Jaime C. Piñero

Managing Oriental Fruit Fly (Diptera: Tephritidae), With Spinosad-Based Protein Bait Sprays and Sanitation in Papaya Orchards in Hawaii

ABSTRACT The efficacy of GF-120 NF Naturalyte Fruit Fly Bait in combination with field sanitation was assessed as a control for female oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), in papaya (Carica papaya L.) orchards in Hawaii. Three different bait spray regimes were evaluated: every row (high use of the bait), every fifth row (moderate use), and every 10th row (low use). Orchard plots in which no bait was applied served as controls. For five of the seven biweekly periods that followed the first bait spray, trapping data revealed significantly fewer female B. dorsalis captured in plots subject to high and moderate bait use than in control plots. Differences in incidence of infestation among treatments were detected only by the third (12 wk after first spray) fruit sampling with significantly fewer infested one-fourth to bonehead ripe papaya fruit in plots subject to high and moderate bait use than in control plots. Parasitism rates by Fopius arisanus (Sonan) (Hymenoptera: Braconidae) were not negatively affected by bait application. Results indicate that foliar applications of GF-120 NF Naturalyte Fruit Fly Bait either to all rows (every other tree), or to every fifth row (every tree) in combination with good sanitation can effectively reduce infestation by B. dorsalis in papaya orchards in Hawaii.

Nonhost Status of Citrus sinensis Cultivar Valencia and C. paradisi Cultivar Ruby Red to Mexican Anastrepha fraterculus (Diptera: Tephritidae)

Anastrepha fraterculus (Wiedemann) is recognized as a pest of citrus, apples, and blackberries in South America. In Mexico, it is mainly found in fruit of the family Myrtaceae and has never been reported infesting citrus. Here, we sought to determine whether females stemming from Mexican A. fraterculus populations (collected in the state of Veracruz) would lay eggs in Valencia oranges and Ruby Red grapefruit and, if so, whether larvae would hatch and develop. We worked under laboratory and seminatural conditions (i.e., gravid females released in fruit-bearing, bagged branches in a commercial citrus grove) and used Anastrepha ludens (Loew), a notorious pest of citrus, as a control species. Under laboratory conditions, A. ludens readily accepted both oranges and grapefruit as oviposition substrates, but A. fraterculus rarely oviposited in these fruit (but did so in guavas, a preferred host) and no larvae ever developed. Eggs were deposited in the toxic flavedo (A. fraterculus) and nontoxic albedo (A. ludens) regions. Field studies revealed that, as was the case in the laboratory, A. fraterculus rarely oviposited into oranges or grapefruit and that, when such was the case, either no larvae developed (oranges) or of the few (13) that developed and pupated (grapefruit), only two adults emerged that survived 1 and 3 d, respectively (5-17% of the time necessary to reach sexual maturity). In sharp contrast, grapefruit exposed to A. ludens yielded up to 937 pupae and adults survived for >6 mo. Therefore, the inability of Mexican A. fraterculus to successfully develop in citrus renders the status of Mexican A. fraterculus as a pest of citrus in Mexico as unsubstantiated.

An Overview of Pest Species of Bactrocera Fruit Flies (Diptera: Tephritidae) and the Integration of Biopesticides with Other Biological Approaches for Their Management with a Focus on the Pacific Region

Fruit flies (Diptera: Tephritidae) are among the most economically important pest species in the world, attacking a wide range of fruits and fleshy vegetables throughout tropical and sub-tropical areas. These species are such devastating crop pests that major control and eradication programs have been developed in various parts of the world to combat them. The array of control methods includes insecticide sprays to foliage and soil, bait-sprays, male annihilation techniques, releases of sterilized flies and parasitoids, and cultural controls. During the twenty first century there has been a trend to move away from control with organophosphate insecticides (e.g., malathion, diazinon, and naled) and towards reduced risk insecticide treatments. In this article we present an overview of 73 pest species in the genus Bactrocera, examine recent developments of reduced risk technologies for their control and explore Integrated Pest Management (IPM) Programs that integrate multiple components to manage these pests in tropical and sub-tropical areas.

Morphological features of the ovaries during oogenesis of the Oriental fruit fly, Bactrocera dorsalis, in relation to the physiological state.

