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Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is the most destructive pest of tomato worldwide. Biological control has always been considered as a promising management approach of this pest in tomatoes. In this context, we evaluated the effectiveness of releasing Trichogramma cacoeciae Marchal parasitoids or Macrolophus pygmaeus (Rambur) predators in controlling T. absoluta in greenhouse tomatoes of northeastern Tunisia. Two weekly releases of either M. pygmaeus at 1 adult/m2 or T. cacoeciae at 20 adults/plant were assessed. Our results indicated that parasitism rates were significantly higher on the apical tomato leaves compared to the middle leaves. We found that the number of T. absoluta eggs and larvae was significantly reduced after releasing T. cacoeciae, while releases of M. pygmaeus did not significantly reduce T. absoluta densities. The present study demonstrated the great potential of releasing T. cacoeciae in controlling T. absoluta in greenhouse tomatoes of northeastern Tunisia. However, further studies are needed to evaluate other release rates of M. pygmaeus that could show promising effectiveness against T. absoluta in northeastern Tunisian greenhouses. [ABSTRACT FROM AUTHOR]

The mating disruption technique using Checkmate® VMB-XL pheromone dispensers, in combination with imidacloprid-based insecticide treatments through drip irrigation, was tested against vine mealybug in Tunisian vineyards for the first time in the South Mediterranean area. The number of male vine mealybugs caught in traps of mating disruption (MD) plots was significantly lower than that of Non-MD plots, indicating that the application of Checkmate® VMB-XL significantly disrupted the male-female vine mealybug sexual communication. The cumulative effect of mating disruption on vine mealybug over time reached 120 days. Two months after Checkmate® VMB-XL application, the density of mealybug nymphs and adult females on grapevine basal leaves was significantly reduced in all MD plots. The obtained results provide evidence that the application of Checkmate VMB-XL under Center-South Tunisian vineyard conditions proved to be very effective in confusing vine mealybug males and disrupting the mating process. The eventual future use of this technique in Integrated Pest Management programs in Tunisia is discussed herein. [ABSTRACT FROM AUTHOR]

Key scale insects that have long been considered as having high economic importance in Tunisia and for which several research studies and pest management programs have been undertaken include the mealybug species Planococcus ficus (Signoret) and Planococcus citri Risso, the soft scale Saissetia oleae (Olivier) and the armoured scale Parlatoria ziziphi (Lucas). The host plants, bio-ecological aspects, auxiliary fauna of each of the aforementioned species as well as the related economic losses and pest management strategies adopted are explored and discussed. Among these species, P. ficus is considered herein as the most economically important in Tunisia. Still, the present contribution constitutes the first review article on key scale insects infesting plants in the South Mediterranean Maghreb area. [ABSTRACT FROM AUTHOR]

Some morphological features of Dacus ciliatus (Loew) reported for the first time in Tunisia were studied herein. Also during this study, the efficacy of food attractants and attract-and-kill devices were tested against D. ciliatus. To do so, McPhail® traps baited with diammonium phosphate (DAP©) and protein hydrolysate (Ceratrap©), already known as food attractants for fruit flies, were compared in zucchini and cucumber crops. A novel attract and kill system (Ceranock© female and male) was also applied in the two cited crops. Moreover, our data highlighted the usefulness of DAP© as effective food attractant with a high number of trapped adults compared to Ceratrap© baited traps. Few adults were recorded by Ceratrap© only in Zucchini treated crop 1 (0.42±0.49 and 0.28±0.69 respectively for males and females) compared to the other surveyed crops. Attract and kill system achieved good control of the pest by decreasing the number of captured flies in treated crops compared to the untreated crops. The use of attract and kill system showed promising results and can successfully be used to manage the lesser pumpkin fly in Tunisian cucurbit crops. [ABSTRACT FROM AUTHOR]

The present paper highlighted the occurrence of Timarcha turbida (Erichson 1841) as an artichoke pest for the first time in Tunisian crops. In fact, Timarcha was never be reported previously to develop on a Compositae (Asteraceae) host plant. Here, larva and adult stages of the pest are described and host plants affinities in genus Timarcha are discussed. [ABSTRACT FROM AUTHOR]

