Population growth parameters of the Dysaphis pyri (Boyer de Fonscolombe) (Hemiptera: Aphididae) were evaluated on four different cultivars (Coscia, Ankara, Williams, and Santa-Maria) of pear (Pyrus communis L.) under field conditions in the Van region of Turkey. Aphids were kept on leaves of 10-yr-old pear trees in Plexiglas clip-cells (20 mm in diameter and 10 mm in height, with the upper side covered with muslin). For the description of the stage differentiation during population growth, we analyzed raw data of developmental time, survival, and fecundity using the age-stage, two-sex life table to take the variable developmental rate among individuals into account. Results indicated that the Coscia and Ankara cultivars are less favorable hosts for D. pyri because of the longer preadult developmental time, higher preadult mortality rate, and lower total fecundity on these cultivars. The intrinsic rate of increase (r), the net reproduction rate (R₀), and the finite rate of increase (λ) values were lower on the Coscia and Ankara cultivars. We discussed the application of the Weibull function, polynomial model, and Enkegaard model in life table studies. Because these models are often inaccurate in describing survival and reproduction parameters, we suggest that their application in life table research should be reevaluated.

Wheat is one of the most important crops globally in cultivation and production. Insects, which are among the factors that cause quality and quantity losses in wheat production, are among the pest groups that should be monitored and kept under control. This study was carried out in Van province and its districts (Bahçesaray, Başkale, Çaldıran, Çatak, Edremit, Erciş, Gevaş, Gürpınar, Muradiye, Özalp, Saray and Tusba) in May-August 2017 and insect species found in wheat fields were determined. The samplings of harmful and beneficial species were carried out using standard sweep nets and by hand collection. At the end of the study, 66 species belonging to 7 orders and 39 families were found in 165 different localities. Distributions of the species were recorded as 26 species belonging to 12 families in Coleoptera, 19 species belonging to 10 families in Hemiptera, 9 species belonging to 8 families in Diptera, 6 species belonging to 5 families in Hymenoptera, 2 species belonging to 2 family in Orthoptera, 2 species belonging to 1 family in Neuroptera, and 1 species in Thysanoptera. With this study, for the first time, comprehensive information was obtained about the pest species found in the wheat fields in and around Van, their distributions, densities, and the presence of their natural enemies in the region.

Wheat is nowadays the most important source of food on earth. Many pest species have been identified that affect wheat yield and quality negatively. This study was conducted to identify harmful and beneficial insect (predator) species and of the distribution of Sunn pest in wheat cultivation areas in the districts (Siirt province Merkez, Kurtalan, Eruh, Tillo, Şirvan, Pervari, and Baykan) of Siirt Province, Türkiye in 2018 and 2019. Samplings were taken periodically for 1-2 weeks from April to July. The sweep nets, frame, pitfall trap, and visual control methods were used for sampling. At the end of the study, 42 species belonging to 6 orders and 25 families were determined. The distributions of the species were recorded as 27 species belonging to 12 families in Coleoptera, 10 species belonging to 7 families in Hemiptera, 2 species belonging to 2 families in Neuroptera, and 1 species belonging to each family in Hymenoptera, Orthoptera and Diptera. The most common and abundant species: the main pest Eurygaster integriceps Puton, 1881 (Hemiptera: Scutelleridae), the secondary pests Aelia acuminata (Linnaeus, 1758), Dolycoris baccarum (Linnaeus, 1758) (Hemiptera: Pentatomidae), Cephus pygmaeus (Linnaeus, 1767) (Hymenoptera: Cephidae) Gryllus bimaculatus De Geer, 1773, (Orthoptera: Gryllidae) were determined. In the study, a total of 16 species were identified, which is the first record for the local fauna of Siirt province. The highest average density of E. integriceps (2 adult + nymph / m2) was found in the Garzan and Gozpinari locations of the Kurtalan district. Besides, among the beneficial species, general predators Chrysoperla carnea (Stephens, 1836) and Coccinella septempunctata (Linnaeus, 1758) are remark as the most common species