Sensitivity of the Quarantine Pest Rough Sweetpotato Weevil, Blosyrus asellus to Postharvest Irradiation Treatment

Rough sweetpotato weevil, Blosyrus asellus (Olivier), is a new quar- antine pest of Hawaii sweetpotatoes. Currently, sweetpotatoes can be exported from Hawaii to the U.S. mainland using a postharvest irradiation treatment of 150 Gy to control three other regulated insect pests. Studies were conducted to deter- mine whether this current radiation dose will also control any rough sweetpotato weevils in export shipments. Adult weevils were treated at various levels between 25 to 125 Gy and egg laying and egg hatch were measured. Rough sweetpotato weevil was found to be highly susceptible to irradiation, with no egg hatch at any radiation dose, even 25 Gy, the lowest dose tested. Results suggest that the 150 Gy irradiation treatment should be sufficient for control of rough sweetpotato weevil in Hawaii sweetpotatoes

Annotated World Bibliography of Host Plants of the Melon Fly, \u3ci\u3eBactrocera cucurbitae\u3c/i\u3e (Coquillett) (Diptera: Tephritidae)

The melon fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae), is a widespread, economically important tephritid fruit fly species. Bactrocera cucurbitae infests fruits and vegetables of a number of different plant species, with many host plants in the plant family Cucurbitaceae, but with additional hosts scattered across many other plant families. Although thought to be native to India, its distribution has spread throughout many countries in Oriental Asia, into a number of Pacific Island nations, and into Africa. The documented introductions into countries outside its native distribution show that this species could establish in other countries where it does not presently occur, particularly through the movement of infested fruit. As with other tephritid fruit fly species, establishment of B. cucurbitae can have signifi cant economic consequences, including damage and loss of food production, as well as requirements for implementation of costly quarantine treatments to permit export of commodities susceptible to infestation by B. cucurbitae and inspection of susceptible imported commodities. In order to avoid these adverse economic consequences, one needs to prevent the entry, establishment and spread of B. cucurbitae into a new habitat. To successfully achieve this, an accurate knowledge of the fly’s host plants is essential. Cognizant of this need, we prepared, and present here, a worldwide list of host plants for B. cucurbitae, with annotations on reported laboratory and field infestation data. Overall, 136 plant taxa from 62 plant genera and 30 plant families are identified as hosts of B. cucurbitae, based on reported field infestation data. The predominant family, as expected, is Cucurbitaceae, with 56 plant taxa (41.2% of all host plant taxa) in which fi eld infestation by B. cucurbitae has been documented. The family with the 2nd highest number of documented infested plant taxa is Solanaceae, for which there are published field infestation data for 20 plant taxa (14.7% of plant taxa for which there is documented field infestation). Papers that list plants as hosts of B. cucurbitae based only on laboratory data, those that list plants as a host but do not report any field infestation data, and those that report interception data add an additional 137 host plant taxa, representing a total of 80 genera and 39 plant families, 20 of which are additional plant families beyond those for which there is field infestation data. These additional species must be considered “undetermined” hosts for which additional data are needed to document actual host status. This paper is a comprehensive documentation of host plants of the melon fl y based on recorded infestations in laboratory and/or field, interceptions at ports of entry, or “listing only” associations. Host records presented here will be used in vetting and developing the official USDA list of host plants of the melon fly, which will be published by APHIS as a federal order

Use of Attractants to Suppress Oriental Fruit Fly and Cryptophlebia spp. in Litchi

Litchi (Litchi chinensis Sonn.) is subject to damage by a range of insect pests, the most important of which are the oriental fruit fly, Bactrocera dorsalis (Hendel) (Diptera: Tephritidae), the koa seedworm, Cryptophlebia illepida (Butler), and the litchi fruitmoth, C. ombrodelta (Lower) (also known as the macadamia nut borer) (Lepidoptera: Tortricidae). The activity of tephritid fruit flies and Cryptophlebia spp. (hereafter referred to as Cryptophlebia) both can lead to several types of fruit defects, including holes, stains, and release of fruit juices, making it difficult to distinguish which pest caused the damage. Field studies were conducted to minimize the occurrence of these types of fruit defects through use of a spinosad-based protein bait (GF-120 Fruit Fly Bait) to suppress oriental fruit fly populations, and an attractant associated with a contact insecticide (attract-and-kill) technique (Last Call) to suppress Cryptophlebia populations in litchi orchards at the scale of individual farms. The Last Call product used was based on a pheromone blend developed for the macadamia nut borer because preliminary tests identified that this blend was more attractive to both C. ombrodelta and C. illepida than was a pheromone blend developed for the oriental fruit moth, Grapholita molesta (Busck). Overall, based on results from four split plot litchi orchards, there was no significant difference in oriental fruit fly trap catch between spray and control sections at any trap service date. However, population reduction in the sprayed section of one orchard with a higher B. dorsalis population may have been a result of the spray application. Cryptophlebia trap catch was significantly lower in the treated orchards after the first Last Call application. Cryptophlebia infestation was more than three-fold greater than infestation by oriental fruit fly in each of the orchards. For both pests, there was no significant difference in infestation rate or infestation-related fruit damage between control and treatment orchards. Improved bait sprays and improved attract-and-kill products and/or larger treatment areas may be needed to provide satisfactory levels of fruit fly and Cryptophlebia suppression

Annotated World Bibliography of Host Plants of the Melon Fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae)

McQuate, Grant T., Liquido, Nicanor J., Nakamichi, Kelly A. A. (2017): Annotated World Bibliography of Host Plants of the Melon Fly, Bactrocera cucurbitae (Coquillett) (Diptera: Tephritidae). Insecta Mundi 2017 (527): 1-339, DOI: http://doi.org/10.5281/zenodo.535358