TRICHOGRAMMA MINUTUM RILEY AS A PARASITE OF THE ORIENTAL FRUIT MOTH (LASPEYRESIA MOLESTA BUSCK.) IN ONTARIO

1934 ◽  
Vol 10 (3) ◽  
pp. 287-314 ◽  
Author(s):  
W. E. Van Steenburgh
Keyword(s):  
Biological Control ◽  
New Jersey ◽  
Special Reference ◽  
Oriental Fruit Moth ◽  
Practical Significance ◽  
Considerable Importance ◽  
Natural Control ◽  
Host Abundance ◽  
Egg Parasite ◽  
Trichogramma Minutum

The investigations described in this paper were carried out during the period 1928–1933, and deal with the egg parasite, Trichogramma minutum Riley, with special reference to its field of usefulness in the biological control of the oriental fruit moth (Laspeyresia molesta Busck.) in Ontario. This cosmopolitan parasite is a factor of considerable importance in regulating the abundance of the fruit moth in southern New Jersey, but appears to be of little practical significance in the natural control of the pest in Ontario. Under certain conditions of weather and host abundance, parasitism may be increased materially by the liberation of Trichogramma in the orchards but, in general, the results are not dependable. A large number of experiments were conducted utilizing three biological races of the species. The technique employed in the work and the results obtained are given as well as a number of important observations on the habits and biology of the parasite.

BIOLOGICAL NOTES ON THE CHRYSOPIDAE

1937 ◽  
Vol 15d (2) ◽  
pp. 29-37 ◽  
Author(s):  
Wm. L. Putman
Keyword(s):  
Biological Control ◽  
Life History ◽  
Oriental Fruit Moth ◽  
Seasonal Prevalence ◽  
Natural Control ◽  
Ecological Data ◽  
Early Stages

This paper presents further biological and ecological data on the Chrysopidae gathered during a study of the predators of the oriental fruit moth. The species concerned are Chrysopa rufilabris Burm.; C. plorabunda Fitch; C. downesi R. C. Smith; C. oculata Say; C. nigricornis Burm.; Meleoma signoretti Fitch and M. emuncta Fitch. Data on life history include relation of development to temperature, number of generations, method of overwintering, and oviposition. The early stages of C. downesi, M. signoretti and M. emuncta are described. Seasonal prevalence and fluctuations in abundance from year to year are discussed and notes are given on natural control agencies. The value of chrysopids in the biological control of the fruit moth is summarized, with the conclusion that only in exceptional seasons are they of appreciable importance.

Gall Midges (Cecidomyidae) as Enemies of Mites

1933 ◽  
Vol 24 (2) ◽  
pp. 215-228 ◽  
Author(s):  
H. F. Barnes
Keyword(s):  
Biological Control ◽  
Original Description ◽  
Considerable Importance ◽  
Natural Control ◽  
Free Living ◽  
Gall Midges ◽  
The World ◽  
Scant Attention

This is a third of a series of papers dealing with zoophagous gall midges of the world. The first, “ Gall Midges as Enemies of Aphids,” was published in 1929 (Bull. Ent. Res., xx, 1929, pp. 433–442) and the second, “ Gall Midges as Enemies of the Tingidae, Psyllidae, Aleyrodidae, and Coccidae,” appeared more recently (op. cit., xxi, 1930, pp. 319–329).In this paper the species of gall midges whose larvae have been reported as preying on mites are dealt with, the first reference mentioned being in each case that of the original description or record. Practically all the literature available consists of specific descriptions and little is stated about the bionomics of the species with a few exceptions. It is a matter for regret that such scant attention has been paid to this aspect of biological control, especially in view of certain statements claiming that the larvae of various gall midges are of considerable importance in the natural control of red spider. It is with a view to stimulating further research in this direction that the present paper has been compiled.It has been thought advisable to divide the paper somewhat arbitrarily into separate sections, dealing firstly with those species of gall midges preying on free-living mites and secondly with those species preying on gall-inhabiting mites. A further section deals with those Cecidomyids which may feed on mites. As an additional convenience, a list of plants on which the mites live is appended. The Cecidomyids which may be predacious on mites (see section 5) are not, however, included in this list.

scholarly journals NATURAL PARASITISM BY TRICHOGRAMMA MINUTUM OF THE EGGS OF THE SUGAR-CANE MOTH BORER, DIATRAEA SACCHARALIS, IN THE CANE FIELDS OF PUERTO RICO

