62 THE entomologist's record. 



climate warmor than several places on the south coast. Meteorologists 

 try, I think unsuccessfully, to explain this away. Entomologists find 

 sundry insects here, such as L. trifoUi, that they think ought not to go 

 so far north. B. (/alii always flourishes here when it visits us, and 

 so forth. It is certain, therefore, that in some way the warm Atlantic 

 waters are deflected along this coast and raise its winter temperature, 

 to he measured by the meteorologists and to be found in its results on 

 insect life by the entomologist. As regards the Wallasey peninsula, 

 there can be no doubt that its temperature is much raised, at least 

 along its sea margins, by the constant renewal of the sea water bathing 

 its shores, 'i.e., by the large volumes of water constantly running in 

 and out of the estuaries of the Dee and ]\Iersey with the tides. A 

 similar consideration is, no doubt, applicable to the estuary of the 

 Thames, where the extensive fiats, nearly at sea level, must benefit 

 largely by the constant renewal by the tides of their adjacent water. 

 How far the Thames estuary gets first choice of the warm water coming 

 through the Dover Strait, I do not know. 



Phnrodcsma siiiaraijilaria is very localised in England in the Thames 

 estuary. It certainly obtains considerable climatic advantages here 

 compared with its Continental habitats, as it is a hibernating larva, 

 and so probably gets the advantage of a late autumn and earlier 

 spring than it would inland, I am not aware of the natural condition 

 either of the larva or its food-plant in midwinter with us. This 

 climatic advantage cannot, however, be the whole matter, or it Avould 

 be found on our south and west coasts also, and even inland, as it has 

 a considerable range of food-plants amongst ('u)upositae ; what the further 

 element is I cannot suggest, unless it has something to do with the 

 larva being restricted to one food-plant with us. Its continental range 

 is hardly north of our south coast mean isotherm. 



Two other species, Kufiithcvia innutata and K. e.itensaria, both 

 attached to Artciiiisio, and both found on our east coasts f]']. cxtcnsan'a 

 only there), must also have some other reason than climate for affect- 

 ing the coast. They hibernate as pupcns, which makes it less likely 

 that climate is at all effectual. I have an idea that Artemisia viaritiitta, 

 though occurring on all our coasts, is much more abundant on the east 

 coast than elsewhere ; if this be so this would no doubt assist in ex- 

 plaining the localising of these species and of P. smarat/daria. 



MalacosoNia castrensis, another Thames estuary species, is very 

 puzzling. I do not think temperature is an element at all in the dis- 

 tribution of this insect, its northern (as well as southern) and mountain 

 distribution on the continent make this very unlikely, nor does there 

 seem to be any restriction involved in its food-plant. There is some 

 indication of a partiality to occasionally flooded areas, which would 

 no doubt be most satisfactorily met in flats of the Thames and other 

 east coast estuaries. Unless this, and the destruction of inland 

 stations by cultivation, are the effective agents in determining the dis- 

 tribution of the species, I am unable to say what they ar(>. 



A'v/N.s/V^ zonaria is with us a coast insect, but I see no climatic reason 

 why it should be so, nor do its food-plants cause any such restriction. 

 Its continental distribution is not extensive, and suggests that it could 

 not go very far north in these islands. That it requires some of the 

 assistance our coast climate gives, is suggested by its occurring in 

 England in the specially warm inlet off the Cheshire coast, and in 



