reproduction of Aphidoletes Aphidimyza diptera cecidomyiidae on a banker plant system of sorghum with melanaphis sacchari hemiptera aphididae and its oviposition selection between this system and eggplant with aphis gossypii hemiptera aphididae

To control Aphis gossypii Glover infestation of eggplant during the hot season in greenhouses, a banker plant system for Aphidoletes Aphidimyza (Rondani) was developed using Melanaphis sacchari (Zehntner) as an alternative prey on sorghum as banker plants. In this study, reproduction of Aphidoletes Aphidimyza on this banker plant system was studied by estimating the intrinsic rate of increase (r m) based on results of laboratory and greenhouse experiments and the effects of the density ratio of Aphis gossypii to M. sacchari on its oviposition selection between this system and the system of eggplant with Aphis gossypii. Our results showed that r m of Aphidoletes Aphidimyza reared on M. sacchari was 0.193 at 25 °C, which was higher than that of Aphidoletes Aphidimyza reared on Aphis gossypii (0.147) (Higashida et al. 2016 Appl Entomol Zool 51: 445–456). Aphidoletes Aphidimyza always laid more eggs on sorghum with M. sacchari than on eggplant with Aphis gossypii except at the highest density ratio of Aphis gossypii to M. sacchari. In greenhouse experiments where equal numbers of both aphid species were provided, Aphidoletes Aphidimyza laid more eggs on eggplant with Aphis gossypii than on sorghum with M. sacchari.

reproduction and oviposition selection by Aphidoletes Aphidimyza diptera cecidomyiidae on the banker plants with alternative prey aphids or crop plants with pest aphids

Aphidoletes Aphidimyza (Rondani) larvae are aphidophagous predators and females oviposit in or nearby aphid colonies. Aphidoletes Aphidimyza is an effective natural enemy to control aphids in greenhouse crops. To stabilize its effect, introductions could be made by means of a banker plant system. A banker plant system for A. Aphidimyza, using Rhopalosiphum padi (L.) as an alternative prey on barley plants as banker plants, has been used to control Aphis gossypii Glover infesting eggplant plants in greenhouses. In the banker plant system for A. Aphidimyza, it should reproduce well both on barley and eggplant plants. Recently emerged females from barley plants should move quickly to eggplant plants. On the basis of studies on development, survival, and fecundity, we found that the intrinsic rate of increase of A. Aphidimyza reared on A. gossypii was higher than that on R. padi. Aphidoletes Aphidimyza females laid more eggs on eggplant plants with A. gossypii than on barley plants with R. padi when the females were offered the two combinations of aphids and plants. Conditioning (according to feeding experience) of A. gossypii or R. padi, and the density ratio between the two aphid species, did not affect the oviposition preference for A. gossypii of A. Aphidimyza females.

An Attractant of the Aphidophagous Gall Midge Aphidoletes Aphidimyza From Honeydew of Aphis gossypii

Many natural enemies of insects use honeydew as a volatile cue to locate hosts or prey, as an oviposition stimulant, and as an arrestant for foraging. The aphidophagous gall midge Aphidoletes Aphidimyza (Rondani) (Diptera: Cecidomyiidae) has predacious larval stages and can be used to control aphid populations, especially in greenhouses. Previous studies have shown that the honeydew, excreted by the aphid Myzus persicae, attracts A. Aphidimyza , but the crucial attractants have not been identified. Using an olfactometer, we studied behavioral responses of female A. Aphidimyza to volatiles emitted from honeydew excreted by the aphid Aphis gossypii on eggplants. The volatiles attracted female midges and induced oviposition. Moreover, using gas chromatography coupled with mass spectrometry (GC/MS), we identified phenylacetaldehyde as the attractant compound in the honeydew, although it did not induce oviposition in olfactometer experiments.