1969 ◽  
Vol 27 (2) ◽  
pp. 39-83
Author(s):  
George N. Wolcott
Keyword(s):  
Puerto Rico ◽  
Sugar Cane ◽  
Late Summer ◽  
Natural Control ◽  
Sudden Drop ◽  
Host Abundance ◽  
Diatraea Saccharalis ◽  
Trichogramma Minutum ◽  
Biologic Control ◽  
Natural Parasitism

The initiation in the formation of waves of abundance of egg-clusters of Diatraea saccharalis F. each spring in the northwestern corner of Puerto Rico is seasonal, but their height, duration and sudden drop is late summer are due to the near perfection of natural control by Trichogramma minutum Riley. In the remaining four-fifths of Puerto Rico, the factors responsible for the initiation, height and usually much shorter duration of waves of abundance, of egg-clusters lare not seasonal at all, but apparently depend on temporary and partial failure of biologic control in previous generations of the host. Natural control in the egg stage, even with often almost as many egg-clusters eaten by ants as attacked by parasites, rarely occurs, because of the shortness of the period of the wave. Irrigation so modifies humidity that rainfall, varying from less than 30 inches to nearly 90 inches per year, can not be proved to be 3 factor, and the variations in temperature are within too narrow limits to produce an effect. Height of cane and- variety of cane has no effect on egg-clusters, but ratoon cane averages greater abundance of host eggs, and higher parasitism, than plant cane or ratoon cane of which the trash has been burned. Parasitism invariably averages higher when or where host eggs are most numerous, but great variation in abundance of eggs in individual fields is paralleled by comparable variation in parasitism not depending on host abundance. Fields with more than five fresh eggclusters per man-hour and less than 33% parasitism are one out of every ten or eleven, and generalized predictions as to the occurrence of such conditions can be made. The release of laboratory-reared parasites can be commercially justified only in fields meeting these conditions, which occur most often in plant cane on the south coast during the winter.

A Study in the History of Clare, Suffolk; with Special Reference to its Development as a Borough (Alexander Prize Essay, 1928)

1928 ◽  
Vol 11 ◽  
pp. 83-115
Author(s):  
Gladys A. Thornton
Keyword(s):  
Special Reference ◽  
Middle Ages ◽  
Subsequent Development ◽  
Considerable Importance ◽  
Medieval Period ◽  
South West ◽  
Full Development ◽  
History Of ◽  
The Town ◽  
Prize Essay

Clare is situated in the south-west corner of Suffolk, in the valley of the Stour River. At the present day it is only a village, for its market is no longer held; yet its history shows that in earlier times it was of considerable importance, especially during the medieval period, when it was a favourite residence of the Clare lords. The town then had a busy market and a flourishing cloth-making industry; and at one time it seemed possible that Clare might attain full development as a borough, possessing as it did some burghal characteristics. In the following pages it is proposed to study in detail the history of Clare as a seignorial borough during the Middle Ages, and its subsequent development.

A Note on the Sanskrit Monologue-Play (Bhana), with special reference to the Caturbhani

1926 ◽  
Vol 58 (1) ◽  
pp. 63-90
Author(s):  
S. K. De
Keyword(s):  
Special Reference ◽  
Considerable Importance ◽  
Sanskrit Drama

Popular and (as attested by theory) undoubtedly old as the bhāṇa must have been, the specimens of this form of composition which have been hitherto known to exist belong to comparatively recent times. Considerable importance, therefore, attaches to the discovery and publication (1922) of four bhāṇas. under the title Caturbhāṇī, by M. Ramakrishna Kavi and S. K. Ramanatha Sastri from Śivapurī, for which great antiquity is claimed by the editors and which, whatever might be their date, are certainly older than any of the late existing specimens. The Caturbhāṇī consists of Ubhayâbhisārikā (Ubh), Padma-prābhṛtaka (Pp), Dhūrtaviṭa-saṃvāda (Dvs) and Pāda-tāḍitaka (Pt), ascribed respectively, on the authority chiefly of a traditional verse, to Vararuci. Śūdraka, Īśvaradatta and Śyāmilaka. Professor Keith, in his recently published Sanskrit Drama (p. 185, fn. 3), throws doubt on the first two ascriptions, and declares rather dogmatically that “ none of these plays need be older than a.d. 1000”.

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