Trichogramma

Wolbachia (á-proteobacteria) strains are intracellular endosymbiont bacteria found in reproductive tissues of many arthropod species. In Trichogramma wasps, thelytokous parthenogenesis is mostly induced by this bacterium which inherited transovarially. In this study, the Wolbachia infection was detected based on the PCR method and wsp gene cloning in 49.5, 3.6 and 2.5% of Baboulsar, Chamestan and Nour populations of Trichogramma brassicae Bezdenko collected from Mazandaran province. The Baboulsar bacterium strain is submitted to GenBank (FJ441291) under the name wBaT.bra. The phylogenetic tree based on wsp sequences of Wolbachia strains in Trichogramma wasps indicates that the Iranian strains, wBaT.bra and Uro3 belonged to the same group (Sib group). With regard to the high rate infection in Baboulsar population of T. brassicae as a dominant species in Iran, it will be possible to assess the potential advantages of its asexual line in biological control projects.

The egg parasitpoids Trichogrammadanausicida (Nagaraja) and Trichogrammacacaeciae (Marchal) (Hymenoptera: Trichogrammatidae), are reported for the first time in Israel. Moreover, our discovery of T.danausicida is the first report of this parasitoid species outside of India. The occurrence of those trichogrammatids was first discovered and documented in May 2016 during a survey of egg parasitoids of the False codling moth Thaumatotibialeucotreta (Lepidoptera: Tortricidae). The field survey was conducted on castor bean fruits (Ricinuscommunis) in the Israeli central coastal plain. The identity of the parasitoids was revealed by means of sequencing a portion of the cytochrome oxidase I gene (COI) of the studied parasitoids.

The Mediterranean flour moth, Ephestia kuehniella Zeller, 1879 (Lep.: Pyralidae) is a polyphagous pest that its eggs and larvae are used to rear some important biological control agents. In this study, the effect of three photoperiods including complete darkness, complete lightness and 14:10 (L:D) on life table parameters of E. kuehniella investigated, using diet containing a mixture of wheat flour (68%), wheat bran (29%) and 3% yeast was tested at temperature 25 ± 1°C and 65±5% RH. The results show that the intrinsic rate of increase (rm), finite rate of population increase (λ), the net reproductive rate (R0) and the mean generation time (T) in full darkness were 0.10 day-1, 1.116 day-1, 157.06 offspring and 45.98 days, respectively. Also, these mentioned parameters for full lightness and 14:10 (L:D) were 0.083 day-1, 1.087 day-1, 64.72 offspring ,49.73 days and 0.11 day-1, 1.117 day-1, 141.26 offspring, 44.59 days, respectively. The values of the intrinsic rate of increase (rm), finite rate of population increase (λ), the net reproductive rate (R0) and the mean generation time (T) in the photoperiod of 14:10 (L:D) were significantly shorter than those of other treatments. The results indicated that changing in photoperiod has noticeable effect on life table parameters of Mediterranean flour moth and should be considered for mass rearing of this moth.

Biscuit beetle (Stegobium paniceum) and webbing clothes moth (Tineola bisselliella) cause much damage to museum objects. Some objects and materials are very attractive to these two pest species and objects are often re-infested after treatment. For some years parasitoid wasps have been used in biological pest control to treat and reduce infestations of stored product pests in food processing facilities. Their application in museums is still new and in a research stage. Results from five different museums in Germany and Austria and their application are presented. Lariophagus distinguendus wasps were released against Stegobium paniceum in the municipal library Augsburger Stadtarchiv (Germany), the Ethnological Museum in Berlin (Germany) and the Picture Gallery in the Kunsthistorisches Museum in Vienna (Austria). Trichogramma evanescens were released against Tineola bisselliella in the Technisches Museum in Vienna (Austria) and in the Deutsches Museum Verkehrszentrum in Munich (German...

