Rapid assessment of the sex of codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) eggs and larvae

Abstract

Two different methods were tested to identify the sex of the early developmental stages of the codling moth Cydia pomonella (Linnaeus) (Lepidoptera: Tortricidae) with a WZ/ZZ (female/male) sex chromosome system. First, it was shown that the sex of all larval stages can be easily determined by the presence or absence of sex chromatin, which is formed by the female‐specific W chromosome in interphase nuclei. This trait can also be used to identify the sex of newly hatched larvae but it does require care and accuracy. Secondly, a new sexing technique was developed based on a molecular marker of the codling moth W chromosome. Flanking regions of an earlier described W‐specific sequence (CpW2) were isolated and sequenced and a 2.74 kb sequence (CpW2‐EcoRI), specific for the W chromosome, was obtained. Several PCR tests were conducted, which confirmed that the CpW2‐EcoRI sequence is a reliable marker for the sex identification in codling moth samples of different geographical origin. In addition, a fragment of a codling moth gene, period (Cpper) was isolated and sequenced. Results of southern hybridization of the Cpper probe with female and male genomic DNA suggested that the Cpper gene is located on the Z chromosome. Then a multiplex PCR assay was developed, which co‐amplified the CpW2‐EcoRI sequence to identify the W chromosome and the Z‐linked Cpper sequence, which served as a positive control of accurate processing of tested samples. The multiplex PCR provides an easy and rapid identification of the sex of embryos and early larval instars of the codling moth.

Adult Sex Ratio in the Parnassius Mnemosyne Butterfly: Effects of Survival, Migration, And weather

“…Available methods, such as emergence cages (Goffart et al, 2010), exist, but their use in the diverse woodland environments may be more difficult then, e.g., on rather uniform grasslands. Another alternative may be repeated search for larvae during the larval period and the construction of survival tables, with the larvae sex determined using up-to-date molecular methods (Fukova et al, 2009).…”

Neo-sex chromosomes and adaptive potential in tortricid pests

“…Additionally, a partial sequence of the C. pomonella circadian gene period (per) was acquired from GenBank [accession no. JX996071 (17)]. Hybridization probes generated from the cloned gene fragments were used for screening of the C. pomonella bacterial artificial chromosome (BAC) library.…”

Improvement of the sterile insect technique for codling moth Cydia pomonella (Linnaeus) (Lepidoptera Tortricidae) to facilitate expansion of field application

“…The 956‐bp PCR fragment from cDNA was used as a probe in Southern hybridization, resulting in hybridization signals which were twice as strong with male DNA as with female DNA. This indicated that this Cpper fragment is located on the Z‐chromosome (Fuková et al. 2009).…”

“…Recently, one of the motifs, CpW2, was extended by sequencing of flanking regions with the aim to develop a molecular marker of the W‐chromosome. The resulting 2.74‐kb long Eco RI DNA fragment (CpW2‐ Eco RI) proved to be female‐specific by Southern hybridization and by polymerase chain reaction (PCR) testing and proved to be a reliable marker for the sex identification in codling moth samples of different geographical origin (Fuková et al. 2009).…”