Survey and revision of leaf miners to some plants from different localities of Iraq

This investigation showed (31) species belonging to (15) genera under (five) families and two orders. The leafminers Dipter families (Agromozidae, Anthomyiidae, Drosophilidae), Agromyzid flies is the highest level of investigated many host plants, but other families have lowest host plants. The synonyms of species were provided from GBIF scarlet's. The date and localities of sampling collection were recorded.

Evaluation of different traps for the invasive leaf miner, Liriomyza huidobrensis in potato (Solanum tuberosum) fields of the Nilgiris district, Tamil Nadu, India

Potatoes are currently threatened by the pea leaf miner (Liriomyza huidobrensis Blanchard), an exotic, exceedingly polyphagous, and chemically resistant pest that attacks a wide range of crops, ornamental plants, and weeds. The present work was conducted to study the attractiveness of various traps to Liriomyza leaf miner, one of the invasive pests recently observed in potato fields of Kotagiri and Ooty in Nilgiris district of Tamil Nadu. A trial was conducted at these two different locations, the Nilgiris district, in 2021. The results revealed that among different traps tested for their efficacy in attracting the leaf miner, L. huidobrensis, yellow sticky trap was found to be more efficient in attracting adult leaf miner flies with the mean trap catches of 40.49 and 36.64 adult flies/ 10 cm2 areas at Kotagiri and Ooty respectively. The peak population of leaf miners was recorded in the last week of April (45.67 adult flies/ 10 cm2 areas) at Ooty and during the 3rd week of June (52.33 adult flies/ 10 cm2 areas) at Kotagiri. The correlation study revealed a significant positive correlation of the trap catches with maximum temperature, diurnal variation (DV) and growing day degrees (GDD). Multiple regression equation was also developed, where the abiotic factors contributed 46.1% and 65.5% to the Liriomyza leaf miner population fluctuation in the potato ecosystem. The trappers may be used to determine the initial presence of a leaf miners’ population and in projecting their future population through pest management models and management decisions.

In search for the unlikely: Leaf-mining caterpillars (Gracillariidae, Lepidoptera) from Upper Cretaceous and Eocene ambers

Fossil leaf-mining caterpillars from amber are firstly described as the new species Phyllocnistis cretacea from Upper Cretaceous Myanmar amber and Phyllonorycter inopinata from Eocene Baltic amber. Both show typical traits of leaf-miners, and specifically, of later instars of caterpillars of their respective genera. The findings give further evidence for these being quite old and conservative genera of Gracillariidae. These are basal Ditrysia which retained the larval feeding and mining live mode. The findings also represent direct fossil evidence of individual stages of hypermetamorphosis known from extant Gracillariidae. The finds from the Upper Cretaceous and their putative identifications give direct evidence for a minimal geological age for the genus Phyllocnistis (Phyllocnistinae) and, by indirect conclusion based on their divergence, also for the genus Phyllonorycter in a sister clade (Lithocolletinae). It also predates mining habit closer to the time of radiation of their angiospermous host plants.

Non-native plant drives the spatial dynamics of its herbivores: the case of black locust (Robinia pseudoacacia) in Europe

Non-native plants typically benefit from enemy release following their naturalization in non-native habitats. However, over time, herbivorous insects specializing on such plants may invade from the native range and thereby diminish the benefits of enemy release that these plants may experience. In this study, we compare rates of invasion spread across Europe of three North American insect folivores: the Lepidoptera leaf miners Macrosaccus robiniella and Parectopa robiniella, and the gall midge Obolodiplosis robiniae, that specialize on Robinia pseudoacacia. This tree species is one of the most widespread non-native trees in Europe. We find that spread rates vary among the three species and that some of this variation can be explained by differences in their life history traits. We also report that geographical variation in spread rates are influenced by distribution of Robinia pseudoacacia, human population and temperature, though Robinia pseudoacacia occurrence had the greatest influence. The importance of host tree occurrence on invasion speed can be explained by the general importance of hosts on the population growth and spread of invading species.

