Robert V. Dowell

Attraction of non-target insects to three male fruit fly lures in California

Abstract. The attraction of non-target insects to the male fruit fly lures methyl eugenol (1,2-Dimethoxy-4-prop-2-en-1-ylbenzene), cue-lure (4-[4-(acetyloxy)pheny1]-2-butanone), and trimedlure (t-Buty1-2-methy1-4-chlorocyclohexanecarboxylate) was examined in the main plant communities in California, except the desert, in 2012 and 2013. A total of 39,166 non-target insects were trapped during the study. Of these, 27 species or morphospecies in five orders and 20 families were deemed as attracted to one of the male lures. The most common of these were in the Syrphidae (Diptera) genera: Platycheirus Le Peletier & Serville, 1828, Melanostoma Schiner, 1860, Meliscaeva Zetterstadt, 1843, Ferdinandea Latreille, 1802, Hadromyia Verrall, 1901, Blera Billberg, 1820, and Melangyna Williston, 1882, as well as the genus Empis Linnaeus, 1758 (Diptera: Empididae) and the genus Orchesia Latreille, 1807 (Coleoptera: Melandryidae). The low capture rate of these non-target insects (<4/day maximum), combined with the discrete nature of the California Department of Food and Agricultures trapping and fruit fly eradication programs using the lures, indicates that the use of these lures will not have a significant impact on non-target insects attracted to them.

Survivorship of male and femaleBactrocera dorsalisin the field and the effect of male annihilation technique

Male annihilation technique (MAT) is a key component of management of the Oriental fruit fly, Bactrocera dorsalis Hendel (Diptera: Tephritidae), because of the ‘strong’ attraction of males to the lure methyl eugenol. The optimal application density for MAT has not been investigated for this economically important pest species. We tested the effect of two levels of MAT application density compared to a no‐MAT control on the daily survivorship of male and female B. dorsalis estimated by mark‐release‐recapture (MRR) using a 1‐km2 passive sampling network. Estimated daily survivorship from two separate MRR trials under control (no MAT) conditions was 0.751 for males and 0.948 for females. Male survivorship was similar under control (no MAT) and high application density (256 spots km−2; daily survivorship 0.704). However, estimated male survivorship was significantly lower under the low application density (100 spots km−2; daily survivorship 0.211). A similar pattern was observed in estimated female survivorship, with a significant reduction in survivorship under the low rate compared with control and high application density (low‐density estimated survivorship 0.652, high density 0.881). The results suggest that a lower application density may be more effective against B. dorsalis than the high application density. A lower application density for effective MAT would benefit growers and the public with respect to management of B. dorsalis through reduced labor and material costs, limiting potential environmental impacts, and increased logistical simplicity finding application sites in urban environments.

Influence of Freezing Temperatures on the Distribution of Umbonia crassicornis (Hemiptera: Membracidae) in Florida

Umbonia crassicornis mortality in single cold temperature exposures increased with decreasing temperature, and the equation, Y = 8.43X + 1.758X 2 + 4.295, describes the relationship between mortality (Y) and cold temperature (X). Multiple exposures to freezing temperatures increased mortality by 1.7 to 12.3 fold. Periods of freezing temperature occur every other year at the insect’s northern limit of its range in Florida and are one factor responsible for limiting its distribution in the state. La mortalidad de Umbonia crassicornis aumento con la disminucion de la temperatura, y la ecuacion, 8.43X + 1.758X2 + 4.295, describe la relacion entre la mortalidad (Y) y la temperatura fria (X). Exposiciones multiples a temperaturas bajas aumento la mortalidad en un 1.7 a 12.7 veces. Los periodos de temperaturas de congelacion que suceden cada otro ano en el limite norte de los insectos de la Florida es uno de los factores responsables de la limitacion de su distribucion en el estado. View this article in BioOne

Survival of brooding females and characteristics of oviposition sites of Umbonia crassicornis (Amyot & Serville, 1843) (Hemiptera: Membracidae)

Abstract The goals of this study were to 1) determine the field survival rate of single and multiple U. crassicornis females tending their offspring, 2) determine if a female will adopt an egg mass or nyphal aggregation that has lost its parental female as is seen in other treehoppers, 3)determine the physical characteristics of the sites selected by female U. crassicornis for oviposition and 4) show how these data interrelate and explain the pattern of U. crassicornis egg mass deposition within and among the host plants. An average of 27.9% of the female U. crassicornis survived until their offspring reached maturity. Having two or more females at a site doubles the probability of at least one surviving until the offspring reach maturity. An egg mass or nymphal aggregation without a guarding female may be adopted by another female. Females need four to seven cm of plant tissue 2.5 to 3.5 mm in diameter that they can encircle with their mesothoracic legs in which to oviposit. The females do not aggregate their egg masses but rather randomly distributed them among sites with the proper physical characteristics. The random distribution of egg masses provides a bridge between maximizing offspring survival and fecundity of the daughters.

The first record of the Palearctic mirid Brachynotocoris puncticornis Reuter, 1880 (Hemiptera: Miridae) in California

Specimens of the Palearctic mirid Brachynotocoris puncticornis Reuter, 1880 were captured in Riverside, Riverside County, California on 28 May 2013. The bugs were found on Fraxinus augustifollia Vahl. (Oleaceae) Fraxinus augustifollia is native to Europe and closely related to Fraxinus excelsior L. (Rushforth 1999), the only known host for B. puncticornis (Wheeler &Henry 1980). Previous North American records for B. puncticornis are from the eastern United States at Washington D.C., Prince George’s County, Maryland and Ithaca, New York, all on F. excelsior (Wheeler & Henry 1980). Wheeler & Henry (1980) provide information about the taxonomy and biology of B. puncticornis. There was no damage reported to the host tree and this is the only B. puncticonris population known in California. A pinned series of 19 ♂♂, 36 ♀♀ and four larval specimens of B. puncticornis initially identifi ed by R. W. Garrison are in the California State Collection of Arthropods, Plant Pest Diagnostic Center, California Department of Food and Agriculture, Sacramento, California.

Attraction of nontarget insects to a monofluoro analog of methyl eugenol in California

Abstract. This study evaluated the attraction of insects previously shown to be attracted to methyl eugenol to a monofluorinated analog of methyl eugenol. Orchesia Latreille, 1807 (Coleoptera: Melandryidae), an Empis Linneaus, 1758 (Diptera: Empididae) and six Syrphidae (Diptera) (Allograpta obliqua (Say,1823), Blera scitula Williston, 1881, Hadromyia pulchra Williston, 1882, Ferdinandea Rondani, 1884, Melanosoma mellinum (Linnaeus, 1758) and Platycheirus LePeleteier & Serville, 1828) previously shown to be attracted to methyl eugenol were found to be attracted to the monofluorinated methyl eugenol analog. Three additional Diptera: Syrphidae. Dasysyrphus Enderlien ,1938, Pseudoscaeva diversifasciatus Knab, 1914 and Blera humeralis Williston, 1882) were deemed to be attracted to the monofluorinated methyl eugenol. A number of insects attracted to methyl eugenol were not attracted to monofluorinated methyl eugenol including Diptera in Lauxaniidae, Scatopsidae, Mycetophilidae, and Drosphilidae, Lepidoptera in Noctuidae,Tortricidae and Pyralidae, a Hemiptera in Miridae, and Coleoptera in Chrysomelidae, Cantharidae, Cerambycidae, Elataeridae and Mordellidae.