SCALE-INSECTS, BARK-LICE, MEALY-BUGS. 211 
AA. Body of insect covered by a scale composed in part 
of moulted skins, and part of a secretion of the 
LCISSS (1 5 USE gr ana Pare, DS cen eee a DIASPINA.” 
SUB-FAMILY COCCINA. 
In this sub-family the females undergo the least change in 
form. In the majority of cases they retain the form of the 
young larvze, while in some genera the body becomes a globular 
mass with little or no indications of segmentation. In most 
genera the body of the female is permanently covered with a 
cottony sac, but in the mealy bugs this only takes place just 
before they begin to deposit eggs. The caudal style of the male 
is short, and two long and waxy filaments are borne by the last 
abdominal segment, each of which is supported by one or more 
hair-like spinnerets at the base. 
Dactylopius species. (The Mealy-bugs). 
These insects are exceedingly troublesome in greenhouses 
and in the South to many plants growing outdoors. Two species 
are shown in the illustrations, Figs. 168, 169 and 170. 
Dactylopius destructor Comst. (The Destructive Mealy-bug) 
is about one-twelfth of an inch wide, and one-eighth of an inch 
long; it has a plump body, brownish-yellow below, white with 
faint indication of a median line above (Fig. 168). Unlike other 
scale-insects it can move about slowly. The segments of the 
body are distinct, and the edge of the body bears 34 white fila- 
ments. The eggs are deposited in a cottony sac at the posterior 
end of the body, in which they remain until hatched. 
Dactylopius longifilis Comst. (The Long-threaded Mealy- 
bug) is slightly larger, but narrower, so that it appears much 
more slender. It is also white, but differs greatly by having the 
four posterior filiaments very much longer, equalling or exceed- 
ing the length of the entire body (Fig. 169). Fig. 170 shows 
the winged male. ; 
Both species have similar habits, and in the well-heated 
greenhouses we can find at the same time the insects in all stages. 
In greenhouses fumigated at regular intervals they are never 
very destructive. 
