A comparison of two parasitoids (hymenoptera: encyrtidae) of the vine mealybug: rapid, non-discriminatory oviposition is favored when ants tend the host (original) (raw)
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Biological Control, 2004
The inXuence of temperature on Anagyrus pseudococci (Girault) development and overwintering was investigated to improve biological control of the vine mealybug, Planococcus Wcus (Signoret), in California vineyards. At a constant 32°C, egg development required 2 days, larval development ranged from 0.7 § 0.1 (second instar) to 1.9 § 0.1 (Wfth instar) days, and pupal development was 3.9 § 0.1 days. Under eight constant temperatures (12, 14, 17, 22, 27, 32, 34, and 36°C), A. pseudococci completed development (egg to adult eclosion) from 14 to 34°C. Development times ranged from 79.1 § 1.0 days (14°C) to 10.2 § 0.3 days (34°C). We determined optimal, maximum and minimum development temperatures to be 24.7, 36.0 and 11.6°C, respectively, and the thermal constant is 223.5 degree-days. We compared these laboratory-derived temperature relationships to A. pseudococci Weld-monitored populations from March through November. Laboratory-data suggests there are seven to eight A. pseudococci generations during this period, two generations to each vine mealybug generation. Overwintering studies show that A. pseudococci emergence was concentrated over a 15 day period in early May, regardless of when vine mealybugs were exposed (October 2001 to March 2002. Results suggest that cues other than temperature are used to synchronize overwintered A. pseudococci adult emergence with Weld availability of vine mealybug.
This article appeared in a journal published by Elsevier. The attached copy is furnished to the author for internal non-commercial research and education use, including for instruction at the authors institution and sharing with colleagues. Other uses, including reproduction and distribution, or selling or licensing copies, or posting to personal, institutional or third party websites are prohibited. In most cases authors are permitted to post their version of the article (e.g. in Word or Tex form) to their personal website or institutional repository. Authors requiring further information regarding Elsevier's archiving and manuscript policies are encouraged to visit: http://www.elsevier.com/copyright a b s t r a c t Anagyrus sp. and Coccidoxenoides perminutus are well known parasitoids used for the biological control of the vine mealybug Planococcus ficus, a key pest in vineyards. In South Africa, three ant species, Anoplolepis steingroeveri, Crematogaster peringueyi and Linepithema humile form a trophobiotic relationship with the vine mealybug in vineyards and promote the latter's infestations to unacceptable levels. In a manipula-tive laboratory experiment, ants and parasitoids were allowed to forage on vine mealybug-infested butternuts and numbers were recorded for a 1 min period at 10 min intervals for 2 h. Parasitoid mortality and the number of parasitized vine mealybug females were then recorded in the presence and absence of the three ant species. Data were analyzed using a repeated measures generalized linear model (GEEs). The mean number of ants and parasitoids on the mealybug-infested butternuts differed significantly between ant species and time intervals (p < 0.0001 in all cases). Crematogaster peringueyi and L. humile caused significantly higher mortality of both parasitoids than A. steingroeveri during the 24-h exposure period (p < 0.0001). Coccidoxenoides perminutus parasitized significantly more vine mealybugs than Anagyrus sp. for all treatments (p < 0.0001). Ants should therefore be controlled prior to release of para-sitoids to suppress populations of ant-tended Hemiptera in vineyards. Crown
Egyptian Journal of Biological Pest Control
Background This study was conducted to investigate host stage preference and demographic parameters of the parasitoid species, Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae), the parasitoid of vine mealybug Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), an important pest in vineyards in many countries. Results The results revealed that L. dactylopii was not able to develop on the 1st and 2nd nymphal instars of P. ficus and preferred female mealybugs as the host to the 3rd nymphal instar. Hind tibia length and head capsule width of both female and male parasitoids emerged from the mummies of mealybugs parasitized in the female stage were greater than the values of the parasitoids emerged from the mummies of mealybugs parasitized in the 3rd nymphal instar. Demographic parameters of the parasitoid were calculated with the use of development and reproduction data obtained from life table of L. dactylopii. The intrinsic rate of increase was determined as (r = 0.1527 d...
