Shin-ya Ohba - Academia.edu (original) (raw)

Papers by Shin-ya Ohba

Research paper thumbnail of Variation in flash speed of Japanese firefly, Luciola cruciata (Coleoptera: Lampyridae), identifies distinct southern “quick‐flash” population on Goto Islands, Japan

Research paper thumbnail of Factors Affecting a Fauna of Aquatic Insects in Swimming Pools of Schools in the Southern Part of Nagasaki, Japan

Japanese Journal of Applied Entomology and Zoology

Aquatic insects colonize the swimming pools of schools during the off-season. The present study a... more Aquatic insects colonize the swimming pools of schools during the off-season. The present study aimed to investigate 30 swimming pools in southern Nagasaki Prefecture in spring middle April to middle May and autumn late October to early November 2014. We found 11 families of aquatic insects including 9 Heteroptera, and 9 Coleoptera. Appasus japonicus Heteroptera: Belostomatidae , Hesperocorixa kolthoffi Heteroptera: Corixidae , and Cybister tripunctatus lateralis Coleoptera: Dytiscidae designated as Red Data List species red list species were collected from the school pools. The community composition of aquatic insects was divided into spring and autumn, and its variance was related to the water temperature and organic matter. The major environmental factor related to the number of red list species was considered to be location near the potential natural habitat of the species. The organic matter falling into the pools affected the existence of Orthetrum species nymphs Orthoptera: Libellulidae . Odonata nymphs, Notonecta triguttata Heteroptera: Notonectidae , Anisops ogasawaraensis Heteroptera: Notonectidae , Aquarius paludum paludum Heteroptera: Gerridae , and Eretes griseus Coleoptera: Dytiscidae were found from most of the pools studied, indicating that these species may be used as teaching materials for science in most schools irrespective of their location.

Research paper thumbnail of Notes on Several Japanese Species of Iwogumoa and Coelotes (Araneae: Agelenidae: Coelotinae)

Research paper thumbnail of Density-Dependent Effects of Amphibian Prey on the Growth and Survival of an Endangered Giant Water Bug

Insects

Amphibian predator-insect prey relationships are common in terrestrial habitats, but amphibian la... more Amphibian predator-insect prey relationships are common in terrestrial habitats, but amphibian larvae are preyed upon by a variety of aquatic hemipterans in aquatic habitats. This paper suggests that the survival of the nymphs of the endangered aquatic hemipteran Kirkaldyia (=Lethocerus) deyrolli (Belostomatidae: Heteroptera) is directly and indirectly affected by the abundance of their amphibian larval prey (tadpoles). Young nymphs of K. deyrolli mainly feed on tadpoles, regardless of differences in prey availability. Nymphs provided with tadpoles grow faster than nymphs provided with invertebrate prey. Therefore, tadpole consumption seems to be required to allow the nymphs to complete their larval development. In addition, the survival of K. deyrolli nymphs was greater during the period of highest tadpole density (June) than during a period of low tadpole density (July). Higher tadpole density moderates predation pressure from the water scorpion Laccotrephes japonensis (Nepidae: Heteroptera) on K. deyrolli nymphs; i.e., it has a density-mediated indirect effect. These results suggest that an abundance of tadpoles in June provides food for K. deyrolli nymphs (a direct bottom-up effect) and moderates the predation pressure from L. japonensis (an indirect bottom-up effect). An abundance of amphibian prey is indispensable for the conservation of this endangered giant water bug species.

Research paper thumbnail of Effects of irrigation system alterations on the trophic position of a threatened top predator in rice‐field ecosystems

Research paper thumbnail of Female mate preference for egg-caring males in the giant water bug Diplonychus rusticus (Heteroptera Belostomatidae)

Ethology Ecology & Evolution

Research paper thumbnail of Mouth morphology of the diving beetle Hyphydrus japonicus (Dytiscidae: Hydroporinae) is specialized for predation on seed shrimps

Biological Journal of the Linnean Society

Two-shelled organisms, such as bivalves and seed shrimps, protect themselves from external stress... more Two-shelled organisms, such as bivalves and seed shrimps, protect themselves from external stresses by firmly closing both shells. We found that larvae of the diving beetle Hyphydrus japonicus Sharp, 1873 (Dytiscidae: Hydroporinae) frequently prey on seed shrimps. Other predatory aquatic insects have difficulty in capturing seed shrimps owing to the general form of the insects' mandibles. Larvae of Hyphydrus japonicus bear a projection on the head (the nasale), which is used in conjunction with vertical movements of the mandibles to fixate the valves of their prey and gain access to the soft body within them. This capture method does not destroy shells and is extremely efficient. The present study provides the first report on the use of a unique morphological trait for attacking prey animals without destroying their shells.

