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Xavier Belles - One of the best experts on this subject based on the ideXlab platform.
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leucomyosuppressin modulates cardiac rhythm in the cockroach blattella germanica
Journal of Insect Physiology, 2011Co-Authors: Jose L Maestro, Stephen S Tobe, Xavier BellesAbstract:Several lines of evidence point to leucomyosuppressin (LMS) and myosuppressin-related peptides as inhibitory modulators of heartbeat frequency in arthropods. Previous studies in Blattella germanica demonstrated that heartbeat frequency decreases after Ootheca formation, and remains low during the period of Ootheca transport. Subsequent work in this cockroach resulted in the characterization of LMS and the cloning and sequencing of its precursor. The present paper describes the activity of LMS on modulation of heartbeat in B. germanica. Assays using semi-isolated heart preparations revealed that LMS reduces heartbeat frequency in a dose dependent manner, at physiological concentrations. Additional experiments showed that LMS inhibits heartbeat rates in vivo. Finally, injection of dsRNA for LMS elicited a decrease in LMS mRNA to virtually undetectable levels and heartbeat frequency increased significantly in females carrying Oothecae. These data suggest that LMS contributes to the modulation of cardiac rhythm in B. germanica during the reproductive cycle.
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Ovarian 3-hydroxy-3-methylglutaryl-CoA reductase in Blattella germanica (L.): pattern of expression and critical role in embryogenesis
Journal of Insect Physiology, 2002Co-Authors: Rafael Zapata, Maria-dolors Piulachs, Xavier BellesAbstract:In the ovary of adult Blattella germanica, the enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) is highly expressed in mid-late vitellogenesis, suggesting a functional link of the mevalonate pathway with choriogenesis. The inhibitor of HMG-CoA reductase, fluvastatin, applied in females in late vitellogenesis, inhibits the activity of the enzyme in the ovary and in the developing embryos within the Ootheca. This does not affect choriogenesis or Ootheca formation but reduces the number of larvae per Ootheca. Our results suggest that fluvastatin is incorporated into the oocytes and has delayed inhibitory effects on the oviposited eggs. HMG-CoA reductase is essential for embryogenesis, but not for chorion formation.
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Effects of hypocholesterolaemic agents on the expression and activity of 3-hydroxy-3-methylglutaryl-CoA reductase in the fat body of the German cockroach.
Archives of insect biochemistry and physiology, 2002Co-Authors: Rafael Zapata, Maria-dolors Piulachs, David Martin, Xavier BellesAbstract:In the fat body of adult Blattella germanica females, the expression of 3-hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) during the first reproductive cycle is parallel to that of vitellogenin, suggesting a functional link between the mevalonate pathway, and vitellogenesis and reproduction. We have studied the effects of compactin and fluvastatin, two inhibitors of HMG-CoA reductase, on the expression and activity of the enzyme in the fat body, and on the Ootheca formation, Ootheca viability, and number of larvae per viable Ootheca. Short-term assays showed that both compounds reduce the protein levels and enzymatic activity of HMG-CoA reductase, and long-term experiments revealed that fluvastatin impairs embryo development. Arch. Insect Biochem. Physiol. 49:177‐186, 2002. © 2002 Wiley-Liss, Inc.
J P Edwards - One of the best experts on this subject based on the ideXlab platform.
