I 
Feb. i, iSys.] THE TROPICAL AGRICULTURIST. 503 
double brooded it is quite a serious rest. The fly is a 
sraill bUok four- winded species, aud belongs to the 
saw-fly family, or Tenthredinidae. The flies of this 
family are m ore flat than most species of the order 
Hynieno.;tera. aud the females are pec il ar in hiving 
a saw at the tip of her body, which s >e uses to prep ire 
a groove for her e.'gs. Tho larvao of all saw-flies are 
easily dist nguished, as they have 18, 2) or 22 legs, 
which is true of no other iarva>. The sau-fly larva) 
often secrete a mucu3, which fact gives them the 
comm. m name of slugs. The pear of cherry sing secre- 
tes this slime, is brown iu colour, larger at the h ad 
end, an I tauering to the anal extremity; it has -0 legs. 
It is an iut re3ti"g fact, as well as practically im- 
portant, that when this elug is full grow ■, and casts 
its skin the last time, it becomes bright yellow and 
is clean from the mucus. Th i larva leives the tree 
and goes into the earth to pupate ; as do all insects 
of this famdy. I do not know the precise dates for 
this State or region, btr I think that the flies must 
deposit their eggs in May and again in late July or 
early Augu t. I found the slugs in June and a :ain 
in August. They are easily found, as the/ simply 
remove the epi ermis of the leaves, making them 
look gray and blighted They might as well eat the 
leaves tntire, for to rob th m of their ssih is to 
kill them. 
It is very easy to destroy these slugs ; wood a flies, 
lime, or even the road dust or earth from beneath 
the trees thrown upon them will often destroy them. 
The arsenites and ker sene emu siou are equally 
efficacious. So easy a remedy should never ba 
neglected. When the trees show the blight d leaves, 
search should be m ide for the slugs, aud if found, 
the remedy as ab -ve explaiue 1 should at once be 
appliel. If the earth, ashes, etc., bo thrown onto 
the slugs after the last molt, or just bef jro any molt, 
they may not ba effective, for in the first case, as 
the insect is without the s'irno, the powder will not 
s ick, and in the second, they at once shed their 
skins and so are rid of irritant, *kiu and all. I have 
known these slugs to be alarmingly abundant. The 
mucus seems to make them offensive to birds and 
possibly to other insects, so it is ail the more im 
perative that wa coat them with the cankering dust 
as soon as they appear in our orchards, or what 
wll often be more satisfactory, treat them to a meal 
of the prisonous arseuite3. Au Ichneumon parasite 
preys upon these slugs in the East. 
PuEDACBous and Parasitic Insects. — I need not 
urge upon y m the importance of such insects a3 the 
ladybirds and chalcid flies. You knjw what benefits 
hive come from the Vedalia, and we a-e all hope- 
ful that an equal benefaction is to come ffom the 
Khiz ibii. These ladybirtl beetles are the more our 
fricnl , as they aie ravenous feeders both as grubs 
or larvae, and also as mature beules. They aho 
have tooth for eggs as wed as meat and tlius they 
are always at work, and frequently nip the insect 
evil in the very bud, by eating exteusively the eggs 
of the most destructive sp-aies that infest our orchards. 
Tuu3 whi'e we are under a great debt of gratitude 
to the little oval bestles, we are even more indebted 
to the elongate hairy grubs, or baby ladybi.ds. It 
is dot alone the importations from Australia that 
b nefit us, but often our native species c nfer bcuefii.s 
that we can hardly over-esti mate. Two ye rs ago 
I was visiting for a brief period in mid winter in this 
region, mid visitod the orchar I of Mr. Meserve, 
south-wo t of this city. I found the black scale 
^scanium oleao) in great abundance. I also found 
the o m uon Twice-stabbed ladybird bee le (Chiloco- 
rus bivuluerus) in great numbers. I said then to | 
Mr. Meserve that I thought in a year or two his 
olives would bo mostly rid of tho black scale, and 
today, I am happy to say, he has comparatively few 
sc»les in his olive orchard. 
Some years ago many spoci«s of our forest trees 
in Michigan wore attacked by i species of Leoauiuai, 
very lik ) tho b'.ack sc le in appearance aud like history. 
