Correction to: Thermal biology of Tuta absoluta: demographic parameters and facultative diapause

Journal of Pest Science - Formula, Equation 2 and the table 3 are published incorrectly in the original publication of the article. The correct version of the article is given below     

First report of Tuta absoluta resistance to diamide insecticides

Journal of Pest Science - The tomato borer Tuta absoluta (Lepidoptera: Gelechiidae) is an invasive pest of tomato crops that is rapidly expanding around the world. It is considered a devastating...     

Effects of X-rays on Tuta absoluta for use in inherited sterility programmes

Tuta absoluta is a key pest of tomato crops originating from South America. The consequences of X-radiation on this species were studied under laboratory controlled conditions. The effect of radiation on adult emergence was evaluated exposing male and female pupae to increasing X-rays. Adult emergence decreased as doses of X-radiation increased, with the appearance of deformities such as malformed wings and bent legs at doses ≥350?Gy. Besides, males and females obtained from irradiated pupae were out crossed with untreated counterparts to explore the effects of X-radiation on inherited sterility. (a) Irradiated male?×?untreated female crosses. Both fecundity and fertility of the untreated females were reduced by radiation, and the effect was stronger as the doses increased. Neither the longevity of parental males and F1 adults nor the sex ratios of the F1 and F2 generations were affected by X-radiation (F1 and F2: first and second generation of descendants of irradiated adults). Inherited sterility effects were manifested by a significant reduction in the F1 fecundity, F1 fertility, and the amount of larvae and pupae produced. Doses of 200–250?Gy could be used to induce inherited sterility in T. absoluta males. (b) Untreated male?×?irradiated female crosses. The minimum dose at which irradiated females were completely sterile was 200?Gy. The present study is the first study in T. absoluta that provides the starting point for implementing the inherited sterility in this species.     

Mating behaviour of female Tuta absoluta (Lepidoptera: Gelechiidae): polyandry increases reproductive output

Tuta absoluta (Meyrick) is an important pest of tomato. Mass trapping of males has seldom proved an effective control measure, probably due to the pest’s reproductive biology. There are few studies on female mating behaviour. For this reason, this study aimed to determine female mating frequency and its effects on reproductive output and female longevity; the effects of male mating status on female reproductive output and longevity and the fate of the spermatophore inside the bursa copulatrix. The studied population of T. absoluta mated only once a day at the beginning of the photophase, females remated frequently and can be classified as polyandrous. The refractory period of both T. absoluta males and females was very short and was not observed in many cases. The lack of refractory period could be due to the female’s rapid metabolism of the spermatophore thus allowing the female to reduce the intermating interval and mate again. Remating had direct benefits for T. absoluta females increasing their fecundity, fertility and longevity. These benefits were greater when females could remate to virgin males instead of to the same male. In this species, therefore, polyandry has direct benefits for the female. The occurrence of polyandry together with other known or unknown reasons can explain the failure of control methods based on pheromones in the open greenhouses in some tomato-growing areas.     

Integrated pest management of Tuta absoluta: practical implementations across different world regions

Journal of Pest Science - The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), has invaded most Afro-Eurasian countries and is threatening worldwide tomato...     

Basis and monitoring of methoxyfenozide resistance in the South American tomato pinworm Tuta absoluta

The South American tomato pinworm, Tuta absoluta (Meyrick, 1917) (Lepidoptera: Gelechiidae), is heavily targeted by insecticide applications. Methoxyfenozide is highly effective against T. absoluta with reduced side effects to natural enemies. This work aimed to (1) genetically and biochemically characterize resistance of the T. absoluta GBN population to methoxyfenozide, (2) establish cross resistance profiles with other insecticide groups and (3) monitor resistance in populations with the goal of improving T. absoluta insecticide resistance management (IRM). Methoxyfenozide resistance was completely recessive, polyfactorial and autosomal. Effective dominance revealed that 10 mg methoxyfenozide/L would be enough to eliminate susceptible homozygotes and heterozygotes, thus used to diagnose resistance in field populations. The synergism of methoxyfenozide toxicity in the resistant population for PBO (SR?=?95×), DEF (SR?=?51×) and DEM (SR?=?45×), suggested monooxygenases, esterases and glutathione S-transferases as resistance mechanisms. However, only monooxygenase activity appeared to be involved in methoxyfenozide resistance. Resistance ratio for methoxyfenozide (2352-fold) after selection and cross-resistance ratios of a lab-selected GBN strain (“GBN-Sel”) were significant relative to a susceptible strain “JDR1-Sus” for tebufenozide (656-fold), cartap hydrochloride (10.68-fold), deltamethrin (4.70-fold), abamectin (2.65-fold), lufenuron (2.22-fold) and indoxacarb (1.92-fold), with negative cross-resistance to spinetoram (0.32-fold). Evidence of control failures was observed in 10 field populations of T. absoluta (mortalities between 13 and 76%), and all populations showed frequencies of resistant phenotypes (percentage survivorship ranging between 4 and 96%). A rational basis for managing resistance to bisacylhydrazines is discussed, along with details of recommended T. absoluta resistance management tactics.