The koinobiont endoparasitoid Leptomastix dactylopii Howard (Hymenoptera: Encyrtidae) has been widely used as a biological control agent of the citrus mealybug, Planococcus citri (Risso) (Hemiptera: Pseudococcidae), in citrus orchards and ornamental greenhouses. Previous studies showed that the vine mealybug, Planococcus ficus (Signoret) (Hemiptera: Pseudococcidae), is a suitable host for the parasitoid to complete its development. In the current experiment, the preference of L. dactylopii for the two hosts was investigated in a two-choice test. Newly-emerged parasitoid females, reared on one of the two mealybug species, were mated and exposed to third-instar nymphs and young adult females of both P. ficus and P. citri in an experimental arena. In order to investigate the influence of a previous oviposition experience on the host preference, the experimental wasps were naïve (inexperienced) or had oviposition experience with one of the two hosts before the release in the test arena....
Biological Control, 2004
Properties relevant to the ovipositional activity and lifetime productivity of Coccidoxenoides peregrinus (Timberlake) were assessed in the laboratory, to determine the potential of this species as a biocontrol agent against the citrus mealybug, Planococcus citri (Risso). In general, this species has not performed well in orchards, except for a few localities on different continents. The mode of reproduction of C. peregrinus is almost entirely thelytokous, with males produced sporadically and at low frequency. The females have both pro-ovigenic and synovigenic traits, which raises questions of the utility of this distinction. The females have a high reproductive potential with 10-20 eggs per day available within the first two days (after a short (12 h) pre-oviposition period), and 80-150 eggs per day thereafter until death at about eight days. Mean lifetime fecundity was 239.2 AE 34.3 eggs. C. peregrinus oviposits across a range of P. citri instars, but productivity relies predominantly on second instar hosts. Second stage (N2) hosts received most eggs in choice (about 52%) and no-choice (about 50%) tests. Most eggs deposited into N2 hosts (82%) reached adult stage whereas only a few of those deposited into N1 and N3 (about 5% each) developed successfully. The haemolymph of parasitised reproductive mealybugs contained granular structures and no parasitoid eggs were found 24 h after exposure to ovipositing wasps. Also, no wasps emerged from parasitised adult hosts that were kept alive. Parasitoid eggs deposited into adult hosts were presumed encapsulated and destroyed, as control mealybugs (not exposed to female wasps) had no granular structures in their haemolymph. Wasps exposed to an abundance of hosts soon started ovipositing, but only for a relatively short time each day (about 2.5 h out of a 7 h exposure). They stopped ovipositing despite eggs judged to be mature in their ovaries. The reproductive output of C. peregrinus is discussed in relation to the ecological factors that could influence this output, and the implications for biocontrol are discussed.
Biodiversitas Journal of Biological Diversity
Parasitoid, Anagyrus lopezi (De Santis) (Hymenoptera: Encyrtidae) was introduced into Indonesia in 2014 to control the invasive cassava mealybug, Phenacoccus manihoti Matile-Ferrero (Hemiptera: Pseudococcidae). Among ants associated with honeydew-producing hemipterans, there are three common species in Indonesia i.e., Anoplolepis gracilipes (Smith), Dolichoderus thoracicus (Smith), and Oecophylla smaragdina (Fabricius) (Hymenoptera: Formicidae). The objective of this research was to investigate the relative influence of the three ant species on the parasitism of A. lopezi under laboratory conditions. Experiments were carried out by allowing a number of ants and parasitoids to forage on mealybugs-infested waterleaf (Talinum triangulare (Jaqc.) Willd.). The average time spent by individual parasitoid foraging was significantly longer (27.39 minutes) on ant-excluded plants compared to ant-attended plants (2.47-4.68 minutes). Accordingly, parasitoid spent less time in finding hosts on ant-excluded plants, while spent a longer time in handling hosts. More oviposition activities by parasitoids on mealybug were occurred on ant-excluded plants compared to those on ant-attended plants. As a result, the percentage of parasitism and the number of wasps that emerged from the hosts on ant-excluded plants were almost 2-3 folds higher than those on ant-attended plants.