An Attractant of the Aphidophagous Gall Midge Aphidoletes Aphidimyza From Honeydew of Aphis gossypii

Many natural enemies of insects use honeydew as a volatile cue to locate hosts or prey, as an oviposition stimulant, and as an arrestant for foraging. The aphidophagous gall midge Aphidoletes Aphidimyza (Rondani) (Diptera: Cecidomyiidae) has predacious larval stages and can be used to control aphid populations, especially in greenhouses. Previous studies have shown that the honeydew, excreted by the aphid Myzus persicae, attracts A. Aphidimyza , but the crucial attractants have not been identified. Using an olfactometer, we studied behavioral responses of female A. Aphidimyza to volatiles emitted from honeydew excreted by the aphid Aphis gossypii on eggplants. The volatiles attracted female midges and induced oviposition. Moreover, using gas chromatography coupled with mass spectrometry (GC/MS), we identified phenylacetaldehyde as the attractant compound in the honeydew, although it did not induce oviposition in olfactometer experiments.

effects of aphid honeydew sugars on the longevity and fecundity of the aphidophagous gall midge Aphidoletes Aphidimyza

Abstract The predatory gall midge Aphidoletes Aphidimyza, which is used for augmentative biological control of aphids in greenhouses, uses aphid honeydew as an energy source. Currently, Rhopalosiphum padi on barley plants and Melanaphis sacchari on sorghum plants are used as the banker plant systems for A. Aphidimyza to control Aphis gossypii on eggplant in Japan. We analyzed the sugar components of the honeydew of these three species by HPLC. The major components of honeydew were sucrose, fructose, and melezitose for A. gossypii; glucose and fructose for R. padi; and glucose, fructose, and melezitose for M. sacchari. Maltose and trehalose were minor components of the honeydew of these species. We investigated the influence of sugars, including three artificial aphid honeydews, six sugar components, and distilled water, on the longevity of unmated A. Aphidimyza. Both females and males attained the greatest longevity on sucrose and artificial honeydew of A. gossypii. Mean longevities of both females and males were shortest when they were provided only with water. We conducted another experiment in which a mated female was released in a cage with an eggplant seedling infested with A. gossypii and fed with sucrose or only water. Females fed with sucrose lived significantly longer and had higher lifetime fecundity than those fed only water.

monogenie bei Aphidoletes Aphidimyza rond diptera cecidomyiidae 1

Monogeny in Aphidoletes Aphidimyza (Rond.)

The progeny of the gall-midge Aphidoletes Aphidimyza (Rond.) is unisexual. There is evidence of monogeny. Apparently the males have no influence on the sex of their progeny. In breeding the ratio of arrhenogenic to thelygenic females as well as that of males to females is 1: 1. This proved to be in accordance with the monogenie species of the families Sciaridae and Calliphoridae. Possibly a similar mechanism of sex-determination exists in A. Aphidimyza.

Zusammenfassung

Die Nachkommenschaft von A. Aphidimyza ist unisexuell. Es liegt Monogenie vor. Die Mannchen haben wahrscheinlich keinen Einfls auf das Geschlecht der Nachkommen. In der Zucht war das Verhaltnis von arrhenogenen zu thelygenen Weibchen und dasjenige von Mannchen zu Weibchen 1: 1. Hier besteht mit den monogenen Sciariden und Calliphoriden Ubereinstimmung. Dieses deutet darauf hin, das bei A. Aphidimyza moglicherweise ein ahnlicher Mechanismus der Geschlechtsdetermination vorliegt.

untersuchungen zur prufung der wirkungen von pflanzenschutzmitteln auf leistungen der rauberischen gallmucke Aphidoletes Aphidimyza rond diptera cecidomyiidae und deren nachkommen

Investigations for testing effects of pesticides on the efficiency of the predacious gall midge Aphidoletes Aphidimyza (Rond.) (Diptera, Cecidomyiidae) and their progeny

Sublethal effects on adults of Aphidoletes Aphidimyza (Rond.) and their progeny (F1-generation) were investigated after dipping three days old larvae with conventional application concentration and LC30 of Metasystox R (0,10%; 1,12%), Nexion EC 25 (0,10%; 3,24%) and Saprol (0,15%; 13.12%). None of the pesticides affected the longevity of the adults, the preoviposition-time and the time by which 50% of the eggs were laid. There were but indications of influences on the total egg production. In the F1-Generation their was a significant reduction of the egg production from larval reserve-substances.

Effects of residual films of the above pesticides on adults of A. Aphidimyza were also tested on treated glasssfibre-tissue. Neither the efficiency of the survivors nor those of the F1-generation were affected if the lethal exposition-time with 30% mortality (LE30) was chosen.

