Trichogramma cacoeciae as a biological control agent of the tomato pinworm Tuta absoluta in Northeastern Tunisia

To Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) αποτελεί ένα πολύ σημαντικό έντομο-εχθρό της τομάτας στην Τυνησία και σε πολλές άλλες χώρες σε όλο τον κόσμο. Στη μελέτη αυτή αξιολογήθηκε η αποτελεσματικότητα του παρασιτοειδούς Trichogramma cacoeciae στην αντιμετώπιση του Τ. absoluta στη βορειοανατολική Τυνησία. Σε συνθήκες πεδίου, το Τ. cacoeciae έδειξε καλή αποτελεσματικότητα στη μείωση του αριθμού των ωών του Τ. absoluta αλλά και των προνυμφών μετά την απελευθέρωση 30 ενηλίκων του παρασιτοειδούς / φυτό τον Μάιο του 2012. Το αποτέλεσμα δείχνει ότι αυτό το Τ. cacoeciae μπορεί να αποτελέσει έναν σημαντικό παράγοντα για την αντιμετώπιση του T. absoluta στην Τυνησία.Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is considered as key pest attacking tomato in Tunisia and in many other countries around the world. In order to investigate the efficacy of Trichogramma cacoeciae (Marchal) (Hymenoptera: Trichogrammatidae) for biological control of this pest in Northeastern Tunisia, releases were performed in open field conditions. T. cacoeciae showed a good efficacy on reducing the number of T. absoluta eggs and larvae when releasing 30 adults/plant in plots covered with insect-proof netting in May 2012. The results showed that this parasitoid may be a promising agent for T. absoluta biological control in Tunisia

Phytoseiid mites (Acari: Mesostigmata) of Tunisian citrus orchards: Catalogue, biogeography and key for identification

This study presents the results of a survey aimed to determine the species composition of phytoseiid mites on citrus trees, inter-row grasses and conifers planted as break winds within and around citrus orchards. This survey was carried out in fourty six citrus orchards in the main citrus growing regions of Tunisia, from September 2009 to August 2011. Twenty six species belonging to ten genera were found, among which eleven are new for the Tunisian fauna. This paper provides a catalogue of all these species, with some information on their biogeography and biology when available. In addition, a key for the identification of all known Tunisian species (38 species belonging to 17 genera) is given

A morphological and molecular characterization of vine mealybug populations (Hemiptera, Pseudococcidae) from Tunisia

Some vine mealybug, Planococcus ficus (Signoret) populations in Tunisian vineyards have been morphologically and genetically characterized. The morphological examination was based on the main distinctive characteristics of species of Planococcus, namely the number and distribution of the multilocular disc pores and tubular ducts on the adult female. This showed the existence of two different vine mealybug populations in Tunisia. Likewise, in the molecular analyses, two separate clades were revealed in the neighbour-joining phylogenetic tree, supporting the morphological studies and suggesting that there are two distinct populations of P. ficus on grapevine in Tunisia

A survey of scale insects (Hemiptera: Coccoidea) occurring on olives in Tunisia.

A survey performed in 2009 within 52 Tunisian olive groves, located in 17 different olive-growing sites, revealed the occurrence of six scale insects on olives. The identified species were: the armoured scales Aspidiotus nerii Bouché, Lepidosaphes ulmi (L.), and Parlatoria oleae (Colvée), the soft scales Saissetia oleae (Olivier) and Filippia follicularis (Targioni Tozzetti) and the mealybug species Peliococcus cycliger (Leonardi). The soft scale F. follicularis is a new record for the Tunisian insect fauna. A mong these species, S. oleae was the predominant scale insect occurring throughout olive groves of northeastern Tunisia, whereas the mealybug P. cycliger was by far the most abundant species within olives groves of the Northwest region of Tunisia. However, P. oleae was the least abundant species, being present in only one olive-growing site in northeastern Tunisia. L arvae of the noctuid moth Eublemma scitula (Rambur) were reported feeding on S. oleae and the coccinellid Chilocorus bipustulatus L . was found feeding on both S. oleae and A. nerii. The two hymenopteran species Scutellista cyanea Motschulsky and Metaphycus spp. were recorded as the main parasitoids of S. oleae

Management of the Tomato Leaf Miner Tuta absoluta in Tunisia: A Three Years’ Survey

Tuta absoluta is considered as one of the most devastating pest causing significant losses to tomato production worldwide. Thus, the knowledge of its biological characteristics makes its management less challenging. Here, the population dynamics of this pest was monitored in protected tomato crop in Takelsa region (Northeastern of Tunisia). Monitoring the flight activity of males by pheromone traps and leaf sampling revealed the presence of four generations. A maximum of 120 males / trap / week and 74.66 larvae / 40 leaves were recorded on May 13, 2016. Furthermore, there was a significant linear relationship between trapped adults and laid egg

Control of the Cotton Bollworm Helicoverpa armigera in Tunisian Tomato Open Field Plot by the Application of Some Insecticides

The cotton bollworm, Helicoverpa armigera is considered a serious pest that attacks tomato in Tunisia and in other countries around the world. Thus, it is a necessity to control this pest and to establish a management program. The monitoring of the insect flight activity using sex pheromone traps, under Takelsa open field plot, revealed that this insect developed up to three generations. The study of its population dynamics showed that on leaves, eggs and larvae are able to achieve two peaks. However, on fruits, only larvae were present in an important number and produced two generations. Pupae are almost absent in leaves and fruits. In this study, the management of this pest was performed through the chemical treatment by testing the efficacy of some insecticides. Two trials were tested on June, 2011. All tested insecticides were proved to be efficient in controlling H. armigera under field conditions

Effect of developmental temperatures on Aphidius colemani host-foraging behavior at high temperature

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

Phytophagous and predatory mites on olive trees in Tunisia. Catalogue, description of one new species and key for identification (Acari, Eriophyidae, Tetranychidae, Tenuipalpidae and Phytoseiidae)

International audienceDespite the importance of olive trees in Tunisia, very little is known about mite populations. A survey of phytophagous and predatory mites species in 21 orchards distributed over several sites was conducted from 2007 to 2013. During this study, 14 species of predatory mites along with 5 species of phytophagous mites were collected and identified. Almost all species are newly identified from olive trees, five of them are new to the Tunisian fauna and one species is new to Science. This paper provides a catalogue of these species and elements on their biogeographical distribution and biology. Identification keys are also provided. The Phytoseiidae species described in this study may provide new opportunities for the integrated pest management of Eriophyidae and Tenuipalpidae mites on olive trees

Comparative toxicities of a wild Plant essential oil and blends of its major constituents on mortality and fecundity of spider mites (Acari: Tetranychidae)

peer reviewe

Assessment of the acaricidal activity of several plant extracts on the phytophagous mite Tetranychus urticae (Tetranychidae) in Tunisian citrus orchards

peer reviewedTo develop sustainable pest control in Tunisian citrus orchards, the present work aimed to evalute the toxicity of 31 plant extracts obtained from Tunisia and two synthetic acaricides (spirodiclofen and fenbutatin oxide) on the phytophagous mite species Tetranychus urticae (Koch)