Quality control charts were employed to monitor the quality of several parameters during mass rearing of the T: Y(WP +)30C strain of Ceratitis capitata (Wiedemann), in which male and female flies emerge from brown and white puparia, respectively. Egg hatch and pupal recovery in this genetic sexing strain were below that reported for a wild‐type ‘Sohag’ strain, whereas pupal size, adult emergence and flight ability were higher. The overall recovery from eggs to adult flies capable of flight was similar in the two strains but egg production in T: Y(wp +)30C was reduced to about 56% of that of ‘Sohag’. The quality control charts showed an acceptable level of variation within sets of data but the level between data sets was occasionally out of control. This indicated the presence of uncontrolled conditions during the rearing process, possibly arising from variations in the quality of the larval diet. It is concluded that the quality of T: Y(wp +)30C renders this strain suitable for mass rearing in sterile insect technique (SIT) programmes requiring the elimination of the female flies prior to the release of sterilized males. The next step should involve further quality assessments both under field cage and under field release conditions. The importance of optimal and standardized dietary conditions is stressed in relation to the quality of mass reared medflies. Résumé Bases du contrôle de l'état des Ceratitis capitata au cours d'un élevage de masse d'une lignée présentant un dimorphisme sexuel pupal Des normes de qualité ont été utilisées pour relever la valuer de plusieurs paramètres lors de l'élevage industriel de la souche T: Y(wp +)30C de C. capitata Wied. dont les mâles et les femelles émergent respectivement de pupes brunes et blanches. Les taux d'éclosion et d'obtention de pupes sont plus faibles avec cette souche qu'avec la souche souvage ‘Sohag’; par contre, la taille des pupes, le taux d'émergence des adultes et l'aptitude au vol étaient plus élevés. La fréquence totale des adultes capables de voler par rapport au nombre initial d'œufs a été de 0,297 contre environ 0,311 pour Sohag. Cependant, la production d'œufs a été réduite à environ 56% de celle de Sohag. Les tableaux de contrôle de la qualité ont révélé un niveau de variation acceptable à l'interieur des lots de données, mais la variabilité entre les lots excédait les normes admissibles. Ceci implique des paramètres incontrôlés pendant l'élevage de masse, probablement liés à des variations de la qualité de l'aliment. On peut en conclure que la qualité de la souche T: Y(wp +)30C la rend utilisable pour un élevage de masse dans des programmes d'utilisation d'insectes stériles (SIT) exigeant l'élimination des femelles avant le lâcher de mâles stériles. La prochaine étape impliquera de nouvelles épreuves de qualité dans des cages en champ et dans les conditions de libération dans la nature. L'importance des conditions optimales d'une alimentation standardisée est soulignée par la qualité des mouches obtenues en élevage de masse.
The frequency of male recombination (r) between the translocation breakpoint and the wp + gene, and the selection coefficient (s) against wp/ wp, in the genetic sexing strain T : Y( wp + )30C of the Mediterranean fruit fly Ceratitis capitata (Wied.) were measured in population experiments over 11 generations. The population was 50 females and 50 males in the first generation, after which 150 pupae were used to start each subsequent generation. A computer program was used to estimate values of r and s. The best fit to the observed data was obtained when r= 0.14 0.04 per cent and s= 26.0 2.7 per cent. Using these estimated values, predictions were made on the frequency of brown females and white males for up to 100 generations. The frequency of white males was predicted never to exceed 0.5 per cent, to be reached after 25 generations, while the frequency of brown females was expected to exceed 33 per cent after 25 generations. Published data on the mass reared T:Y(wp)30C strain, maintained with a population size of 240,000 adult flies, were subjected to the same analysis, indicating a higher value of s (38.0 3.2-52.0 0.3 per cent) under these conditions, but a similar value of recombination. Again, the frequency of white males was predicted never to exceed 0.5 per cent as a result of recombination. When analysing published data on T : Y( wp ÷ ) 101, another genetic sexing strain, a lower stability was indicated, i.e. a more rapid generation of brown females and white males than in T : Y( wp + )30C. No suitable values of s and r could be calculated from the T : Y( wp ÷ )101 data. It is concluded that outside contamination had probably occurred in the latter strain during both periods when it was mass reared.
The T:Y(ωp†)30c genetic sexing strain of Ceratitis capitata (Wiedemann), which is designed to generate males with brown (wild-type) pupae and females with white pupae, was contaminated artificially in a series of population experiments, to investigate the pattern of breakdown of the strain. The frequency of brown female pupae increased whether contamination was with males, unmated females or mated females, but the frequency of white male pupae increased only after male or mated female contamination. Contamination with either sex, mated or unmated, caused a rise in the overall frequency of brown pupae. A fitness advantage of the ωp† gene, when not attached to the Y chromosome, seemed to be indicated. The sex ratio became distorted in favour of females after contamination with females, mated or unmated, but not after male contamination which caused a temporary increase in males. The experiments revealed evidence of a low frequency of natural recombination between ωp† and the translocation breakpoint on the Y chromosome, shown by the appearance of a small number of white males that could not be attributed to the experimental procedure. These findings are shown to be relevant in determining whether wild type contamination has taken place in mass rearing of this strain for sterile male release.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.