Trichogramma egg parasitoids are successfully used for biological control of a wide range of lepidopteran pests worldwide. However, the field success depends upon their performance that could be influenced by the conditions of laboratory mass rearing. Hence, reviewing all scientific information on the most suitable mass rearing techniques of Trichogramma parasitoids is of utmost importance to those seeking successful biological pest control action. Trichogramma mass production techniques, mainly using alternative hosts, and characteristics of artificial diet(s) are explored herein. Scientific and technical information on (i) how diet could influence Trichogramma adult reproductive behaviour, (ii) the effect of continuous rearing on the egg parasitoid genetic diversity, (iii) Trichogramma preferences to host eggs and impact of host quality on the wasp performance, and (iv) effect of storage methods and abiotic factors (temperature, relative humidity and photoperiod) on the fitness of reared Trichogramma parasitoid are emphasised in this review. [ABSTRACT FROM AUTHOR]

Tomato production in geothermal greenhouses in Tunisia showed remarkable growth during the last decade and has been considered an important economic sector within the Tunisian agriculture. However, since 2010, this sector is constrained by the tomato leaf miner Tuta absoluta, which is considered one of the most destructive pests of tomato crops. The aim of this study was to evaluate the efficacy of the mating disruption with TUTATEC® in tomato crops in heated greenhouses. The efficacy of TUTATEC® at the theoretical doses of 55.5 and 111 g active ingredient of sex pheromone per hectare (300 and 600 dispensers/ha) to control T. absoluta was compared with mechanical control (manual deleafing) and conventional insecticides (Azadirachtin, 10 g/L and Cyantraniliprole, 100 g/L). The number of trapped males in water traps as well as the percentages of infested leaves and fruits were monitored weekly and compared with manual deleafing and insecticide-treated greenhouses. In greenhouses disrupted with 300 and 600 dispensers/ha, a reduction of 47.79 and 63.01% in male trap captures was observed, respectively, compared with mechanical control. The leaf damage was significantly lower in greenhouses disrupted with 600 dispensers/ha and insecticide treated greenhouses, with a reduction of infestation 29.53% and 32.02%, respectively. No significant differences were found in fruit damage between greenhouses disrupted with 300 and 600 dispensers/ha and the mechanical control. These results suggest that mating disruption is effective in the management of T. absoluta, and could be used in the framework of Integrated Pest Management strategies to control this pest. [ABSTRACT FROM AUTHOR]

Applying botanical extracts with potential insecticidal actvity has long been considered a promising eco-friendly alternative to the use of chemical insecticides. In the present study, we evaluated the contact toxicity of Mentha pulegium essential oil (applied at either 2.73 mg/L, 9.56 mg/L, 13.65 mg/L, 27.31 mg/L, or 40.96 mg/L) toward three pest scales, Planococcus citri, Aonidiella aurantii, and Chrysomphalus aonidum, and two chemical insecticides, chlorpyrifos (100 mL/hL) and spirotetramat (120 mL/hL), against P. citri and A. aurantii under laboratoty conditions. Toxicity of M. pulegium essential oil and both insecticides was also assessed on the coccinellid predator Cryptolaemus montrouzieri. The highest mortality rates for all scale insect nymphs (> 97% for A. aurantii and 100% for P. citri or C. aonidum) were obtained following essential oil application at a dose of 40.96 mg/L. Lowest mortality rate (3.6 ± 0.92%) of C. montrouzieri adults was induced by an essential oil application at a dose of 8.95 mg/L, compared to either dose 11.26 mg/L or 17.66 mg/L. Both chemical insecticides significantly affected survival of mealybug and armored scale insect nymphs until 21 days after treatment. Chlorpyrifos, being highly effective against P. citri and A. aurantii, was significantly more toxic than spirotetramat toward both A. aurantii nymphs and predatory C. montrouzieri adults until three weeks after treatment. Using M. pulegium essential oil in combination with spirotetramat could be recommended for eco-friendly, sustainable control of P. citri, A. aurantii and C. aonidum in citrus orchards while minimizing harmful side effects on C. montrouzieri. [ABSTRACT FROM AUTHOR]

