Maskell. — On the " Honeydew " of Coccid89. 41 



Aet. II. — On the " Honeydeiv" of Coccidas, and the Fungus 

 accompanyinrj these Insects. 



By W. M. Maskell, F.E.M.S. 

 [Read before the Wellington Philosophical Society, 25th August, 1886.] 



Plate I. 



It has long been known that, in common with the Aphididce, 

 PsyUidcE, and other Ehynchota, the Coccids secrete a glutinous 

 fluid, which has received the name of "honeydew." In 

 the other families mentioned, this fluid serves to attract 

 and to feed various insects : thus, for example, Aphides are 

 commonly visited by ants, which devour the honeydew, and 

 even, it is said, go so far as to tickle the Aphides, in order 

 to make them secrete additional fluid. Whether the secretion 

 of Coccids may serve as food for other insects is not certain. 

 I have never noticed anything tending to this idea: often, 

 minute dipterous and hymenopterous insects may be seen 

 amongst Coccids on leaves, but I incline to the belief that 

 certainly the latter, and possibly the former, are seeking 

 rather a place for depositing their eggs than a meal of honey- 

 dew. Hymenopterous insects are very often parasitic on 

 Coccids : and out of a hundred pupae of, say, Ctenochiton 

 perforatus, as many as seventy-five may often be found with 

 hymenopterous pupje or larvse inside them. Acarids of various 

 kinds are also very numerous on leaves where Coccid® are 

 found ; but, whilst it is quite possible that they may be 

 attracted by the honeydew, this may not be the case, as 

 Acarids are numerous and common on all plants, whether 

 infested with Coccids or not. On the whole, I cannot afiirm 

 that the Coccid honeydew affords nutriment to any insects. 

 I have never seen an ant amongst Coccids : but ants are not 

 common in New Zealand, and this point is only negative, 

 after all. 



Still, the fact remains that Coccidfe exude, like other 

 Ehynchota, a glutinous fluid. This is well known, but I think 

 that nobody as yet has described either the mode or the organ 

 of the secretion. An observation lately made enables me to 

 fill this lacuna, and the points noted are not without interest 

 in the study of the family. It happened that I was lately 

 examining some specimens of the second, or pupa, stage of 

 the female of Ctenochiton elceocarpi, mihi.* In one of these 

 I noticed a sudden protrusion of an organ from between the 



• " Trans. N.Z. Inst.," vol. xvii., 1884, p. 26. 