A new species of Trichogramma Westwood (Hymenoptera: Trichogrammatidae) parasitizing eggs of the golden twin-spot moth (or tomato looper) Chrysodeixis chalcites (Esper) (Lepidoptera: Noctuidae) on banana crops in the Canary Islands, Spain, is described as Trichogramma canariensis del Pino & Polaszek, sp.n. The new species is closely related to T. brassicae Bezdenko. Limited aspects of morphology, coupled with ITS2 and COI sequences and reproductive data are presented to distinguish T. canariensis sp.n. from T. brassicae.

No sistema de Produção Integrada de Maçã (PIM) o controle biológico de pragas é uma importante tática de controle, no entanto, a sua utilização pode ser limitada pela utilização de agrotóxicos. Nesse contexto, objetivou-se, com este trabalho, avaliar a persistência (duração da atividade nociva) de dez agrotóxicos recomendados na PIM sobre o parasitóide de ovos Trichogramma pretiosum. Insetos adultos foram expostos ao contato com resíduos de agrotóxicos pulverizados sobre folhas de videira cv. Isabel, sendo avaliado o efeito residual dos agrotóxicos sobre o parasitismo de T. pretiosum, aos 3, 10, 17, 24 e 31 dias após a pulverização, de acordo com a metodologia sugerida pela IOBC. O parâmetro utilizado para classificar os agrotóxicos foi a redução no parasitismo. Os resultados demonstraram que os produtos comerciais/ingredientes ativos (g ou mL da formulação comercial.100 L-1): o inseticida Malathion® 1000 CE/malationa (100) e os fungicidas Domark® 100 CE/tetraconazole (50), Manzate®...

A temperatura e um dos fatores que mediam as interacoes troficas, incluindo as relacoes entre insetos-praga e predadores. A resposta funcional e frequentemente usada para determinar a adequacao de predadores como agente de controle biologico e pode ser fundamental para adocao de estrategias de manejo integrado. Euborellia annulipes (Lucas) (Derm.: Anisolabididae) e registrada como um potencial predador de lagartas de Plutella xylostella (L.) (Lep.: Plutellidae), mas o entendimento de sua interacao com as condicoes termicas e pouco conhecido. Assim, objetivou-se avaliar o efeito da temperatura na resposta funcional de femeas da tesourinha com diferentes densidades de lagartas de quarto instar de P. xylostella . Avaliaram-se o numero de presas consumidas em funcao de sete densidades da presa (30, 40, 50, 60, 70, 80 e 90) e tres condicoes de temperatura (18 °C, 25 °C e 32 °C), sendo estimado o tipo de resposta funcional, a taxa de ataque ( a ’) e o tempo de manipulacao ( T h ) para E. ...

Tomato fruit borer, Helicoverpa armigera (Hübner) is a serious pest of many crops tomato, cotton and okra in Pakistan. Experiments were conducted to find out effectiveness of the Trichogramma chilonis against Helicoverpa armigera in field and effects of commonly used insecticide on Trichogramma chilonis under lab condition. Experiments were conducted with three replicated trials at Faisalabad for three years in different villages. Egg card of Trichogramma @ 300, 400, 500 and 600 eggs/card were used once. Percentage of effectiveness of Trichogramma against tomato fruit borer was calculated, which was increased with the increasing of card numbers 65.00% (2010), 48.09% (2011) and 83.51% (2012) after 4th release of Trichogramma @ 600 eggs/card, but it was least (00.00%) in control conditions during whole trial period. Similarly study of adult emergence of T. chilonis was also studied during 2010-11 at Entomological laboratory, Ayub Agricultural Research Institute, Faisalabad against fre...

Afin de pouvoir developper a grande echelle une lutte biologique par Trichogramma chilonis contre le foreur de la canne a sucre, il est necessaire d'en diminuer les couts. Savoir stocker les auxiliaires avant leur utilisation sur le terrain represente un avantage indispensable, tant au niveau de la biofabrique que des professionnels sur le terrain. A cet effet, un nouveau programme de recherche, financee par le Ministere Francais de l'Agriculture et de la Peche, est en cours. L'objectif est de determiner les conditions optimales (T°, HR, photoperiode, stade de developpement) pour mettre en place un arret de developpement (quiescence ou diapause). Les premiers resultats obtenus montrent deja la possibilite de stocker au froid pendant 2 mois, sous forme de quiescence, les Trichogramma produits. (Resume d'auteur)

Una nueva especie de Trichogramma Westwood, llamada T. lopezandinensis, es descrita a partir de especímenes obtenidos en cultivos sobre Sitotroga cerealella (Olivier). Los tipos son descendientes de avispas co­lectadas en huevos de la mariposa Colias dimera Doubleday & Hewiltson en zonas altas de los Andes Colombianos. 

