32 NATURAL ENEMIES OF THE COCCIDM. 



after death it retains its form indefinitely. The para- 

 sitised insect rarely lays eggs, and the character of the 

 pygidium is often much changed. This minute para- 

 site is exceedingly active, and in captivity spends most 

 of its time on the glass lid of its cage endeavouring to 

 escape ; occasionally I have seen it stop at a larva, 

 puncture it, and apparently lay an egg in its body. 

 The moment the larva is pierced it stops, and for a 

 while remains perfectly still, but afterwards proceeds 

 on its journey as if little or nothing had happened. 



Encyrtus (Apliycus) papus, Walker. I have bred this 

 parasite freely fromPseudococcns,spp. 9 obtained in Ches- 

 hire, at Weston-super-mare, and at Ringstead in Nor- 

 folk. In the latter locality large masses of the female 

 ovisacs almost covered the main steins of the gorse ( Ule<r 

 europaeus), and I noted that in such colonies it was 

 difficult to find an unparasitised female or ovisac, while 

 the single isolated ovisacs were practically immune. 

 The cause of this partiality for masses of the female 

 ovisacs, and not for the isolated examples on the leaves 

 and small branches of the bushes in quite exposed 

 situations, is, I think, due to the fact that the latter 

 are such perfect imitations of bird-droppings that they 

 thereby escape detection from their insect enemies. 

 (See Plate C, fig. 1, <i,<i, immune examples; b, b 9 para- 

 sitised colonies. From a photograph taken from life.) 



Of the remaining parasites Dr. L. O. Howard 

 kindly writes, " That from Riper xia comprises appa- 

 rently two forms, the one a species of Oerchysius ; the 

 other apparently represents a new genus not far from 

 Dihocarsis. From the Pseudococcus, sp., you have also 

 bred specimens of Lygocerus hyalinatns, Tomson 

 (according to Ashmead), but this is probably not a 

 true parasite of the Pseudococcus, but rather of some 

 dipterous larva, which itself, perhaps, preys upon the 

 Coccids" (in lit., November 6th, 1899). 



The time of the appearance of these hymenopterous 

 parasites is simultaneous with the larvae of their host, 

 and, although so minute, the latter are immediately 