Research paper thumbnail of 絶滅危惧種タガメの生態

Research paper thumbnail of Ecology of giant water bugs (Hemiptera: Heteroptera: Belostomatidae)

Entomological Science

Giant water bugs (Heteroptera: Belostomatidae) are aquatic predators of freshwater habitats, and ... more Giant water bugs (Heteroptera: Belostomatidae) are aquatic predators of freshwater habitats, and include ca. 150 species distributed throughout the world's subtropical and tropical areas. They have unique mating systems, which involve female competition, and exhibit paternal care, wherein males attend eggs laid by the females on emergent plants (Lethocerinae) or on their backs (Belostomatinae). I review here, the studies on predator-prey relationship, morphology, migration, mating behavior, and conservation of this family of insects. Predatory efficiency of the water bug Sphaerodema annulatum on mosquito larvae (Culex This article is protected by copyright. All rights reserved. 23 quinquefasciatus) and its effect on the adult emergence. Bioresource Technology 95, 169-172. Alonzo SH (2012) Sexual selection favours male parental care, when females can choose. Proceedings of the Royal Society B: Biological Sciences 279, 1784-1790. Amato SB, Amato JFR (2006) Belostoma dilatatum (Dufour) (Hemiptera, Belostomatidae) hosting metacercariae of Stomylotrema vicarium Braun (Digenea, Stomylotrematidae) in southern Brazil. Revista Brasileira de Zoologia 23, 307-310. Appleton CC, Hofkin BV, Baijnath A (2004) Macro-invertebrate predators of freshwater pulmonate snails in Africa, with particular reference to Appasus grassei (Heteroptera) and Procambarus clarkii (Decapoda).

Research paper thumbnail of Male description of <I>Coelotes nasensis</I> Shimojana 2000 (Araneae: Agelenidae) from Amami-ōshima Island, Japan

Acta Arachnologica

Species sex Collection localities Accession No.

Research paper thumbnail of The number of tadpoles consumed by the nymphs of the giant water bug Kirkaldyia deyrolli under laboratory conditions

Research paper thumbnail of Food shortage affects flight migration of the giant water bug Lethocerus deyrolli in the prewintering season

Limnology

The endangered giant water bug Lethocerus deyrolli (Vuillefroy) is frequently attracted in large ... more The endangered giant water bug Lethocerus deyrolli (Vuillefroy) is frequently attracted in large numbers to artificial lights in Japan. To examine factors enhancing flight migration for L. deyrolli, we carried out field work in western Hyogo Prefecture, central Japan, in September during the nonreproductive and prewintering season. The body weight of specimens collected under flight migration (flight bugs) was significantly less than that of those collected in ponds (pond bugs). A field experiment using open cages in a rice paddy field was carried out with two treatments, with and without a food supply. The remaining rate of L. deyrolli for the food present treatment was significantly higher than that for the food absent treatment for the first two days. These results suggest that L. deyrolli would fly in search of food when the food supply of the present habitat becomes unsuitable.

Research paper thumbnail of Water mites (Acari:Hydrachnidiae and Stygothrombiae) parasitic on aquatic animals in Japan

Journal of the Acarological Society of Japan

Research paper thumbnail of Effect of water depth on predation frequency by diving beetles on mosquito larvae prey

Entomological Science

Diving behavior and its frequency may differ between species of mosquito larvae owing to differen... more Diving behavior and its frequency may differ between species of mosquito larvae owing to differences in predation pressure. The present study aimed to investigate the relationship between water depth and predation frequency on two mosquito species, Culex tritaeniorhynchus (wetland breeder) and Aedes albopictus (container breeder), by the diving beetle Eretes griseus. Culex tritaeniorhynchus spends more time at the surface than A. albopictus, which spends more time thrashing underwater. When intact mosquito larvae of both species were present, the diving beetles consumed almost A.