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The influence of the juvenile hormone analogue (S)-hydroprene on Aprostocetus hagenowii (Hymenoptera: Eulophidae), an Oothecal parasitoid of the oriental cockroach Blatta orientalis (Dictyoptera: Blattidae)
Bulletin of Entomological Research, 1998Co-Authors: H.a. Bell, G.c. Marris, J P EdwardsAbstract:AbstractThe synthetic juvenile hormone analogue (S)-hydroprene can control populations of the oriental cockroachBlatta orientalisLinnaeus. Eradication ofB. orientalisinfestations, however, can take in excess of two years. In an attempt to reduce the time (S)-hydroprene takes to eliminate a population of oriental cockroaches, we explored the possibility of using the Oothecal endoparasitoidAprostocetus hagenowiiRatzeburg in combination with (S)-hydroprene. For such a strategy to be successful, it is important that the parasitoid remains substantially unaffected by (S)-hydroprene. WhenA. hagenowiiwas exposed toB. orientalisOothecae in the presence of (S)-hydroprene, female parasitoids showed no reduction in their capacity to attack hosts and their fecundity was not compromised. (S)-hydroprene, at dose rates of 18 mg/m2and 100 mg/m2, induced deformity in approximately 12% and 33% respectively of parasitoids that emerged. No reduction in reproductive viability was seen in morphologically normal F1parasitoids. Deformed F1parasitoids, exposed to the higher (S)-hydroprene dose, showed a 71% reduction in the number of Oothecae attacked and a 50% reduction in the number of offspring produced. These results indicate thatA. hagenowiicould be used in combination with (S)-hydroprene in an integrated pest management programme againstB. orientalis.
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a novel technique for the elimination of populations of the oriental cockroach blatta orientalis l dictyoptera blattidae using s hydroprene delivered from simple point sources
1993Co-Authors: J E Short, J P EdwardsAbstract:Two mixed-age (semi-natural) populations of the Oriental cockroach Blarra orienralis were established in identical artificial domestic environments contained in steel freight containers. Each population was allowed a 10 week period of acclimation, during which the populations were monitored using Roatel traps. Subsequently, one population was treated with two point sources (filter papers) impregnated with 750mg of the insect juvenile hormone analogue S-hydroprene and 150mg of the anti-oxidant butylated hydroxy toluene (BHT). The other (control) population was exposed to point sources impregnated with BHT only. Each source was suspended from the ceiling under a cockroach-proof guard to ensure that physical contact with cockroaches could not occur. Treatments were repeated at six monthly intervals throughout the experiment. Changes in these populations were monitored for approximately two years by trapping every two weeks with live catch Roatel traps. On each occasion, trapped cockroaches were counted, the sexes of adults determined, and adults were examined for external deformities. Trapped nymphs were assigned to 1 of 3 arbitrary size catagories (small, medium or large). Subsequently all trapped insects were released back into their respective containers. In addition, at monthly intervals, 20 adult females were randomly selected from the trapped insects and confined with several trapped males until ten Oothecae had been produced. The viability and numbers of nymphs emerging from these Oothecae was recorded. During the first 5 months of the experiment both populations showed a general increase. Subsequently, the control population increased substantially and then remained high for the duration of the experiment. After an initial small increase, the population in the hydroprene treated environment gradually declined and was eliminated after approximately 30 months. In the hydroprene treated container the percentage of adults exhibiting deformities exeeded 90% after 10 months and Ootheca production was halted in this population at the same time. This inhibition of reproduction resulted in the eventual eradication of the population. These results suggest that hydroprene point sources could provide an extremely simple, and effective control technique for cockroaches infesting hospital, industrial, food manufacturing and domestic premises.
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reproductive and developmental biology of the oriental cockroach blatta orientalis dictyoptera
Medical and Veterinary Entomology, 1991Co-Authors: J E Short, J P EdwardsAbstract:: At 27 degrees C and 45% r.h. in the laboratory, the oriental cockroach Blatta orientalis (L.) developed to adulthood in seven to nine instars for males (66% had eight instars) and eight to ten instars for females (67% had nine instars) in mixed groups, with up to twelve instars for isolated females. Nymphal development lasted 185 +/- 2 days for males, 216 +/- 4 days for females, with 89% survival to adulthood. Adult longevity was significantly more for males than females in mixed groups. Virgin females lived for 135 +/- 6 days compared with 87 +/- 9 days for females kept with males. After an initial maturation time of 12.2-13.5 +/- 0.4 days for mated and unmated females, Oothecae were produced, on average, every 6-7 (range 2-29) days. Ootheca viability was 68% from females kept with males, 32% from females kept apart from males. Numbers of nymphs emerging were 14.1 +/- 0.26 after 45 days from mated female Oothecae 8.2 +/- 0.3 after 49 days from unmated females. With sexual reproduction the sex ratio of progeny reaching adulthood was 1.1 males per female (n = 443), whereas unmated females produced only female progency, which is consistent with parthenogenetic reproduction. Drawings of the ventral aspect of the terminalia are given to show features useful for instar determination and for distinguishing between male and female nymphs and adults of B. orientalis.