Herbivory on the pedunculate oak along urbanization range in Europe: effects of local forest cover and insect feeding guild

Urbanization is recognized as an important driver of the diversity and abundance of tree associated insect herbivores, but its consequences for insect herbivory are controversial. A likely source of variability among studies is the insufficient consideration of intra-urban variability in forest cover. With the help of citizen scientists, we investigated the independent and interactive effect of urbanization and local canopy cover on insect herbivory in the pedunculate oak (Quercus robur) throughout most of its geographic range in Europe. The damage caused by chewing insect herbivores as well as the incidence of leaf-mining and gall-inducing herbivores consistently decreased with increasing urbanization around focal oaks. Herbivory by chewing herbivores increased with increasing forest cover, regardless of urbanization. In contrast, an increase in local canopy cover buffered the negative effect of urbanization on leaf-miners and strengthened its effect on gall-inducers. These results show the complexity of plant-herbivore interactions in urbanized areas, highlighting that the presence of local canopy cover within cities has the potential to attenuate or modify the effect of urbanization on biotic interactions.

Growing Tomato under Protected Cultivation Conditions: Overall Effects on Productivity, Nutritional Yield, and Pest Incidences

Tomato continues to be one of the most important crops worldwide, and protected cultivation is practiced to overcome the biotic and abiotic stresses to which the plant are exposed during growth. In this study we evaluated the effect of colored net houses on the growth, yield and nutritional values, as well as the incidence of common pests under three different light conditions: (1) colored (magenta), (2) conventional (white), and open field conditions. A colored net house led the plants to grow taller with higher lycopene content, but recorded a higher number of whiteflies, compared to the conventional net house and open field conditions. Furthermore, plants under protected structures recorded lower SPAD values, but larger terminal leaflets, lower damage by leaf miners, but more damage caused by spider mites compared to those plants grown under open field conditions. Overall, we found that the use of colored net houses provided a positive effect on tomato production in terms of improvement in morphometric parameters, however, to obtain higher yields under this production system, it is important to reduce the elevated temperature and increase the relative humidity inside the protective structures to be adapted for local growing conditions in Taiwan.

Early Morphological Growth Response and Incidence of Key Pests Under Two Spacing Regimes of Coffea canephora

Coffea canephora has non-limiting but unexploited yield and quality potential when compared with C. arabica. Coffee tree density optimization can improve fortunes of smallholder farmers. An attractive example is that high productive countries where high plant densities do increase area yield but across boardrecommendations are illogical especially with variety and agroecological variations. We aimed to compare two spacing regimes for growth response and pest incidence using Kituza Robusta clone. Randomized complete block designs with three replications and eight plants per plot were established at four agroecologically diverseon-farm locations. Eleven plant growth variables were measured. In addition incidences of five key pests were assessed. Data was collected on a 3-month interval starting from 12 up to 21 months after planting. Highly significant differences between spacing regimes (p<0.01) were obtained for majority of variables. Mean growth response was generally higher under 3 m x 1 m (high density) than 3 m x 3 m (low density) particularly with stem girth, plant height, length of longest primary branch, and leaf blade length. Conversely, pest incidence of black coffee twig borer, leaf eating beetles, leaf miners, and tailed caterpillars, except skeletonizers was higher under high than low plant densities. The findings provide aguide on implications of high plant densities on growth robustness which is translatable into yield potential; amidst a pest prevalence dilemma in studied type of C. canephora.

Foliage-browsing Lepidoptera (Insecta) in deciduous forests of Ukraine for the last 70 years

As insect development depends on temperature, so the change in biology, behavior habits, frequency, and severity of outbreaks of foliage-browsing insects considered pests can follow the climate change. The reactions of species to the same climate changes can be specific, therefore, an unpredictable change in their ratio in the community will affect the consequences of climate change. The details of such changes must be studied to quantitatively assess future trends and the threats to deciduous forests. The aim of this research was to evaluate the representation in deciduous forests the foliage-browsing lepidopterous insects if different groups of size, lifestyle, voltinism, trophic relations, and ability to mass propagation in different periods of assessment for recent 70 years. In the analysis, we used a list of 118 lepidopterous species of foliage-browsing insects of deciduous forests, compiled on the basis of archival data from 1940–1975, and in the course of our own field research from 1975 to the present in the forests of Ukraine. Following trends were expected to be confirmed for these time intervals: to increase the number of species of small size, the number of species with hidden lifestyle, multivoltine species, polyphagous species, and so-called indifferent species. For each species, all these parameters were identified and proportions of species of each category for certain time intervals (1940–1950, 1960–1970, 1980–1990, and 2010–2020). Their distribution for size, voltinism, lifestyle, trophic features, and outbreak potential at these time intervals was compared using χ2-test. Among lepidopterous foliage-browsing insects of deciduous forests of Ukraine, the increase for recent 70 years was proved for the proportion of indifferent species (do not able to mass propagation), small species (with wingspan below 20 mm), as well as species with hidden (leaf-miners) and semi-hidden lifestyle (leaf-rollers). All trends are expressed the most obviously in 1940–1950 and further periods. The hypothesis about decrease the proportion of the univoltine and monophagous species for this period is not supported statistically.

