Elliptic Fourier Analysis in the Study of the Male Genitalia to Discriminate Three Macrolophus Species (Hemiptera: Miridae).

Within the genus Macrolophus (Heteroptera: Miridae), the species M. costalis (Fieber), M. melanotoma (Costa) and M. pygmaeus (Rambur) are present in the Mediterranean region on a wide variety of plant species. While M. costalis can easily be separated from the other two by the black tip at the scutellum, M. pygmaeus and M. melanotoma are cryptic species, extremely similar to one another in external traits, which has resulted in misidentifications. M. pygmaeus is an efficient biological control agent, both in greenhouse and field crops. The misidentification of these cryptic species could limit the effectiveness of biological control programs. Although the morphology of the left paramere of the male genitalia has been used as a character for identification of these two cryptic species, there is controversy surrounding the reliability of this character as a taxonomic tool for these species. Using geometric morphometric techniques, which are a powerful approach in detecting slight shape variations, the left parameres from these three Macrolophus species were compared. The paramere of M. costalis was larger and had a different shape to that of M. melanotoma and M. pygmaeus; however, no differences in size or shape were found between the left paramere of M. melanotoma and that of M. pygmaeus. Therefore, our results confirm that this character is too similar and it cannot be used to discriminate between these two cryptic species.

Routine ureteric stenting before cytoreductive surgery plus hyperthermic intraperitoneal chemotherapy in managing peritoneal carcinomatosis from gynecologic malignancies: a single-center experience.

BACKGROUND: Iatrogenic ureteric injury is a rare, yet serious operative complication in gynecologic procedures and associated with substantial morbidities such as prolonged hospitalization, additional financial-based ureter-related repairing procedures, impaired renal function, and compromised quality of life. Direct visual identification of ureters can be very challenging in managing patients with primary advanced or recurrent disseminated intraperitoneal gynecologic malignancies, who are referred to complex procedures such as cytoreductive surgery (CRS) and hyperthermic intraperitoneal chemotherapy (HIPEC). AIMS: To report our single-center experience (feasibility and morbidity) with prophylactic ureteric stents as a routine practice before CRS+HIPEC procedure in managing peritoneal carcinomatosis (PC) from gynecologic malignancies. METHODS: From June-2010 to March-2014, all patients with gynecologic-related PC, managed with CRS+HIPEC, and underwent prophylactic ureteric stents. The data were retrospectively abstracted and analyzed. RESULTS: Fifty-three patients were identified. Almost all PC cases were secondary/recurrence presentations (90.6 %) and originated from ovarian cancer (84.9 %). Optimal cytoreduction microscopic residual disease) was achieved in 35 patients (60 %). Average insertion time of ureteric stents was 8.9 ± 3.3 min. Fifty-two patients (98.1 %) received bilateral ureteric stents. Forty-nine patients (92.5 %) had their ureteric stents removed by the end of procedure. No patient experienced major peri-operative urinary tract-related complications. CONCLUSIONS: Prophylactic ureteric stents appeared to be feasible, potentially safe, and could reduce the risk of iatrogenic ureteric injuries without incurring an increase in urinary tract-related complications. Prophylactic ureteric stenting does not eliminate the necessity for competent anatomical knowledge, meticulous retroperitoneal dissection and direct intra-operative visualization of ureters.

Taxonomic identification of Macrolophus pygmaeus and Macrolophus melanotoma based on morphometry and molecular markers.

Two Macrolophus species, M. melanotoma (=M. caliginosus) and M. pygmaeus, have been referred to as efficient predators of several key pests on vegetable crops in Europe. However, due to the great morphological similarity of these species, they have been confused, with important consequences for inoculative releases of these predators in greenhouses and for the conservation of their natural populations on greenhouse and outdoor crops. In this work, we developed tools to identify these morphologically very similar species. We first confirmed the specific status of two Macrolophus populations collected on their respective host plants (Dittrichia viscosa and tomato) through crossing experiments. Then, using multivariate morphometric analysis, we proposed a linear discriminant function that combines head measurements separating males from the two species without error. Finally, we designed specific primers for a mitochondrial DNA region that were able to distinguish field-collected Macrolophus individuals through conventional PCR. In conclusion, the tools developed in the present study will allow reliable identification of the Macrolophus species present in crops and in the native flora that are the source of populations that colonise them. They will also allow correct identification of mass reared Macrolophus to be introduced in greenhouse crops in inoculative releases.

Cuticular hydrocarbons discriminate cryptic Macrolophus species (Hemiptera: Miridae).

Macrolophus pygmaeus is commercially employed in the biological control of greenhouse and field vegetable pests. It is morphologically undistinguishable from the cryptic species M. melanotoma, and this interferes with the evaluation of the biological control activity of M. pygmaeus. We analysed the potential of cuticular hydrocarbon composition as a method to discriminate the two Macrolophus species. A third species, M. costalis, which is different from the other two species by having a dark spot at the tip of the scutellum, served as a control. Sex, diet and species, all had significant effects in the cuticular hydrocarbon profiles, but the variability associated to sex or diet was smaller than among species. Discriminant quadratic analysis of cuticular hydrocarbons confirmed the results of previous molecular genetic studies and showed, using cross-validation methods, that M. pygmaeus can be discriminated from M. costalis and M. melanotoma with prediction errors of 6.75% and 0%, respectively. Therefore, cuticular hydrocarbons can be used to separate M. pygmaeus from M. melanotoma reliably.

Development of specific ITS markers for plant DNA identification within herbivorous insects.

DNA-based techniques have proved to be very useful methods to study trophic relationships between pests and their natural enemies. However, most predators are best defined as omnivores, and the identification of plant-specific DNA should also allow the identification of the plant species the predators have been feeding on. In this study, a PCR approach based on the development of specific primers was developed as a self-marking technique to detect plant DNA within the gut of one heteropteran omnivorous predator (Macrolophus pygmaeus) and two lepidopteran pest species (Helicoverpa armigera and Tuta absoluta). Specific tomato primers were designed from the ITS 1-2 region, which allowed the amplification of a tomato DNA fragment of 332 bp within the three insect species tested in all cases (100% of detection at t=0) and did not detect DNA of other plants nor of the starved insects. Plant DNA half-lives at 25°C ranged from 5.8 h, to 27.7 h and 28.7 h within M. pygmaeus, H. armigera and T. absoluta, respectively. Tomato DNA detection within field-collected M. pygmaeus suggests dietary mixing in this omnivorous predator and showed a higher detection of tomato DNA in females and nymphs than males. This study provides a useful tool to detect and to identify plant food sources of arthropods and to evaluate crop colonization from surrounding vegetation in conservation biological control programs.