Zusammenfassung

Tauchbehandlungen drei Tage alter Larven von Aphidoletes Aphidimyza (Rond.) mit praxisublicher Anwendungskonzentration und LC30 von Metasystox R (0,10%; 1,12%), Nexion EC 25 (0,10%; 3,24%) und Saprol (0,15%; 13,12%) wirkten sich weder auf die spatere Lebensdauer adulter Mucken noch auf die Praovipositionszeit und Eiablageintensitat aus. Hinweise fur Einwirkungen ergaben sich bei der Hohe der Eiproduktion.

Von den gepruften Leistungen der Nachkommenschaft (F1-Generation) (Schlupfrate der Larven, Entwicklungsdauer der Larven, Dauer der Puppenruhe, Schlupfrate der Imagines, Gewichte der Larven und Imagines, Eiproduktion aus larvalen Reservestoffen) war die Eiproduktion stark beeinflust worden.

Auswirkungen des unmittelbaren Kontaktes der adulten Mucken mit Ruckstandsbelagen obiger Mittel auf Glasfaser-Gewebe wurden mit der letalen Expositionszeit fur 30% Sterblichkeit (LE30) gepruft. Weder die uberlebenden noch die Nachkommen reagierten mit Leistungsminderungen.

wirkungen von pflanzenschutzmitteln auf leistungen der aphidophagen larven von Aphidoletes Aphidimyza rond diptera cecidomyiidae

Effects of some pesticides on the efficiency of the aphidophagous larvae of Aphidoletes Aphidimyza (Rond.)

The sensibility of the larvae of Aphidoletes Aphidimyza (Rond.) to the insecticides Metasystox R, Nexion EC 25 and the fungicide Saprol decreased with increasing age of the larvae. The determined LC50 were distinctly higher than conventional application concentrations of these pesticides for the two, three and four days old larvae, if they were treated with dipping technique.

Survivors of two days old larvae after dipping with Metasystox R (conventional application concentration and LC30) only responded with decreased aphid feeding, those of three days old larvae with decreased aphid feeding, reduction of weights of mature larvae and adults as well as egg production from larval reserve-substances. In a different way, the four days old mature larvae, which were disposed to pupate, responded with a subsequent reduction of the rate of adult emergency.

Treatments of three and four days old larvae with Nexion EC 25 and Saprol resulted in similar effects.

The oral uptake of Metasystox R and Nexion EC 25 through the food-chain (pesticide-killed aphids) by one, two and three days old larvae during their development showed an age-dependent mortality and sublethal effects. If the larvae were feeded with coldness-killed aphids, there was no lethal effect, but their efficiency was also affected.

Zusammenfassung

Die Empfindlichkeit 2, 3 und 4 Tage alter Larven von Aphidoletes Aphidimyza (Rond.) gegenuber den Insektiziden Metasystox R, Nexion EC 25 und dem Fungizid Saprol nahm mit zunehmendem Alter ab. Die fur die 3 Altersstufen ermittelten LC50-Werte lagen deutlich uber den praxisublichen Anwendungskonzentrationen der Praparate.

Auf Behandlungen mit Metasystox R (praxisubliche Anwendungskonzentration, LC30) reagierten die uberlebenden 2 Tage alter Larven mit geringerer Frasleistung, die 3 Tage alter Larven mit geringerer Frasleistung, verminderten Gewichten der Larven und Imagines und eingeschrankter Eiproduktion aus larvalen Reservestoffen und die 4 Tage alter, verpuppungsbereiter Larven mit einer reduzierten Schlupfrate der Imagines. Entsprechende Leistungsminderungen zeigten die uberlebenden von Behandlungen 3 und 4 Tage alter Larven mit Nexion EC 25 und Saprol. Die hoheren LC30-Konzentrationen bewirkten starkere Leistungsminderungen als die geringeren praxisublichen Anwendungskonzentrationen.

Die orale Aufnahme von Metasystox R und Nexion EC 25 uber damit abgetotete Blattlause durch 1 Tag, 2 Tage und 3 Tage alte Larven bis zum Abschlus ihrer Entwicklung hatte altersabhangige letale Auswirkungen. Abhangigkeit von dem Alter der Larven zeigte sich auch bei den mehr oder weniger deutlichen Leistungsminderungen der Larven nach Aufnahme von durch Kalte abgetoteten Beutetieren. Daruber hinausgehende Effekte der Insektizide waren nicht festzustellen.