Establishment of Encarsia smithi (Silvestri) (Hymenoptera: Aphelinidae) on Pohnpei for Control of the Orange Spiny Whitefly, Aleurocanthus spiniferus (Quaintance) (Homoptera: Aleyrodidae)

2 Pages·1992·0.09 MB·

by  Muniappan, R

Vol. 31, December31,1992 243
SCIENTIFIC NOTE
Establishment of Encarsia smithi
(Silvestri) (Hymenoptera: Aphelinidae) on
Pohnpei for Control of the Orange Spiny
Whitefly, Aleurocanthus spinifems
(Quaintance) (Homoptera: Aleyrodidae)
R. MUNIAPPAN1, M. MARUTANI1 and NELSON ESGUERRA-
ABSTRACT. Alntmcanlhus \pinifrrus (Quaintance) was recognized as a serious problem on
Pohnpei in 1987. Enraniasmithi (Silvestri) wasreleasedonJanuary7, 1988. The parasite was
recoveredonApril28, 1988.andan effectivecontrolofA spinifmiswasachievedbvFebruary
1989. '
Theorangespinywhitefly (OSW),Meuwcanthusspinifems (Quaintance),
was identified as a serious pesi of citrus trees it) the Kolouia district of
Pohnpei in 1987. Surveysconducted on October21, 1987 failed tofind any
natural enemies ofOSW. The undersurfacesofleaveswere heavily infested
by OSW and the upper surfaces were covered witli black sooty mold.
OnJanuary7, 1988, 150adultsofEncarsiasmithi(Silvestri) were shipped
from Guam to Pohnpei. Ofthese only65 survived shipment. The parasites
were field released on the same day at two sites, about a mile apart, in the
district of Kolonia.
On April 28, 1988, we conducted surveys ofOSW in Kolonia to deter
mine the status of establishment of E. smithi. OSW infested leaves from
citrustreesateach releasesitewerecollected, pooled, and foursub-samples
were drawn at random for counting OSW and E. smithi emergence holes.
The numberofemergence holes in 100 OSWwas determined, toderive at
the percentage of parasitism. The number of trees from which OSW in
fested leaves were collected varied, depending upon the number of trees
found in that site. The April 28, 1988 survey indicated the establishment
ofE. smithi.3 The percentage ofparasitism ranged from 2 to 6%, x =3.75
and 1 to 8%, x =4.25 at release sites 1 and 2, respectively.
Furthersurveys conducted on February6and 7, 1989 revealed that the
percentage ofparasitism had increased to between 24.3 and56.0, x =41.3.
These results represent parasitism over the whole district ofKolonia, as we
could notfind OSW infested leaves in the original E. smithirelease sites. In
general, the OSW population was very low in Kolonia, and it was not
considered to be a problem in February 1989.
■Agricultural ExperimentStation,UniversityofGuam, Maiifrilao.Guam96923. U.S.A.
■'CollegeofTropicalAgricultureandScience, P. O. Box 1179, Pohnpei, FSM96941.
'Identityofadult parasitesrearedfrom A. spinifems,collectedon Pohnpei during November
1990,wasconfirmed asE. smithiby M. Marutaniand R. Muniappan.
244 Proceedings,Hawaiian EntomologicalSociety