scholarly journals Comparison of Biological and Chemical Control of Greenhouse Whitefly on Poinsettia Stock Plants

1992 ◽  
Vol 2 (4) ◽  
pp. 457-460 ◽  
Author(s):  
R.W. McMahon ◽  
R.K. Lindquist ◽  
M.L. Casey ◽  
A.C. Witt ◽  
S.H. Kinnamon
Keyword(s):  
Biological Control ◽  
Chemical Control ◽  
Trialeurodes Vaporariorum ◽  
Euphorbia Pulcherrima ◽  
Encarsia Formosa ◽  
Greenhouse Whitefly ◽  
Wild Stock ◽  
Control Compartment

A demonstration study was conducted to compare the effectiveness of biological and chemical control treatments on the greenhouse whitefly (GHWF) (Trialeurodes vaporariorum, Westwood) using poinsettia (Euphorbia pulcherrima Wild.) stock plants. Two identical greenhouse compartments, each containing 84 stock plants, were used. In the biological control compartment, three biweekly releases of Encarsia formosa (EF) were made, while in the chemical control compartment eight weekly applications of resmethrin or acephate aerosol treatments were made. Results showed that overall greenhouse whitefly populations in the chemical control compartment were slightly lower than in the biological control compartment. Cuttings taken from stock plants in the biological control compartment at the end of the experiment were commercially acceptable with regard to the presence of GHWF adults. Chemical names used: O,S-dimethyl acetylphosphoramidothioate (acephate), [5-(phenylmethyl)-3-furanyl] methyl 2,2-dimethyl-3-(2-methyl-1-propenyl)cyclopropane-carboxylate (resmethrin).

scholarly journals Comparison of Commercially and Locally Produced Encarsia formosa Gahan on the Control of Sweetpotato Whitefly on Poinsettias

1994 ◽  
Vol 4 (3) ◽  
pp. 295-298 ◽  
Author(s):  
R.W. McMahon ◽  
R.K. Lindquist ◽  
B.D. Baith ◽  
T.L. Makin ◽  
M.L. Casey
Keyword(s):  
Biological Control ◽  
Integrated Pest Management ◽  
Pest Management ◽  
Bemisia Tabaci ◽  
Euphorbia Pulcherrima ◽  
Encarsia Formosa ◽  
Sweetpotato Whitefly ◽  
Greenhouse Whitefly

A 2-year demonstration study was conducted to compare the effectiveness of two sources of Encarsia formosa (EF) on the biological control of the sweetpotato whitefly (SPWF) (Bemisia tabaci Gennadius) on poinsettias (Euphorbia pulcherrima Wild.). Commercially produced EF were raised on the greenhouse whitefly (GHWF) (Trialuerodes vaporariorum Westwood), while the locally produced EF were raised on the SPWF. Results showed that SPWF populations were reduced considerably both years, and maximum nymph parasitism ranged from 60% to >80%. No large differences were observed in the ability of EF to control SPWF populations whether raised on SPWF or GHWF nymphs. This study suggests that there is potential for controlling SPWF populations on poinsettia by EF in conjunction with an integrated pest management (IPM) program.

ASPECTS OF THE INTERACTION BETWEEN A CHALCID PARASITE AND ITS ALEURODID HOST

1967 ◽  
Vol 45 (4) ◽  
pp. 539-578 ◽  
Author(s):  
T. Burnett
Keyword(s):  
Larval Mortality ◽  
Trialeurodes Vaporariorum ◽  
Host Population ◽  
Population Variation ◽  
Encarsia Formosa ◽  
Greenhouse Whitefly ◽  
Parasite Abundance ◽  
Tomato Plants ◽  
Host Mortality ◽  
Dominant Process

Three populations of the greenhouse whitefly, Trialeurodes vaporariorum, and its chalcid parasite Encarsia formosa were propagated each year for three consecutive years on tomato plants in the greenhouse. The abundance of the host and parasite species fluctuated either with peaks of increasing amplitude, with peaks of decreasing amplitude, or with irregular peaks. The dominant process in the interaction was the occurrence of two qualitatively different types of host larval mortality: (a) parasitization, and (b) almost immediate killing after attack by adult parasites. Fluctuations in host and parasite abundance resulted from the almost immediate killing of small host larvae and the death of the short-lived adult parasites. The parasite population tended to destroy similar percentages of host populations of different densities but host mortality was also related to the age structure of the host population. Variation in host reproduction, caused by differences in rearing temperature and by seasonal variation in the physical environment, influenced host and parasite densities.

