15 research outputs found
Functional responses of larval instars of Cryptolaemus Montrouzieri Mulsant (Coleoptera: Coccinellidae) to the Cochineal Scale, Dactylopius Opuntiae (Cockerell) (Hemiptera: Dactylopiidae)
Cryptolaemus montrouzieri Mulsant (Coleoptera: Coccinellidae) is native to Australia and commonly known as 'cochineal destroyer'. This predator has been introduced in many countries worldwide for biological control of many scale pest species including the cochineal of cactus pear, Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae). The functional responses of larval instars of C. montrouzieri on D. opuntiae (Cockerell) adult females were evaluated under laboratory conditions at 26°C and 12:12 (L:D) h. All larval instars of the predator were first starved for 12 h, then placed individually in Petri dishes (14.5 cm in diameter) with different densities (5, 10, 15, 20, 25) of D. opuntiae females for 24 h. The logistic regression for larval instars of the predator had a negative and significant linear parameter (P1) indicating a type II functional response. Attack rates (0.010, 0.028, 0.042, and 0.052) and handling times (11.945, 6.834, 4.878, and 3.971 hours) for first to fourth instar larvae, respectively, which were estimated using the Holling's disc equation. This study provides a better understanding of the functional response of C. montrouzieri larval instars to D. opuntiae, which may be useful for effective use of C. montrouzieri in the management of the cactus pear cochineal infestations
Optimisation de la résilience du cactus (Opuntia spp.) au Maroc
La prĂ©sente Ă©tude sur lâoptimisation de la rĂ©silience du cactus au Maroc, met en Ă©vidence les critĂšres propices pour la culture de cette espĂšce, tels que la variabilitĂ© annuelle des prĂ©cipitations, de la tempĂ©rature, de l'humiditĂ© relative de lâair, de la salinitĂ© du sol, du type de sol, sa structure, son pH et sa teneur en carbone organique. Lâanalyse montre que seulement 5% des terres cultivĂ©es sont hautement appropriĂ©es pour la culture du cactus, mais identifie Ă©galement les rĂ©gions ayant une superficie notable de terres agricoles hautement Ă modĂ©rĂ©ment appropriĂ©es, telles que Tanger-TĂ©touan-Al Hoceima, Rabat-SalĂ©-KĂ©nitra, BĂ©ni Mellal-KhĂ©nifra, FĂšs-MeknĂšs et Marrakech-Safi. Ce travail Ă©value Ă©galement l'impact de la cochenille Dactylopius opuntiae (Cockerell) sur les niveaux de CO2 de lâair et de carbone organique dans le sol au Maroc. La destruction complĂšte des cultures du cactus en raison de leur infestation par la cochenille a conduit Ă une augmentation significative des niveaux de CO2 dans l'air et une rĂ©duction du carbone organique dans le sol. Ainsi, cette Ă©tude souligne dâune part l'importance des facteurs climatiques et Ă©daphiques dans la dĂ©termination des zones propices Ă la culture du cactus au Maroc, et dâautre part l'importance de mettre en place des stratĂ©gies de lutte contre la cochenille du cactus pour protĂ©ger l'Ă©cosystĂšme et optimiser la rĂ©silience de cette culture
Efficacy of some biorational insecticides against the cactus scale pest Diaspis echinocacti (Bouché, 1833) (Hemiptera: Diaspididae) in Morocco
