First case of parthenogenesis in Cryptolaemus montrouzieri (Mulsant) (Coccinellidae: Scymninae) under laboratory conditions in Morocco

Bien que Cryptolaemus montrouzieri (Mulsant) (Coccinellidae: Scymninae) ait été largement utilisé dans la lutte biologique contre un large éventail de ravageurs, aucune étude n'a été rapportée sur le phénomène de la reproduction asexuée de cet important prédateur. Dans notre étude qui a été réalisée dans des conditions contrôlées de température (27°C) et de photopériode (12 H), un lot de 250 larves du quatrième stade (stade préimaginal ultime) de développement de C. montrouzieri a été retiré des cages d'élevage et déposé dans des boîtes de pétri (14,5 cm de diamètre) renfermant différents stades de la cochenille comme nourriture. Après émergence de jeunes adultes (24 h) de la coccinelle, ils ont été pris individuellement et introduits dans de nouvelles boîtes de Pétri où différents stades de développement de Dactylopius opuntiae (Hemiptera: Dactylopiidae) sont maintenus dans les mêmes conditions de température et de photopériode. Vingt jours après l'émergence, il a été constaté qu'une partie des femelles non accouplées ont pondu des oeufs, et que 100 % des adultes qui ont émergé de ces femelles vierges étaient des mâles. Nos résultats montrent, d'une part, qu'un certain nombre de population de C. montrouzieri peut se reproduire par parthénogenèse par arrhénotoky, et que d'autre part, il semble que le coton cireux produit par les femelles de la cochenille stimule les femelles de Cryptolaemus montrouzieri à se reproduire par parthénogenèse.Although Cryptolaemus montrouzieri (Mulsant) (Coccinellidae: Scymninae) has been widely used in biological control against a wide range of pests, no studies have been reported regarding asexual reproduction of this important predator. Our study was carried out under controlled temperature (27 °C) and photoperiod (12 H) conditions. A cohort of 250 C. montrouzieri 4th instar (late preimaginal stage) larvae was collected from the rearing cages and placed in Petri dishes (14.5 cm diameter) containing different developmental stages of Dactylopius opuntiae (Hemiptera: Dactylopiidae) as food. After the emergence of C. montrouzieri young adults (24 h old), they were taken individually and introduced into new Petri dishes where different developmental stages of the mealybug were maintained under the same temperature and photoperiod conditions. Twenty days after emergence, it was observed that a small portion of C. montrouzieri unmated females laid eggs, and 100 % of the adults that emerged from these virgin females were males. Our results show, on one hand, that several C. montrouzieri populations can reproduce by arrhenotokous parthenogenesis, and on the other hand, it seems that the waxy cotton produced by the scale insect females stimulates C. montrouzieri females to reproduce by parthenogenesis

Adult Sitona crinitus H. (Coleoptera: Curculionidae) feeding preference on some legume species

We determined the feeding preference under artificial infestation in plastic house conditions of Sitona crinitus Herbst on several legumes:  Vicia sativa, V. ervilia, V. faba, Lens culinaris (small Syrian local " ILL: 4401"), Medicago polymorpha, Trifolium angustifolium, Cicer arietinum, and three Lathyrus species: Lathyrus sativus, L. ochrus and L. cicera. Beginning with the least-preferred leguminous food and feed crops, the order of feeding preference by Sitona was: V. sativa, L. culinaris, V. ervilia, T. sativum, M. sativa, L. cicera, L. Sativus, L. ochrus. No significant differences in preference were found between V. sativa, L. culinaris, V. ervilia and T. sativum. However, there were significant differences in feeding preference (P<0.05) between these species and Lathyrus spp. Cicer arietinum and Vicia faba were not hosts of S. crinitus. The genotypes of L. ochrus were less preferred than those of the other two Lathyrus species; the selection # 549 was the least preferred among L. ochrus genotypes. This nonprefernce may be related to the high level of the neurotoxin 3-(N-Oxalyl)-L-2, 3 diominopropionic acid (ß-ODAP) content of L. ochrus.We determined the feeding preference under artificial infestation in plastic house conditions of Sitona crinitus Herbst on several legumes: Vicia sativa, V. ervilia, V. faba, Lens culinaris (small Syrian local " ILL: 4401"), Medicago polymorpha, Trifolium angustifolium, Cicer arietinum, and three Lathyrus species: Lathyrus sativus, L. ochrus and L. cicera. Beginning with the least-preferred leguminous food and feed crops, the order of feeding preference by Sitona was: V. sativa, L. culinaris, V. ervilia, T. sativum, M. sativa, L. cicera, L. Sativus, L. ochrus. No significant differences in preference were found between V. sativa, L. culinaris, V. ervilia and T. sativum. However, there were significant differences in feeding preference (P<0.05) between these species and Lathyrus spp. Cicer arietinum and Vicia faba were not hosts of S. crinitus. The genotypes of L. ochrus were less preferred than those of the other two Lathyrus species; the selection # 549 was the least preferred among L. ochrus genotypes. This nonprefernce may be related to the high level of the neurotoxin 3-(NOxalyl)-L-2, 3 diominopropionic acid (ß-ODAP) content of L. ochrus