Nanopesticides are novel formulations that can be applied against a wide range of insect pests as a sustainable alternative to less effective chemical pesticides. Here, acute toxicity of nano (abamectin-PLA-NS (1%) and abamectin-PLA-NS (0.1%)) and commercial formulations of abamectin was evaluated against the South American tomato pinworm, Tuta absoluta, in laboratory and open-field conditions in northeastern Tunisia. Additionally, side effects of nano and commercial formulations of abamectin were also investigated towards the two predatory mirids Macrolophus pygmaeus and Nesidiocoris tenuis either under laboratory or open-field conditions. Laboratory results of acute toxicity revealed no differences between the tested abamectin formulations (against T. absoluta larvae. LC50 values were 0.28, 0.23, and 0.23 for abamectin EC; 0.30, 0.18, and 0.18 for abamectin-PLA-NS (1%) and 0.57, 0.28, and 0.25 for abamectin-PLA- NS (0.1%) corresponding to three time intervals (24, 72 and 120 h after treatment). Abamectin EC, abamectin-PLA-NS (1%) and abamectin-PLA-NS (0.1%) applied at higher doses (0.6 mL/L and 1.2 mL/L) showed higher efficacy percentages (> 90%) in controlling T. absoluta larvae, fourteen days after treatment in open-field tomatoes. Commercial abamectin formulation showed higher toxicity toward M. pygmaeus adults and N. tenuis nymphs compared to nano formulations applied at the two aforementioned doses. High mortality rates, reaching 100%, were reported for M. pygmaeus adults exposed to 1 and 3 day-old residues for commercial formulation at 0.6 mL/L and 1.2 mL/L in laboratory conditions. However, in open-field tomatoes, low acute toxicity was induced by abamectin-PLA-NS (0.1%), ranging from 25 to 41.17%, compared to abamectin EC, ranging from 58.33 to 94.11%, and abamectin-PLA-NS (1%), ranging from 58.33 to 76.47%, at 0.6 mL/L against N. tenuis nymphs at apical leaves. For middle leaves, only abamectin-PLA-NS (0.1%) applied at 0.3 mL/L did not show significant toxicity against N. tenuis nymphs with low mortality level up to 7%, fourteen days after treatment. The practical implications of these results for enhancing integrated pest management programs of T. absoluta in tomatoes are discussed herein. [ABSTRACT FROM AUTHOR]

Temperatures experienced by insects during their adult life often differ from developmental temperatures. Yet, developmental thermal acclimation can play an important role in shaping physiological, morphological, and behavioral traits at the adult stage. We explored how three rearing temperatures (10, 20, and 28 °C) affected host-foraging behaviors and associated traits under warm conditions in the parasitoid Aphidius colemani , a key model in behavioral ecology and an important natural enemy of aphids. Developmental time was longer at lower temperatures, resulting in bigger emerging parasitoids, with higher egg-loads. Parasitism rates, emergence rates, and parasitoid survival (once placed at high temperature) were the highest for parasitoids developed at 20 °C. When exposed to 28 °C, the expression of all behavioral items (time spent walking searching for hosts, number of antennal and ovipositor contacts with hosts) was higher for parasitoids reared at 20 °C, followed by those reared at 10 °C, then those reared at 28 °C. Finally, we showed that parasitoid residence time on aphid patches was determined by both developmental temperatures and the number of host encounter without oviposition, representative of the resource quality. We revealed that developing at 28 °C did not lead to increased adult performance at this temperature, probably because of complex interactions and trade-offs between developmental costs at high temperature and optimal foraging behaviors (e.g., parasitoid size and host-handling capacities). Our results strengthen the idea that thermal developmental plasticity may play an important role in insect behavioral responses to varying temperatures, and is important to consider in the context of climate change. • Resource-exploitation behaviors depend on the temperature insects have developed in • Rearing temperature affects behavioral traits, host-searching and host-handling performance • Insects reared at high temperatures were those that performed the least at warm conditions • Trade-offs between developmental costs at high temperature and optimal foraging behaviors [ABSTRACT FROM AUTHOR]

