Many insects benefit from bacterial symbionts that provide essential nutrients and thereby extend the hosts’ adaptive potential and their ability to cope with challenging environments. However, the implications of nutritional symbioses for the hosts’ defence against natural enemies remain largely unstudied. Here, we investigated if the cuticle-enhancing nutritional symbiosis of the saw-toothed grain beetle Oryzaephilus surinamensis confers protection against predation and fungal infection. For this, we exposed age-defined symbiotic and symbiont-depleted (aposymbiotic) beetles to two antagonists that must actively penetrate the cuticle for a successful attack: wolf spiders (Lycosidae) and the fungal entomopathogen Beauveria bassiana. While young beetles suffered from high predation and fungal infection rates regardless of symbiont presence, symbiotic beetles were able to escape this period of vulnerability and reach high survival probabilities significantly faster than aposymbiotic beetles. To understand the mechanistic basis underlying these differences, we conducted a time-series analysis of cuticle development in symbiotic and aposymbiotic beetles by measuring cuticular melanisation and thickness. The results reveal that the symbionts accelerate their host’s cuticle formation and thereby enable it to quickly reach a cuticle quality threshold that confers structural protection against predation and fungal infection. Considering the widespread occurrence of cuticle enhancement via symbiont-mediated tyrosine supplementation in beetles and other insects, our findings demonstrate how nutritional symbioses can have important ecological implications reaching beyond the immediate nutrient provisioning benefits.

The pine wood nematode Bursaphelenchus xylophilus (Parasitaphelenchidae, Nematoda) is one of the most important pathogens of high ecological and economic importance worldwide, causing the Pine Wilt Disease. Following the routes and pathways employed by the international trade, B. xylophilus has managed to expand beyond its natural range with Wood Packaging Material (WPM) and has soon become one of the most notorious quarantine organisms. To prevent its further expansion, national survey programs are examining samples from pine and other coniferous trees showing suspicious symptoms that could potentially be attributed to B. xylophilus. In this direction, 45 wood samples were collected from trees located at nine regions of Northern and Central Greece. Nematode extraction was carried out using a modified Baermann funnel technique, and identification was based on their morphological traits. Even though B. xylophilus was not retrieved from any of these samples, four other species of the Bursaphelenchus genus were identified. In addition to them, other taxa that contain saprophytic, predatory and entomophilic nematodes were also recorded. It is thus evident that beside preventing the introduction of B. xylophilus in Greece, the national survey program can substantially contribute to increase our knowledge on the nematode species inhabiting pine trees in Greece.

The pine processionary moth (PPM), namely Thaumetopoea pityocampa or T. wilkinsoni, feeds on pine needles, causing defoliation and promoting tree decline. The production and emission of volatile organic compounds is one of the most effective plant defense mechanisms against herbivory. The present work reviewed available reports on the influence of plant volatiles on PPM behavior. Eighteen volatiles were reported to be detected by the PPM, to inhibit feeding and oviposition, or to reduce attraction to pheromones. High biological activities were reported for limonene or β-pinene enantiomers. Infested pines showed increased production of bornyl acetate, β-pinene and caryophyllene oxide. Uncovering the volatile cues that influence parasitic PPM behavior provides an important contribute to the establishment of safer pest management practices to control this pine pest.

Structural polytene chromosome maps of the two Tephritid (Order- Diptera) fruit fly species were studied. Bactrocera zonata originates in South and South-East Asia. It attacks more than 50 host plants, several of which are commercial species- guava, mango, peach, apricot, fig and citrus. The probable risk of its introduction to a new country is aided by travel and trade, and is influenced by changes in climate and land use. The EPPO classified it as A1 Pests, suggesting for regulation as a quarantine pest. Zeugodacus tau is widespread in Asia and Australia. It attacks 34 hosts from 9 families, major commercial hosts- melon, cucumber, pumpkin, luffa, sapodilla, bitter gourd and guava. The aim of the study was to identify polytene chromosomes from the 3^rd instar larval salivary glands and to construct structural polytene maps based on the banding patterns of the polytene arms. In both species, five polytene chromosomes (10 polytene arms) corresponding to the five autosomes of the mitotic chromosomes and a heterochromatic mass were observed in polytene nuclei. Heterochromatic mass is a granular network and supposed that it corresponds to sex chromosomes. Polytene maps were constructed by dividing each of chromosome arms into twenty sections. The tips of each chromosome arm, prominent landmarks, characteristic banding patterns and puffs were recognized that reflected the fundamental differences in the chromosomes. The structural map presented here could help to explain each section of the chromosome arm which allow to identify/ locate any chromosomal rearrangements or any structural differences within other tephritid species.