     

The parasitoid Dolichogenidea gelechiidivoris eavesdrops on semiochemicals from its host Tuta absoluta and tomato

Journal of Pest Science - Semiochemicals such as herbivore-induced plant volatiles (HIPVs) and host chemicals serve as communication signals for parasitoids searching for oviposition sites. The...     

Biology of two key Palaearctic larval ectoparasitoids when parasitizing the invasive pest Tuta absoluta

During the last few years following the invasion of European tomato crops by the invasive South American tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), several indigenous larval parasitoid species were recorded as natural enemies of this pest. Necremnus cf. artynes (Walker) and to a lesser extent Stenomesius sp. nr. japonicus (Ashmead) (Hymenoptera: Eulophidae) have been frequently reported attacking T. absoluta in tomato greenhouses in Europe and they are considered as possible biocontrol agents. Few biological data are available on these two species, notably when they parasitize T. absoluta. Therefore, the present study documents their biology when parasitizing T. absoluta, and provides scientific bases for potential development of biological control programs relying on larval ectoparasitoids in invaded areas. We demonstrated the ability of the two parasitoid species to reproduce on T. absoluta as host on tomato plants. On average, N. cf. artynes female parasitized 28.5 larvae and killed 26.2 larvae during its life time whereas S. sp. nr. japonicus female was more long-lived and consequently more efficient; it parasitized 144.3 larvae and killed 90.1 larvae. In a second step, we also explored the effect of T. absoluta larvae instar on parasitism by S. sp. nr. japonicus and subsequent development of the parasitoid offspring. Best results were obtained with the third larvae instar with a higher number of offspring produced, bigger individuals and a higher proportion of females. Our results support the hypothesis that the two species are good candidates for biological control programs targeting T. absoluta in Europe.     

Biological invasion of European tomato crops by Tuta absoluta: ecology, geographic expansion and prospects for biological control

The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a devastating pest of tomato originating from South America. After its initial detection in eastern Spain in 2006, it rapidly invaded various other European countries and spread throughout the Mediterranean basin. If no control measures are taken, then the pest can cause up to 80–100% yield losses in tomato crops in recently invaded areas and may pose a threat to both greenhouse and open-field tomato production. The exceptional speed and extent of T. absoluta invasion have called for studies documenting its biology and ecology, while indicating an urgent need for efficient and sustainable management methods. The development of approaches to manage T. absoluta would be facilitated through a detailed revision of information on this pest in its area of origin. This review combines information on the invasion by T. absoluta, its ecology, and potential management strategies, including data that may help the implementation of efficient biological control programs. These programs, together with a variety of other management tactics, may allow efficient integrated pest management of T. absoluta in Europe and Mediterranean Basin countries.     

First evidence of deuterotokous parthenogenesis in the tomato leafminer, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae)

The tomato leafminer, Tuta absoluta (Lepidoptera: Gelechiidae), originates from South America and is now considered to be one of the most damaging invasive pests of tomatoes in the Mediterranean Basin countries of Europe and North Africa. The preventing pest mating control methods include: (1) the use of synthetic pheromones for male attraction and annihilation inside insecticide-containing traps; (2) mating disruption by saturating the atmosphere with sex pheromones which alter the ability of males to locate females; and (3) massive applications of sterile males to alter the overall reproductive success of the pest population. However, all these methods achieve only a poor success rate in controlling T. absoluta populations under greenhouse conditions. Sex pheromone management and sterile insect techniques are both based on an important biological trait: the insect must breed through sexual reproduction. Here, we report for the first time laboratory evidence of deuterotokous parthenogenesis, an asexual reproduction where both males and females are produced from unfertilized eggs. We discuss the consequences for T. absoluta control strategies.     