Research paper thumbnail of Dietary items of predacious aquatic bugs (Nepoidea: Heteroptera) in Japanese wetlands

Limnology

Some species of predatory aquatic bugs (Nepoidea, including Belostomatidae and Nepidae) are desig... more Some species of predatory aquatic bugs (Nepoidea, including Belostomatidae and Nepidae) are designated as threatened-vulnerable species in the Red Data Book of Japan and are regarded as effective predators of freshwater snails and mosquito larvae. To reveal the feeding habits of Nepoidea, we investigated their dietary items in wetlands and obtained data from the published literature. Lethocerus deyrolli (Vuillefroy) preys mainly upon frogs, and the major diet of the nymphs is tadpoles. Laccotrephes japonensis (Scott) adults prey mainly upon tadpoles. Lethocerus deyrolli nymphs and L. japonensis adults compete against each other as same-guild members because they are sympatric in wetlands. Both nymphs and adults of Appasus japonicus (Vuillefroy) feed on snails, and L. japonensis nymphs feed on aquatic insects, including mosquito larvae (39.3% of aquatic insects). These species are effective predators of medically important pests such as snails, and mosquito larvae.

Research paper thumbnail of Water mites (Acari: Hydrachnidiae) parasitic on aquatic hemipterans in Japan, with reference to host preferences and selection sites

International Journal of Acarology

Research paper thumbnail of Paternal care behaviour of the giant water bug Kirkaldyia deyrolli (Heteroptera: Belostomatidae) against ants

Research paper thumbnail of Sexual selection of male parental care in giant water bugs

Royal Society open science, 2016

Paternal care can be maintained under sexual selection, if it helps in attracting more mates. We ... more Paternal care can be maintained under sexual selection, if it helps in attracting more mates. We tested the hypothesis in two giant water bug species, Appasus major and Appasus japonicus, that male parental care is sexually selected through female preference for caring males. Females were given an opportunity to choose between two males. In the first test of female mate choice, one male carried eggs on its back, while the other did not. The egg status was switched between these two males in the second test. The experiment revealed that females of both species preferred caring males (i.e. egg-bearing) to non-caring males. Nonetheless, the female mate preference for egg-bearing males was stronger in A. major than in A. japonicus. Our results suggest that sexual selection plays an important role in maintaining elaborate paternal care in giant water bugs, but the importance of egg-bearing by males in female mate choice varies among species.

Research paper thumbnail of Young giant water bug nymphs prefer larger prey: changes in foraging behaviour with nymphal growth in Kirkaldyia deyrolli

Biological Journal of the Linnean Society, 2015

Raptorial characteristics may evolve in predators because of their importance in obtaining food. ... more Raptorial characteristics may evolve in predators because of their importance in obtaining food. The giant water bug, Kirkaldyia deyrolli, possesses a claw on the terminal segment of the raptorial foreleg that is crucial for capturing prey. Claw curvature has been previously shown to change during growth in this species, but the adaptive significance of this change has not yet been explored. Predation experiments have demonstrated that young nymphs with highly curved claws caught proportionally larger prey than older nymphs with less-curved claws. Catching behaviours for a certain prey size differed significantly between young and older nymphs. The observation that nymphal growth affects prey-catching behaviour in the giant water bug supports the hypothesis that predators can change catching behaviours based on changes in raptorial characteristics in order to maximize prey resources acquired at each developmental stage.

Research paper thumbnail of Potential use of pyriproxyfen for control of mosquito-borne diseases: (2) Impact on Aedes albopictus populations in semi-field condition

Pyriproxyfen (PPF) is classified as a juvenile hormone analog (JHA) and has been used against a r... more Pyriproxyfen (PPF) is classified as a juvenile hormone analog (JHA) and has been used against a range of pest insects including mosquitoes since early 1990s. Aedes albopictus is an important vector of dengue and chikungunya and expanding distribution in European and American countries. In this study, impact of PPF treated bed net on populations of Ae. albopictus in a semi-field condition was evaluated using 6 small microcosms. Three microcosms were containing a miniature bed net treated with 350 mg/m2 and 35 mg/m2 PPF in Experiment I and II respectively, and remained 3 microcosms were used for controls with untreated bed net. One hundred pairs of Ae. albopictus were released into each microcosm and allowed to feed on a mouse around one week intervals under the miniature bed nets which have artificial holes. The number of laid eggs from the released adults was significantly reduced in PPF treatment compared to untreated controls. The egg hatchability was also significantly suppressed...