Storage insect pests are inflicting severe economic loss leading to food insecurity and hunger. Research evidence suggests that synthetic chemicals are toxic to humans and are creating deleterious impacts on biodiversity. Therefore, this study evaluated natural plant extracts as alternatives to synthetic insecticides in controlling storage insect pests in an eco-friendly manner. Fresh and dry leaves, and seed kernel extracts of Azadirachta indica, Gliricidia sepium, Ocimum tenuiflorum (Holy basil or Thulsi), Cascabela thevetia (yellow oleander) were tested against storage insect pests Tribolium confusum (Confused flour beetles) and Sitophilus oryzae (Rice weevils). Yellow oleander fresh leaves, flowers, seed kernels, and fresh leaves of neem, gliricidia, and thulsi were collected and aqueous extracts were derived. Two laboratory trials were conducted. The first one was to understand the toxicity of aqueous extracts on pests. Therefore, 100 adult insects of red flour beetles and rice weevils were topically applied with treatments at the rate of 10g/100 mL. The second trial was to test the repellent properties of the aqueous solutions. Therefore, extracts were applied over the sealed bait bags in a large closed container at the same rate. Immediately after treatment application, 100 adult insects of each group were released into the container containing baits, and the container closed. Both trials were arranged in a completed randomized design (CRD), replicated three times including the untreated control. From the first trial, the number of live insect per treatments was counted after 30 seconds, 1 minute, 5-minute, 10-minute, 1 h, 2 h, and 24 h, and mortality percentage were calculated. From the second trial, the number of insects inside the sealed bags was counted 24 h, 48 h, 5 d after treatment. The data were subjected to ANOVA using SAS 9.1. Tukey's HSD multiple comparison test was used to identify the best treatment combination. The result showed that C. thevetia dried seed kernels exhibited highly significant mortality of 50% against rice weevils and 100% against flour beetles, after an hour and one minute, respectively, at P <0.01. Ocimum tenuiflorum and A. indica showed 100 % mortality against flour beetles after 24 h, but not in rice weevil. Repellency percentage was highly significant in C. thevetia dried leaf extract (91.30% and 75.00%) and fresh leaf extract (86.36% and 78.05 %) after 24 hours and five days, respectively at P <0.01. In the repellency treatment, C. thevetia dried leaf and seed kernel extract showed highly significant repellency of 96.91% and 98.99%, respectively, against red flour beetles. The repellency percentage of C. thevetia dried leaf, seed kernel extract and O. tenuiflorum were 81.79%, 66.67% and 59.15% after 24 hours, respectively, and significant at P <0.05. The results suggest that leaf and seeds of C. thevetia have high insecticidal properties and can be used to repel storage insects in warehouses once potential toxicity to humans is determined.

The Mediterranean fly (Medfly), Ceratitis capitata causes important economic and agricultural losses due to its peculiar ability to invade and adapt to different climates throughout tropical and subtropical regions. Traditional control methods should be implemente by innovative tools among which those based on nsect symbiont seem very promising. Our study aimed to characterize the microbial communities of different anatomical districts (gut and reproductive organs) of three different strains of C. capitata, to determine whether selected symbionts could be translated into potential tools for the symbiotic control of medfly. While confirming the presence of Asaia in both organs, we revealed for the first time the presence of Propionibacterium and Chroococcidiopsis in the reproductive organs of Medfly. These findings paves the way for the development of control methods based on the use of symbiotic bacteria.