Potential for combined use of parasitoids and generalist predators for biological control of the key invasive tomato pest Tuta absoluta

The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) has recently invaded Mediterranean countries and is a major pest in tomato crops. Trichogrammatid oophagous parasitoids have shown promising potential for controlling the pest before the yield decreases in the greenhouse. In protected tomato crops (greenhouse), mirid predators are commonly used for biological control of whiteflies and they also prey on T. absoluta. These predators do not attack Trichogramma adults but they may partially decrease the overall impact of parasitoids on T. absoluta if intraguild predation (IGP) occurs on parasitized eggs. Under laboratory conditions, we tested if the mirid predator Macrolophus pygmaeus shows preference between parasitized and unparasitized T. absoluta eggs. We also tested if the predator reduces the number of parasitized eggs on caged tomato plants (microcosms) and assessed the efficacy of natural enemies used alone or together in limiting T. absoluta populations. We found that IGP is inflicted on the parasitoid Trichogramma achaeae by M. pygmaeus and that the risk of IGP depends on the developmental stage of T. achaeae inside the egg because the larva is at risk mostly early in its development (when parasitized egg is still yellow). In addition, we observed that non-consumptive events, likely probing of the predator on parasitized eggs, may induce mortality in parasitoid offspring without actual feeding on parasitized eggs. However, both IGP and non-consumptive events decreased when the predator was not confined with parasitized eggs in small arenas. Despite negative effects of the predator to the parasitoid, results demonstrate that adding Trichogramma parasitoids may significantly increase the level of control of the pest over what could be attained when only the mirid predator M. pygmaeus is present on tomato. Implications of results are discussed regarding potential of these natural enemies for biological control of T. absoluta in greenhouse tomato crops.     

Supercooling capacity and cold tolerance of the South American tomato pinworm,Tuta absoluta,a newly invaded pest in China

Journal of Pest Science - Tuta absoluta is a devastating invasive pest worldwide, causing severe damage to the global tomato industry. It has been recorded recently in the northwestern border areas...     

Natural enemies of the South American moth, Tuta absoluta, in Europe, North Africa and Middle East, and their potential use in pest control strategies

The South American tomato leafminer, Tuta absoluta Meyrick (Lepidoptera: Gelechiidae), is an invasive Neotropical pest. After its first detection in Europe, it rapidly invaded more than 30 Western Palaearctic countries becoming a serious agricultural threat to tomato production in both protected and open-field crops. Among the pest control tactics against exotic pests, biological control using indigenous natural enemies is one of the most promising. Here, available data on the Afro-Eurasian natural enemies of T. absoluta are compiled. Then, their potential for inclusion in sustainable pest control packages is discussed providing relevant examples. Collections were conducted in 12 countries, both in open-field and protected susceptible crops, as well as in wild flora and/or using infested sentinel plants. More than 70 arthropod species, 20 % predators and 80 % parasitoids, were recorded attacking the new pest so far. Among the recovered indigenous natural enemies, only few parasitoid species, namely, some eulophid and braconid wasps, and especially mirid predators, have promising potential to be included in effective and environmentally friendly management strategies for the pest in the newly invaded areas. Finally, a brief outlook of the future research and applications of indigenous T. absoluta biological control agents are provided.     

Effects of ungulate browsing on recruitment of aspen and rowan: a demographic approach

Aspen (Populus tremula L.) and rowan (Sorbus aucuparia L.) are important for biodiversity conservation and aesthetic reasons. Intensified levels of ungulate browsing the last decades have raised concerns over the recruitment of aspen and rowan in boreal forests. Demographic data are vital to understand and quantify how the structure of tree populations are affected over time by browsing and other factors but such data are rare. In a five-year study, we quantified vital demographic rates for co-occurring aspen and rowan using exclosures in a productive forest area in eastern-central Sweden. Mean annual browsing rate on small (<1 m) aspen and rowan stems was 20 vs. 38%, whereas the order in browsing intensity was reversed for stems of medium (1–2 m) size (28 vs. 14%). Browsing had a clear negative effect on transition rate from small to medium size class in both species, but had a much smaller impact on transition rate from medium to large (2–3 m) size class. Residence time for small stems and regeneration rate was much higher in aspen than in rowan, but browsing did not affect these dynamics. Transition to ungulate safe height (>3 m) was reduced with a factor of two in rowan and four in aspen by browsing.     