Gortyna xanthenes (Germar) and Depressaria erinaceella (Staudinger) are key pests of artichoke in Tunisia causing major losses. To this end, a 2-year field survey was carried out in order to assess possible damage caused by these two pests. The results showed that serious attacks were found on artichoke flower heads ranging from 17 to 26% and from 7 to 10% for D. erinaceella and G. xanthenes, respectively. On stems, damages caused by G. xanthenes may exceed 60%. Measures of the length of the larva and the width of head capsule in the laboratory showed the presence of six and seven instar larvae for G. xanthenes and D. erinaceella, respectively. These results could be very useful to develop effective management tools against artichoke pests in Tunisia. [ABSTRACT FROM AUTHOR]

Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), a pinworm native to South America, has invaded Tunisia, as well as the whole African continent, since 2008 inducing severe crop damages and substantial economic losses in all tomato-producing areas. During the last decade, several research studies and management efforts have been performed in an attempt to find out the most effective and sustainable pest control options against this devastating pest. Herein we explore, comprehensively summarize and discuss the most up-to-date state of scientific knowledge regarding bio-ecological aspects of the pest, its indigenous natural enemies and all categories of management strategies adopted so far against this economic pest in Tunisia. [ABSTRACT FROM AUTHOR]

The South American tomato pinworm Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is a serious threat to tomato and can occur on other solanaceous crops worldwide. Here we evaluated the development time, fecundity and longevity of T. absoluta on three different host plant cultivars grown in Tunisia: tomato (cv. "Sankara"), potato (cv. "Spunta") and eggplant (cv. "A336"), under controlled laboratory conditions. Results showed a higher capacity of T. absoluta to develop on tomato with a shorter development time (about 31 days) and a higher fecundity (20.47 eggs per female) and longevity (14 days) compared to developing on either potato or eggplant. The development time (egg to adult) of T. absoluta on tomato plant was longer at both lower temperature (21 °C), as compared to the higher 28 °C, and higher relative humidity (either 52 or 72%), as compared to the lower 32% relative humidity. Fecundity of T. absoluta females on tomato plant was highest at 28 °C and 52% relative humidity, as compared to that obtained at 21 °C. The present study provides evidence that host plant, temperature and relative humidity are factors that greatly influence key biological parameters of T. absoluta. The obtained results would be useful for developing and implementing suitable control strategies for this major economic pest. [ABSTRACT FROM AUTHOR]

Tuta absoluta (Meyrick) is a key insect pest of tomato crop causing major economic losses worldwide. Biological control using Trichogramma parasitoids is considered a promising, eco-friendly management tactic of this pest. We performed inundative releases of Trichogramma cacoeciae (Marchal) (Hymenoptera: Trichogrammatidae) against T. absoluta in Takelsa (northeastern Tunisia). Three weekly releases of either (i) 10, 20 or 30 Trichogramma per plant in protected (greenhouse) tomato crops or (ii) 20 or 40 Trichogramma per plant in open field tomatoes were evaluated for their effectiveness. Results indicated that 20 Trichogramma per plant was the most effective release rate in significantly decreasing the pest's life stage densities. Parasitism rates were significantly higher on apical tomato leaves (estimated at 58.6% for the rate 20 Trichogramma per plant in greenhouses and at about 56% for the rate 40 Trichogramma per plant in open field) compared to those observed on middle leaves (24.6% and 45.26% for rate 2 respectively under greenhouse and open field conditions). Furthermore, the overall number of T. absolua eggs and larvae was significantly reduced after releases of Trichogramma parasitoids. These results clearly indicate that T. cacoeciae could be a promising biocontrol agent of T. absoluta in the largest tomato-producing area in Tunisia. [ABSTRACT FROM AUTHOR]