Distribution spatio-temporelle des principaux Lépidoptères de la Menthe verte dans la région de Chaouia

Population dynamics of three Lepidoptera species has been monitored by adult pheromonetrapping and caterpillar sampling on mint crop in three localities in the Chaouia regionduring the year 2013. A predominance of flight activity of Chrysodeixis chalcytes followedby Spodoptera littoralis was recorded, with three to four peaks between May and July. Lowcatches for Helicoverpa armigera species were noted on mint fields in the region. The flightactivity for all Lepidoptera species were discontinuous throughout the season. Highinfestation levels of caterpillars of the three Lepidoptera covered the months of May, June,and July. The highest larval numbers were recorded for the loopers, C.chalcytes. Populationmonitoring of these three Lepidoptera by pheromone traps on mint allowed to detect the firstflights and periods of pic emergence, which could be taken into account for rationalinsecticide applications.La dynamique des populations de trois lépidoptères a été suivie par piégeage à phéromonedes adultes et par échantillonnage des chenilles sur menthe verte dans trois localités dans larégion de Chaouia, durant l’année 2013. Une prédominance d’activité de vol de l’espèceChrysodeixis chalcytes, suivie par Spodoptera littoralis a été relevée. Trois à quatre picssont enregistrés pour ces espèces entre les mois de Mai et Juillet. Une faible capture a éténotée pour l’espèce Helicoverpa armigera sur les champs de menthe dans la région.L’activité de vol pour toutes les espèces est discontinue durant toute la saison. Les fortespériodes de pullulation des chenilles des trois espèces lépidoptères couvrent les mois deMai, Juin, et Juillet. L’effectif larvaire le plus élevé a été enregistré surtout pour leschenilles arpenteuses C. chalcytes. La surveillance des populations de ces lépidoptères parpiégeage sexuel sur menthe a permis de détecter les premiers vols ainsi que les périodes deforte émergence qui pourraient être pris en compte dans les interventions phytosanitairesraisonnées d’insecticides

Sources of resistance in durum wheat and its wild relatives to Russian wheat aphid (Hemiptea: Aphididae)

Russian wheat aphid (RWA), Diuraphis noxia (Kurdjumov), is a serious pest of cereals in many parts of the world, particularly in dry areas. As limited resistance sources to this pest were previously identified in durum wheat, 144 accessions of Aegilops spp. and 72 advanced durum wheat lines were evaluated for resistance to RWA in the field and in the plastic house at Tel Hadya, Syria. Ten Aegilops accessions and 14 advanced durum wheat lines showed good level of resistance to RWA. The best five lines were studied for categories of resistance, and the results showed that antibiosis, antixenosis and tolerance are involved in various combinations

Massive Shift in Gene Expression during Transitions between Developmental Stages of the Gall Midge, Mayetiola Destructor

Citation: Chen, M. S., Liu, S. Z., Wang, H. Y., Cheng, X. Y., El Bouhssini, M., & Whitworth, R. J. (2016). Massive Shift in Gene Expression during Transitions between Developmental Stages of the Gall Midge, Mayetiola Destructor. PLoS One, 11(5), 1-19. https://doi.org/10.1371/journal.pone.0155616Mayetiola destructor is a destructive pest of wheat and has six developmental stages. Molecular mechanisms controlling the transition between developmental stages remain unknown. Here we analyzed genes that were expressed differentially between two successive developmental stages, including larvae at 1, 3, 5, and 7 days, pupae, and adults. A total of 17,344 genes were expressed during one or more of these studied stages. Among the expressed genes, 38-68% were differently expressed between two successive stages, with roughly equal percentages of up-and down-regulated genes. Analysis of the functions of the differentially expressed genes revealed that each developmental stage had some unique types of expressed genes that are characteristic of the physiology at that stage. This is the first genome-wide analysis of genes differentially expressed in different stages in a gall midge. The large dataset of up-and down-regulated genes in each stage of the insect shall be very useful for future research to elucidate mechanisms regulating insect development and other biological processes

