Production and assortment of dry beans in Serbia

Dry beans belong to pulses, species from Fabaceae family. Its dry grain is used in human nutrition. It is valued as traditional and modern food and medicine, protein source, and high-energy concentrated food. It is an important crop in agricultural production and international trade of many countries, economically viable and good preceding crop. Dry beans are considered the national dish of all people from Balkans, and it is inviolable in Serbia. Crossing of important trade routes, land and climate, turbulent history, which caused frequent population migrations, led to a great divergence of bean germplasm in our area. Domestic bean populations are exceptional genetic potential for breeding of new varieties that could give satisfactory results in these environmental conditions, with the application of appropriate cultivation technology. Areas under beans in Serbia are declining. Due to short vegetation and other biological traits, bean is very intensive and sensitive crop. This is emphasized by exceptional sensitivity to polyphagous insects, as well as the presence numerous pathogens. Low average yield is affected by weather, primarily high temperatures and drought. Yields could be increased by correct and timely application of modern agronomic knowledge, irrigated cultivation, in a joint crop or by sowing as second crop.

Diversity of bacterial symbionts associated with Myzus persicae (Sulzer) (Hemiptera: Aphididae: Aphidinae) revealed by 16S rRNA Illumina sequencing

Aphids are known to be associated with a variety of symbiotic bacteria. To improve our knowledge of the bacterial diversity of polyphagous aphids, in the present study, we investigated the microbiota of the cosmopolitan agricultural pest Myzus persicae (Sulzer). Ninety-two aphid samples collected from different host plants in various regions of China were examined using high-throughput amplicon sequencing. We comprehensively characterized the symbiont diversity of M. persicae and assessed the variations in aphid-associated symbiont communities. We detected a higher diversity of symbionts than has been previously observed. M. persicae hosted the primary endosymbiont Buchnera aphidicola and seven secondary symbionts, among which Wolbachia was the most prevalent and Rickettsia, Arsenophonus, and Spiroplasma were reported for the first time. Ordination analyses and statistical tests revealed that the symbiont flora associated with M. persicae did not change with respect to host plant or geography, which may be due to frequent migrations between different aphid populations. These findings will advance our knowledge of the microbiota of polyphagous insects and will enrich our understanding of assembly of host-microbiome systems.

Efek subletal campuran ekstrak daun srikaya (Annona squamosa L.) dan rimpang kunyit (Curcuma domestica Val.) terhadap larva Spodoptera litura F.

Spodoptera litura (Lepidoptera: Noctuidae) larvae are polyphagous insects whose populations cause damage to various types of plantations, horticulture, and food so that control efforts need to be done. One way to control the environment of environmentally friendly S. litura larvae is to use a plant-based insecticide, a mixture of A. squamosa leaf extract and C. domestica rhizome (test extract appendix). The purpose of this study was to determine the subletal effect of the test extract mixture on S. litura larvae, namely the duration of larvae and pupae stage, pupae weight, morphology and imago viability, and the ability of female imago to lay eggs to produce offspring. The test was carried out by the method of feed dip into the test extract mixture. Data on pupae weight were analyzed with ANOVA, followed by Duncan's further test with a 5% confidence level using SPSS 21 program. The results showed that the test extract mixture extended the stages of larvae and pupae, reduced pupa weight, imago wings did not develop fully, reduced imago size, and did not imago able to produce eggs. The results of this study could then be further tested on a greenhouse scale and photochemical analysis of a test extract mixture to determine bioactive compounds that act as plant-based insecticides.

Aspek Biologi Sycanus annulicornis Dohrn. (Hemiptera: Reduviidae) Yang Dipelihara Dengan Pakan Alternatif Larva Alphitobius diaperinus Panzer (Coleoptera: Tenebrionidae)

Assassin Bug, Sycanus annulicornis Dohrn. (Hemiptera: Reduviidae) is one of the predatory polyphagous insects that has the potential to be used as a natural enemy in pest control in food crops, horticulture, plantations, and forestry plants. This study aimed to evaluate the biological aspects of S. annulicoris maintained with alternative feeds of Alphitobius larvae diaperinus Panzer. The results showed that S. annulicornis maintained with A. diaperinus larvae produced an egg incubation period of 19.0 ± 2.1 days, fecundity of 88.1 ± 46.0 eggs, fertility of 41.8 ± 11.4%, time of development of nymphs 82.4 ± 6.4 days, mortality of nymphs 53.5 ± 3.3%, duration of male and female imago: 36.3 ± 12.8 and 61.1 ± 18.1 days, male sex ratio: female 1: 4, and the male and female S. annulicornis imago life cycle: 118.7 ± 9.6 and 143.5 ± 12.3 days. The results showed that A. diaperinus larvae could be used as an alternative feed for mass propagation of S. annulicornis in an integrated pest control program.