Diaspis echinocacti (Bouché) is a significant pest affecting various cactus pear species worldwide. Over the past three years, this scale insect was able to build up a considerable population and had now reached a pest status in Morocco. To control this pest, insecticides with different modes of action were evaluated in laboratory and greenhouse. In laboratory bioassays, d-limonene at 30-150 cc/hl, mineral oil at 700-2400 cc/hl, potassium salts of fatty acid at 15-60 cc/hl, and pyriproxyfen at 8-37 cc/hl were evaluated against first instar nymphs and adult females of the cochineal, while only d-limonene applied at 150 cc/hl, mineral oil applied at 2000 and 2400 cc/hl, and potassium salts of fatty acid applied at 60 cc/hl were used in greenhouse tests. In laboratory tests, mineral oil at 2400 cc/hl, d-limonene at 150 cc/hl, and potassium salts of fatty acid at 60 cc/hl were the most effective against nymphs and adult females of the cochineal 48 hours after exposure to insecticide treatments, resulting in LT50 values of 24, 24 and 48 h (nymphs), and 48 h (adult females), respectively. Under greenhouse conditions, mineral oil at 2400 cc/hl and d-limonene at 150 cc/hl showed significantly higher mortality rates [70 and 67% (nymph) and 45 and 42% mortality (adult female), respectively] and a high potential for degrading waxy carapace covering the body of the cochineal. Effective control of this harmful pest depends on a justified use of these two insecticides (mineral oil and d-limonene) and requires the development of an integrated management approach
Ennemis naturels associés à Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) au Maroc et leurs fluctuations démographiques
Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) is the most important pest of prickly pear cactus Opuntia ficus-indica in Morocco in recent years. In order to identify the natural enemies associated with this pest, and determine their population fluctuations, samplings were carried out at two distinct areas, sampling area 1- Zemamra in the Sidi Bennour region (120 km north-west of Marrakech), Morocco and sampling area 2-Gharbia in the same region. 15 species were found and identified: Episyrphus balteatus de Geer, Eupeodes corollae Fabricius (Diptera: Syrphidae), Hyperaspis campestris (Herbst, 1783), Scymnus interruptus (Goeze). Scymnus loewii, Nephus redtenbacheri (Mulsant, 1846), Scymnus latemaculatus, Scymnus guttulatus LeConte, Exochomus nigripennis (Erichson, 1843), Coccinella septempunctata (Linnaeus, 1758), Hippodamia convergens, Chilocorus bipustulatus (Linnaeus, 1758), and Chilocorus politus (Mulsant, 1850) (Coleoptera: Coccinellidae) and Emmelina Monodactyla (Lepidoptera: Pterophoridae). Hyperaspis campestris was found to be the most important specie associated with D. opuntiae in study area-1 and Chilocorus bipustulatus in study area-2.
Keywords: Dactylopius opuntiae, Hyperaspis campestris, Chilocorus bipustulatus, biocontrolDactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae) est le principal ravageur du cactus Opuntia ficus-indica, au Maroc, ces derniĂšres annĂ©es. Afin d'identifier les ennemis naturels associĂ©s Ă cet insecte nuisible et de dĂ©terminer leurs fluctuations dĂ©mographiques,des Ă©chantillonnages ont Ă©tĂ© effectuĂ©s dans deux zones distinctes durant deux annĂ©es 2017- 2018, la zone d'Ă©chantillonnage 1- Zemamra dans la rĂ©gion de Sidi Bennour (120 km au nord-ouest de Marrakech), au Maroc et zone d'Ă©chantillonnage 2- Gharbia localitĂ© dans la mĂȘme rĂ©gion. 15 espĂšces ont Ă©tĂ© trouvĂ©es et identifiĂ©es: Episyrphus balteatus de Geer, Eupeodes corollae Fabricius (Diptera: Syrphidae), Hyperaspis campestris (Herbst, 1783), Scymnus interruptus (Goeze). Scymnus loewii, Nephus redtenbacheri (Mulsant, 1846), Scymnus latemaculatus, Scymnus guttulatus LeConte, Exochomus nigripennis (Erichson, 1843), Coccinella septempunctata (Linnaeus, 1758), Hippodamia convergens, Chilocorus bipustulatus (Linnaeus, 1758), and Chilocorus politus (Mulsant, 1850). (Coleoptera: Coccinellidae), and Emmelina Monodactyla (Lepidoptera: Pterophoridae). Hyperaspis campestris s'est rĂ©vĂ©lĂ© ĂȘtre l'espĂšce la plus importante associĂ©e Ă D. opuntiae dans la zone d'Ă©tude 1 et Ă Chilocorus bipustulatus dans la zone d'Ă©tude 2.
