The bio-ecology and control of Coproica vagans and Coproica hirtula (diptera: Sphaeroceridae) in cattle feedlots

Loading...
Thumbnail Image
Date
1998-12
Authors
Badenhorst, Daniel
Journal Title
Journal ISSN
Volume Title
Publisher
University of the Free State
Abstract
English: Sphaeroceridae are generally known as "lesser dung flies". These are small to medium sized dark-brown to blackish flies ranging from about 0.5 mm to 6 mm in length. They are saprophagous and occur throughout the tropical and subtropical regions of the world. A unique scenario involving Sphaeroceridae flies that constitute a serious problem at South African feedlots is discussed. Two species, namely Coproica vagans (Haliday) and Coproica hirtula (Rondani) are both associated with cattle dung at feedlots, with the former species reflecting dominance. The flies cause a nuisance to the cattle by forming black clouds of swarming flies. It therefore became imperative to find a way to control these flies. The establishment of separate sphaerocerid laboratory colonies from which experimental studies could be conducted was successful and is described. The seasonal occurrence and relative abundance of the Diptera fauna occurring within undisturbed cattle droppings exposed to shaded and sunny locations in the central Free State was investigated. The Sphaeroceridae was of particular interest, but only five presumably new species were discovered among the 21 fly species reared from these droppings. No C. vagans or C. hirtula specimens were encountered. The influence of physical parameters such as temperature and moisture content of the dung on the development and survival of immature stages and adult flies is described. Temperature had a major effect on all stages of both species, and both too low and too high temperatures led to severe mortality. Optimum developmental temperatures were between 24°C and 30°C. The development time of all stages also increased with a decrease in temperature. Moisture content of the dung had the same influence on all stages of the Sphaeroceridae, and optimum moisture content levels were at approximately 90%. Development times also increased somewhat with a decrease in moisture content levels of the dung. Oviposition by adult females of both sphaerocerid species and the influence of temperature and photo periodicy was determined and is described. Oviposition continued for more than 60 days at colder temperatures, although the number of eggs produced was often very low. Higher temperatures on the other hand resulted in large numbers of eggs produced by sphaerocerid females (up to 607 eggs per female) at 24°C, but the duration of oviposition dropped. Different photoperiods had no severe effect on oviposition or egg production. Development and survival of immature stages and adult Sphaeroceridae were also influenced by the type of dung which they were offered and the effect of this phenomenon on the flies is also described. Some dung types, e.g. horse, buffalo and rhino dung, had a negative influence on larval and adult survival most probably as a result of the higher fiber contents of these dung types. The other dung types such as cattle, sheep and elephant dung, led to successful development and survival of all stages. Biological control was attempted with several Coleoptera (a staphylinid, Philonthus caffer (Boheman) and scarabaeids Aphodius pseudolividus Balthasar and Harmogaster strydomi Endrëdi), Diptera (Musea xanthomelas Wiedemann and Coboldia fuscipes (Meigen)) and mite species. These biological control agents all failed to control Sphaeroceridae numbers mainly because of their inability to survive in wet feedlot dung. Chemical control on the other hand produced positive results and seemed like the only option available. Several insecticides and chemicals were tested but only two, namely Neporex (cyromazine) and Scatterkill (piperonyl butoxide), showed irradication potential. A further advantage of Scatterkill is its long residual effect in feedlot dung.