The South American tomato pinworm, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a devastating invasive pest of tomato crops in several areas around the world including Africa. Here, we comprehensively review and discuss the relevant scientific knowledge on its occurrence, biological and ecological aspects, fortuitous insect natural enemies, and potential advantages and constraints of pest management scenarios adopted against this pest in tomato crops in both Northern and Sub-Saharan Africa. We conclude the manuscript with a comprehensive research agenda providing future priorities towards sustainable control of this important tomato pest. [ABSTRACT FROM AUTHOR]

Since its first detection in Tunisia in 2008, the tomato pinworm, Tuta absoluta, has become a serious problem to tomato crops by causing heavy yield losses. The aim of this work was to evaluate the efficacy of some actives ingredients, commonly used by Tunisian farmers, under laboratory and greenhouse conditions in controlling T. absoluta larvae. We also tested the role of mass trapping as control method for T. absoluta while performing two greenhouse trials: one to test the most effective number of pheromone traps to be used and the second evaluating the combination of insecticides and pheromone traps. Our study demonstrated that the product combining abamectin and chlorantraniliprole was the most effective 2 h after the treatment in laboratory trials. Moreover, this study indicated that the dose of two sex pheromone traps/greenhouse was the most effective compared to the other tested dose. Also, mass trapping alone (2 sex pheromone traps/greenhouse) was not effective in reducing larval populations: flubendiamid and cyromazin caused 96 and 77% larval mortality, respectively. [ABSTRACT FROM AUTHOR]

Honeydew-excreting hemipterans, such as mealybug pests, can be protected from their natural enemies by tending ants in return for honeydew, thereby compromising the aims of biological control. In this respect, antagonistic interactions between the ant Tapinoma nigerrimum, native to the Mediterranean basin, and the main natural enemies of both the vine mealybug (VMB), Planococcus ficus, and the citrus mealybug (CM), Planococcus citri, were assessed in laboratory conditions. Parasitism of vine and CMs by their respective parasitoids, Anagyrus sp. nr. pseudococci and Leptomastix dactylopii, was negatively affected by the ant T. nigerrimum. Similarly, T. nigerrimum was shown to significantly disrupt the predatory potential of ladybird larvae, Cryptolaemus montrouzieri, when foraging on host CMs. By contrast, the presence of the ant did not negatively influence the predatory activity of C. montrouzieri adults when feeding on CMs. Consequently, the encyrtid parasitoids A. sp. nr. pseudococci and L. dactylopii and the larval stage of the predator C. montrouzieri may be considered as T. nigerrimum-sensitive, whereas the adults of C. montrouzieri may be regarded as T. nigerrimum-resistant predators. Accordingly, the ant T. nigerrimum constitutes a threat to the biological control of mealybugs by either the encyrtids A. sp. nr. pseudococci and L. dactylopii or the larval stage of the ladybird C. montrouzieri. Hence, adequate control of T. nigerrimum is highly recommended before any release of these mealybugs' natural enemies. [ABSTRACT FROM PUBLISHER]

Control of the invasive vine mealybug Planococcus ficus (Signoret) can be achieved through integration of different management strategies such as the application of chemical treatments and biological control. However, compatibility between these control methods is considered crucial when adopting integrated pest management (IPM) programs against this insect pest. The recently used insecticides Prev-Am®, a contact biopesticide, and spirotetramat, a systemic tetramic acid insecticide, were assessed in laboratory conditions for their side effects on the vine mealybug parasitoid Anagyrus sp. near pseudococci with reference to chlorpyriphos-methyl, an organophosphate insecticide conventionally used for mealybug control in vineyards. Regarding contact toxicity, chlorpyriphos-methyl caused 100% parasitoid mortality 24 h after treatment, but parasitoid mortality from Prev-Am® or spirotetramat was almost absent. Neither the total parasitoid offspring/female nor the sex ratio of the progeny was negatively affected by Prev-Am® or spirotetramat relative to the untreated control. According to the IOBC classification for laboratory trials, both Prev-Am® and spirotetramat were rated harmless (IOBC category 1), whereas chlorpyriphos-methyl was categorized as harmful (IOBC category 4) to A. sp. near pseudococci. None of the insecticides adversely affected the development of the parasitoid pupal stage inside mealybug mummies or the survival of the emerged parasitoids. The practical implications of the results for implementing mealybug IPM programs in vineyards are emphasized and discussed. [ABSTRACT FROM AUTHOR]