Imidacloprid is a systemic insecticide used for the control of the vine mealybug Planococcus ficus. However, biological control of P. ficus is the primary alternate management method recommended for the integrated control of this pest. We therefore aimed to establish the detrimental effects on the development of Anagyrus. sp. near pseudococci and Coccidoxenoides perminutus feeding on imidacloprid-contaminated vine mealybugs as indicated by the subsequent emergence and survival of the F 1 generation. The results imply that A. sp. near pseudococci and C. perminutus were equally susceptible to imidacloprid, based on probit analysis. However, survival was significantly different between the control and insecticide treatment for C. perminutus (χ 2 = 23.80; d.f. = 3; p < 0.001), but not for A. sp. near pseudococci (χ 2 = 5.07; d.f. = 3; p = 0.17). As this study was laboratory based, the effect of imidacloprid on populations of parasitoids in the field should be assessed further. Treatment recommendations to minimise the impact on parasitoids are discussed briefly.
Biological Control, 2013
ABSTRACT The developmental biology of Trichogrammatoidea lutea Girault (Hymenoptera: Trichogrammatidae) was studied at six constant temperatures (18, 21, 24, 27, 30 and 35 °C) on eggs of three lepidopteran host species: Helicoverpa armigera (Hübner) (Noctuidae), Chilo partellus (Swinhoe) (Crambidae) and Cadra cautella (Walker) (Pyralidae). T. lutea did not complete development at 35 °C on any of the three host species. Parasitism levels were highest on H. armigera at 27 °C (58%), C. cautella at 27 and 30 °C (31% and 28%) and C. partellus between 24 and 30 °C (13–17%). Realized progeny of T. lutea per parasitized host egg was influenced by host size. The number of progeny of T. lutea per parasitized host egg was highest on H. armigera, followed by C. partellus and lowest on C. cautella. The sex ratio was female biased on C. partellus, female biased on C. cautella with the exception of 21 °C and close to 1:1 on H. armigera. The rate of development from egg to pupa and egg to adult was fastest on H. armigera and slowest on C. partellus. Lower thresholds for development and degree days (DD) of T. lutea from egg to adult were 12.8 °C and 105.4 DD on H. armigera, 11.3 °C and 141.6 DD on C. partellus and 12.9 °C and 118.2 DD on C. cautella, respectively. Based on these results, H. armigera is the most suitable host for mass rearing of T. lutea for biological control of Lepidoptera pests because of the relatively high parasitism levels, short development time, greater clutch size and balanced sex ratio. C. cautella may also be used although longer exposure times might be required due to lower parasitism levels.
Present study was conducted to investigate the biological characteristics and host stage preference of mealybug parasitoid, Aenasius bambawalei Hayat (Hymenoptera: Encyrtidae) an endophagous, nymphal and solitary parasitoid of cotton mealybug , Phenacoccus solenopsis Tinsley (Homoptera: Pseudococcidae). Preliminary experiments were conducted in vitro regarding its biological characteristics and host stage preference at controlled conditions (28 oC±1, 70 ± 5% % (RH) and 18 h L /6 h D). Our findings show that host swells, ceases its movement and turns in to hard leathery structure called “Mummy” after 4 and 8 days of parasitization respectively and 12-17 days are required to complete its development from first day of parasitization till emergence of adults from the mummies. Only single parasitoid adult was emerged from each mummy. Female lived for 15-32 days under laboratory conditions, whereas male died within one week. Female of the parasitoid parasitizes 165 mealybugs in its entire life and sex ratio of male and female was recorded as 1:2. Further, it is reported that 3rd instar host nymphal stage is the most preferred and suitable stage for parasitization by A. bambawalei as compared to other two host stages (1st and 2nd). This preliminary information regarding its biology and host stage preference will help us in its effective rearing and exploring its parasitization potential in biological control programmes of mealybugs.