Abstract Determination of physiological state in insects is useful in furthering the understanding of how insect behavior changes with age. Central to this determination is the identification of characters that allow assessment of physiological age. While non-destructive measures produce the most desired outcomes, internal markers may be more diagnostic and reliable. In this study, key morphological characters during previtellogenesis through vitellogenesis and ovulation were assessed as markers to determine physiological states of the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae). Ovary length and width, ovarian index (length × width), and egg load of laboratory-reared B. dorsalis females recorded daily from eclosion up to 80 days old suggested significant differences in the ovarian index and egg load between females from each oogenesis stage. Parity status determined by the presence of follicular relics was found to provide high-accuracy classifications for B. dorsalis females. The presence of follicular relics with distinct morphological features provides a reliable identification tool to determine the physiological state of wild female oriental fruit fly. The potential applications of this technique to identify the physiological age of female fruit flies to study behavioral attributes in their natural habitat, and also the potential applications in relation to field control, are discussed.

TESTING HUMAN URINE AS A LOW-TECH BAIT FOR ANASTREPHA SPP. (DIPTERA: TEPHRITIDAE) IN SMALL GUAVA, MANGO, SAPODILLA AND GRAPEFRUIT ORCHARDS

Abstract We evaluated the attractiveness of three aqueous dilutions of human urine (HU 50, 25, and 12.5%) to adults of pestiferous and nonpestiferous Anastrepha species (Diptera: Tephritidae) in small guava, grapefruit, mango, and sapodilla orchards with glass McPhail traps. As control treatments we used a commercially available hydrolyzed protein bait (Captor Plus®) and tap water. In the guava orchard, the three urine dilutions were as effective as hydrolyzed protein in attracting A. fraterculus. Also, when 25 and 50% urine were used, 93 and 96%, respectively, of the adults captured were females. In the grapefruit orchard, protein-baited traps captured significantly more A. ludens than urine-baited traps. In the mango orchard, both A. obliqua and A. serpentina were more attracted to hydrolyzed protein than to any other bait treatment. In the sapodilla orchard, traps baited with 50% urine surpassed all other treatments in the capture of A. serpentina and A. obliqua. Our findings indicate that human urine performs as well or better than hydrolyzed protein in certain types of orchards. They also support the notion that there is no “universal” Anastrepha bait. We conclude that human urine is a viable, low-tech alternative Anastrepha bait for subsistence or low income, small-scale fruit growers in rural Latin America.

Comparison of Rain-Fast Bait Stations Versus Foliar Bait Sprays for Control of Oriental Fruit Fly, Bactrocera dorsalis, in Papaya Orchards in Hawaii

Abstract Bait stations represent an environmentally friendly attract-and-kill approach to fruit fly population suppression. Recently a novel, visually attractive, rain-fast bait station was developed in Hawaii for potential use against multiple species of pestiferous fruit flies. Here, we compared the efficacy of GF-120 NF Naturalyte Fruit Fly Bait applied either as foliar sprays or onto bait stations in reducing female oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), population density and level of fruit infestation in commercial papaya orchards in Hawaii. Trapping and infestation data were used as indicators of the effectiveness of the two bait application methods. For the first 10 weeks of the study, captures of female B. dorsalis in monitoring traps were significantly greater in control plots than in plots treated with foliar sprays or bait stations. Six weeks after the first bait spray, incidence of infestation (i.e. number of fruit with one or more B. dorsalis larvae) of quarter to half-ripe papaya fruit was reduced by 71.4% and 63.1% for plots with bait stations and foliar sprays, respectively, as compared to control plots. Twelve weeks after first spray, incidence of infestation was reduced by only 54.5% and 45.4% for plots with bait stations and foliar sprays, respectively, as compared to control plots. About 42% less GF-120 was used in orchard plots with bait stations compared to those subject to foliar sprays. The impact of field sanitation on the outcome is also discussed. The results indicate that bait stations can provide a simple, efficient, and economical method of applying insecticidal baits to control fruit flies and a safer alternative to foliar sprays.