Michael Lenz - One of the best experts on this subject based on the ideXlab platform.
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Froggatt (Isoptera: Mastotermitidae): homology with cockroach Oothecae
2016Co-Authors: Christine A Nalepa, Michael LenzAbstract:The basal termite Mastotermes darwiniensis produces an egg mass, the nature of which is controversial. The debate centres on whether it is homologous with the Oothecae of mantids and cockroaches and, if so, whether its simple structure is plesiomorphic or apomorphic within the Dictyoptera. To help resolve these issues we observed primary reproductives of M. darwiniensis during oviposition and examined the morphology of the reproductive product. Oviposition is cockroach-like in that the egg mass is assembled within the vestibulum and the eggs are issued externally in pairs. The reproductive product is an Ootheca of the blattarian type. A distinct, tanned outer covering is stretched over the two parallel rows of eggs. No keel is present and no calcium oxalate crystals were apparent in the outer covering. We cannot rule out the possibility that the simple structure of the Ootheca is plesiomorphic within Dictyoptera. However, based on (i) apomorphies shared by Mastotermes and Blattaria, and (ii) the life habits of Isoptera, a secondary reduction is the more plausible explanation
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the fine structure of colleterial glands in two cockroaches and three termites including a detailed study of cryptocercus punctulatus blattaria cryptocercidae and mastotermes darwiniensis isoptera mastotermitidae
Arthropod Structure & Development, 2008Co-Authors: Annie Courrent, Christine A Nalepa, Michael Lenz, Alain Robert, Andre Quennedey, Christian BordereauAbstract:The colleterial glands of insects are organs associated with the female genital apparatus. In cockroaches, these glands produce secretions that cover two parallel rows of eggs during oviposition, and in oviparous species, these secretions become the tanned, sculpted, rigid outer casing of the Ootheca. The goal of this study was to compare the gross anatomy of the colleterial glands and the ultrastructure of their component tubules in the phylogenetically significant genera Cryptocercus (Blattaria) and Mastotermes (Isoptera). Recent studies indicate that cockroaches in the genus Cryptocercus are the sister group of termites, and Mastotermes is the only termite known to produce a cockroach-like Ootheca. One additional oviparous cockroach, Therea, and two additional termites, Zootermopsis and Pseudacanthotermes, were also examined. As in other cockroaches, the colleterial glands of Cryptocercus and Therea are asymmetrical, with a well developed bipartite left gland and a smaller right gland. In the termites Mastotermes, Zootermopsis, and Pseudacanthotermes, the colleterial glands are composed of a well-developed, paired, anterior gland and a small posterior gland; histological staining and cytological evidence suggest that these are homologues of the left and the right colleterial glands of cockroaches, respectively. At the ultrastructural level, colleterial gland tubules are made of cells belonging to a modified class 1 type cell in the cockroaches, in Mastotermes, and in Zootermopsis; the latter lays its eggs singly, without a surrounding Ootheca-like structure. In the advanced termite Pseudacanthotermes, the tubules are made of secretory units belonging to the class 3 cell type. This study demonstrates that the cytological characteristics of colleterial glands in basal termites are similar to those of cockroaches, whether the termite secretes an Oothecal casing that covers two parallel rows of eggs, as in Mastotermes, or lays its eggs singly, as in Zootermopsis. The function of colleterial glands in non-mastotermitid termites is unknown.