Mots-clés: Dactylopius opuntiae, Hyperaspis campestris, Chilocorus bipustulatus, biocontrÎl
Insecticidal potential of Streptomyces sp. dichloromethane extracts against the cactus cochineal Dactylopius opuntiae (Cockerell)
Destructive damages caused by Dactylopius opuntiae (Cockerell) to cactus worldwide require an ecofriendly IPM approach. Streptomyces sp. produce wide range of biologically active secondary metabolites that can be an interesting alternative to chemical insecticides for pest control, as they are less toxic and easily biodegradable. The efficacy of dichloromethane extracts of four Moroccan Streptomyces sp. strains: Streptomyces bellus- E23-2, Streptomyces galilaeus- E23-9, Streptomyces africanus- E23-3, and Streptomyces bellus- E25-12 (applied at 11, 13, 15, 17 and 20 mg mL-1) against D. opuntiae nymphs and adult females was evaluated under laboratory and greenhouse conditions. Results showed that Streptomyces bellus- E23-2 and Streptomyces galilaeus- E23-9 dichloromethane extracts applied at 20 mg mL-1 were more effective, causing higher mortality against nymphs (92% and 91%, respectively) and adult females (90% and 95%, respectively) after 8 days of exposure, resulting in an LT50 value of 3.0 days (nymph), and 3.0 and 6.0 days (adult female), respectively. Streptomyces bellus- E25-12 extract had the lowest mortalities [88% (nymph) and 68% (adult female)]. In greenhouse experiment, the highest first instar nymph mortality was achieved by Streptomyces bellus- E23-2 (55.5%) and Streptomyces galilaeus- E23-9 (50.5%) dichloromethane extracts at 20 mg mL-1. The metabolites found in dichloromethane extracts of Streptomyces bellus- E23-2 and Streptomyces galilaeus- E23-9 show considerable potential to be used in the development of new biopesticide formulations for use in integrated pest management programs against D. opuntiae
La fertilisation minérale module la survie, la reproduction et la croissance de la population de la cochenille du cactus Dactylopius opuntiae (Cockerell)
Opuntiae cactus cochineal Dactylopius opuntiae (Cockerell) is a specific scale pest that causes enormous economic losses on cactus pear worldwide. In this study, the effects of synthetic fertilizer N-P-K applications on the development, biology and reproduction of cactus cochineal were investigated. The experiments were carried out under greenhouses at 28°C/17°C (day/night). Synthetic fertilizer N-P-K tested treatments were T1: 0â0â0; T2: 30â40â40; T3:60â80 â80; T4: 60â0â0; T5: 0â80â0; T6: 0â0â80; and T7: 40â100-80 kg ha-1. Cactus cochineal feeding on Cactus opuntia ficus-indica [L.] Mill. plants receiving the highest nitrogen level fertilizer (T4) had the shortest total time of development (79.1 and 27.2 days for female and male, respectively), the highest pre-adult survival rate (80%), the highest proportions of females (40%), the shortest pre-oviposition period (34.4 days), and the longest oviposition period (22.4 days), as well as the greatest fecundity (406.7 egg/female) and fertility (90%) compared to the other treatments. The net reproductive rate (R0) (163.84 females/female/generation), the intrinsic rate of natural increase (rm) (0.12 females/female/day) and the finite rate of increase (l) (1.13 days-1) were significantly the highest at T4 and the lowest at T7 treatments. In contrast, increasing concentration of potassium and phosphorus from T5 to T7 treatments decreased the host suitability for the cactus cochineal and negatively affected its biology, reproduction and population incidence (population incidence = 1.2 at T7 treatment). This means that, compared to potassium and phosphorus, higher nitrogen fertilization