Basic Behavior of Rhagoletis turpiniae (Diptera: Tephritidae) with Comparative Notes on the Sexual Behavior of Rhagoletis pomonella and Rhagoletis zoqui

Abstract We describe the daily activity patterns of resting, feeding, oviposition and mating of adult Rhagoletis turpiniae Hernández (Diptera: Tephritidae), a recently described fruit fly species from Mexico that inhabits both tropical evergreen rain and temperate cloud forests. We also compare certain mating behaviors of R. turpiniae, R. pomonella (Walsh) and R. zoqui Bush. Studies were performed under natural, field-cage and laboratory conditions. In natural settings, i.e., trees of Turpinia insignis (H.B. & K.) Tul. (Staphyleaceae) significantly more males (n = 1,059) than females (n = 178) were observed, mostly on the lower part of the host fruit (because flies were not marked, these numbers likely include resightings of the same individual over time). Only a few adults (1.13%) were observed feeding in the host plant. Of the 70 ovipositions observed, 88.9% were recorded in unripe fruits, and 11.1% took place in semiripe or ripe fruits. Greatest oviposition activity (egglaying and aculeus-dragging behavior) was observed between 1000 and 1100 hours. There was a significant positive correlation between fruit size and number of larvae in a fruit. The greatest proportion of matings (n = 89) occurred between 1100 and 1600 hours and took place on the fruit. Mean copulation duration under natural conditions was 41.78 ± 1.77 min. Studies carried out in field cages and under laboratory conditions confirmed that the “resource defense polygyny” mating system characteristic of other Rhagoletis species is also present in R. turpiniae. Under highly artificial laboratory conditions R. turpiniae females mated, on average, 10.47 ± 0.4 times, whereas R. pomonella and R. zoqui females mated, on average, 4.17 ± 0.6 and 1.61 ± 0.3 times, respectively. The maximum number of matings of a single female in one observation day was 15, 14, and 5 in R. turpiniae, R. pomonella and R. zoqui, respectively.

Use of Pheromones in Insect Pest Management, with Special Attention to Weevil Pheromones

Insect pheromones are essential components of monitoring and management tools targeting pests of agricultural crops. Mating disruption, mass trapping, attract-and-kill, and push-pull are some of the direct pest control strategies that depend on the use of pheromones. In the case of weevil pests, pheromones are produced by males to attract both males and females and are thus referred to as aggregation pheromones. The composition of these pheromones is summarized here for several species of weevil. Weevil aggregation pheromones often have multiple components and their effect can be synergized by the presence of host-plant volatiles. In this chapter, the uses of insect pheromones in integrated pest management are discussed. In particular, we discuss research on the use of pheromones for the monitoring and management of weevil pests. A review of four case studies (boll weevil, plum curculio, cranberry weevil, and pepper weevil) is also provided.

Regional Susceptibilities of Rhopalosiphum padi (Hemiptera: Aphididae) to Ten Insecticides

Abstract Rhopalosiphum padi (L.) (Hemiptera: Aphididae) is one of the most significant cereal pests worldwide. Control of R. padi has relied heavily on chemical insecticides. We sampled 12 populations of R. padi from 11 provinces in China and analyzed their regional susceptibilities to 10 insecticides by using the leaf dip method. The R. padi populations showed susceptibility or minor resistance to chlorpyrifos, malathion, thiamethoxam, beta-cypermethrin, acetamiprid, and pymetrozine, but minor to moderate resistance to bifenthrin, decamethrin, and abamectin. Correlation analysis indicated positive and significant correlations between R. padi resistance levels to thiamethoxam and beta-cypermethrin, between R. padi resistance levels to chlorpyrifos and 4 other insecticides (decamethrin, abamectin, acetamiprid, and beta-cypermethrin), and between R. padi resistance levels to acetamiprid and 3 other insecticides (decamethrin, thiamethoxam, and beta-cypermethrin). Due to the widespread and variable nature of resistance in R. padi, we strongly urge rotation of insecticide classes to delay the onset of high levels of resistance.

Male Annihilation, Past, Present, and Future

We review past use of the male lures, methyl eugenol (ME), cue-lure (CL)/raspberry ketone (RK) and trimedlure (TML), for eradication and suppression of invasive fruit flies (Diptera: Tephritidae), primarily on islands. In addition, we describe the more recent application of these attractants, during the last 25 years, to Area-Wide Integrated Pest Management (AW-IPM) programs and their current use in eradication programs on the U.S mainland (i.e., California and Florida). Finally, we summarize future trends for their application, such as the use of reduced risk insecticides, new lures, lure mixtures, and new dispenser formulations.