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the Ootheca of mastotermes darwiniensis froggatt isoptera mastotermitidae homology with cockroach Oothecae
Proceedings of The Royal Society B: Biological Sciences, 2000Co-Authors: Christine A Nalepa, Michael LenzAbstract:The basal termite Mastotermes darwiniensis produces an egg mass, the nature of which is controversial. The debate centres on whether it is homologous with the Oothecae of mantids and cockroaches and, if so, whether its simple structure is plesiomorphic or apomorphic within the Dictyoptera. To help resolve these issues we observed primary reproductives of M. darwiniensis during oviposition and examined the morphology of the reproductive product. Oviposition is cockroach-like in that the egg mass is assembled within the vestibulum and the eggs are issued externally in pairs. The reproductive product is an Ootheca of the blattarian type. A distinct, tanned outer covering is stretched over the two parallel rows of eggs. No keel is present and no calcium oxalate crystals were apparent in the outer covering. We cannot rule out the possibility that the simple structure of the Ootheca is plesiomorphic within Dictyoptera. However, based on (i) apomorphies shared by Mastotermes and Blattaria, and (ii) the life habits of Isoptera, a secondary reduction is the more plausible explanation.
Chow-yang Lee - One of the best experts on this subject based on the ideXlab platform.
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cockroach Oothecal parasitoid evania appendigaster hymenoptera evaniidae exhibits oviposition preference towards Oothecal age most vulnerable to host cannibalism
Journal of Economic Entomology, 2017Co-Authors: Hui-siang Tee, Chow-yang LeeAbstract:Many female parasitoid wasps optimize host selection to balance the benefits of high-quality hosts and the costs of predator- or hyperparasitoid-induced mortality risks to maximize their fitness. Cannibalism exists in many insect species and affects survival of parasitoid larvae developing in or on parasitized hosts. However, little is known about how parasitoid wasps resolve the fitness consequence of host cannibalism-induced mortality risk during host selection. We examined the effect of Oothecal age on cannibalism in the American cockroach Periplaneta americana (L.) (Dictyoptera: Blattidae) and its effect on host age selection and fitness of its Oothecal parasitoid Evania appendigaster (L.) (Hymenoptera: Evaniidae). P. americana differentially cannibalized 1-d-old (30‒60%) versus 10- to 40-d-old Oothecae (<9%). However, parasitoid females did not avoid but still preferred to parasitize 1-d-old (45%) over 10- to 40-d-old Oothecae (1.6‒20%). The parasitism rate was greater and the handling time was shorter on 1-d-old compared to older Oothecae. For parasitoid progeny emerging from different-aged Oothecae, regression analysis showed that development time increased and body size (measured as hind tibia length) and longevity decreased with Oothecal age. These results demonstrate that reduced parasitoid progeny survival due to host cannibalism did not change the parasitoid's oviposition preference for newly laid Oothecae, and that E. appendigaster females traded progeny survival for fitness gains for themselves and their progeny.
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Influences of Temperature and Ootheca Age on the Life History of the Cockroach Ootheca Parasitoid Aprostocetus hagenowii (Hymenoptera: Eulophidae).
