Control of Edaphic Populations of Woolly Apple Aphid using Entomopathogenic Nematodes and a Systemic Aphicide

1992 ◽  
Vol 27 (3) ◽  
pp. 224-232 ◽  
Author(s):  
M. W. Brown ◽  
J. J. Jaegers ◽  
A. E. Pye ◽  
J. J. Schmitt

The effects of an entomopathogenic nematode, Steinernema carpocapsae (Weiser), and an experimental systemic aphicide, RH-7988, on edaphic populations of the woolly apple aphid, Eriosoma lanigerum (Hausmann), were investigated. Laboratory experiments showed that presence of the nematode in a culture of woolly apple aphids increased the mortality rate. Nematodes were found inside the body cavity of several aphids with entry possibly being through the anus via a droplet of honeydew. Field trials in an unsprayed six-year-old and four-year-old apple orchard tested the efficacy of broadcast spray and topdressing applications, respectively, of nematodes at a rate of 376,600 nematodes/m2. The broadcast spray trees had fewer aphid colonies on roots than the untreated controls (P = 0.10), but the topdressing treatment had no effect. The systemic aphicide, RH-7988, was tested in a two-year-old apple orchard. Two rates of foliar and soil application were tested, with all treatments significantly reducing arboreal woolly apple aphid populations. Edaphic populations were also significantly reduced one month after treatment, but no difference was found four months after treatment. Both control methods show promise as potential management options for edaphic woolly apple aphid populations.

2005 ◽  
Vol 137 (1) ◽  
pp. 67-70 ◽  
Author(s):  
Brent D. Short ◽  
J. Christopher Bergh

The woolly apple aphid, Eriosoma lanigerum (Hausmann, 1802) (Hemiptera: Aphididae), is a cosmopolitan, indirect pest of cultivated apple, Malus domestica (Borkh.) (Rosaceae), (Baker 1915) that can colonize both the roots and arboreal portions of trees and adversely affect the growth, vigor, and productivity of the host (Weber and Brown 1988; Brown and Schmitt 1990; Brown et al. 1991, 1995). Historically, the solitary endoparasitoid Aphelinus mali (Haldeman, 1851) (Hymenoptera: Aphelinidae) has been considered the most important biological control agent for E. lanigerum in many, but not all, apple-growing regions (Yothers 1953; Nicholas 2000). The role of arthropod predators in regulating woolly apple aphid populations, particularly early in the growing season, has long been recognized (Dumbleton and Jeffreys 1938; Bodenheimer 1947; Nicholas 2000; Mols and Boers 2001) but has not been adequately addressed (Asante 1997).


Parasitology ◽  
1924 ◽  
Vol 16 (1) ◽  
pp. 111-112
Author(s):  
Edward Hindle

In December, 1922, whilst dissecting a large female example of Bufo regularis, one of my students noticed a cylindrical structure extending along the ventral region of the body-cavity. A careful examination showed that this structure consisted of an elongated sac-like diverticulum of the right lung, containing an almost full-grown specimen of a dipterous larva, which could be seen through the membraneous wall of the diverticulum. The base of the latter, in addition to its point of origin from the lung, was also connected to the dorsal surface of the liver by strands of fibrous tissue, suggesting that the growth had been in existence some considerable time in order to cause such adhesions. Posteriorly, the diverticulum hung freely in the body cavity and extended to the extreme hinder end. Its dimensions were 5·5 cm. in length, by 0·5 cm. in diameter, but tapering towards each extremity.


1961 ◽  
Vol 51 (4) ◽  
pp. 755-764 ◽  
Author(s):  
G. B. Whitehead ◽  
J. A. F. Baker

Early in 1959, observations on the farm Tayside, in the East London district of South Africa, suggested that populations of the ‘two-host’ red tick, Rhipicephalns evertsi Neum., were more difficult to control with toxaphene preparations than they had been in the past. Resistance to toxaphene was suspected, and both field and laboratory experiments were carried out to investigate this possibility. Field trials indicated an increase in tolerance by Tayside populations of the tick to toxaphene, γ BHC and dieldrin, but showed no increased tolerance to sodium arsenite or DDT. Similar results were obtained in laboratory experiments where Tayside adults were compared with those of other populations of the tick known to be sensitive to insecticides. Laboratory experiments with larvae indicated a high degree of resistance to toxaphene and γ BHC in the Tayside population, but no increased tolerance to sodium arsenite, Delnav, Sevin or DDT could be detected. This pattern of cross-resistance is similar to that occurring in resistant populations of Boophilus dccoloratus(Koch).


Nematology ◽  
2018 ◽  
Vol 20 (7) ◽  
pp. 653-669 ◽  
Author(s):  
Oleg Gorgadze ◽  
Elena Fanelli ◽  
Manana Lortkhipanidze ◽  
Alberto Troccoli ◽  
Medea Burjanadze ◽  
...  