Modelling diapause termination and phenology of the Japanese beetle,Popillia japonica

We deve?loped a mechanistic, stage-structured model simulating the phenology of Popillia japonica. The model simulates the influence of soil temperature on the larval diapause termination and on the development rate function of post-overwintering larvae and pupae. Model parameters are estimated based on literature evidence for pupae development and on a parameterisation process that allows estimating parameters for larval diapause termination and for the development rate function (and the related uncertainty) of post-overwintering larvae. Data used for model parameterisation and validation refer to time-series adult trap catches collected during the P. japonica monitoring programme performed by the Phytosanitary Service of Lombardy Region within the infested area in Lombardy (Italy) from 2015 to 2019. A total of 12 randomly selected locations are used to estimate biologically realistic model parameters (parameterisation dataset). We applied a Jackknife nonparametric resampling procedure on the parameterisation dataset to quantify uncertainty associated with parameters’ estimates. Parameterised model is then validated on time-series adult trap catches data referring to a different set of 12 randomly selected locations (validation dataset) surveyed in Lombardy. The model successfully predicted the beginning of adult emergence and the overall curve of adult emergence in the validation dataset. The model presented can support the definition of the best timing for the implementation of monitoring and control activities for the local and the area-wide management of P. japonica.

     

The effect of Maya traditional harvesting on the leaf production, and demographic parameters of Sabal palm in the Yucatán Peninsula, Mexico

Palm leaves are an important resource for family households. The effect of harvest on leaf production, growth and fecundity of wild individual palm trees has been studied, but little is known about palm harvest in agro-forestry systems. In the Maya area of the Yucatán Peninsula, Mexico, leaves of the xa’an palm (Sabal yapa, and Sabal mexicana) have been used since pre-Hispanic days for thatching the roofs of traditional Maya houses. The Maya have introduced xa’an palms in homegardens and the care they provide them improves their growth. Maya householders agree on what they consider to be the best harvest intensity for xa’an, recommending one or two harvest events per year, and leaving one or two leaves in each event; however, there is not ecological information documenting whether the traditional harvesting practices are the most adequate to maintain or increase leaf production, and their effect on the growth and fecundity of the palm trees. In Maxcanú, Yucatán, we studied eight family homegardens with S. yapa and S. mexicana. The selected individuals from each homegarden (n = 252) underwent six harvest treatments for 2 years C: control, no harvest, Al: annual harvest, leaving three leaves on the palm, Am: annual harvest leaving two leaves, Ah: annual harvest leaving one leaf, Sl: two harvests per year leaving three leaves, Sm: two harvests per year leaving two leaves. Treatments Ah and Sm simulated the traditional harvest method, and the remaining treatments simulated higher or lower harvest intensities and frequencies. Leaf production was higher in individual palms under higher harvest intensities and frequencies (Ah, Sl and Sm), but palm growth and leaf size were not affected by harvest. Number of inflorescences per palm differed between treatments and between homegardens during the first year only, but we could not find a clear pattern of variation. Production of new leaves was affected by initial palm size and initial leaf number. Removing mature leaves while leaving the young ones, as well as the intensity and frequency, with which traditional harvest is practiced, stimulate palms to compensate the defoliation effects by producing new leaves. This practice is based on empirical Maya knowledge that enables the manipulation of micro-environmental conditions and the development of sustainable harvesting strategies for the xa’an palm in traditional agro-forestry systems.     

Factors influencing the loss of forest cover in bangladesh: An analysis from socioeconomic and demographic perspectives

Some studies have attributed forest shrinkage to population growth, economic development, conversion of forest land to agricultural use and harvesting of trees for timber and fuelwood. But the statistical support for these hypotheses is not strong. This paper attempts to test the above hypotheses statistically in the case of Bangladesh. Factor analysis extracted 4 important factors—(a) exploitation of forests for timber, fuelwood, tea, and shrimp production, (b) demographic pressure in agriculture, (c) economic development, and (d) expansion of crop lands—as causes of deforestation. The statistical test supports the hypotheses that the exploitation of forests for timber, fuelwood, tea and shrimp production, and conversion of forests to crop lands have a negative influence on forest cover. Economic development and demographic pressure in agriculture are also negatively correlated with forest cover. Results of regression analysis show the conversion of forests to agricultural land is the most important cause of deforestation. Other important causes, in order of their relative importance, are the relative price of forest products, population growth, economic development, demographic pressure in agriculture, increasing production of shrimps, export of tea and shrimps, increasing production of timber and fuelwood, and expansion of tea lands. The statistical tests support the above relationships.