Journal of economic entomology, 2017Co-Authors: Hui-siang Tee, Chow-yang LeeAbstract:The influences of Ootheca age and temperature on the life history of Aprostocetus hagenowii (Ratzeburg) (Hymenoptera: Eulophidae), a gregarious Ootheca parasitoid of the American cockroach Periplaneta americana (L.) (Dictyoptera: Blattidae), were evaluated. Oothecae were incubated at 20, 25, and 30 °C to produce Oothecae aged 1–60, 1–40, and 1–30 d old, respectively. Fitness traits (development time, percentage emergence, number of progeny, percentage female progeny, and female body size) of A. hagenowii developing in these different-aged Oothecae were determined. For Oothecae incubated at 20, 25, and 30 °C, parasitoids successfully developed in Oothecae aged up to 50, 30, and 20 d old, which represent 72.9%, 65.9%, and 61.9% of the total embryonic development time of P. americana, respectively, without any changes in their fitness traits. When A. hagenowii from Oothecae kept at constant temperatures (20, 25, 30, 32, and 35 °C) were compared, the immature development time (71.0–34.0 d) and adult life span decreased with increasing temperature. No parasitoid emerged at 35 °C. The lower, upper, and optimal temperature-dependent developmental thresholds were 9.5, 34.2, and 31.1 °C, respectively. Thermal constant for total immature development was 666.7 degree-days. Temperature did not affect lifetime realized fecundity and number of Oothecae parasitized by females but did influence parasitism activities over time. Sugar-fed females sustained longer periods of high parasitism rates (≥70%) at 20–30 °C (15–30 d) than at 32–35 °C (1–5 d). These results are useful for determining the Ootheca age and temperature range optimal for parasitoid rearing and for estimating the effectiveness of biological control by the wasps.
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Feasibility of cold-stored Periplaneta americana (Dictyoptera: Blattidae) Oothecae for rearing the Oothecal parasitoids Aprostocetus hagenowii and Evania appendigaster (Hymenoptera: Eulophidae; Evaniidae): Effect of Ootheca age and storage duration
Biological Control, 2013Co-Authors: Hui-siang Tee, Chow-yang LeeAbstract:Abstract The minimum time of heating (48, 50, and 53 °C) required to kill Periplaneta americana (L.) (Dictyoptera: Blattidae) Oothecae aged 1, 2, 3 and 4 weeks was determined and their suitability as hosts after different storage conditions (live, heat killed and cold stored for 0.5, 1, 2, 3, and 4 months at 4 °C) for rearing parasitoids Aprostocetus hagenowii (Ratzeburg) and Evania appendigaster (L.) (Hymenoptera: Eulophidae; Evaniidae) was investigated. Heating at 48 °C for 45 min killed 100% of the Oothecae of all ages. Both parasitoids had low emergence in live 4-week-old Oothecae but emergence improved after Oothecae were heat killed. For A. hagenowii, an interaction effect between Ootheca age and storage duration was found for percentage emergence. Emergence rates were reduced in cold-stored 3- and 4-week-old Oothecae (1–4 and 3–4 months, respectively) but not in 1–2-week-old Oothecae. The number of progeny produced in 1–2-week-old and 3–4-week-old Oothecae decreased significantly after cold storage for 3–4 and 0.5–4 months, respectively. In all conditions, the development time was 34.5–39.9 d and the progeny sex ratio was female-biased (88.2–94.3%). E. appendigaster had low parasitism and emergence rates (0–20%) in cold-stored Oothecae and took longer to develop in heat-killed and cold-stored Oothecae than in live Oothecae. In all conditions, the proportion of females was 0.619–0.821. These results illustrate the effects of Ootheca age on host treatment and storage and can be used to develop efficient ways to use Oothecae for rearing Oothecal parasitoids.
