by 

 and by. — Chas. G. Barrett, King's Lynn, Norfolk : March 9th, 1889. 