Pathogen resistance in the moth Orgyia antiqua: direct influence of host plant dominates over the effects of individual condition

The role of pathogens in insect ecology is widely appreciated but remains insufficiently explored. Specifically, there is little understanding about the sources of the variation in the outcome of insect-pathogen interactions. This study addresses the extent to which immune traits of larvae and pupae of the moth Orgyia antiqua L. (Lepidoptera: Lymantriidae) depend on the host plant species and individual condition of the insects. The two host plants, Salix myrsinifolia Salisb. and S. viminalis L., were chosen because they differ in the concentration of phenolic glycosides, harmful to most polyphagous insects. Individual condition was assumed to be reflected in body weight and development time, and was manipulated by rearing larvae either singly or in groups of four. The resistance traits recorded were survival and time to death after fungal infection in the larval stage and the efficiency of encapsulating a nylon implant by the pupae. The survival of the infected larvae was mainly determined by the species of the host plant. Encapsulation response was not associated with the resistance to the pathogen, suggesting that the host plant affected the pathogen rather than the immune system of the insect. Interestingly, the host plant supporting better larval growth led to inferior resistance to the pathogen, indicating a trade-off between different aspects of host plant quality.

Response of the polyphagous whitefly Bemisia tabaci B-biotype (Hemiptera: Aleyrodidae) to crop diversification – influence of multiple sensory stimuli on activity and fecundity

A fundamental question concerning crop diversification is which mechanisms determine pest population size in polycultures compared to monocultures. It has been proposed that polyphagous insects experience a difficulty in decision-making when selecting food and oviposition sites in the presence of different host plants. This hypothesis was tested in the extremely polyphagous whitefly Bemisia tabaci (Gennadius) B-biotype, where behaviour (movement) and fecundity of females were compared in choice and no-choice experiments in the laboratory. Two parallel tests, one on different crops, including cucumber, bean and tomato, and one on different tomato cultivars, were conducted using both a mixture of crops and of tomato cultivars, as opposed to the same crop or cultivar respectively. Bemisia tabaci showed a distinct behavioural preference for cucumber when exposed to different crops simultaneously suggesting that B. tabaci has no difficulty in choosing a host plant, i.e. in making a decision, when one of the plants offered in the choice test is a high-ranking host plant. Conversely, when only low-ranking hosts of similar, but not identical, signatures were present, female whiteflies appeared to have difficulty in making a decision, resulting in increased movement and reduced fecundity. This is consistent with both the hypothesis that polyphagous insects have a problem selecting a host plant when given multiple choices and with the hierarchy threshold model, under which egg loads are lessened between periods of searching for better host plants. The study illustrates how insect behaviour can be affected by intercropping not only with different crops, but also with different cultivars of the same crop, thus potentially providing a simple and efficient way of reducing whitefly population build-up.

LIFE HISTORY OF THE POPLAR BEETLE CHRYSOMELA TREMULAE F. IN THE CENTRAL REGION OF FRANCE

The need to exploit new sources of energy has recently led France to encourage several research programs toward the cultivation of crops for biomass production to extract alcohol, glucides, and chips for burning. To produce large quantities of biomass rapidly, several species of Populus have been selectively tested in short rotation coppices on about 400 ha in several parts of the country.Among the practical consequences of this policy, one appears to be harmful, namely the spatial extension of several pests, mainly leaf eaters or polyphagous insects. These insects previously were located in poplar nurseries. Among the leaf eaters, larvae and adults of the poplar leaf beetles Chrysomela (= Melasoma) populi L. and Chrysomela tremulae F. feed on many poplar species in central France (e.g. Populus tremula L., Populus trichocarpa Torrey and Gray, Populus deltoides Bartram, Populus lasiocarpa Oliver).