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Evaluation of Aprostocetus hagenowii (Hymenoptera: Eulophidae) for the Control of American Cockroaches (Dictyoptera: Blattidae) in Sewers and Crevices Around Buildings
Journal of economic entomology, 2011Co-Authors: Hui-siang Tee, Ahmad Ramli Saad, Chow-yang LeeAbstract:The objective of this study was to evaluate the potential of Aprostocetus hagenowii (Ratzeburg) (Hymenoptera: Eulophidae) to control American cockroaches, Periplaneta americana (L.) (Dictyoptera: Rlattidae), in sewer manholes and in crevices around buildings. Parasitoids were released weekly for 12 wk from laboratory parasitized heat-killed Oothecae, and parasitism monitored using sentinel Oothecae of American cockroaches. In addition, preference of A. hagenowii for 1– to 4-wk-old Oothecae was evaluated in the laboratory. A. hagenowii females showed no preference for any Ootheca age. Twenty of the 30 tested females parasitized one Ootheca, whereas the other 10 parasitized two Oothecae. The total progeny (males, females, and total) that emerged from a single Ootheca parasitized by a female was not significantly different to the total progeny that emerged from two Oothecae parasitized by a female. The number of males, females, and total progeny that emerged from the second parasitized Ootheca was significantly less than the number that emerged from the first parasitized Ootheca. The weekly mean sentinel Oothecal parasitism rate in wall crevices was 18.1 ± 3.2% and in sewer manholes was 13.3 ± 2.0%. The mean number of released A. hagenowii females per number of parasitized sentinel Oothecae recorded in crevices was 189 ± 18, whereas it was 428 ± 50 in sewers. A. hagenowii females were more effective at parasitizing sentinel Oothecae placed at high and middle levels in manholes than at a low level when releases were made at the midpoint of the manhole shaft.
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Suitability of Heat- and Freeze-Killed Oothecae of the American Cockroach (Dictyoptera: Blattidae) as Hosts for an Oothecal Parasitoid, Aprostocetus hagenowii (Hymenoptera: Eulophidae)
Journal of economic entomology, 2010Co-Authors: Hui-siang Tee, Ahmad Ramli Saad, Chow-yang LeeAbstract:The objective of this study was to evaluate the suitability of heat- and freeze-killed Oothecae of Periplaneta americana (L.) (Dictyoptera: Blattidae) as hosts for parasitoid Aprostocetus hagenowii (Ratzeburg) (Hymenoptera: Eulophidae). The Oothecae were subjected to -20, 45, 48, 50, and 55°C at different exposure times (15, 30, 45, and 60 min). The effects of heat- and freeze-killed Oothecae on several biological parameters (e.g., parasitism and emergence rates, developmental times, progeny number, and sex ratio) of A. hagenowii were determined. Embryonic development of 2-d-old Oothecae was terminated by either freezing at -20°C or heating at ≥48°C for ≥30 min. A. hagenowii parasitized live Oothecae as well as both heat- and freeze-killed Oothecae. Percentage parasitism, emergence rates, and developmental times of A. hagenowii in both heat- and freeze-killed Oothecae were not significantly different from those of the live Oothecae. Both heating and freezing did not influence progeny number (male and female) and sex ratio of A. hagenowii emerged from killed Oothecae.
R G Evans - One of the best experts on this subject based on the ideXlab platform.
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effects of fenoxycarb on development and reproduction of the oriental cockroach blatta orientalis
Medical and Veterinary Entomology, 1995Co-Authors: R G Evans, A Sunley, C Bradford, R I PatmoreAbstract:. In a laboratory study, groups of third-instar Blatta orientalis nymphs were reared to adulthood in arenas containing fenoxycarb (48 mg a.i./m2) treated ceramic or plywood tiles. The reproductive capacity of the emergent adults was assessed by pairing each individual with two untreated individuals of the opposite sex. Oothecal production, Oothecal hatch and the numbers of nymphs emergent from each hatched Ootheca were monitored. Exposure to 1-day-old deposits of fenoxycarb reduced adult emergence by 45–75% in comparison with an untreated control treatment. Substantial (>40%) mortality also resulted when nymphs were exposed to deposits up to 3 months old on plywood and up to 6 months old on ceramic. Exposure to fenoxycarb significantly extended the time taken to reach adulthood of males contacting 6-month-old deposits on both surfaces, and of females contacting 1-year-old deposits on ceramic. Adult females exposed as nymphs to fenoxycarb were unable to produce Oothecae, except one female laid a non-viable Ootheca. Untreated females paired with treated males produced large numbers of Oothecae of normal appearance but very low viability, with only 0–7.1% hatching. With marked effects on both development and reproduction in B. orientalis, fenoxycarb is a promising agent for control of this species.