Research paper thumbnail of Variation in flash speed of Japanese firefly, Luciola cruciata (Coleoptera: Lampyridae), identifies distinct southern “quick‐flash” population on Goto Islands, Japan

Research paper thumbnail of Factors Affecting a Fauna of Aquatic Insects in Swimming Pools of Schools in the Southern Part of Nagasaki, Japan

Japanese Journal of Applied Entomology and Zoology

Aquatic insects colonize the swimming pools of schools during the off-season. The present study a... more Aquatic insects colonize the swimming pools of schools during the off-season. The present study aimed to investigate 30 swimming pools in southern Nagasaki Prefecture in spring middle April to middle May and autumn late October to early November 2014. We found 11 families of aquatic insects including 9 Heteroptera, and 9 Coleoptera. Appasus japonicus Heteroptera: Belostomatidae , Hesperocorixa kolthoffi Heteroptera: Corixidae , and Cybister tripunctatus lateralis Coleoptera: Dytiscidae designated as Red Data List species red list species were collected from the school pools. The community composition of aquatic insects was divided into spring and autumn, and its variance was related to the water temperature and organic matter. The major environmental factor related to the number of red list species was considered to be location near the potential natural habitat of the species. The organic matter falling into the pools affected the existence of Orthetrum species nymphs Orthoptera: Libellulidae . Odonata nymphs, Notonecta triguttata Heteroptera: Notonectidae , Anisops ogasawaraensis Heteroptera: Notonectidae , Aquarius paludum paludum Heteroptera: Gerridae , and Eretes griseus Coleoptera: Dytiscidae were found from most of the pools studied, indicating that these species may be used as teaching materials for science in most schools irrespective of their location.

Research paper thumbnail of Notes on Several Japanese Species of Iwogumoa and Coelotes (Araneae: Agelenidae: Coelotinae)

Research paper thumbnail of Density-Dependent Effects of Amphibian Prey on the Growth and Survival of an Endangered Giant Water Bug

Insects

Amphibian predator-insect prey relationships are common in terrestrial habitats, but amphibian la... more Amphibian predator-insect prey relationships are common in terrestrial habitats, but amphibian larvae are preyed upon by a variety of aquatic hemipterans in aquatic habitats. This paper suggests that the survival of the nymphs of the endangered aquatic hemipteran Kirkaldyia (=Lethocerus) deyrolli (Belostomatidae: Heteroptera) is directly and indirectly affected by the abundance of their amphibian larval prey (tadpoles). Young nymphs of K. deyrolli mainly feed on tadpoles, regardless of differences in prey availability. Nymphs provided with tadpoles grow faster than nymphs provided with invertebrate prey. Therefore, tadpole consumption seems to be required to allow the nymphs to complete their larval development. In addition, the survival of K. deyrolli nymphs was greater during the period of highest tadpole density (June) than during a period of low tadpole density (July). Higher tadpole density moderates predation pressure from the water scorpion Laccotrephes japonensis (Nepidae: Heteroptera) on K. deyrolli nymphs; i.e., it has a density-mediated indirect effect. These results suggest that an abundance of tadpoles in June provides food for K. deyrolli nymphs (a direct bottom-up effect) and moderates the predation pressure from L. japonensis (an indirect bottom-up effect). An abundance of amphibian prey is indispensable for the conservation of this endangered giant water bug species.

Research paper thumbnail of Effects of irrigation system alterations on the trophic position of a threatened top predator in rice‐field ecosystems

Research paper thumbnail of Female mate preference for egg-caring males in the giant water bug Diplonychus rusticus (Heteroptera Belostomatidae)

Ethology Ecology & Evolution

Research paper thumbnail of Mouth morphology of the diving beetle Hyphydrus japonicus (Dytiscidae: Hydroporinae) is specialized for predation on seed shrimps

Biological Journal of the Linnean Society

Two-shelled organisms, such as bivalves and seed shrimps, protect themselves from external stress... more Two-shelled organisms, such as bivalves and seed shrimps, protect themselves from external stresses by firmly closing both shells. We found that larvae of the diving beetle Hyphydrus japonicus Sharp, 1873 (Dytiscidae: Hydroporinae) frequently prey on seed shrimps. Other predatory aquatic insects have difficulty in capturing seed shrimps owing to the general form of the insects' mandibles. Larvae of Hyphydrus japonicus bear a projection on the head (the nasale), which is used in conjunction with vertical movements of the mandibles to fixate the valves of their prey and gain access to the soft body within them. This capture method does not destroy shells and is extremely efficient. The present study provides the first report on the use of a unique morphological trait for attacking prey animals without destroying their shells.