improves the suitability of cactus O. ficus-indica for cactus cochineal D. opuntiae, whose performance and reproduction are then increased.La cochenille de cactus Dactylopius opuntiae (Cockerell) est un ravageur spĂ©cifique qui a causĂ© d'Ă©normes pertes Ă©conomiques sur le cactus dans le monde entier. Dans cette Ă©tude, les effets de l'application d'engrais synthĂ©tiques N-P-K sur le dĂ©veloppement, la biologie et la reproduction de la cochenille ont Ă©tĂ© Ă©tudiĂ©s. Les expĂ©riences ont Ă©tĂ© rĂ©alisĂ©es sous serres Ă 28°C/17°C (jour/nuit). Les traitements d'engrais synthĂ©tiques N-P-K testĂ©s Ă©taient T1: 0-0-0; T2: 30-40-40; T3: 60-80-80; T4: 60-0-0; T5: 0-80-0; T6: 0-0-80; et T7: 40-100-80 kg ha-1. Les cochenilles se nourrissant de plantes du Cactus Opuntia ficus-indica [L.] Mill. ayant reçu une fertilisation azotĂ©e plus Ă©levĂ©e (T4) avaient une durĂ©e totale de dĂ©veloppement plus courte (79,1 et 27,2 jours pour les femelles et les mĂąles, respectivement), un taux de survie prĂ©-adulte plus Ă©levĂ© (80 %), de grandes proportions de femelles (40 %), une pĂ©riode de prĂ©-oviposition plus courte (34,4 jours), une pĂ©riode de ponte plus longue (22,4 jours), ainsi qu'une fĂ©conditĂ© plus Ă©levĂ©e (406,7 oeufs/femelle). Le taux de reproduction net (R0) (163,84 femelle/femelle/gĂ©nĂ©ration), le taux intrinsĂšque d'accroissement naturel (rm) (0,12 femelle/femelle/jour) et le taux d'accroissement fini () (1,13 jours-1) Ă©taient significativement plus Ă©levĂ©s au traitement T4 et plus faibles au traitement T7. En revanche, l'augmentation de la concentration du potassium et du phosphore entre les traitements T5 et T7 a diminuĂ© l'adĂ©quation du Cactus pour la cochenille et a affectĂ© nĂ©gativement sa biologie, sa reproduction et l'incidence de sa population (incidence de la population = 1,2 au traitement T7). Cela signifie que, par rapport au potassium et au phosphore, une fertilisation azotĂ©e plus Ă©levĂ©e amĂ©liore l'aptitude du Cactus O. ficus-indica pour la cochenille D. opuntiae, et par consĂ©quent augmente sa performance et sa reproduction
Efficacité de certains insecticides biorationnels contre la cochenille de cactus Diaspis echinocacti (Bouché, 1833) (Hemiptera: Diaspididae) au Maroc
Diaspis echinocacti (Bouché) is a significant pest affecting various cactus pear species worldwide. Over the past three years, this scale insect was able to build up a considerable population and had now reached a pest status in Morocco. To control this pest, insecticides with different modes of action were evaluated in laboratory and greenhouse. In laboratory bioassays, d-limonene at 30-150 cc/hl, mineral oil at 700-2400 cc/hl, potassium salts of fatty acid at 15-60 cc/hl, and pyriproxyfen at 8-37 cc/hl were evaluated against first instar nymphs and adult females of the cochineal, while only d-limonene applied at 150 cc/hl, mineral oil applied at 2000 and 2400 cc/hl, and potassium salts of fatty acid applied at 60 cc/hl were used in greenhouse tests. In laboratory tests, mineral oil at 2400 cc/hl, d-limonene at 150 cc/hl, and potassium salts of fatty acid at 60 cc/hl were the most effective against nymphs and adult females of the cochineal 48 hours after exposure to insecticide treatments, resulting in LT50 values of 24, 24 and 48 h (nymphs), and 48 h (adult females), respectively. Under greenhouse conditions, mineral oil at 2400 cc/hl and d-limonene at 150 cc/hl showed significantly higher mortality rates [70 and 67% (nymph) and 45 and 42% mortality (adult female), respectively] and a high potential for degrading waxy carapace covering the body of the cochineal. Effective control of this harmful pest depends on a