Ecophysiological Effects Induced by an Oligophagous Insect Herbivore in an Early Spring Geophyte

Insect herbivores, whose larval stages live and feed inside a plant leaf, are expected to have an impact on the leaf beyond the actual tissue damage. They might influence leaf photosynthesis. Here, we provide a brief insight by studying a simple model relationship between the spring geophyte ramsons Allium ursinum with short-lived green leaves and its oligophagous, leaf-mining hoverfly Cheilosia fasciata. We expected that the effect of leaf miners on short-lived leaves could interfere with resource allocation for the next season. Measurements of leaf greenness and chlorophyll fluorescence were performed to evaluate the stress impact of leaf miner damage upon photosynthesis during the short vegetative season of ramsons. Results showed that the onset of leaf senescence occurred earlier in infested leaves, which was also indicated by lower maximum efficiency of photochemistry compared to non-infested leaves. There was no evidence that infested leaves were able to compensate for the damage by increasing the rate of photosynthesis. Given the short lifespan of leaves and the earlier onset of senescence in infested leaves, we discuss two differential hypotheses: negative effects for the plant if the larvae have already left the mine, and negative effects for the leaf miner if the larvae are still developing inside the leaf.

Seasonal diversity of entomofauna, their impact and management practices in tomato fields in Meru district, Tanzania

Tomato is a highly cultivated vegetable in Tanzania. The intensive tomato cultivation and production in Tanzania has resulted in high pests and diseases build-up. A survey to identify and quantify entomofauna diversity in different seasons and pest management practices in Meru District was conducted. In addition, a laboratory experiment was done to assess the effectiveness of commonly used pesticides SnowBecco (Thiamethoxam)and Belt (Flubendiamide) against two dominating insect pests, white flies (Bemisia tabaci (Gennadius, 1889)) and leaf miner (Tuta absoluta (Meyrick, 1917)), respectively. The results obtained revealed that, tomato fields in Meru District had significantly higher entomofauna build up during dry season than the rainy season (U0.05 (df, 24)= 45, p = 0.0441). More than 70% of all collected entomofauna were dominated by the whiteflies (Bemisia tabaci) and tomato leaf miners (Tuta absoluta) belonging to orders Hemiptera and Lepidoptera, respectively. It was also observed that, the common pesticides management practices were the use of pesticidal cocktail, broad spectrum insecticides, use of botanical pesticides, frequent application of pesticide and insecticides over dosage. Moreover, yield reduction due to whiteflies and tomato leaf miners infestation were observed in terms of reduced fruits number per plant (38 and 18.4%), fruit size (22.4 and 14.2%), and fruits weight per plant by 43.6 and 26.2%, for Bemisia tabaci and Tuta absoluta, respectively. The study showed that the recommended doses in both tested insecticides caused significant pest mortality (F0.05 (df, 19) = 4.367, p = 0.0199) and (F0.05(df, 19) = 4.761, p = 0.0147) for B. tabaci and T. absoluta, respectively, within a specified period of time. The results suggest that high insect pest infestations could be caused by factors other than development of insecticidal tolerance including inappropriate identification of insect pests due to lack of training, and inappropriate selection and application of insecticides. Consequently, frequent application of broad spectra insecticides not only increases production expenses but also disrupts agroecosystem by killing beneficial entomofauna and disrupting soil organisms that are susceptible to insecticide toxicity.