Project "Evolutionary aspects of reproductive biology and cytogenetics of hemipteroid insects (Hemiptera)"

 

As a model group to examine the evolutionary significance and interconnections of the aberrant reproductive strategies encountered in animals will be applied insects of suborder Hemiptera. Reproductive strategies and underlying cytogenetic mechanisms will be carefully examined in selected taxa of different families of Coccinea, Aleyrodinea, Psyllinea, Cicadinea, and Heteroptera by the team of the project. A comparative analysis of such phenomena as ovoviviparity/viviparity, neoteny, paedogenesis and some other ones in Hemiptera will be made. A number of previously published hypotheses that ovoviviparity/viviparity correlates with the lack of imaginal structures and functions of the organism will be tested on the wide range of examples.

 

The studied strategies and underlying mechanisms will be phylogenetically considered and their plesiomorphic and apomorphic states will be hypothesized. With economically important species (plant pests), new data on their reproductive biology will form the basis for studies in the field of applied entomology and development of scientifically based measures to control and reduce fertility of these pests in terrestrial ecosystems.

 

 

 

 

06.03.2020

The first results from the project are published in the journal „Comparative Cytogenetics“, in a paper titled: “New data on karyotype, spermatogenesis and ovarian trophocyte ploidy in three aquatic bug species of the families Naucoridae, Notonectidae, and Belostomatidae (Nepomorpha, Heteroptera)”. (CompCytogen 14(1): 139–156 (2020) doi: 10.3897/CompCytogen.v14i1.48709) 

Although many true bugs (Hemiptera, Heteroptera) species are pests, most of the aquatic bugs are predators controlling the populations of mosquitoes.. We studied the number of chromosomes and their behaviour during cell division in a saucer bug (Iyocoris cimicoides) and two other species of aquatic bugs. We found that Ilyocoris cimicoides differs from all the other studied so far species of the family Naucoridae in the type of meiosis, which is  important part of the production of  gamete cells. During meiosis, visible connections (chiasmata) between homologous chromosomes are usually formedas a result  of the recombinations – chiasmate meiosis. This is the case for other species of the family Naucoridae, but not for Ilyocoris cimicoides. In the males of this species the homologs lie in parallel whitout any chiasmata – the meiosis is achiasmate.  This finding was surprising as most of the studied families of true bugs seem to be homogenous in respect to the presence or absence of chiasmata.