justified use of these two insecticides (mineral oil and d-limonene) and requires the development of an integrated management approach.Diaspis echinocacti (Bouché) est un ravageur important qui affecte différentes espÚces de de cactus dans le monde entier. Au cours des trois derniÚres années, cet insecte a réussi à constituer une population considérable et est maintenant considéré comme un ravageur au Maroc. Afin de contrÎler ce ravageur, des insecticides avec différents modes d'action ont été évalués au laboratoire et sous serre. Dans les essais du laboratoire, le d-limonÚne à des doses de 30 à 150 cc/hl, l'huile minérale à des doses de 700 à 2400 cc/hl, les sels de potassium d'acides gras à des doses de 15 à 60 cc/hl, et le pyriproxyfÚne à des doses de 8 à 37 cc/hl ont été évalués contre les nymphes du premiÚre stade et les femelles adultes de la cochenille. Sous serre, seules les doses de d-limonÚne à 150 cc/hl, d'huile minérale à 2000 et 2400 cc/hl, et de sels de potassium d'acides gras à 60 cc/hl ont été utilisées. Au laboratoire, l'huile minérale à 2400 cc/hl, le d-limonÚne à 150 cc/hl et les sels de potassium d'acides gras à 60 cc/hl se sont révélés les plus efficaces contre les nymphes et les femelles adultes de la cochenille, 48 heures aprÚs exposition aux traitements insecticides, résultant en des valeurs de LT50 de 24, 24 et 48 heures (pour les nymphes) et 48 heures (pour les femelles adultes), respectivement. Sous serre, l'huile minérale à 2400 cc/hl et le d-limonÚne à 150 cc/hl ont montré des taux de mortalité significativement plus élevés (70 et 67 % sur les nymphes et 45 et 42 % de mortalité sur les femelles adultes, respectivement) et un fort potentiel de dégradation de la carapace cireuse qui couvre le corps de la cochenille. La lutte efficace contre ce ravageur dépend de l'utilisation justifiée et judicieuse de ces deux insecticides (l'huile minérale et le d-limonÚne) et nécessite le développement d'une approche de gestion intégrée
Temperature Dependence for Survival, Development, and Reproduction of the Cactus Cochineal Dactylopius opuntiae (Cockerell)
The effect of temperature on Dactylopius opuntiae (Cockerell) life cycle parameters was evaluated at 20, 23, 26, 32, and 40 ± 1 °C, 65 ± 5% RH, and a photoperiod of 12 L:8 D. Temperatures ranging from 26 °C to 32 °C were suitable for survival, development, and reproduction of D. opuntiae. The total developmental time of females ranged from 94.23 d (20 °C) to 43.55 d (40 °C). The average development time of males from egg to death ranged from 26.97 days at 32 °C to 50.75 days at 20 °C. The probability that a newly laid egg would survive to the adult stage was highest at 26 °C and 32 °C (44–60%). The parthenogenesis in females was not observed during our study. The longest oviposition period was observed when the cochineal was reared at 32 °C (17.97 days), and the highest fecundity was observed at 32 °C (355.29 egg/female). The highest proportion of females (0.80) was observed at 40 °C. According to the age-stage-two-sex life table, the highest value of the intrinsic rate of natural increase (rm) was recorded at 32 °C. The lower developmental thresholds for the total pre-adult female and male and adult female and male stages, were 10.15, 12.21, 10.54, and 21.04 °C, respectively. Dactylopius opuntiae females needed a higher thermal constant (769.23 D°) than males (357.14 D°) to achieve their development and reach the mature adult stage. These findings will be useful for the development of an integrated pest management strategy for D. opuntiae