Research paper thumbnail of 絶滅危惧種タガメの生態

Research paper thumbnail of Ecology of giant water bugs (Hemiptera: Heteroptera: Belostomatidae)

Entomological Science

Giant water bugs (Heteroptera: Belostomatidae) are aquatic predators of freshwater habitats, and ... more Giant water bugs (Heteroptera: Belostomatidae) are aquatic predators of freshwater habitats, and include ca. 150 species distributed throughout the world's subtropical and tropical areas. They have unique mating systems, which involve female competition, and exhibit paternal care, wherein males attend eggs laid by the females on emergent plants (Lethocerinae) or on their backs (Belostomatinae). I review here, the studies on predator-prey relationship, morphology, migration, mating behavior, and conservation of this family of insects. Predatory efficiency of the water bug Sphaerodema annulatum on mosquito larvae (Culex This article is protected by copyright. All rights reserved. 23 quinquefasciatus) and its effect on the adult emergence. Bioresource Technology 95, 169-172. Alonzo SH (2012) Sexual selection favours male parental care, when females can choose. Proceedings of the Royal Society B: Biological Sciences 279, 1784-1790. Amato SB, Amato JFR (2006) Belostoma dilatatum (Dufour) (Hemiptera, Belostomatidae) hosting metacercariae of Stomylotrema vicarium Braun (Digenea, Stomylotrematidae) in southern Brazil. Revista Brasileira de Zoologia 23, 307-310. Appleton CC, Hofkin BV, Baijnath A (2004) Macro-invertebrate predators of freshwater pulmonate snails in Africa, with particular reference to Appasus grassei (Heteroptera) and Procambarus clarkii (Decapoda).

Research paper thumbnail of Male description of <I>Coelotes nasensis</I> Shimojana 2000 (Araneae: Agelenidae) from Amami-ōshima Island, Japan

Acta Arachnologica

Species sex Collection localities Accession No.

Research paper thumbnail of The number of tadpoles consumed by the nymphs of the giant water bug Kirkaldyia deyrolli under laboratory conditions

Research paper thumbnail of Food shortage affects flight migration of the giant water bug Lethocerus deyrolli in the prewintering season

Limnology

The endangered giant water bug Lethocerus deyrolli (Vuillefroy) is frequently attracted in large ... more The endangered giant water bug Lethocerus deyrolli (Vuillefroy) is frequently attracted in large numbers to artificial lights in Japan. To examine factors enhancing flight migration for L. deyrolli, we carried out field work in western Hyogo Prefecture, central Japan, in September during the nonreproductive and prewintering season. The body weight of specimens collected under flight migration (flight bugs) was significantly less than that of those collected in ponds (pond bugs). A field experiment using open cages in a rice paddy field was carried out with two treatments, with and without a food supply. The remaining rate of L. deyrolli for the food present treatment was significantly higher than that for the food absent treatment for the first two days. These results suggest that L. deyrolli would fly in search of food when the food supply of the present habitat becomes unsuitable.

Research paper thumbnail of Water mites (Acari:Hydrachnidiae and Stygothrombiae) parasitic on aquatic animals in Japan

Journal of the Acarological Society of Japan

Research paper thumbnail of Effect of water depth on predation frequency by diving beetles on mosquito larvae prey

Entomological Science

Diving behavior and its frequency may differ between species of mosquito larvae owing to differen... more Diving behavior and its frequency may differ between species of mosquito larvae owing to differences in predation pressure. The present study aimed to investigate the relationship between water depth and predation frequency on two mosquito species, Culex tritaeniorhynchus (wetland breeder) and Aedes albopictus (container breeder), by the diving beetle Eretes griseus. Culex tritaeniorhynchus spends more time at the surface than A. albopictus, which spends more time thrashing underwater. When intact mosquito larvae of both species were present, the diving beetles consumed almost A.

