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Pasture wireworm, Conoderus exsul (Sharp) fed more on larvae of the Australian soldier fly (Inopus rubriceps (Macquart)) than on germinating wheat seed when given a choice in the laboratory. Conversely, Agrypnus variabilis (Candeze), another wireworm found in New Zealand pastures, fed more on wheat seed. As determined by a serological technique (immuno-osmophoresis), 19% of C. exsul larvae, 20% of A. variabilis larvae and 80% of the adults of a staphylinid, Thyreocephalus oxthodoxus, (Olliff) collected in a pasture, had fed on I. rubriceps larvae. A predation rate of 12 soldier fly larvae/m2/day was estimated for C. exsul larvae. RESUME Determination serologique des Elateridae et des Staphylinidae predateurs d'Inopus rubriceps (Stratiomyidae), et alimentation de ces Elateridae sur vegetaux et animaux Pour determiner la valeur de Conoderus exsul Sharp comme predateur d'Inopus rubriceps Macquart, ravageur des prairies en Nouvelle Zelande, cet elateride a ete sur nourri des vegetaux et animaux. En 72 heures, il s'est alimente plus abondamment sur I. rubriceps que sur grains de ble. Par contre, un autre elateride des prairies, Agrypnus variabilis Candeze, a consomme plus de grains de ble que de I. rubriceps. Une technique serologique, l'immuno-osmophorese, a montre que 19% des larves de C. exsul, 20% de celles de A. variabilis et 80% des adultes du staphylin, Thyreocephalus orthodoxus Olliff recoltes dans la nature, avaient consomme des larves de I. rubriceps. En se basant sur la densite en Elaterides, sur le pourcentage de reactions positives, sur les taux de consommation quotidiens, et la periode d'observation de proies dans le tube digestif des predateurs, on peut estimer que 12 larves/m2/jour de I. rubriceps ont ete detruites par les larves de C. exsul pendant les 7 semaines de la periode utilisee.

Marked beetles and pitfall traps were used in studying dispersal on the soil surface of adults of two species of wireworms, and their incidence of flight was determined by tanglefoot wind-traps. Approximately 7% of 1200 marked males and 4% of 855 marked females of Ctenicera destructor (Brown) were recovered. At 120 yards from the central release point, marked males were captured 24 hours after release, females in a minimum of 9 days. No evidence was obtained that adults of C. destructor fly. Of Hypolithus bicolor Esch., approximately 3% of 475 marked males and 2% of 1852 marked females were captured; both males and females were trapped at 60 yards in a minimum period of 6 days, and one female was taken at a maximum distance of 80 yards 10 days after release. Adults of H. bicolor flew during all three seasons of the study. There was a difference in the rate at which females of both species tended to disperse on the ground, suggesting a heterogeneity in the marked populations with respect to dispersal.

