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The initial slocks of M. (lIICy/i fJOrllJ were obtained from southern New Jersey in 1929 and 1930.
Establishmelll was immediate and in the fi rst yeaf of release in the Ni;lgar3 Peninsula the effect of the
parasite was :I pparent in cleaner fruit in the colonization orchards. During the yC.1TS following 1930
the parasites were ei ther collected from the areas where they had become established or wefe prop:lgated
at Belle\'ille for release in other areas of Oriental fruit moth infestation. The years and
numbers releascd in Ontario were: 1929- 2,350, 1930-tJ,063, 1931- 3.736, 1932-+,251, 1933-
1,33 1, 1934-4,090, 1935- 15,247, 1936-10,398. 1937- 5,527, 1938- 2,806, 1939- 3,309, 1940-
2,822, 1941- 835. 1942- 164, 1945-2,686, 1946- 26,915 and 1947- 9, 110.
T hough 111;IIIY species of nati\'e parasites :lIld predators attack C. IIIv/es/n none is as crrect;\'e as
1'1. (Illcy/ivoml. The most important Imti\'e species is C/ypw rlljis(II/clluris Cress. Boyce and Dustan
( 1954) reported on the effect of DDT and parathion on the par:lsites during the period of their
illvestig:lIions from 1946 to 1953 as follows: " The introduced parasite JlflCfOUl1lrllS ollcyfiuorlls
Rohw. appears in some manner to ha\'e been f:lI'o ured by DDT and parathion applied for the colltrol
of the Oriental fruit moth in eOnl mercial orchards of Essex Count)' (south-western Ontario) ami the
Nia).:ara Peninsula.
"A nati\'e p:uasitc, C. rllfiUlilellaris Cress. has rapidly decreased in abundance du ring the six
)'e:lrs that DDT or p:muhioll has been in general use in Olll:lrio peach orch:l rds."
"i\ lost of the less effective species of na ti\'e parasites appe:lr 10 h:lve been unaffected by the
applications ofdll'se two chemicals; but M. ddiwlIIS, in Essex County, where it h:ls alw:lYs been more
ahlludant than in the Niag:trH Peninsula, :Ippcars to have been aided by the insecticidal treatments or
fa mured by some other environmental change. Populations of /loro1:(,II ('I obli/crallls (Cre5..'l.) appe:lr
to ha\'e been somewhat rcduced by DDT and parathion."
.\!. (lIIcy/ivorlis pro\'ed to be :l \'aluable natural control agent thM provided a measure of control
and pre\'ent ed serious losses to the peach growers during a period when no suitable insect icide was
;I\'ailablc. It has continued to be a v;lluable control agent in conjunct ion with chemi t.';11 control after
suit.lble insecticitles were disco\'ered. Evidence of this is contai ned in an unpublished Scicnce Sen'ice
Report on Fruit I nseCl I nn .'Stig:lIions fo r July, 1957. After reporting 58·1 per cent. parasitism of first
gener.ttion Orientnl fruit moth larvae it states: " It is evident from these results that M. (Illey/it.·oms
contin ues to thrive in pe;\ch orchards in the presence of p:lr:uhion and DDT which arc c. ... tensi \·cly
IIscd to control the Oriental fTliit moth". ,\lIen (1958) reported similar results in New Jersey peach
orchards.
Tri{/iogTlIllIllIfI spp. (11),lllenopter.t: Triehogrammatidae) (three species) were released in the
Kiagar.t Peninsui:t in 1928 to 1933, and in numbers ranging from 250,000 to 10 million per year.
Concerning the three species, \' ;11) Steenburgh and Boyce (1938) state: "The work was begun with
T. evall('scellJ \Vesm., a gr:IY Slr:tin the initi:tl stock of which was secured from the southern United
States. When it was found that a yellow strain, T. cmbryoplltlglls (Htg.), appeared naturally in the
orchards, it was introduced into the labora.tory breeding and toward the latter pa rt of the work was
used exclusively. One large heavily infested block of peaches was treated with 5,000,000 1'. sell/hlidis
(A uri\'.). The li berations with T. evlllleJCClI1 gave good parasitism following the releases but the species
f;liled 10 persist in the orchards. Collections of Triclwgrrllllll/fl made the fo llowing spring after hlrge
releases of ev(II/CSct'IIS always yielded elllbryoplm!:lIs. 1'. selllblidis appeared entirely unsuited to orchard
conditions alld reco\'ery collect ions made one month after the large release of this species failed to
show its presence ill the orchard."
The value of 'f'riclwgrmlllll(j as a control for the Orient:11 fruit moth was summarized by va n
Steellhu rgh :lIId Boyce (1938): "While it was early recogni ;;,ed th:lt the usc of 'J'richogrfllllm(/ as an
Orielllal fruit 1I10th control has se\'cral limiting factors, the urgent need for at least partial cOlll rol
:\ppe:lred to justify its comined usc umil a more satisfa ctory method had been secured".
T hree additiOlJ:lI species of Oriental fruil moth parasites were released : Pristomcrlls vllll/cra/or
(Panz.). Tell/ellielm mil/or (Cush.) and C/ypla Tlljisclllel/(lriJ Cress. (I IYUlenoptera: Ichneumonidae).
All :tre external parasites that pass the winter in mature la rvae of the host. A small colony of 30
P. 'millera/or adults was obt;lined from Fr.tnce in 1930. T he species failed to become cstnblishcd
possibly because of the small number rdeased. Colonies totalling 410 of 1'. millor and 775 of C .
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