It seem 'd as if many of our moat desirable trees, 
like tho hicko y, tulip, maplo aud linden, wore to 
be swept fro.n our forests as by fire. The second 
year of this foarful attack, as the trees began to 
hang out the yel'ow flag of distress, I found ' a 
miuute Chalcid fly that was increasing in great 
number , and reported to tho press that our forests 
were s .ved. i'wo years after. I could hardly find 
specimsns of the scales to show to my classes. Fouc 
or five years ago 'he wheat crop of Michigan Indiana 
aid Iliin us was seriously attacks I by the grain ap ds, 
and was thre teued with entire destruction. When 
the aphides were well at work, a little Braconid 
appeared, whipped out the plant lice, aud saved about 
one-t' ird of the crop. These Braconid flies a e ex- 
ceedingly prolific, and so are more than the equals 
of ev ' i the very fecund aphides or c •ccids. I fi id 
about here in aome orchards very numerous brown 
scale (fj ciuium he.sporidum). Often these are so 
aoun laut that to touch a branch or t *ig is to touch 
several of these suction pumps. In some cases I 
find that the scale is rapidly succumbing to a chalcid, 
or to chalcids, as there are more than one species. 
Thus, these natural enemies, the pr--daceous insects 
as il strated in the lidybirdi and the parasitic 
spec : es repress ted by the Chalcids aud Br acouids, 
are far more satisfactory tbaniare artificial remedies. 
They work for noihi °g an 1 board thsmselvc ; they 
do no injury to tree or fruit: they mike thorough 
work so t.iat there is no need of repetition before 
the w >rk is fairly completed. 
Practical Suggestions. — This leads me to two 
suggestions that this fruit g owers, in my judgment, 
ea mot afford to pass lightly by. One is' that a p :rson 
like Mr. Koebele should be kept constantly in se irch, 
in Australia E iropo or the eastern states, for these 
benefiaal insects. There are no doubt other Vedalias, 
and tne salary and expense of the peson iu quest 
of tho q would be a mere bagatelle, compared with 
the pos ible, I may say probable, outcome. I 
m dee no apology in urging all fruit growers t ) unite 
in demanding that Mr. Koebele, or some other equally 
competent mm, be kept for a period of years iu 
seir.-h of other Vedalia or Rhizobii, that we may 
not only be 'id of the cottony cushion and black scale, 
but gi the red and yellow, the per.iicio is and purple, 
anl all others, aud hall not be forced to the ex- 
pensive, unsatisfactory and unreliable methods of 
warfare htratofori thought valuable aud necessary. 
Ag'ato, it g ies without saying that immense good 
might come from a wise and tim-ly distribution of 
even our native parasitic aud pr da:eous species. 
Mr. Craw did adm rable work colleetiug and distribut- 
ing the Khizo Ji, but it would be more than wise 
to keep close watch of our or. hard i that any valuable 
species nvght be distributed. This is the more desir- 
able as our beneficial species must die with the 
dsstruct on of their food, so thai in collecting and 
distributing them with discretion we not only con- 
tinue their g >od work but their lives as we'l. Again, 
even the friendly insects have their enemies, which 
multij ly more aud more as the insects remain longer 
and longer in any place. Thus a removal or distribution 
is oft-n the ve-y savior of these little friends. In this 
section we find the Rhizobii falling before the Aphis 
Lion or larva of the lace-wing fly, Chrysopa Ca'if jrni- 
ca, a i is als > the Ohiloooros bivuln ris. In each a case 
no one can doubt but that removal and distribution 
wo :ld be exceedingly wise. The Rhizobii seem also 
t) have fallen before a parasite in Mr. Wright's 
orchard. This parasite, whatever it may have beeu, 
may be local, or of short life, so that a w d r dis- 
tribution or introduction a 1 , different times might 
iiave prevented its partial or complete overthrow. 
Again, we mist remember that disss enmiies are 
already in the field in force, and thoroughly intrenched. 
We bring only a few of the Rhizobii, ete., and of 
course tlu-y find it difficult or impossih'e to ho d their 
own. The case demands, then, the closest attention, 
aud in case we find enemies present, we should 
introduce an «rmy of our friends into a sin le 
orohard, that they mi^ht be able t > gain a foothold 
even in the face of un army of foes. If we could 
have ku wa jus; how s rious an attack was to have 
been made on the Rhizobii, it would have been 
wise to have introduced the nearly 200,001) Rhizobii 
which were brought from Santa Barbara county to 
this region, into a few or possibly into a sialic orchard 