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Effects of fenoxycarb on development and reproduction of the oriental cockroach, Blatta orientalis.
Medical and veterinary entomology, 1995Co-Authors: R G Evans, A Sunley, C Bradford, R I PatmoreAbstract:. In a laboratory study, groups of third-instar Blatta orientalis nymphs were reared to adulthood in arenas containing fenoxycarb (48 mg a.i./m2) treated ceramic or plywood tiles. The reproductive capacity of the emergent adults was assessed by pairing each individual with two untreated individuals of the opposite sex. Oothecal production, Oothecal hatch and the numbers of nymphs emergent from each hatched Ootheca were monitored. Exposure to 1-day-old deposits of fenoxycarb reduced adult emergence by 45–75% in comparison with an untreated control treatment. Substantial (>40%) mortality also resulted when nymphs were exposed to deposits up to 3 months old on plywood and up to 6 months old on ceramic. Exposure to fenoxycarb significantly extended the time taken to reach adulthood of males contacting 6-month-old deposits on both surfaces, and of females contacting 1-year-old deposits on ceramic. Adult females exposed as nymphs to fenoxycarb were unable to produce Oothecae, except one female laid a non-viable Ootheca. Untreated females paired with treated males produced large numbers of Oothecae of normal appearance but very low viability, with only 0–7.1% hatching. With marked effects on both development and reproduction in B. orientalis, fenoxycarb is a promising agent for control of this species.
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developmental and reproductive effects of the insect growth regulator fenoxycarb against the oriental cockroach blatta orientalis l
Proceedings of the 1st International Conference on Insect Pests in the Urban Environment, 1993Co-Authors: R G EvansAbstract:In a laboratory study, groups of third instar Blarra orientalis nymphs were reared to adulthood in arenas containing fenoxycarb (48 mg ai/m2) treated ceramic or plywood tiles. The reproductive capacity of the emergent adults was assessed by pairing each individual with two untreated individuals of the opposite sex. Oothecal production, Oothecal hatch and the numbers of nymphs emerging from each hatched Ootheca were monitored. Exposure to one-day old deposits of fenoxycarb reduced adult emergence by 45-75% in comparison with an untreated control treatment. Substantial (>35%) mortality also resulted when nymphs were exposed to deposits up to 3.5 months old on plywood, and up to six months old on ceramic. All adult females exposed as nymphs to fenoxycarb failed to reproduce. Untreated females paired with treated males produced several Oothecae of normal appearance, but the viability of these Oothecae was extremely low with <3% hatching. With strong effects both on the development and reproduction of B. orientalis, fenoxycarb is an extremely promising agent for control of infestations of this species.
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DEVELOPMENTAL AND REPRODUCTIVE EFFECTS OF THE INSECT GROWTH REGULATOR, FENOXYCARB, AGAINST THE ORIENTAL COCKROACH, BLATTA ORIENTALIS L.
1993Co-Authors: R G EvansAbstract:In a laboratory study, groups of third instar Blarra orientalis nymphs were reared to adulthood in arenas containing fenoxycarb (48 mg ai/m2) treated ceramic or plywood tiles. The reproductive capacity of the emergent adults was assessed by pairing each individual with two untreated individuals of the opposite sex. Oothecal production, Oothecal hatch and the numbers of nymphs emerging from each hatched Ootheca were monitored. Exposure to one-day old deposits of fenoxycarb reduced adult emergence by 45-75% in comparison with an untreated control treatment. Substantial (>35%) mortality also resulted when nymphs were exposed to deposits up to 3.5 months old on plywood, and up to six months old on ceramic. All adult females exposed as nymphs to fenoxycarb failed to reproduce. Untreated females paired with treated males produced several Oothecae of normal appearance, but the viability of these Oothecae was extremely low with