Genes Expressed Differentially in Hessian Fly Larvae Feeding in Resistant and Susceptible Plants

Citation: Chen, M. S., Liu, S. Z., Wang, H. Y., Cheng, X. Y., El Bouhssini, M., & Whitworth, R. J. (2016). Genes Expressed Differentially in Hessian Fly Larvae Feeding in Resistant and Susceptible Plants. International Journal of Molecular Sciences, 17(8), 14. https://doi.org/10.3390/ijms17081324The Hessian fly, Mayetiola destructor, is a destructive pest of wheat worldwide and mainly controlled by deploying resistant cultivars. In this study, we investigated the genes that were expressed differentially between larvae in resistant plants and those in susceptible plants through RNA sequencing on the Illumina platform. Informative genes were 11,832, 14,861, 15,708, and 15,071 for the comparisons between larvae in resistant versus susceptible plants for 0.5, 1, 3, and 5 days, respectively, after larvae had reached the feeding site. The transcript abundance corresponding to 5401, 6902, 8457, and 5202 of the informative genes exhibited significant differences (p <= 0.05) in the respective paired comparisons. Overall, genes involved in nutrient metabolism, RNA and protein synthesis exhibited lower transcript abundance in larvae from resistant plants, indicating that resistant plants inhibited nutrient metabolism and protein production in larvae. Interestingly, the numbers of cytochrome P450 genes with higher transcript abundance in larvae from resistant plants were comparable to, or higher than those with lower transcript abundance, indicating that toxic chemicals from resistant plants may have played important roles in Hessian fly larval death. Our study also identified several families of genes encoding secreted salivary gland proteins (SSGPs) that were expressed at early stage of 1st instar larvae and with more genes with higher transcript abundance in larvae from resistant plants. Those SSGPs are candidate effectors with important roles in plant manipulation

Effet insecticide des huiles essentielles sur la mineuse de pois chiche, Liriomyza cicerina R.

Quatre huiles essentielles obtenues par hydrodistillation à partir des plantes marocaines de la famille des myrtacées et lamiacées sont testées pour déterminer leur activité insecticide vis-à-vis des adultes et des larves de la mineuse de pois chiche (Liriomyza cicerina. R). La menthe pouliot, avec une dose de 33µl/l d’air a causé une mortalité de 100% sur les adultes et les larves, après trois heures et six heures d’exposition, respectivement. L’eucalyptus a montré une mortalité de 100% avec les doses de 33, et 83 µl/l, après six et trois heures d’exposition pour les adultes et les larves, respectivement. Puisque le test de l’activité insecticide de ces huiles essentielles par fumigation a montré des résultats prometteurs, il serait souhaitable d’étudier d’autres modes d’actions pour le contrôle de la mineuse sur la culture de pois chiche.

Comparative Biology and Life Cycle of The Barley Stem Gall Midge and Hessian fly (Diptera: Cecidomyiidae) in Morocco

The barley stem gall midge, Mayetiola hordei (Keiffer) is the most serious pest of barley in Morocco. The biology and life cycle of this insect were studied in a laboratory and under natural weather conditions. The results showed that similarly to Hessian fly, barley stem gall midge has two feeding instars and a third non-feeding instar. The generation time was longer for barley stem gall midge than for Hessian fly (45 vs 32 days at 18 ± 1°C, and a 12:12 (L: D) h photoperiod). The eggs of barley stem gall midge hatched in 7 days compared to 4 days for Hessian fly. The largest discrepancy in developmental time was for second instar and pupa. Second instars and pupae of barley stem gall midge required twice as long as those of Hessian fly to develop and molt into next stage (12 vs. 6 days). The first and third instars of barley stem gall midge also required a little bit longer to complete development (9 and 10 days vs. 7 and 8 days for Hessian fly). Like for Hessian fly, barley stem gall midge reproduces mostly by unisexual progenies. Four progeny classes were observed; unisexual female progenies, unisexual male progenies, predominantly female progenies, and predominantly male progenies. The proportion of unisexual female and male progenies and the proportion of predominantly female and predominantly male progenies were similar. Overall, the sex ratio of both species was about 1:1. Under field weather conditions that prevail in the Chaouia region of Morocco, barley stem gall midge has two complete generations and a third partial one. The first generation starts late October, and ends late December. The second generation develops from January until early March. A high proportion of third instars of this generation fail to pupate (35%). The third generation is only partial; adults of the second generation emerge during March, oviposit and larvae develop to third instars but all go into summer diapause.