Afrikaans: Sphaeroceridae staan in die algemeen bekend as "klein misvliegies". Hulle is klein tot medium grootte donkerbruin tot swart vlieë wat wissel van 0.5 mm tot 6 mm in lengte. Hulle is saprofagies en kom meestal in die tropies en subtropiese gedeeltes van die wêreld voor. 'n Unieke aangeleentheid met betrekking tot Sphaeroceridae vlieë wat 'n ernstige probeem inhou by Suid-Afrikaanse voerkrale is bespreek. Twee spesies, naamlik Coproica vagans (Haliday) en Coproica hirtula (Rondani) word beide met beesmis by voerkrale geassosieer, waar die eersgenoemde spesie dominant was. Die Sphaeroceridae veroorsaak 'n irritasie vir die beeste deurdat hulle 'n swart wolk van vlieë vorm. Daarom was dit uiters noodsaaklik om die vlieë uit te roei. Die vestiging van afsonderlike Sphaeroceridae laboratorium kolonies waarmee eksperimentele studies uitgevoer kon word was suksesvol en word ook beskryf. Ondersoek is ingestel na die seisonale voorkoms en relatiewe volopheid van die Diptera fauna wat in beesmis voorkom wat aan skadu en son gebiede in die sentrale Vrystaat blootgestel was. Die Sphaeroceridae was van besondere belang, maar ongelukkig was net vyf vermoedelik nuwe spesies ontdek uit die 21 vlieg spesies wat uit die mis gebroei het. Geen C. vagans of C. hirtula is hier teëgekom nie. Die invloed van fisiese parameters soos temperatuur en voginhoud van die mis op die ontwikkeling en oorlewing van onvolwasse stadia en volwasse vlieë is beskryf. Temperatuur het 'n groot invloed op all stadia van beide spesies gehad, en beide te lae en te hoë temperature het tot hoë mortaliteite gelei. Optimum ontwikkelingstemperature was tussen 24°C en 30°C. Ontwikkelingstye van alle stadia het ook verhoog met 'n afname in temperatuur. Voginhoud van die mis het dieselfde invloed op alle stadia van die Sphaeroceridae gehad, met optimum voginhoud vlakke van ongeveer 90%. Ontwikkelingstye het ook effens toegeneem met 'n daling in voginhoud vlakke van die mIS. Eierlegging van volwasse vlieë van beide Sphaeroceridae spesies en die invloed van temperatuur en fotoperiode daarop was bepaal en is ook beskryf. Eierlegging het vir langer as 60 dae by kouer temperature geduur, alhoewel die getal eiers wat soms baie laag was. Hoër temperature het aan die ander kant daartoe gelei dat groot getalle eiers geproduseer is deur Sphaeroceridae wyfies (tot soveel as 607) by 24°C geproduseer is, maar die duur van die eierleggingsperiode het gedaal. Verskillende fotoperiodes het geen ernstige effek op eierlegging gehad nie. Ontwikkeling en oorlewing van onvolwasse stadia en volwasse Sphaeroceridae was ook deur die tipe mis wat die vlieë ontvang het beïnvloed en die effek wat hierdie verskynselop die vlieë gehad het is ook beskryf. Sommige missoorte, soos bv. Die van perde, buffels en renosters het 'n negatiewe invloed op die larwes en volwassens se oorlewing gehad, heel waarskynlik as gevolg van die hoër veselinhoud wat hierdie mistipes gehad het. Ander missoorte soos bees-, skaap- en olifantmis tot suksesvolle ontwikkeling en oorlewing van alle stadia gelei het. Biologiese beheer was met verskeie Coleoptera ('n Staphylinidae kewer, Philonthus caffer (Boheman), en twee Scarabaeidae kewers, Aphodius pseudolividus Balthasar en Harmogaster strydomi Endrëdi), Diptera (Musea xanthomelas Wiedemann en Coboldiafuscipes (Meigen)) en myt spesies probeer. Hierdie biologiese agente het nie een daarin geslaag om Sphaeroceridae getalle te beheer nie, hoofsaaklik as gevlog van hulonvermoë om in nat voerkraalmis te oorleef. Chemiese beheer, aan die ander kant, het positiewe resultate opgelewer en dit blyk die enigste oplossing te wees. Verskeie insektisiede en chemikalieë was getoets maar slegs twee, naamlik Neporex cyromazine) and Scatterkill (piperonyl butoksied), het potentiaal getoon sover dit die uitroei van vlieë betref. 'n Verdere voordeel van Scatterkill was die lang tydperk wat dit aktief in die voerkraaimis gebly het.
Description
Keywords
Sphaeroceridae -- South Africa -- Control, Flies -- Control -- South Africa, Dung beetles -- South Africa, Thesis (Ph.D. (Zoology and Entomology))--University of the Free State, 1998
Citation