Biomedical subjects

W F Chamberlain

Publications and source records attributed to W F Chamberlain.

At least 19 recordsLinked to original sources

PubMed1991

New procedures to enhance survival of third-instar Hypoderma lineatum (Villers) (Diptera: Oestridae) in artificial media.

New techniques for the maturation of late third instars of the common cattle grub, Hypoderma lineatum (Villers), in artificial media are described. Larvae were held in either 24-well culture plates with media plus penicillin, streptomycin sulfate, nystatin, and chloramphenicol or in small salve jars on Perlite and media plus the same antibiotics. Chloramphenicol was not always necessary in the jars. Survival to pupariation of young third instars increased from 5% without nystatin and chloramphenicol to 73% when the two antibiotics were present in the culture plates. The survival of mature third instats to pupariation increased from approximately 53 to 80% after addition of nystati and chloramphenicol to the culture plates. Survival to pupariation of more mature grubs was similar in the jar and culture plate techniques. The former was more convenient, but the young grubs did not survive well in the jars.

Abattoirs↗

PubMed1989

Azadirachtin as a larvicide against the horn fly, stable fly, and house fly (Diptera: Muscidae).

Effects of azadirachtin, a triterpenoid extracted from neem seed, Azadirachta indica A. Juss., were similar to those of insect growth regulators against the immature stages of the born fly, Haematobia irritans (L.), the stable fly, Stomoxys calcitrans (L.), and the house fly, Musca domestica L. When an ethanolic extract of ground seed was blended into cow manure, LC50 and LC90's for larval horn flies were 0.096 and 0.133 ppm azadirachtin, respectively. An emulsifiable concentrate (EC) had an LC50 for larval horn flies of 0.151 ppm and an LC90 of 0.268 ppm. For larval stable flies, the EC formulation had an LC50 of 7.7 ppm and an LC90 of 18.7 ppm azadirachtin in manure. Against larval house flies, the LC50 and LC90 were 10.5 and 20.2 ppm, respectively. When the EC formulation was administered orally to cattle at a rate of greater than or equal to 0.03 mg azadirachtin per kg of body weight per day or when ground neem seed was given as a daily supplement of greater than or equal to 10 mg seed per kg body weight, horn fly development in the manure was almost completely inhibited. In contrast, ground seed mixed in cattle feed at the rate of 100-400 mg seed per kg of body weight per day caused less than 50% inhibition of stable flies in the manure.

Animals↗

PubMed1989

Technique for age-grading late third-instar Hypoderma lineatum (Diptera: Oestridae).

Three developmental phases are described for age-grading third-instar Hypoderma lineatum (Villers) based on color and development of the posterior spiracles. Early Phase 1 (P1) larvae are white in appearance, and their kidney-shaped posterior spiracular plates have no melanization. By the end of this phase, the cuticle has become yellow, and the margins of the spiracular plates begin to melanize. The cuticle of P2 larvae continues darkening from yellow to tan to light brown and is accompanied by a progressive melanization of the spiracular plates. The third phase, P3, has a cuticle that is not black like larvae that are ready to emerge from the hides for pupation, but the posterior spiracular plates are fully developed and melanized without a space between the two plates.

Animals↗

PubMed1988