Simple Summary: Individual insects can experience different temperatures across their lives. In consequence, development of immature stages can take place at temperatures contrasting with those that the adult will encounter. In order to study the adaptation of organisms to warm environments, it is interesting to establish the links between developmental temperature and responses of the adult generation, in terms of physiology, morphology, and behavior. We exposed the parasitoid Aphidius colemani to three temperatures during larval development (10, 20, or 28 °C). We then measured the responses of adult parasitoids regarding their traits (physiology, morphology) and their tolerance to high temperatures. Mass, lipid reserves, survival, and heat tolerance of adults were affected by the rearing temperature regime. This means that, overall, developmental temperatures may affect how insects respond to a given temperature once they are adults, which may consequently influence the ability of parasitoids to control their aphid hosts. These results are important in the context of biological control in hot environments, such as the Maghreb, where this species of parasitoid is used in mass release techniques to control aphids in various crops. Developmental temperature plays important roles in the expression of insect traits through thermal developmental plasticity. We exposed the aphid parasitoid Aphidius colemani to different temperature regimes (10, 20, or 28 °C) throughout larval development and studied the expression of morphological and physiological traits indicator of fitness and heat tolerance in the adult. We showed that the mass decreased and the surface to volume ratio of parasitoids increased with the development temperature. Water content was not affected by rearing temperature, but parasitoids accumulated more lipids when reared at 20 °C. Egg content was not affected by developmental temperature, but adult survival was better for parasitoids reared at 20 °C. Finally, parasitoids developed at 20 °C showed the highest heat stupor threshold, whereas parasitoids developed at 28 °C showed the highest heat coma threshold (better heat tolerance CTmax1 and CTmax2, respectively), therefore only partly supporting the beneficial acclimation hypothesis. From a fundamental point of view, our study highlights the role of thermal plasticity (adaptive or not) on the expression of different life history traits in insects and the possible correlations that exist between these traits. From an applied perspective, these results are important in the context of biological control through mass release techniques of parasitoids in hot environments. [ABSTRACT FROM AUTHOR]

The names of the varieties cultivated in the two study regions were given wrongly in the Materials and Methods section. The correct names are as follows. [ABSTRACT FROM AUTHOR]

Synthetic chemicals are extensively used to limit the substantial crop damage induced by two closely related scale insects, the vine mealybug Planococcus ficus (Signoret) and the citrus mealybug Planococcus citri Risso (Hemiptera: Pseudococcidae). Both organisms are economically important pests occurring in vineyards and/or in citrus orchards worldwide. Synthetic chemicals can be either incorporated in pesticides aimed at directly controlling these pests or used as semiochemicals (i.e., sex pheromones) for monitoring, mass trapping, mating disruption, and/or for kairomonal attraction to enhance parasitoid performances. Growing evidence of both an alarming bee decline and destruction of auxiliary fauna driven by pesticides have stimulated an urgent need for in-depth research clarifying the adverse side effects of pesticides on beneficial arthropods. We have reviewed the current knowledge on mealybug pest control based on insecticides and semiochemicals. We highlight the following major advances: (1) How the active substances of insecticides (four organophosphates, imidacloprid, buprofezin, and spirotetramat) affect target and non-target organisms, (2) in which contexts and how a semiochemical-based strategy could be applied to deal with serious mealybug infestations, and (3) the implications of the appropriate exploitation of these synthetic chemicals for sustainable development. Using selective insecticides with novel modes of action and long-lasting efficacy in combination with eco-friendly semiochemical-based tools is a promising strategy for developing sustainable integrated pest management programs. This would help to maintain biodiversity dynamics and vital ecosystem services, thereby sustaining crop yields. [ABSTRACT FROM AUTHOR]