Corcyra cephalonica (Stainton) is a laboratory host for mass production of Trichogramma spp. and other biocontrol agents. In the present study for rearing Corcyra , three diets were used as broken maize alone, broken maize + yeast (2%) and broken maize + protinex (2%). Maize + yeast combination gave the best results in terms of mean total adults emergence (2211), mean total females (985), mean fecundity (397.85) and mean duration of moths emergence (52.31 days), while average developmental period was lowest (36 days) when compared with other two diets. The effect of egg laying on parasitization by T. chilonis revealed that highest mean per cent parasitization of 51.96 (mean of 1 st to 6 th day laying) was obtained on eggs laid by moths reared on maize + yeast diet. The highest mean per cent parasitization (73.9) was obtained on 2 nd day egg laying.

Individuals of two populations of Trichogramma maxacalii (Hymenoptera: Trichogrammatidae) were collected from eggs of Euselasia apisaon (Lepidoptera: Riodinidae), a lepidopteran defoliator of Eucalyptus, in plantations in the states of São Paulo and Minas Gerais, Brazil. This study investigated the sex ratio, number of parasitoids per egg, and longevity of individuals of these two populations of T. maxacalii, when this parasitoid was reared receiving eggs of the factitious host Anagasta kuehniella (Lepidoptera: Pyralidae) in different periods after emergence, and with or without honey. Sex ratio of T. maxacalii varied from 0.44 to 0.60, and was affected by the interaction between populations, availability of food (honey), and length of time in which the parasitoid stayed without host eggs after their emergence. The population of T. maxacalii collected in São Paulo produced a larger number of individuals per egg of the host A. kuehniella and lived longer when fed.

Trichogramma species are known to prefer young host eggs, However, they could found themselves in environments populated in majority with old host eggs, or could become increasingly aged as they could spend days searching fruitlessly for hosts. As anticipation of their behaviours in such circumstances, One, two and three-day old Trichogramma oleae and Trichogramma cacoeciae females, were examined in order to determine the impact of alternating two different Ephestia kuehniella egg qualities (fresh and four-days old), on their fecundity and their offspring’s survivorship. Results showed that T. oleae females significantly accepted more fresh eggs than older eggs, whatever was the presentation order of these eggs during both tests 1 and 2. However, T. cacoeciae significantly parasitized more, the eggs presented during the first half of tests 1 and 2, whatever was their quality. Also, female age effect on parasitization preferences was more visible on T. oleae adults, which tended to a...

Duckweed production is highly hampered due to the attack of a pyralid insect (Synclita occidentalis) in pond ecosystem. The insect attained pest status in its larval stage and continued up to pupal stage. Total 250 larvae were sampled for examining the morphological and physiological adaptations. Different appendicular and visceral organs of the larvae were considered for examination. The examinations were made under SKT binocular microscope (4x and 10x magnifications). Anatomical features of digestive, excretory and respiratory organs were examined by dissecting the larvae. Adaptability in the larval morphology was found highly significant. The 1 st thoracic and 1 st , 2 nd 3 rd , 4 th , 5 th , 6 th abdominal segments bear spiracles. The 3 rd to 6 th and 10 th abdominal segments bear prolegs on either side of the body. The alimentary canal was found developed and adapted to consume a large amount of leaf-biomass. The principal execratory organ composed of six malpighian tubules. The neural organs were highly developed. The tracheal system was found terrestrio-aquatic in adaptations. The larvae had no gills or additional structures. The larval case was a characteristic air chamber, in which the larva breaths through spiracles.