Ăvaluation de la mĂ©thode de plantation et de l'auxine pour la multiplication vĂ©gĂ©tative des variĂ©tĂ©s de de figuier de Barbarie (Opuntia spp.) rĂ©sistantes Ă Dactylopius opuntiae (Hemiptera : Dactylopiidae) au Maroc
Cactus Opuntia spp. is a perfectly appropriate crop for land rehabilitation in the arid and semi-arid regions of Morocco. Unfortunately, the sustainability of this extremely resilient crop has become seriously threatened by the appearance of Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), a cochineal specific to Opuntia spp cacti that was introduced in Morocco in 2014. Thus, eight Opuntia spp. varieties were identified by National Institute of Agricultural Research in Morocco as resistant to the cochineal, to provide a solid basis for the national emergency program of rehabilitating the devastated Opuntia spp. ecosystems throughout the country. To produce large quantities of planting material, a rapid Ex-situ propagation method for prickly pears have been developed. For each of the eight varieties, cladodes were harvested in march, 2019 and 2020 in the Experimental Station of the Regional Office of Agricultural Development of Doukkala (ORMVAD). They were cut into 6 pieces of about 140 cm2 with at least two bud areolas. After 25 days of drying at a temperature range from 17 to 28 °C, the cuttings were soaked for 5 min in 2.5 g/l of a Rhizogen product (containing 0.3% IBA), which represents for us the Auxin, or in talc powder or in talc powder and a rapid soaking in auxin solution (mix 1) or soaking in water then in talc powder (mix 2) or in water. The cuttings were planted in normal polarity in black plastic cylindrical containers (24.6 cm long and 14.1 cm wide), filled with a mixture of fine sand (2/3 w/w) and peat (1/3 w/w) and placed at an average ambient temperature of 28°C/17°C (day/night) in field for growth. In general, auxin (2.5 g/l) and mix 1 treatments were found to be the most effective regarding rooting (20-73 roots number) and growth of cuttings. This research has also allowed us to demonstrate that, in general, for all the varieties studied, basal cuttings planted in orientation (N-S) and normal polarity show very interesting results under optimal conditions concerning rhizogenesis and caulogenesis.Le cactus Opuntia spp. est une culture parfaitement adaptĂ©e Ă la rĂ©habilitation des terres dans les rĂ©gions arides et semi-arides du Maroc. Malheureusement, la pĂ©rennitĂ© de cet Ă©cosystĂšme extrĂȘmement rĂ©silient est devenue sĂ©rieusement menacĂ©e par l'apparition de Dactylopius opuntiae (Cockerell) (Hemiptera: Dactylopiidae), une cochenille spĂ©cifique Ă lâ Opuntia spp. qui a Ă©tĂ© introduite au Maroc en 2014. Ainsi, dans un premier temps, lâInstitut National de la Recherche Agronomique du Maroc a identifiĂ© huit variĂ©tĂ©s de dâOpuntia cactus comme rĂ©sistantes Ă la cochenille qui constitueront une base solide pour le programme national de reconstitution des Opuntia spp. dĂ©cimĂ©s Ă travers le pays. Pour produire le matĂ©riel vĂ©gĂ©tal nĂ©cessaire Ă ce programme, une mĂ©thode de multiplication rapide Ex situ des cactus a Ă©tĂ© dĂ©veloppĂ©e. Pour chacune des huit variĂ©tĂ©s, les cladodes collectĂ©es en mars 2019 et 2020 Ă partir de la Station ExpĂ©rimentale de lâOffice RĂ©gional de Mise en Valeur Agricole du Doukkala (ORMVAD). Elles ont Ă©tĂ© coupĂ©es en 6 morceaux d'environ 140 cm2, comportant au moins deux arĂ©oles de bourgeons dans l'une de ses bases. AprĂšs 25 jours de sĂ©chage Ă une tempĂ©rature comprise entre 17 et 28 °C, ces boutures ont Ă©tĂ© trempĂ©es pendant 5 min dans 2.5 g/l dâun produit rhizogĂšne (contenant 0.3% dâAIB) et qui reprĂ©sente pour nous lâauxine, ou dans le talc, ou dans le talc suivi par un trempage rapide dans une solution de lâauxine (mĂ©lange 