The Lesser Date Moth (LDM) Batrachedra amydraula (Lepidoptera: Batrachedridae) is a serious pest of fruits of date palm trees that causes economic losses in nearly all growing regions globally. As one of the main methods for controlling this pest, overuse of broad-spectrum insecticides is applied. Population sampling methods are fundamental in the chemical control-based IPM system, minimizing the negative effects of insecticides on the environment. A tentative sampling method for LDM is recommended; however, conventional sampling schemes are complained due to the time-consuming. Alternatively, binomial sequential sampling plans are often more efficient and may allow sampler to fast classify pest infestations and make a control decision. The objectives of this study were to determine the spatial distribution and develop binomial sequential sampling for fast reliable estimation of LDM infestation on date palms. Throughout the province of Basra, Iraq, eighty-four 1 ha date palm orchards were sampled from 2017 to 2019. The results of spatial distribution pattern analyses by using Taylor’s power law (a = 0.0695 and b = 1.4041) indicated that LDM on sampling units (date palm spikelets) were highly aggregated in date palm orchards. The mean vs. proportion infested (PT-m) (T= 0 to 5) models for LDM infesting sampling units (lower leaves) revealed relatively strong fits for LDM. Binomial sequential sampling plans for LDM on date palms were developed for action thresholds of 0.10, 0.15, 0.25, and 0.35 proportions of spikelets with at least three infested fruit (T=3). Binomial sequential sampling plans were validated using RVSP software by the evaluation of operating characteristics (OC) and average sample number (ASN) functions. We recommend a minimum sample size of 12 and sampling efforts should be terminated at 90 samples for these sampling plans.

Climate change and global warming are affecting many of insect species in different ways. Organisms develop diverse mechanisms responding to variable environmental conditions. Due to the global warming and rise in mean and extreme temperatures, the importance of an individual’s ability to adapt to temperature stress will further increase. Our focus in this study is thermal response, which is considered to be one of the crucial elements of individual fitness and survival in fast changing environment. We investigated stress resistance traits: desiccation and heath shock mortality in two Drospohila subobscura populations from two diffrent altitudes (1080mand 1580m a.s.l.)along Stara planina mountain slopes in Serbia. The F1 progeny of the mass populations from both localities was used to establish six experimental groups at three different temperature regimes: 25⁰C, 19⁰C and 16⁰C. Our aim was to determine whether there is a correlation between altitude/origin of populations and/or laboratory thermal evolution within these resistance traits. The sample of flies from all groups were tested (scored every hour) for desiccation mortality at those temperatures. To score heath shock mortality all groups were placed into vials with moistened cotton plugs to prevent desiccation, kept at 37⁰C for seven hours and mortality was checked every 30 minutes. Our results indicate that the population origin, as well as laboratory thermal evolution have a significant influence on the analysed traits. Individuals originating from the higher altitudes reared at higher temperatures show better resistance to thermal shock.

"Harvest Flight Synapse (HFS)" refers to the way in which a pollinator communicates and interconnects the organization of a flower system through a sequence of flight performed through the space of the vegetative architecture of a plant. It was identified HFS of Apis mellifera performed in a territory of the desert of Sonora, Mexico by visual monitoring of Stenocereus thurberi cacti individuals, located around the periphery of a cultivation area of Medicago sativa during flowering´s season. The importance of the HFS is that the pollinators establish a pre-designed flight transit order on the vegetative architecture so that subsequent visitors perform a flight sequence in which they include more floral structures, ensure pollination - harvest and at the same time stimulate the flowering. HFS prevailed initially from the east and the differences in time of stay in each column were not governed by their height or distance between them but by the number of columns with the presence of floral appendixes determined by their respective floral range and flowering scale. Communication and interconnection coexist in the bee-cactus relationship and allow sequencing the ecological processes in both organisms from the HFS.

Knowledge gaps in taxonomy and systematics are present in all insect groups, differing just in size. Generally, size of the gap is negatively correlated with body size and positively with number of species within the group. As an example, we present the size of the knowledge gap within the subfamily Aphidiinae (Hymenoptera: Braconidae). As solitary koinobiont endoparasitoids of aphids, Aphidiinae are widely used as biocontrol agents and consequently one of the best studied parasitoid groups. In the last decade, taxonomical studies on Aphidiinae have been focused on an integrative approach which resulted in numerous new findings: description of new species, detection of alien species, resolving the taxonomical status of genera and species groups, proposition of new classification schemes, etc. All those findings are critically summarized. Availability of different types of data is discussed and propositions for future studies and optimal research practices are given.