Summary A new species of entomopathogenic nematode, Steinernema borjomiense n. sp., was isolated from the body of the host insect, Oryctes nasicornis (Coleoptera: Scarabaeidae), in Georgia, in the territory of Borjomi-Kharagauli. Morphological characters indicate that the new species is closely related to species of the feltiae-group. The infective juveniles are characterised by the following morphological characters: body length of 879 (777-989) μm, distance between the head and excretory pore = 72 (62-80) μm, pharynx length = 132 (122-142) μm, tail length = 70 (60-80) μm, ratio a = 26.3 (23.0-29.3), H% = 45 (40-51), D% = 54 (47-59), E% = 102 (95-115), and lateral fields consisting of seven ridges (eight incisures) at mid-body. Steinernema borjomiense n. sp. was molecularly characterised by sequencing three ribosomal regions (the ITS, the D2-D3 expansion domains and the 18S rRNA gene) and the mitochondrial COI gene. Phylogenetic analyses revealed that S. borjomiense n. sp. differs from all other known species of Steinernema and is a member of the monticolum-group.


1962 ◽  
Vol 40 (7) ◽  
pp. 1269-1275 ◽  
Author(s):  
Joan F. Bronskill

In third and fourth instar larvae of Aedes aegypti (L.), juveniles of the rhabditoid, DD136, penetrate the blood sinus and cardial epithelium of the proventriculus to enter the body cavity of the host, where they complete their development. By 5 hours, a thick capsule developed about many of the ensheathed immature adults of DD136 within the body cavity of A. aegypti larvae. This rapid defence reaction of the mosquito to DD136, which has both a melanin and a cellular manifestation, occurs both in the exotic mosquito A. aegypti and in the two endemic species tested, Aedes stimulans (Walker) and Aedes trichurus (Dyar). The resistance of A. stimulans to an endemic rhabditoid, possibly of the Diplogasteridae, is also similar. The histological structure of the capsule is not affected during metamorphosis in A. aegypti; however, during histogenesis of adult tissue displacement and (or) distortion of some tissues and organs may be caused by the presence of the capsule within the host's body cavity. The activity of the adult A. aegypti is normal when this distortion or displacement is minor. Though usually encapsulated DD136 are retained within the body cavity of A. aegypti during metamorphosis, sometimes they are partially or completely expelled from the host's body cavity at the time of molting.


1979 ◽  
Vol 193 (1) ◽  
pp. 169-175
Author(s):  
S. D. Drew ◽  
H. J. Hignett ◽  
P. E. Johnson ◽  
G. I. Crabb

This paper describes the design, development and application of pillar dynamometers to measure the forces on discs cutting through rock both in field trials using full-face tunnelling machines and in laboratory experiments.


BioControl ◽  
2005 ◽  
Vol 50 (2) ◽  
pp. 271-291 ◽  
Author(s):  
Adrian H. Nicholas ◽  
Robert N. Spooner-Hart ◽  
Richard A. Vickers

1949 ◽  
Vol 26 (1) ◽  
pp. 1-15
Author(s):  
J. D. SMYTH

1. Plerocercoid larvae of the pseudophyllidean cestode Ligula intestinalis from the body cavity of roach, were cultured in vitro at 40°C. in a variety of saline and nutrient media. About 65% of such cultures were aseptic. 2. During cultivation, larvae produced acid by-products (unidentified) and the pH fell rapidly. 3. The presence of these acid by-products slowed down development, or, if present in sufficient quantity, caused death. 4. In order to obtain development in nutrient media in a period (3 days) comparable to that required in a bird (the normal host) it was necessary to renew the medium 24-hourly. 5. 6% of the eggs produced from a worm cultured in horse serum were fertile. Fertile eggs were never obtained from larvae cultured in any other media. 6. Certain bacterial infections had no apparent detrimental effect on development, but others were toxic. 7. Some larvae underwent development in non-nutrient medium (¾ strength Locke's solution). The exact conditions under which this occurred was not determined. 8. Fragments (3 cm. long), of larvae or larvae with either scolex or posterior half removed, underwent development to the stage of oviposition in nutrient media. 9. Histochemical examination revealed that the plerocercoid larvae were almost fat-free. During cultivation, very large quantities of cytoplasmic fat were produced the quantity being proportional to the duration of cultivation. Fat was produced even under starvation conditions (i.e. during cultivation in saline) and can be considered a metabolic by-product. 10. The fresh plerocercoid contained great quantities of glycogen in the parenchyma and muscle regions. After cultivation in nutrient or saline media, considerable quantities were still present.


Author(s):  
M. Barson

Clarias gariepinus were collected from Lake Chivero, Zimbabwe, and examined for nematode parasites from November 2000 to May 2002. Of the 202 specimens collected, 42.6 % were infected with third-stage larvae of Contracaecum sp. in the body cavity. The intensity of the infection was 1-7 worms per fish (mean intensity = 2.2). Seasonal variation in the prevalence of the parasite was not obvious and there was no significant difference in the prevalence of infection between males and females (c2 = 2.228; P > 0.05). No significant relationship between host size and prevalence was established. There was also no significant relationship between intensity and the body condition factor (r = 0.11; P > 0.05). The low parasite prevalence may have been caused by the disruption of the infection cycle since piscivorous birds, which are the final hosts of the parasite, do not feed on C. gariepinus in Lake Chivero.


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