1), ou un trempage dans l'eau puis dans le talc (mĂ©lange 2) ou dans l'eau. Les boutures ont Ă©tĂ© plantĂ©es en polaritĂ© normale dans des rĂ©cipients cylindriques en plastique noir (24,6 cm de long et 14,1 cm de large), remplis d'un mĂ©lange de sable fin (2/3 w/w) et de tourbe (1/3 w/w) et placĂ©s Ă une tempĂ©rature ambiante moyenne de 28°C/17°C (jour/nuit) dans le champ pour la croissance. En gĂ©nĂ©ral, les traitements Ă l'auxine (2,5 g/l) et le mĂ©lange 1 se sont avĂ©rĂ©s les plus efficaces pour l'enracinement (20-73 nombre de racines) et la croissance des boutures. Egalement, et pour toutes les variĂ©tĂ©s Ă©tudiĂ©es, les boutures basales plantĂ©es en orientation (N-S) et en polaritĂ© normale ont donnĂ© des rĂ©sultats trĂšs apprĂ©ciables de rhizogenĂšse et de caulogenĂšse dans les conditions optimales
Potentiel de prédation et préférence alimentaire de Cryptolaemus montrouzieri sur Dactylopius opuntiae en laboratoire
Recently the introduced mealybug, Dactylopius opuntiae, has been the most devastating insect of cactus in Morocco. The cochineal has spread to many regions of the kingdom and caused enormous socio-economic and environmental losses. To control this menace, predatory potential of Cryptolaemus montrouzieri was investigated under laboratory conditions at 26±2°C, 60±10% RH and 12:12 h L:D regime. In this study, the experiments were conducted in choice feeding tests (D. opuntiae second instar, first instar nymphs and eggs were offered simultaneously). C. montrouzieri adults and fourth instar larvae were the most feedersâ predators on different stages of D. opuntiae. Manlyâs preference index values showed that all predator stages preferred younger stages of mealybug (p < 0.5), (negative switching). Furthermore, studies on development time showed that egg, larvae, prepupal, pupal and adult stages duration were 3.60±0.67, 4.05±0.90, 4.45±0.85, 5.48±0.91, 8.15±0.36, 1.48±0.60, 10.80±0.65, and 103.28±2.37, respectively. The results of this study showed that C. montrouzieri has the ability to be exploited as a predator of D. opuntiae in Morocco.
Keywords: Dactylopius opuntiae, Cryptolaemus montrouzieri, Opuntia ficus-indica, biological control, MoroccoRĂ©cemment, la cochenille Ă carmin introduite, Dactylopius opuntiae, est l'insecte le plus dĂ©vastateur du cactus au Maroc. La cochenille s'est Ă©tendue Ă de nombreuses rĂ©gions du royaume et a provoquĂ© d'Ă©normes pertes socio-Ă©conomiques et environnementales. Pour contrĂŽler cette menace, le potentiel prĂ©dateur de Cryptolaemus montrouzieri a Ă©tĂ© Ă©tudiĂ© en laboratoire Ă une tempĂ©rature de 26±2 °C, 60±10% HR et 12:12 h L: D. Dans cette Ă©tude, les expĂ©riences ont Ă©tĂ© menĂ©es dans le cadre dâessais dâalimentation en choix (nymphes de deuxiĂšme stade, nymphes de premier stade et les Ćufs de D. opuntiae offerts simultanĂ©ment au prĂ©dateurs). Les adultes de C. montrouzieri et les larves de quatriĂšme stade Ă©taient les prĂ©dateurs les plus nourris Ă diffĂ©rents stades de D. opuntiae. Les valeurs de l'indice de prĂ©fĂ©rence de Manly ont montrĂ© que tous les stades prĂ©dateurs prĂ©fĂ©raient les stades plus jeunes de la cochenille (p <0.5) (commutation nĂ©gative). En outre, des Ă©tudes sur le temps de dĂ©veloppement ont montrĂ© que les Ćufs, les larves, La durĂ©e des phases prĂ©pupale, pupal et adulte Ă©tait de 3.60±0.67, 4.05±0.90, 4.45±0.85, 5.48±0.91, 8.15±0.36, 1.48±0.60, 10.80±0.65 et 103.28±2.37, respectivement. Les rĂ©sultats de cette Ă©tude ont montrĂ© que C. montrouzieri pouvait ĂȘtre exploitĂ© comme prĂ©dateur de D. opuntiae au Maroc.
Mots-clés: Dactylopius opuntiae, Cryptolaemus montrouzieri, Opuntia ficus-indica, contrÎle biologique, Maro