Oviposition behaviour and host selection of different German strains of the egg parasitoid Trichogramma aurosum Sugonjaev and Sorokina (Hymenoptera: Trichogrammatidae) were examined on eggs of five Lepidopteran hosts (Cydia pomonella (L.), Spodoptera littoralis (Boisd.), Helicoverpa armigera (Hübner), Agrotis segetum (Schiff.) and Lobesia botrana (Den. and Schiff.)). The parasitization behaviour of individual female wasps was examined in choice and non-choice tests. Single female wasps were observed for 90 min. using a rectangular grid. Results from the choice test revealed that 75–90% of C. Pomonella eggs attacked by T. aurosum strains were successfully parasitized. Values for L. Botrana and for A. segetum ranged between 40–80% and 40–70%, respectively. No significant preference was found between C. Pomonella eggs and host eggs of both L. botrana and A. segetum. Time needed by the female wasps to drill on eggs of L. Botrana was shorter than the time needed for drilling on C. Pomone...

Several plant characters are known to affect the searching behaviour and parasitization efficiency of Trichogramma spp. (Hymenoptera: Trichogrammatidae). In this study, plant characters contributing to the low Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) egg parasitism levels on pigeonpea (Cajanus cajan (L.) Millspaugh) were investigated. The efficiency of T. chilonis on pigeonpea was dependent on the plant structure on which the host eggs were found. In a cage experiment, more than 55% of eggs placed on leaves were parasitized, while 1% of eggs on calyxes and no eggs on pods were parasitized. In a filter paper bioassay, parasitoids were deterred by acetone and hexane surface extracts from pigeonpea pods but showed no response to water extract. The searching behaviour of the parasitoids was not affected by different solvent extracts from the surface of pigeonpea leaves. In a four‐armed airflow olfactometer, T. chilonis was repelled by volatiles from pigeonpea pods but show...

The response of Trichogramma spp. egg parasitoids to colored sticky traps was evaluated in the field during two seasons (1995/1996, 1996/1997). Traps consisted of a glass tube coated with Bird-Tanglefoot® into which colored paper was inserted or clear traps without paper. Colors tested were white, green, blue, yellow and red in the first season and white, green, yellow and black

Understanding interactions between biocontrol agents and their pest hosts under climate change should assist implementation of biocontrol strategies, by identifying appropriate biocontrol agents for release or determining the optimal timing of releases. Species Distribution Models (SDMs) are applied to evaluate the distributions of Trichogramma ostriniae and its native host, Ostrinia furnacalis, in southeastern Asia, and a non-native host, Ostrinia nubilalis, in a novel range, North America, using MAXENT and CLIMEX modelling approaches. Both models led to similar predictions about the expected distribution of the two species in Asia, and emphasized likely mismatches between host and natural enemy. Trichogramma ostriniae was predicted to occur in the summer corn region of China, with distribution limits linked to its sensitivity to cold, seasonality of radiation and precipitation. Modelled Ostrinia nubilalis distribution overlaps with the main corn production areas of northeastern Un...

Egg parasitoids of the genus Trichogramma are natural enemies of many lepidopteran borers in agricultural areas around the world. It is important to identify the correct species and ideally focus on endemic Trichogramma for pest control in particular crops. In this study, Trichogramma wasps were collected from parasitized eggs of Asian corn borer in Southwestern Taiwan. Three Trichogramma species, Trichogramma ostriniae Pang and Chen, Trichogramma chilonis Ishii, and T. sp. y, were identified based on morphology and the nucleotide sequence of the internal transcribed spacer 2 (ITS-2) region of rDNA. Although T. ostriniae and T. sp. y appear to be morphologically similar, ITS-2 identity between these two taxa is only 89%. Surprisingly, a commercially released Trichogramma colony thought to be T. chilonis possessed 99% identity (ITS-2) with the field T. sp. y individuals. This suggests past contamination leading to subsitution of the laboratory-reared T. chilonis colony by T. sp. y. N...