Research paper thumbnail of Dietary items of predacious aquatic bugs (Nepoidea: Heteroptera) in Japanese wetlands

Limnology

Some species of predatory aquatic bugs (Nepoidea, including Belostomatidae and Nepidae) are desig... more Some species of predatory aquatic bugs (Nepoidea, including Belostomatidae and Nepidae) are designated as threatened-vulnerable species in the Red Data Book of Japan and are regarded as effective predators of freshwater snails and mosquito larvae. To reveal the feeding habits of Nepoidea, we investigated their dietary items in wetlands and obtained data from the published literature. Lethocerus deyrolli (Vuillefroy) preys mainly upon frogs, and the major diet of the nymphs is tadpoles. Laccotrephes japonensis (Scott) adults prey mainly upon tadpoles. Lethocerus deyrolli nymphs and L. japonensis adults compete against each other as same-guild members because they are sympatric in wetlands. Both nymphs and adults of Appasus japonicus (Vuillefroy) feed on snails, and L. japonensis nymphs feed on aquatic insects, including mosquito larvae (39.3% of aquatic insects). These species are effective predators of medically important pests such as snails, and mosquito larvae.

Research paper thumbnail of Water mites (Acari: Hydrachnidiae) parasitic on aquatic hemipterans in Japan, with reference to host preferences and selection sites

International Journal of Acarology

Research paper thumbnail of Paternal care behaviour of the giant water bug Kirkaldyia deyrolli (Heteroptera: Belostomatidae) against ants

Research paper thumbnail of Sexual selection of male parental care in giant water bugs

Royal Society open science, 2016

Paternal care can be maintained under sexual selection, if it helps in attracting more mates. We ... more Paternal care can be maintained under sexual selection, if it helps in attracting more mates. We tested the hypothesis in two giant water bug species, Appasus major and Appasus japonicus, that male parental care is sexually selected through female preference for caring males. Females were given an opportunity to choose between two males. In the first test of female mate choice, one male carried eggs on its back, while the other did not. The egg status was switched between these two males in the second test. The experiment revealed that females of both species preferred caring males (i.e. egg-bearing) to non-caring males. Nonetheless, the female mate preference for egg-bearing males was stronger in A. major than in A. japonicus. Our results suggest that sexual selection plays an important role in maintaining elaborate paternal care in giant water bugs, but the importance of egg-bearing by males in female mate choice varies among species.

Research paper thumbnail of Young giant water bug nymphs prefer larger prey: changes in foraging behaviour with nymphal growth in Kirkaldyia deyrolli

Biological Journal of the Linnean Society, 2015

Raptorial characteristics may evolve in predators because of their importance in obtaining food. ... more Raptorial characteristics may evolve in predators because of their importance in obtaining food. The giant water bug, Kirkaldyia deyrolli, possesses a claw on the terminal segment of the raptorial foreleg that is crucial for capturing prey. Claw curvature has been previously shown to change during growth in this species, but the adaptive significance of this change has not yet been explored. Predation experiments have demonstrated that young nymphs with highly curved claws caught proportionally larger prey than older nymphs with less-curved claws. Catching behaviours for a certain prey size differed significantly between young and older nymphs. The observation that nymphal growth affects prey-catching behaviour in the giant water bug supports the hypothesis that predators can change catching behaviours based on changes in raptorial characteristics in order to maximize prey resources acquired at each developmental stage.

Research paper thumbnail of Potential use of pyriproxyfen for control of mosquito-borne diseases: (2) Impact on Aedes albopictus populations in semi-field condition

Pyriproxyfen (PPF) is classified as a juvenile hormone analog (JHA) and has been used against a r... more Pyriproxyfen (PPF) is classified as a juvenile hormone analog (JHA) and has been used against a range of pest insects including mosquitoes since early 1990s. Aedes albopictus is an important vector of dengue and chikungunya and expanding distribution in European and American countries. In this study, impact of PPF treated bed net on populations of Ae. albopictus in a semi-field condition was evaluated using 6 small microcosms. Three microcosms were containing a miniature bed net treated with 350 mg/m2 and 35 mg/m2 PPF in Experiment I and II respectively, and remained 3 microcosms were used for controls with untreated bed net. One hundred pairs of Ae. albopictus were released into each microcosm and allowed to feed on a mouse around one week intervals under the miniature bed nets which have artificial holes. The number of laid eggs from the released adults was significantly reduced in PPF treatment compared to untreated controls. The egg hatchability was also significantly suppressed...