THE ENTOMOLOGIST. 167 
May there was not an Aphis to be seen on a mostly-shaded 
row of elder-shoots by a pond. At the end of this week there 
were many hundreds of thousands, and the usual attendants 
on clusters of Aphides were not wanting—such as the 
Aphidius watching them close by, the Aphelinus skipping on 
them, the ant running over them, the ladybird nibbling them, 
and various Muscide feeding on their honey. Few kinds of 
Aphis multiply so quickly as the elder Aphis, which is a 
remarkable instance of the shortness of time in which life is 
divided and individualised as organisms by means of the 
abundance of elder sap. The lime Aphis is one of the 
slowest in increasing: it was full grown in April this year, 
but was not more numerous on the same leaves at the end of 
amonth. At the end of May little specks of honey may be 
seen on both sides of a lime-leaf, the surface of the leaf being 
often reversed by a slight wind. These specks are almost 
always few and irregular, notwithstanding the abundance of 
upper leaves, and quite resemble the specks, which are much 
more numerous, on the sycamore. A sycamore-leaf may be 
seen with one half quite covered with honey, of which 
substance there is no trace on the other half, the first half 
being just under a colony of Aphides on a leaf above; and at 
the end of May I saw just the same appearance on a lime-leaf, 
half of which was under another leaf, on whose under side 
there was an unusually great number of the lime Aphis. 
I have observed nearly all the species of Aphides that have 
been recorded as British, and in all cases they emit honey, 
and in every instance there has been no honey without them. 
—Francis Walker. 
(The reader is referred to a paper on this subject, reprinted 
(Entom. vi. 463) from the ‘Gardeners Chronicle.’ Mr. 
Walker’s note appears to have reference to this note, but he 
does not mention it.—Hdward Newman. | 
Is Heat the Chief Agent in Insect Development 2—We 
naturally answer in the affirmative, and indeed reasonably 
so, since much or little experience all points to the same 
conclusion. A warm spring induces early developments, and 
a hot summer causes a second brood of species, which in 
ordinary seasons make but one appearance; to these trite 
assertions every reader of the ‘ Entomologist’ can bear greater 
or less testimony. And although we sometimes read of the 