Bacteria pathogenic to crucifers were isolated from 92% of the eggs from flies of the cabbage maggot, Hylemyia brassicae (Bouche) of a population from rutabaga (Swede; Brassica napus napobrassicd) and from 90% of those from a population from Chinese cabbage (Brassica pekinensis). The larvae transmitted the decay-causing bacteria to healthy tissues and aided in the development and spread of the rot. Of bacterial isolates from the interior of surface-sterile puparia, decay was caused by 100% of those from the rutabaga population and 35% of those from Chinese cabbage. Pathogenic cultures were also obtained from 44% of the prepupal linings of the Chinese cabbage population. The light internal contamination of adults at eclosion showed that the flies became contaminated externally from the interior of the puparia. The two populations of H. brassicae studied were contaminated with distinctly different types of bacteria. Erwinia sp., the predominant isolate from the rutabaga population, grew best on rutabaga. It caused a slow necrotic collapse and a dark pigmentation of the tissues, but not a soft-rot. Many different types of bacterial contaminants were associated with the stages of the cabbage maggot from Chinese cabbage. Green pigmenting, non-pathogenic forms were very prevalent. All pathogenic cultures caused some type of soft-rot. Some of these cultures were identified as Pseudomonas sp. and Aerobacter sp. Zusammenfassung DIE BEZIEHUNG DER KOHLFLIEGE, HYLEMYTA BRASSICAE (BOUCHE), ZUR FAULNIS BEI EINIGEN KOHLGEWACHSEN Es wurde die Beziehung zweier Kohlfliegen-Populationen (Hylemyia brassicae Bouche) zu faulniserregenden Bakterien an Kreuzblutlern in Verbindung mit dem von den Larven verursachten Schaden untersucht. 92 bez. 90% der Eier und 100 bez. 35% der Puparien, die sich an Kohlruben und Chinakohl entwickelten, trugen pathogene Bakterien. Pathogene Kulturen wurden von 44% der Prapuppen-Haute aus Puparien der Chinakohl-Populationen erhalten. Die Larven vermochten faulniserregende Bakterien wirksam auf gesunde Gewebe zu ubertragen und forderten die Entwicklung und Ausbreitung der Faule. Beim Schlupfen waren die Imagines innerlich nicht stark kontaminiert, beschmierten sich aber offenbar auserlich durch Kontakt mit dem Inneren der Puppengehause und der Prapuppen-Haute. Ein als Erwinia spec, identifizierter Bakterientyp konnte durchgangig von allen Stadien der Kohlfliege isoliert werden, die sich an Kohlruben entwickelten. Er verursacht bei Kohlruben eine langsame nekrotische Faulnis und dunkle Verfarbung der befallenen Gewebe. Dieses Bakterium scheint antagonistisch zu anderen Bakterien zu sein, da nur sehr wenige andere Keime mit Stadien der Insekten dieser Population vergesellschaftet gefunden wurden. Umgekehrt fanden sich viele verschiedene Bakterientypen auf Stadien der auf dem Chinakohl lebenden Kohlfliegen. Die Virulenz der pathogenen Kulturen variierte betrachtlich, jedoch verursachten alle irgendeine Art der Weichfaule. Einige dieser aus dem Inneren oberflachlich sterilisierter Puparien isolierten Kulturen wurden als Pseudomonas spec, and Aerobacter spec. bestimmt. Die Art der bakteriellen Kontamination der Kohlfliege scheint hauptsachlich von der Empfanglichkeit ihrer kreuzblutigen Wirtspflanzen gegenuber verschiedenen Typen der Faulnis nach Verletzung durch die Kohlfliegenmaden abhangig zu sein. Die allgemeinen Zusammenhange zwischen dem Insekt und den faulniserregenden Bakterien werden beschrieben.

Eggs of Ctenicera destructor (Brown), Ctenicera aeripennis (Kirby) and bisexual and parthenogenetic strains of Hypolithus bicolor Eschscholtz must absorb water to complete embryonic development.In eggs of C. destructor incubated at 24.4 ± 0.5 °C. in sifted soil containing 15% water (wet weight basis), water absorption started during the second day of development and ended within 24 hours. The mean wet weight increased from 26.6 ± 0.2 (standard deviation) μg. to 39.2 ± 0.6 μg. by the third day. During this period the water content increased from 42% to 64%. After the third day, the mean wet weight remained constant but a significant increase (P < 0.01) in the mean water content and a significant decrease (P < 0.01) in the mean dry weight occurred.The progress of water absorption in eggs of C. aeripennis and the two strains of H. bicolor was similar to that in C. destructor. Differences from C. destructor were apparent, however, in the sizes of the eggs, in the initial and final amounts of dry matter and in the water contents.Water absorption by eggs of C. destructor started after one day of incubation at 25 ± 0.5 °C., after 1 to 2 days at 20°, and after 4 days at 15°. The rate of absorption appeared to be slightly more rapid at higher temperatures within the range of 15–25 °C.

The seasonal occurrence and activity of adults of Aeolus mellillus (Say) in a wheat field and the grassy borders of the field were determined by pitfall trapping. Approximately 4 times as many A. mellillus adults were trapped in the field as in the border areas. The seasonal activity began in late May, reached a peak from about mid-June to mid-July and ended about the end of Aug. Soil samples showed that A. mellillus larvae comprised about 3% of the total wireworm population which also included 50% Ctenicera destructor (Brown) and 47% Hypolithus bicolor (Eschscholtz). Over a period of years, the relative numbers of each species that made up the wireworm complex remained fairly stable, fluctuating by about ± 10% for C. destructor and H. bicolor and by about ± 3% for A. mellillus .

Sitodiplosis mosellana (Gehin) was reared through one complete generation in the laboratory. For the adult stage, avoidance of handling, maintenance of at least 60% RH, low night temperature, and the provision of wheat plants at the correct flowering stage were important to survival. For larvae, adequate moisture was essential to induce them to leave their ecdysial sheaths, to penetrate the soil before diapause, and to promote diapause development. Adult emergence ranged from 10.6 to 51.6%, and at least 112 d at 2°C was required for optimal emergence.

(1983). Attraction of the lesser bulb fly Eumerus strigatus (Diptera: Syrphidae) to decomposing oatmeal. New Zealand Entomologist: Vol. 7, No. 4, pp. 419-419.