AN ENCYCLOPADIA 
187 
OF HORTICULTURE. 
Insects—continued., 
Fig. 302), Cockroaches (see Fig. 303), and Earwigs; 
though some place the last-named Insects in a separate 
Fic. 303, FEMALE COCKROACH, 
order, called Euplexoptera, because of the very neat 
folding of the hind wings below the front ones. The 
Orthoptera are destructive during every stage after 
leaving the egg, and in warm countries they do exces- 
sive damage at times. In Britain, they cannot be re- 
garded as of great consequence; though Cockroaches 
may gnaw the greenhouse plants, and Earwigs are rather 
hurtful to florists’ flowers, and require to be kept in 
check (see Cockroaches, Crickets, and Earwig). 
With the Orthoptera may also be classed the genus 
Fic. 304. THRIPS (magnified). 
Thrips (see Fig. 304)—a genus of very small Insects, 
which live in flowers, and gnaw the surface of the petals 
(see Thrips). 
Neuroptera are at once far less numerous in species 
and in individuals, and practically less important than 
are the orders already discussed. None of the Insects 
in it can be said to be hurtful to plants. On the other 
hand, they are frequently of much service, since several 
of them feed on Insects, and destroy large numbers of 
injurious kinds. The order is characterised by the 
possession of four wings, all alike membranous, and 
supported on a complex network of nervures; a mouth 
fitted for biting. Certain of the sub-orders undergo 
only an incomplete metamorphosis, while in others the 
metamorphosis is complete. The larve are provided 
with six jointed legs. Newroptera are mostly carnivorous, 
alike in the larval state and when mature. Among the 
better-known forms may be noted Dragon Flies, Heme- 
robius, and Lacewing Flies. 
Hymenoptera have the wings all membranous and naked, 
and supported on branching nervures, the hind wings 
being the smaller; the wings bear no scales. The mouth 
has jaws for biting ; but in some of the sub-divisions of the 
order, certain parts of the mouth are modified to serve for 
licking up honey from flowers (in Bees, Wasps, &c.). They 
all pass through a complete metamorphosis. The larve 
vary much in form, often being like maggots (Bees, &c.), 
while the Sawflies have larve not unlike the caterpillars 
of Moths. Sawflies are very injurious to plants, many 
of them being hurtful to garden and field produce 
(Turnip Sawfly, Gooseberry Sawflies, &c.). Some of the 
Sawflies make true galls on Willows; and many of the 
Cynipide, or Gall-flies (see Figs. 305 and 306), make 
galls on Oak, Maple, Roses, &c. Most of the Hymenoptera 
Insects—continued. k 
are of much use in limiting the number of injurious 
Insects; and among these useful species the Ichneumons 
In the mature state, none of the 
hold the first place. 
me ee GALLS AND INSECTS OF RHODITES Rosæ, showing (1) 
m 
Gall; (2) Bedeguar, cut open; (3) Grub, 
natural size; (4) Head of Grub, magnified ; (5) Pupa, magni- 
fied ; (6) Insect, magnified. 
Hymenoptera can be said to be really injurious to plants; 
while many are of great value in conveying pollen from 
flower to flower. 
times to injure the flowers, by boring through the tube — 
* GALL-FLY —— ý — ). The figure below, and to 
o esent hinder rings of the Abdomen, and 
which serves to pierce the plant tissues, still 
of the corolla to gain readier access to the honey con- 
tained therein. See also Ants, Galls, Honey Bee, 
Humble Bee, Ichneumon Flies, and Sawflies. 
spidoptera have the wings usually large (see Figs. 
307 and 308), membranous; and covered all over with 
small scales; the mouth is of no use for biting but 
has the lower jaws (maxillæ) prolonged, so as, when 
placed together, to form a tube, adapted for sucking 
honey from flowers. The metamorphosis is complete. 
The larve (see Figs. 309 and 310) are of the form known 
as Caterpillars; and, apart from points of minor im- 
portance, vary chiefly in the number of sucker feet on 
However, Humble Bees are found ab 