scholarly journals 157 Susceptibility of Poinsettia Cultivars to Whiteflies

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 417A-417
Author(s):  
Robert P. Rice ◽  
Michael Crane
Keyword(s):  
Trialeurodes Vaporariorum ◽  
Natural Resistance ◽  
Euphorbia Pulcherrima ◽  
Silverleaf Whitefly ◽  
Bemisia Argentifolii ◽  
Immature Stages ◽  
Trichome Density ◽  
Greenhouse Whitefly ◽  
Wide Range ◽  
Leaf Trichome

Twenty-four poinsettia cultivars (Euphorbia pulcherrima) were exposed to a population of greenhouse whitefly (Trialeurodes vaporariorum) and silverleaf whitefly (Bemisia argentifolii) for 6 weeks. Evaluation was based on the number of immature whitefly present on each of the marked leaves. The poinsettias that produce white bracts were more heavily infested with immature stages of whitefly than those cultivars that produce red bracts, while those that produce pink bracts were intermediate. There was a wide range in degree of whitefly infestation among poinsettia cultivars. Leaf trichome density also explained a portion of the variance in whitefly oviposition rates among several of the cultivars. Cultivars with high trichome densities sustained less whitefly oviposition than did cultivars with low trichome densities. Certain cultivars tested showed an appreciable natural resistance to whitefly (`Freedom Red', `Freedom Bright Red', `Red Velvet', `Cranberry Punch', `Pepride').

scholarly journals The suitability of biotypes Q and B ofBemisia tabaci(Gennadius) (Hemiptera: Aleyrodidae) at different nymphal instars as hosts forEncarsia formosaGahan (Hymenoptera: Aphelinidae)

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1863 ◽  
Author(s):  
Xin Liu ◽  
Youjun Zhang ◽  
Wen Xie ◽  
Qingjun Wu ◽  
Shaoli Wang
Keyword(s):  
Biological Control ◽  
Feeding Rate ◽  
Trialeurodes Vaporariorum ◽  
Host Feeding ◽  
Encarsia Formosa ◽  
Greenhouse Crops ◽  
Commercial Strain ◽  
Promising Tool ◽  
Adult Parasitoid ◽  
Biotype B

Encarsia formosaGahan (Hymenoptera: Aphelinidae) is a solitary endoparasitoid that is commercially reared and released for augmentative biological control of whiteflies infesting greenhouse crops. In most areas in China, the invasive and destructive whiteflyBemisia tabaci(Gennadius) (Hemiptera: Aleyrodidae) biotype Q has replacedB. tabacibiotype B and has become dominant between the two. A better understanding of the suitability of different nymphal instars ofB. tabacibiotypes Q and B as hosts forE. formosais needed to improve the use of this parasitoid for biological control. Parasitism of the four nymphal instars ofB. tabacibiotypes Q and B by the commercial strain ofE. formosamass reared onTrialeurodes vaporariorum(Westwood) (Hemiptera: Aleyrodidae) was assessed in the laboratory. The results indicated thatE. formosaparasitized and successfully developed on all instars of both biotypes but performed best on the 3rd instar ofB. tabacibiotype B and on the 2nd, 3rd, and 4th instars ofB. tabacibiotype Q. The host-feeding rate of the adult parasitoid was generally higher on nymphal instars ofB. tabacibiotype Q than on the corresponding nymphal instars of biotype B and was significantly higher on the 2nd and 3rd instars. For both whitefly biotypes, the parasitoid’s immature developmental period was the longest on the 1st instar, intermediate on the 2nd and 3rd instars, and the shortest on the 4th instar. The parasitoid emergence rate was significantly lower on the 1st instar than on the other three instars and did not significantly differ betweenB. tabacibiotype B and biotype Q. Offspring longevity was greater on the 3rd and 4th instars than on the 1st instar and did not significantly differ between the twoB. tabacibiotypes. The results indicate that commercially-producedE. formosacan parasitize all instars ofB. tabacibiotypes B and Q, making this parasitoid a promising tool for the management of the two biotypes ofB. tabacipresent in China.

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